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1 <section id="control">
2 <title>User Controls</title>
4 <para>Devices typically have a number of user-settable controls
5 such as brightness, saturation and so on, which would be presented to
6 the user on a graphical user interface. But, different devices
7 will have different controls available, and furthermore, the range of
8 possible values, and the default value will vary from device to
9 device. The control ioctls provide the information and a mechanism to
10 create a nice user interface for these controls that will work
11 correctly with any device.</para>
13 <para>All controls are accessed using an ID value. V4L2 defines
14 several IDs for specific purposes. Drivers can also implement their
15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
16 and higher values. The pre-defined control IDs have the prefix
17 <constant>V4L2_CID_</constant>, and are listed in <xref
18 linkend="control-id" />. The ID is used when querying the attributes of
19 a control, and when getting or setting the current value.</para>
21 <para>Generally applications should present controls to the user
22 without assumptions about their purpose. Each control comes with a
23 name string the user is supposed to understand. When the purpose is
24 non-intuitive the driver writer should provide a user manual, a user
25 interface plug-in or a driver specific panel application. Predefined
26 IDs were introduced to change a few controls programmatically, for
27 example to mute a device during a channel switch.</para>
29 <para>Drivers may enumerate different controls after switching
30 the current video input or output, tuner or modulator, or audio input
31 or output. Different in the sense of other bounds, another default and
32 current value, step size or other menu items. A control with a certain
33 <emphasis>custom</emphasis> ID can also change name and
34 type.<footnote>
35 <para>It will be more convenient for applications if drivers
36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
37 that was never required.</para>
38 </footnote> Control values are stored globally, they do not
39 change when switching except to stay within the reported bounds. They
40 also do not change ⪚ when the device is opened or closed, when the
41 tuner radio frequency is changed or generally never without
42 application request. Since V4L2 specifies no event mechanism, panel
43 applications intended to cooperate with other panel applications (be
44 they built into a larger application, as a TV viewer) may need to
45 regularly poll control values to update their user
46 interface.<footnote>
47 <para>Applications could call an ioctl to request events.
48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
49 shared properties the &func-select; function would indicate
50 readability until any ioctl (querying the properties) is
51 called.</para>
52 </footnote></para>
54 <para>
55 All controls use machine endianness.
56 </para>
58 <table pgwide="1" frame="none" id="control-id">
59 <title>Control IDs</title>
60 <tgroup cols="3">
61 &cs-def;
62 <thead>
63 <row>
64 <entry>ID</entry>
65 <entry>Type</entry>
66 <entry>Description</entry>
67 </row>
68 </thead>
69 <tbody valign="top">
70 <row>
71 <entry><constant>V4L2_CID_BASE</constant></entry>
72 <entry></entry>
73 <entry>First predefined ID, equal to
74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
75 </row>
76 <row>
77 <entry><constant>V4L2_CID_USER_BASE</constant></entry>
78 <entry></entry>
79 <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
80 </row>
81 <row>
82 <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
83 <entry>integer</entry>
84 <entry>Picture brightness, or more precisely, the black
85 level.</entry>
86 </row>
87 <row>
88 <entry><constant>V4L2_CID_CONTRAST</constant></entry>
89 <entry>integer</entry>
90 <entry>Picture contrast or luma gain.</entry>
91 </row>
92 <row>
93 <entry><constant>V4L2_CID_SATURATION</constant></entry>
94 <entry>integer</entry>
95 <entry>Picture color saturation or chroma gain.</entry>
96 </row>
97 <row>
98 <entry><constant>V4L2_CID_HUE</constant></entry>
99 <entry>integer</entry>
100 <entry>Hue or color balance.</entry>
101 </row>
102 <row>
103 <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
104 <entry>integer</entry>
105 <entry>Overall audio volume. Note some drivers also
106 provide an OSS or ALSA mixer interface.</entry>
107 </row>
108 <row>
109 <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
110 <entry>integer</entry>
111 <entry>Audio stereo balance. Minimum corresponds to all
112 the way left, maximum to right.</entry>
113 </row>
114 <row>
115 <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
116 <entry>integer</entry>
117 <entry>Audio bass adjustment.</entry>
118 </row>
119 <row>
120 <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
121 <entry>integer</entry>
122 <entry>Audio treble adjustment.</entry>
123 </row>
124 <row>
125 <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
126 <entry>boolean</entry>
127 <entry>Mute audio, &ie; set the volume to zero, however
128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
130 noise. Actually the entire device should be reset to a low power
131 consumption state.</entry>
132 </row>
133 <row>
134 <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
135 <entry>boolean</entry>
136 <entry>Loudness mode (bass boost).</entry>
137 </row>
138 <row>
139 <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
140 <entry>integer</entry>
141 <entry>Another name for brightness (not a synonym of
142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
143 and should not be used in new drivers and applications.</entry>
144 </row>
145 <row>
146 <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
147 <entry>boolean</entry>
148 <entry>Automatic white balance (cameras).</entry>
149 </row>
150 <row>
151 <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
152 <entry>button</entry>
153 <entry>This is an action control. When set (the value is
154 ignored), the device will do a white balance and then hold the current
155 setting. Contrast this with the boolean
156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
157 activated, keeps adjusting the white balance.</entry>
158 </row>
159 <row>
160 <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
161 <entry>integer</entry>
162 <entry>Red chroma balance.</entry>
163 </row>
164 <row>
165 <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
166 <entry>integer</entry>
167 <entry>Blue chroma balance.</entry>
168 </row>
169 <row>
170 <entry><constant>V4L2_CID_GAMMA</constant></entry>
171 <entry>integer</entry>
172 <entry>Gamma adjust.</entry>
173 </row>
174 <row>
175 <entry><constant>V4L2_CID_WHITENESS</constant></entry>
176 <entry>integer</entry>
177 <entry>Whiteness for grey-scale devices. This is a synonym
178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
179 and should not be used in new drivers and applications.</entry>
180 </row>
181 <row>
182 <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
183 <entry>integer</entry>
184 <entry>Exposure (cameras). [Unit?]</entry>
185 </row>
186 <row>
187 <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
188 <entry>boolean</entry>
189 <entry>Automatic gain/exposure control.</entry>
190 </row>
191 <row>
192 <entry><constant>V4L2_CID_GAIN</constant></entry>
193 <entry>integer</entry>
194 <entry>Gain control.</entry>
195 </row>
196 <row>
197 <entry><constant>V4L2_CID_HFLIP</constant></entry>
198 <entry>boolean</entry>
199 <entry>Mirror the picture horizontally.</entry>
200 </row>
201 <row>
202 <entry><constant>V4L2_CID_VFLIP</constant></entry>
203 <entry>boolean</entry>
204 <entry>Mirror the picture vertically.</entry>
205 </row>
206 <row id="v4l2-power-line-frequency">
207 <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
208 <entry>enum</entry>
209 <entry>Enables a power line frequency filter to avoid
210 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
211 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
212 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
213 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
214 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
215 </row>
216 <row>
217 <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
218 <entry>boolean</entry>
219 <entry>Enables automatic hue control by the device. The
220 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
221 hue control is enabled is undefined, drivers should ignore such
222 request.</entry>
223 </row>
224 <row>
225 <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
226 <entry>integer</entry>
227 <entry>This control specifies the white balance settings
228 as a color temperature in Kelvin. A driver should have a minimum of
229 2800 (incandescent) to 6500 (daylight). For more information about
230 color temperature see <ulink
231 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
232 </row>
233 <row>
234 <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
235 <entry>integer</entry>
236 <entry>Adjusts the sharpness filters in a camera. The
237 minimum value disables the filters, higher values give a sharper
238 picture.</entry>
239 </row>
240 <row>
241 <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
242 <entry>integer</entry>
243 <entry>Adjusts the backlight compensation in a camera. The
244 minimum value disables backlight compensation.</entry>
245 </row>
246 <row>
247 <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
248 <entry>boolean</entry>
249 <entry>Chroma automatic gain control.</entry>
250 </row>
251 <row>
252 <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
253 <entry>integer</entry>
254 <entry>Adjusts the Chroma gain control (for use when chroma AGC
255 is disabled).</entry>
256 </row>
257 <row>
258 <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
259 <entry>boolean</entry>
260 <entry>Enable the color killer (&ie; force a black & white image in case of a weak video signal).</entry>
261 </row>
262 <row id="v4l2-colorfx">
263 <entry><constant>V4L2_CID_COLORFX</constant></entry>
264 <entry>enum</entry>
265 <entry>Selects a color effect. The following values are defined:
266 </entry>
267 </row><row>
268 <entry></entry>
269 <entry></entry>
270 <entrytbl spanname="descr" cols="2">
271 <tbody valign="top">
272 <row>
273 <entry><constant>V4L2_COLORFX_NONE</constant> </entry>
274 <entry>Color effect is disabled.</entry>
275 </row>
276 <row>
277 <entry><constant>V4L2_COLORFX_ANTIQUE</constant> </entry>
278 <entry>An aging (old photo) effect.</entry>
279 </row>
280 <row>
281 <entry><constant>V4L2_COLORFX_ART_FREEZE</constant> </entry>
282 <entry>Frost color effect.</entry>
283 </row>
284 <row>
285 <entry><constant>V4L2_COLORFX_AQUA</constant> </entry>
286 <entry>Water color, cool tone.</entry>
287 </row>
288 <row>
289 <entry><constant>V4L2_COLORFX_BW</constant> </entry>
290 <entry>Black and white.</entry>
291 </row>
292 <row>
293 <entry><constant>V4L2_COLORFX_EMBOSS</constant> </entry>
294 <entry>Emboss, the highlights and shadows replace light/dark boundaries
295 and low contrast areas are set to a gray background.</entry>
296 </row>
297 <row>
298 <entry><constant>V4L2_COLORFX_GRASS_GREEN</constant> </entry>
299 <entry>Grass green.</entry>
300 </row>
301 <row>
302 <entry><constant>V4L2_COLORFX_NEGATIVE</constant> </entry>
303 <entry>Negative.</entry>
304 </row>
305 <row>
306 <entry><constant>V4L2_COLORFX_SEPIA</constant> </entry>
307 <entry>Sepia tone.</entry>
308 </row>
309 <row>
310 <entry><constant>V4L2_COLORFX_SKETCH</constant> </entry>
311 <entry>Sketch.</entry>
312 </row>
313 <row>
314 <entry><constant>V4L2_COLORFX_SKIN_WHITEN</constant> </entry>
315 <entry>Skin whiten.</entry>
316 </row>
317 <row>
318 <entry><constant>V4L2_COLORFX_SKY_BLUE</constant> </entry>
319 <entry>Sky blue.</entry>
320 </row>
321 <row>
322 <entry><constant>V4L2_COLORFX_SOLARIZATION</constant> </entry>
323 <entry>Solarization, the image is partially reversed in tone,
324 only color values above or below a certain threshold are inverted.
325 </entry>
326 </row>
327 <row>
328 <entry><constant>V4L2_COLORFX_SILHOUETTE</constant> </entry>
329 <entry>Silhouette (outline).</entry>
330 </row>
331 <row>
332 <entry><constant>V4L2_COLORFX_VIVID</constant> </entry>
333 <entry>Vivid colors.</entry>
334 </row>
335 <row>
336 <entry><constant>V4L2_COLORFX_SET_CBCR</constant> </entry>
337 <entry>The Cb and Cr chroma components are replaced by fixed
338 coefficients determined by <constant>V4L2_CID_COLORFX_CBCR</constant>
339 control.</entry>
340 </row>
341 </tbody>
342 </entrytbl>
343 </row>
344 <row>
345 <entry><constant>V4L2_CID_COLORFX_CBCR</constant></entry>
346 <entry>integer</entry>
347 <entry>Determines the Cb and Cr coefficients for <constant>V4L2_COLORFX_SET_CBCR</constant>
348 color effect. Bits [7:0] of the supplied 32 bit value are interpreted as
349 Cr component, bits [15:8] as Cb component and bits [31:16] must be zero.
350 </entry>
351 </row>
352 <row>
353 <entry><constant>V4L2_CID_AUTOBRIGHTNESS</constant></entry>
354 <entry>boolean</entry>
355 <entry>Enable Automatic Brightness.</entry>
356 </row>
357 <row>
358 <entry><constant>V4L2_CID_ROTATE</constant></entry>
359 <entry>integer</entry>
360 <entry>Rotates the image by specified angle. Common angles are 90,
361 270 and 180. Rotating the image to 90 and 270 will reverse the height
362 and width of the display window. It is necessary to set the new height and
363 width of the picture using the &VIDIOC-S-FMT; ioctl according to
364 the rotation angle selected.</entry>
365 </row>
366 <row>
367 <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
368 <entry>integer</entry>
369 <entry>Sets the background color on the current output device.
370 Background color needs to be specified in the RGB24 format. The
371 supplied 32 bit value is interpreted as bits 0-7 Red color information,
372 bits 8-15 Green color information, bits 16-23 Blue color
373 information and bits 24-31 must be zero.</entry>
374 </row>
375 <row>
376 <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
377 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
378 <entry>boolean</entry>
379 <entry>Switch on or off the illuminator 1 or 2 of the device
380 (usually a microscope).</entry>
381 </row>
382 <row>
383 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
384 <entry>integer</entry>
385 <entry>This is a read-only control that can be read by the application
386 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
387 The value is the minimum number of CAPTURE buffers that is necessary for hardware
388 to work.</entry>
389 </row>
390 <row>
391 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
392 <entry>integer</entry>
393 <entry>This is a read-only control that can be read by the application
394 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
395 The value is the minimum number of OUTPUT buffers that is necessary for hardware
396 to work.</entry>
397 </row>
398 <row id="v4l2-alpha-component">
399 <entry><constant>V4L2_CID_ALPHA_COMPONENT</constant></entry>
400 <entry>integer</entry>
401 <entry> Sets the alpha color component on the capture device or on
402 the capture buffer queue of a mem-to-mem device. When a mem-to-mem
403 device produces frame format that includes an alpha component
404 (e.g. <link linkend="rgb-formats">packed RGB image formats</link>)
405 and the alpha value is not defined by the mem-to-mem input data
406 this control lets you select the alpha component value of all
407 pixels. It is applicable to any pixel format that contains an alpha
408 component.
409 </entry>
410 </row>
411 <row>
412 <entry><constant>V4L2_CID_LASTP1</constant></entry>
413 <entry></entry>
414 <entry>End of the predefined control IDs (currently
415 <constant>V4L2_CID_ALPHA_COMPONENT</constant> + 1).</entry>
416 </row>
417 <row>
418 <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
419 <entry></entry>
420 <entry>ID of the first custom (driver specific) control.
421 Applications depending on particular custom controls should check the
422 driver name and version, see <xref linkend="querycap" />.</entry>
423 </row>
424 </tbody>
425 </tgroup>
426 </table>
428 <para>Applications can enumerate the available controls with the
429 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
430 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
431 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
432 <constant>VIDIOC_G_CTRL</constant> and
433 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
434 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
435 more menu type controls.</para>
437 <example>
438 <title>Enumerating all controls</title>
440 <programlisting>
441 &v4l2-queryctrl; queryctrl;
442 &v4l2-querymenu; querymenu;
444 static void
445 enumerate_menu (void)
446 {
447 printf (" Menu items:\n");
449 memset (&querymenu, 0, sizeof (querymenu));
450 querymenu.id = queryctrl.id;
452 for (querymenu.index = queryctrl.minimum;
453 querymenu.index <= queryctrl.maximum;
454 querymenu.index++) {
455 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &querymenu)) {
456 printf (" %s\n", querymenu.name);
457 }
458 }
459 }
461 memset (&queryctrl, 0, sizeof (queryctrl));
463 for (queryctrl.id = V4L2_CID_BASE;
464 queryctrl.id < V4L2_CID_LASTP1;
465 queryctrl.id++) {
466 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
467 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
468 continue;
470 printf ("Control %s\n", queryctrl.name);
472 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
473 enumerate_menu ();
474 } else {
475 if (errno == EINVAL)
476 continue;
478 perror ("VIDIOC_QUERYCTRL");
479 exit (EXIT_FAILURE);
480 }
481 }
483 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
484 queryctrl.id++) {
485 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
486 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
487 continue;
489 printf ("Control %s\n", queryctrl.name);
491 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
492 enumerate_menu ();
493 } else {
494 if (errno == EINVAL)
495 break;
497 perror ("VIDIOC_QUERYCTRL");
498 exit (EXIT_FAILURE);
499 }
500 }
501 </programlisting>
502 </example>
504 <example>
505 <title>Changing controls</title>
507 <programlisting>
508 &v4l2-queryctrl; queryctrl;
509 &v4l2-control; control;
511 memset (&queryctrl, 0, sizeof (queryctrl));
512 queryctrl.id = V4L2_CID_BRIGHTNESS;
514 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
515 if (errno != EINVAL) {
516 perror ("VIDIOC_QUERYCTRL");
517 exit (EXIT_FAILURE);
518 } else {
519 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
520 }
521 } else if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) {
522 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
523 } else {
524 memset (&control, 0, sizeof (control));
525 control.id = V4L2_CID_BRIGHTNESS;
526 control.value = queryctrl.default_value;
528 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)) {
529 perror ("VIDIOC_S_CTRL");
530 exit (EXIT_FAILURE);
531 }
532 }
534 memset (&control, 0, sizeof (control));
535 control.id = V4L2_CID_CONTRAST;
537 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &control)) {
538 control.value += 1;
540 /* The driver may clamp the value or return ERANGE, ignored here */
542 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)
543 && errno != ERANGE) {
544 perror ("VIDIOC_S_CTRL");
545 exit (EXIT_FAILURE);
546 }
547 /* Ignore if V4L2_CID_CONTRAST is unsupported */
548 } else if (errno != EINVAL) {
549 perror ("VIDIOC_G_CTRL");
550 exit (EXIT_FAILURE);
551 }
553 control.id = V4L2_CID_AUDIO_MUTE;
554 control.value = TRUE; /* silence */
556 /* Errors ignored */
557 ioctl (fd, VIDIOC_S_CTRL, &control);
558 </programlisting>
559 </example>
560 </section>
562 <section id="extended-controls">
563 <title>Extended Controls</title>
565 <section>
566 <title>Introduction</title>
568 <para>The control mechanism as originally designed was meant
569 to be used for user settings (brightness, saturation, etc). However,
570 it turned out to be a very useful model for implementing more
571 complicated driver APIs where each driver implements only a subset of
572 a larger API.</para>
574 <para>The MPEG encoding API was the driving force behind
575 designing and implementing this extended control mechanism: the MPEG
576 standard is quite large and the currently supported hardware MPEG
577 encoders each only implement a subset of this standard. Further more,
578 many parameters relating to how the video is encoded into an MPEG
579 stream are specific to the MPEG encoding chip since the MPEG standard
580 only defines the format of the resulting MPEG stream, not how the
581 video is actually encoded into that format.</para>
583 <para>Unfortunately, the original control API lacked some
584 features needed for these new uses and so it was extended into the
585 (not terribly originally named) extended control API.</para>
587 <para>Even though the MPEG encoding API was the first effort
588 to use the Extended Control API, nowadays there are also other classes
589 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
590 The Extended Controls API as well as all Extended Controls classes are
591 described in the following text.</para>
592 </section>
594 <section>
595 <title>The Extended Control API</title>
597 <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
598 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
599 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
600 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
601 since it is often required to atomically change several controls at
602 once.</para>
604 <para>Each of the new ioctls expects a pointer to a
605 &v4l2-ext-controls;. This structure contains a pointer to the control
606 array, a count of the number of controls in that array and a control
607 class. Control classes are used to group similar controls into a
608 single class. For example, control class
609 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
610 (&ie; all controls that can also be set using the old
611 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
612 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
613 relating to MPEG encoding, etc.</para>
615 <para>All controls in the control array must belong to the
616 specified control class. An error is returned if this is not the
617 case.</para>
619 <para>It is also possible to use an empty control array (count
620 == 0) to check whether the specified control class is
621 supported.</para>
623 <para>The control array is a &v4l2-ext-control; array. The
624 <structname>v4l2_ext_control</structname> structure is very similar to
625 &v4l2-control;, except for the fact that it also allows for 64-bit
626 values and pointers to be passed.</para>
628 <para>It is important to realize that due to the flexibility of
629 controls it is necessary to check whether the control you want to set
630 actually is supported in the driver and what the valid range of values
631 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
632 check this. Also note that it is possible that some of the menu
633 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
634 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
635 return an error). A good example is the list of supported MPEG audio
636 bitrates. Some drivers only support one or two bitrates, others
637 support a wider range.</para>
639 <para>
640 All controls use machine endianness.
641 </para>
642 </section>
644 <section>
645 <title>Enumerating Extended Controls</title>
647 <para>The recommended way to enumerate over the extended
648 controls is by using &VIDIOC-QUERYCTRL; in combination with the
649 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
651 <informalexample>
652 <programlisting>
653 &v4l2-queryctrl; qctrl;
655 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
656 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
657 /* ... */
658 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
659 }
660 </programlisting>
661 </informalexample>
663 <para>The initial control ID is set to 0 ORed with the
664 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
665 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
666 control with a higher ID than the specified one. When no such controls
667 are found an error is returned.</para>
669 <para>If you want to get all controls within a specific control
670 class, then you can set the initial
671 <structfield>qctrl.id</structfield> value to the control class and add
672 an extra check to break out of the loop when a control of another
673 control class is found:</para>
675 <informalexample>
676 <programlisting>
677 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
678 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
679 if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
680 break;
681 /* ... */
682 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
683 }
684 </programlisting>
685 </informalexample>
687 <para>The 32-bit <structfield>qctrl.id</structfield> value is
688 subdivided into three bit ranges: the top 4 bits are reserved for
689 flags (⪚ <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
690 actually part of the ID. The remaining 28 bits form the control ID, of
691 which the most significant 12 bits define the control class and the
692 least significant 16 bits identify the control within the control
693 class. It is guaranteed that these last 16 bits are always non-zero
694 for controls. The range of 0x1000 and up are reserved for
695 driver-specific controls. The macro
696 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
697 ID based on a control ID.</para>
699 <para>If the driver does not support extended controls, then
700 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
701 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
702 that case the old method of enumerating control should be used (see
703 1.8). But if it is supported, then it is guaranteed to enumerate over
704 all controls, including driver-private controls.</para>
705 </section>
707 <section>
708 <title>Creating Control Panels</title>
710 <para>It is possible to create control panels for a graphical
711 user interface where the user can select the various controls.
712 Basically you will have to iterate over all controls using the method
713 described above. Each control class starts with a control of type
714 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
715 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
716 control class which can be used as the title of a tab page within a
717 control panel.</para>
719 <para>The flags field of &v4l2-queryctrl; also contains hints on
720 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
721 for more details.</para>
722 </section>
724 <section id="mpeg-controls">
725 <title>Codec Control Reference</title>
727 <para>Below all controls within the Codec control class are
728 described. First the generic controls, then controls specific for
729 certain hardware.</para>
731 <para>Note: These controls are applicable to all codecs and
732 not just MPEG. The defines are prefixed with V4L2_CID_MPEG/V4L2_MPEG
733 as the controls were originally made for MPEG codecs and later
734 extended to cover all encoding formats.</para>
736 <section>
737 <title>Generic Codec Controls</title>
739 <table pgwide="1" frame="none" id="mpeg-control-id">
740 <title>Codec Control IDs</title>
741 <tgroup cols="4">
742 <colspec colname="c1" colwidth="1*" />
743 <colspec colname="c2" colwidth="6*" />
744 <colspec colname="c3" colwidth="2*" />
745 <colspec colname="c4" colwidth="6*" />
746 <spanspec namest="c1" nameend="c2" spanname="id" />
747 <spanspec namest="c2" nameend="c4" spanname="descr" />
748 <thead>
749 <row>
750 <entry spanname="id" align="left">ID</entry>
751 <entry align="left">Type</entry>
752 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
753 </row>
754 </thead>
755 <tbody valign="top">
756 <row><entry></entry></row>
757 <row>
758 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant> </entry>
759 <entry>class</entry>
760 </row><row><entry spanname="descr">The Codec class
761 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
762 description of this control class. This description can be used as the
763 caption of a Tab page in a GUI, for example.</entry>
764 </row>
765 <row><entry></entry></row>
766 <row id="v4l2-mpeg-stream-type">
767 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant> </entry>
768 <entry>enum v4l2_mpeg_stream_type</entry>
769 </row><row><entry spanname="descr">The MPEG-1, -2 or -4
770 output stream type. One cannot assume anything here. Each hardware
771 MPEG encoder tends to support different subsets of the available MPEG
772 stream types. This control is specific to multiplexed MPEG streams.
773 The currently defined stream types are:</entry>
774 </row>
775 <row>
776 <entrytbl spanname="descr" cols="2">
777 <tbody valign="top">
778 <row>
779 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant> </entry>
780 <entry>MPEG-2 program stream</entry>
781 </row>
782 <row>
783 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant> </entry>
784 <entry>MPEG-2 transport stream</entry>
785 </row>
786 <row>
787 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant> </entry>
788 <entry>MPEG-1 system stream</entry>
789 </row>
790 <row>
791 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant> </entry>
792 <entry>MPEG-2 DVD-compatible stream</entry>
793 </row>
794 <row>
795 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant> </entry>
796 <entry>MPEG-1 VCD-compatible stream</entry>
797 </row>
798 <row>
799 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant> </entry>
800 <entry>MPEG-2 SVCD-compatible stream</entry>
801 </row>
802 </tbody>
803 </entrytbl>
804 </row>
805 <row><entry></entry></row>
806 <row>
807 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant> </entry>
808 <entry>integer</entry>
809 </row><row><entry spanname="descr">Program Map Table
810 Packet ID for the MPEG transport stream (default 16)</entry>
811 </row>
812 <row><entry></entry></row>
813 <row>
814 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant> </entry>
815 <entry>integer</entry>
816 </row><row><entry spanname="descr">Audio Packet ID for
817 the MPEG transport stream (default 256)</entry>
818 </row>
819 <row><entry></entry></row>
820 <row>
821 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant> </entry>
822 <entry>integer</entry>
823 </row><row><entry spanname="descr">Video Packet ID for
824 the MPEG transport stream (default 260)</entry>
825 </row>
826 <row><entry></entry></row>
827 <row>
828 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant> </entry>
829 <entry>integer</entry>
830 </row><row><entry spanname="descr">Packet ID for the
831 MPEG transport stream carrying PCR fields (default 259)</entry>
832 </row>
833 <row><entry></entry></row>
834 <row>
835 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant> </entry>
836 <entry>integer</entry>
837 </row><row><entry spanname="descr">Audio ID for MPEG
838 PES</entry>
839 </row>
840 <row><entry></entry></row>
841 <row>
842 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant> </entry>
843 <entry>integer</entry>
844 </row><row><entry spanname="descr">Video ID for MPEG
845 PES</entry>
846 </row>
847 <row><entry></entry></row>
848 <row id="v4l2-mpeg-stream-vbi-fmt">
849 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant> </entry>
850 <entry>enum v4l2_mpeg_stream_vbi_fmt</entry>
851 </row><row><entry spanname="descr">Some cards can embed
852 VBI data (⪚ Closed Caption, Teletext) into the MPEG stream. This
853 control selects whether VBI data should be embedded, and if so, what
854 embedding method should be used. The list of possible VBI formats
855 depends on the driver. The currently defined VBI format types
856 are:</entry>
857 </row>
858 <row>
859 <entrytbl spanname="descr" cols="2">
860 <tbody valign="top">
861 <row>
862 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant> </entry>
863 <entry>No VBI in the MPEG stream</entry>
864 </row>
865 <row>
866 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant> </entry>
867 <entry>VBI in private packets, IVTV format (documented
868 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
869 </row>
870 </tbody>
871 </entrytbl>
872 </row>
873 <row><entry></entry></row>
874 <row id="v4l2-mpeg-audio-sampling-freq">
875 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant> </entry>
876 <entry>enum v4l2_mpeg_audio_sampling_freq</entry>
877 </row><row><entry spanname="descr">MPEG Audio sampling
878 frequency. Possible values are:</entry>
879 </row>
880 <row>
881 <entrytbl spanname="descr" cols="2">
882 <tbody valign="top">
883 <row>
884 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant> </entry>
885 <entry>44.1 kHz</entry>
886 </row>
887 <row>
888 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant> </entry>
889 <entry>48 kHz</entry>
890 </row>
891 <row>
892 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant> </entry>
893 <entry>32 kHz</entry>
894 </row>
895 </tbody>
896 </entrytbl>
897 </row>
898 <row><entry></entry></row>
899 <row id="v4l2-mpeg-audio-encoding">
900 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant> </entry>
901 <entry>enum v4l2_mpeg_audio_encoding</entry>
902 </row><row><entry spanname="descr">MPEG Audio encoding.
903 This control is specific to multiplexed MPEG streams.
904 Possible values are:</entry>
905 </row>
906 <row>
907 <entrytbl spanname="descr" cols="2">
908 <tbody valign="top">
909 <row>
910 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant> </entry>
911 <entry>MPEG-1/2 Layer I encoding</entry>
912 </row>
913 <row>
914 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant> </entry>
915 <entry>MPEG-1/2 Layer II encoding</entry>
916 </row>
917 <row>
918 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant> </entry>
919 <entry>MPEG-1/2 Layer III encoding</entry>
920 </row>
921 <row>
922 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant> </entry>
923 <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
924 </row>
925 <row>
926 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant> </entry>
927 <entry>AC-3 aka ATSC A/52 encoding</entry>
928 </row>
929 </tbody>
930 </entrytbl>
931 </row>
932 <row><entry></entry></row>
933 <row id="v4l2-mpeg-audio-l1-bitrate">
934 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant> </entry>
935 <entry>enum v4l2_mpeg_audio_l1_bitrate</entry>
936 </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
937 Possible values are:</entry>
938 </row>
939 <row>
940 <entrytbl spanname="descr" cols="2">
941 <tbody valign="top">
942 <row>
943 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant> </entry>
944 <entry>32 kbit/s</entry></row>
945 <row>
946 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant> </entry>
947 <entry>64 kbit/s</entry>
948 </row>
949 <row>
950 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant> </entry>
951 <entry>96 kbit/s</entry>
952 </row>
953 <row>
954 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant> </entry>
955 <entry>128 kbit/s</entry>
956 </row>
957 <row>
958 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant> </entry>
959 <entry>160 kbit/s</entry>
960 </row>
961 <row>
962 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant> </entry>
963 <entry>192 kbit/s</entry>
964 </row>
965 <row>
966 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant> </entry>
967 <entry>224 kbit/s</entry>
968 </row>
969 <row>
970 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant> </entry>
971 <entry>256 kbit/s</entry>
972 </row>
973 <row>
974 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant> </entry>
975 <entry>288 kbit/s</entry>
976 </row>
977 <row>
978 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant> </entry>
979 <entry>320 kbit/s</entry>
980 </row>
981 <row>
982 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant> </entry>
983 <entry>352 kbit/s</entry>
984 </row>
985 <row>
986 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant> </entry>
987 <entry>384 kbit/s</entry>
988 </row>
989 <row>
990 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant> </entry>
991 <entry>416 kbit/s</entry>
992 </row>
993 <row>
994 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant> </entry>
995 <entry>448 kbit/s</entry>
996 </row>
997 </tbody>
998 </entrytbl>
999 </row>
1000 <row><entry></entry></row>
1001 <row id="v4l2-mpeg-audio-l2-bitrate">
1002 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant> </entry>
1003 <entry>enum v4l2_mpeg_audio_l2_bitrate</entry>
1004 </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
1005 Possible values are:</entry>
1006 </row>
1007 <row>
1008 <entrytbl spanname="descr" cols="2">
1009 <tbody valign="top">
1010 <row>
1011 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant> </entry>
1012 <entry>32 kbit/s</entry>
1013 </row>
1014 <row>
1015 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant> </entry>
1016 <entry>48 kbit/s</entry>
1017 </row>
1018 <row>
1019 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant> </entry>
1020 <entry>56 kbit/s</entry>
1021 </row>
1022 <row>
1023 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant> </entry>
1024 <entry>64 kbit/s</entry>
1025 </row>
1026 <row>
1027 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant> </entry>
1028 <entry>80 kbit/s</entry>
1029 </row>
1030 <row>
1031 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant> </entry>
1032 <entry>96 kbit/s</entry>
1033 </row>
1034 <row>
1035 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant> </entry>
1036 <entry>112 kbit/s</entry>
1037 </row>
1038 <row>
1039 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant> </entry>
1040 <entry>128 kbit/s</entry>
1041 </row>
1042 <row>
1043 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant> </entry>
1044 <entry>160 kbit/s</entry>
1045 </row>
1046 <row>
1047 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant> </entry>
1048 <entry>192 kbit/s</entry>
1049 </row>
1050 <row>
1051 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant> </entry>
1052 <entry>224 kbit/s</entry>
1053 </row>
1054 <row>
1055 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant> </entry>
1056 <entry>256 kbit/s</entry>
1057 </row>
1058 <row>
1059 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant> </entry>
1060 <entry>320 kbit/s</entry>
1061 </row>
1062 <row>
1063 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant> </entry>
1064 <entry>384 kbit/s</entry>
1065 </row>
1066 </tbody>
1067 </entrytbl>
1068 </row>
1069 <row><entry></entry></row>
1070 <row id="v4l2-mpeg-audio-l3-bitrate">
1071 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant> </entry>
1072 <entry>enum v4l2_mpeg_audio_l3_bitrate</entry>
1073 </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1074 Possible values are:</entry>
1075 </row>
1076 <row>
1077 <entrytbl spanname="descr" cols="2">
1078 <tbody valign="top">
1079 <row>
1080 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant> </entry>
1081 <entry>32 kbit/s</entry>
1082 </row>
1083 <row>
1084 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant> </entry>
1085 <entry>40 kbit/s</entry>
1086 </row>
1087 <row>
1088 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant> </entry>
1089 <entry>48 kbit/s</entry>
1090 </row>
1091 <row>
1092 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant> </entry>
1093 <entry>56 kbit/s</entry>
1094 </row>
1095 <row>
1096 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant> </entry>
1097 <entry>64 kbit/s</entry>
1098 </row>
1099 <row>
1100 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant> </entry>
1101 <entry>80 kbit/s</entry>
1102 </row>
1103 <row>
1104 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant> </entry>
1105 <entry>96 kbit/s</entry>
1106 </row>
1107 <row>
1108 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant> </entry>
1109 <entry>112 kbit/s</entry>
1110 </row>
1111 <row>
1112 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant> </entry>
1113 <entry>128 kbit/s</entry>
1114 </row>
1115 <row>
1116 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant> </entry>
1117 <entry>160 kbit/s</entry>
1118 </row>
1119 <row>
1120 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant> </entry>
1121 <entry>192 kbit/s</entry>
1122 </row>
1123 <row>
1124 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant> </entry>
1125 <entry>224 kbit/s</entry>
1126 </row>
1127 <row>
1128 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant> </entry>
1129 <entry>256 kbit/s</entry>
1130 </row>
1131 <row>
1132 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant> </entry>
1133 <entry>320 kbit/s</entry>
1134 </row>
1135 </tbody>
1136 </entrytbl>
1137 </row>
1138 <row><entry></entry></row>
1139 <row>
1140 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant> </entry>
1141 <entry>integer</entry>
1142 </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1143 </row>
1144 <row><entry></entry></row>
1145 <row id="v4l2-mpeg-audio-ac3-bitrate">
1146 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant> </entry>
1147 <entry>enum v4l2_mpeg_audio_ac3_bitrate</entry>
1148 </row><row><entry spanname="descr">AC-3 bitrate.
1149 Possible values are:</entry>
1150 </row>
1151 <row>
1152 <entrytbl spanname="descr" cols="2">
1153 <tbody valign="top">
1154 <row>
1155 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant> </entry>
1156 <entry>32 kbit/s</entry>
1157 </row>
1158 <row>
1159 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant> </entry>
1160 <entry>40 kbit/s</entry>
1161 </row>
1162 <row>
1163 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant> </entry>
1164 <entry>48 kbit/s</entry>
1165 </row>
1166 <row>
1167 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant> </entry>
1168 <entry>56 kbit/s</entry>
1169 </row>
1170 <row>
1171 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant> </entry>
1172 <entry>64 kbit/s</entry>
1173 </row>
1174 <row>
1175 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant> </entry>
1176 <entry>80 kbit/s</entry>
1177 </row>
1178 <row>
1179 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant> </entry>
1180 <entry>96 kbit/s</entry>
1181 </row>
1182 <row>
1183 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant> </entry>
1184 <entry>112 kbit/s</entry>
1185 </row>
1186 <row>
1187 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant> </entry>
1188 <entry>128 kbit/s</entry>
1189 </row>
1190 <row>
1191 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant> </entry>
1192 <entry>160 kbit/s</entry>
1193 </row>
1194 <row>
1195 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant> </entry>
1196 <entry>192 kbit/s</entry>
1197 </row>
1198 <row>
1199 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant> </entry>
1200 <entry>224 kbit/s</entry>
1201 </row>
1202 <row>
1203 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant> </entry>
1204 <entry>256 kbit/s</entry>
1205 </row>
1206 <row>
1207 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant> </entry>
1208 <entry>320 kbit/s</entry>
1209 </row>
1210 <row>
1211 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant> </entry>
1212 <entry>384 kbit/s</entry>
1213 </row>
1214 <row>
1215 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant> </entry>
1216 <entry>448 kbit/s</entry>
1217 </row>
1218 <row>
1219 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant> </entry>
1220 <entry>512 kbit/s</entry>
1221 </row>
1222 <row>
1223 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant> </entry>
1224 <entry>576 kbit/s</entry>
1225 </row>
1226 <row>
1227 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant> </entry>
1228 <entry>640 kbit/s</entry>
1229 </row>
1230 </tbody>
1231 </entrytbl>
1232 </row>
1233 <row><entry></entry></row>
1234 <row id="v4l2-mpeg-audio-mode">
1235 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant> </entry>
1236 <entry>enum v4l2_mpeg_audio_mode</entry>
1237 </row><row><entry spanname="descr">MPEG Audio mode.
1238 Possible values are:</entry>
1239 </row>
1240 <row>
1241 <entrytbl spanname="descr" cols="2">
1242 <tbody valign="top">
1243 <row>
1244 <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant> </entry>
1245 <entry>Stereo</entry>
1246 </row>
1247 <row>
1248 <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant> </entry>
1249 <entry>Joint Stereo</entry>
1250 </row>
1251 <row>
1252 <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant> </entry>
1253 <entry>Bilingual</entry>
1254 </row>
1255 <row>
1256 <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant> </entry>
1257 <entry>Mono</entry>
1258 </row>
1259 </tbody>
1260 </entrytbl>
1261 </row>
1262 <row><entry></entry></row>
1263 <row id="v4l2-mpeg-audio-mode-extension">
1264 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant> </entry>
1265 <entry>enum v4l2_mpeg_audio_mode_extension</entry>
1266 </row><row><entry spanname="descr">Joint Stereo
1267 audio mode extension. In Layer I and II they indicate which subbands
1268 are in intensity stereo. All other subbands are coded in stereo. Layer
1269 III is not (yet) supported. Possible values
1270 are:</entry>
1271 </row>
1272 <row>
1273 <entrytbl spanname="descr" cols="2">
1274 <tbody valign="top">
1275 <row>
1276 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant> </entry>
1277 <entry>Subbands 4-31 in intensity stereo</entry>
1278 </row>
1279 <row>
1280 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant> </entry>
1281 <entry>Subbands 8-31 in intensity stereo</entry>
1282 </row>
1283 <row>
1284 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant> </entry>
1285 <entry>Subbands 12-31 in intensity stereo</entry>
1286 </row>
1287 <row>
1288 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant> </entry>
1289 <entry>Subbands 16-31 in intensity stereo</entry>
1290 </row>
1291 </tbody>
1292 </entrytbl>
1293 </row>
1294 <row><entry></entry></row>
1295 <row id="v4l2-mpeg-audio-emphasis">
1296 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant> </entry>
1297 <entry>enum v4l2_mpeg_audio_emphasis</entry>
1298 </row><row><entry spanname="descr">Audio Emphasis.
1299 Possible values are:</entry>
1300 </row>
1301 <row>
1302 <entrytbl spanname="descr" cols="2">
1303 <tbody valign="top">
1304 <row>
1305 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant> </entry>
1306 <entry>None</entry>
1307 </row>
1308 <row>
1309 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant> </entry>
1310 <entry>50/15 microsecond emphasis</entry>
1311 </row>
1312 <row>
1313 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant> </entry>
1314 <entry>CCITT J.17</entry>
1315 </row>
1316 </tbody>
1317 </entrytbl>
1318 </row>
1319 <row><entry></entry></row>
1320 <row id="v4l2-mpeg-audio-crc">
1321 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant> </entry>
1322 <entry>enum v4l2_mpeg_audio_crc</entry>
1323 </row><row><entry spanname="descr">CRC method. Possible
1324 values are:</entry>
1325 </row>
1326 <row>
1327 <entrytbl spanname="descr" cols="2">
1328 <tbody valign="top">
1329 <row>
1330 <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant> </entry>
1331 <entry>None</entry>
1332 </row>
1333 <row>
1334 <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant> </entry>
1335 <entry>16 bit parity check</entry>
1336 </row>
1337 </tbody>
1338 </entrytbl>
1339 </row>
1340 <row><entry></entry></row>
1341 <row>
1342 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant> </entry>
1343 <entry>boolean</entry>
1344 </row><row><entry spanname="descr">Mutes the audio when
1345 capturing. This is not done by muting audio hardware, which can still
1346 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1347 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1348 </row>
1349 <row><entry></entry></row>
1350 <row id="v4l2-mpeg-audio-dec-playback">
1351 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant> </entry>
1352 <entry>enum v4l2_mpeg_audio_dec_playback</entry>
1353 </row><row><entry spanname="descr">Determines how monolingual audio should be played back.
1354 Possible values are:</entry>
1355 </row>
1356 <row>
1357 <entrytbl spanname="descr" cols="2">
1358 <tbody valign="top">
1359 <row>
1360 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_AUTO</constant> </entry>
1361 <entry>Automatically determines the best playback mode.</entry>
1362 </row>
1363 <row>
1364 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_STEREO</constant> </entry>
1365 <entry>Stereo playback.</entry>
1366 </row>
1367 <row>
1368 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_LEFT</constant> </entry>
1369 <entry>Left channel playback.</entry>
1370 </row>
1371 <row>
1372 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_RIGHT</constant> </entry>
1373 <entry>Right channel playback.</entry>
1374 </row>
1375 <row>
1376 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_MONO</constant> </entry>
1377 <entry>Mono playback.</entry>
1378 </row>
1379 <row>
1380 <entry><constant>V4L2_MPEG_AUDIO_DEC_PLAYBACK_SWAPPED_STEREO</constant> </entry>
1381 <entry>Stereo playback with swapped left and right channels.</entry>
1382 </row>
1383 </tbody>
1384 </entrytbl>
1385 </row>
1386 <row><entry></entry></row>
1387 <row id="v4l2-mpeg-audio-dec-multilingual-playback">
1388 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant> </entry>
1389 <entry>enum v4l2_mpeg_audio_dec_playback</entry>
1390 </row><row><entry spanname="descr">Determines how multilingual audio should be played back.</entry>
1391 </row>
1392 <row><entry></entry></row>
1393 <row id="v4l2-mpeg-video-encoding">
1394 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant> </entry>
1395 <entry>enum v4l2_mpeg_video_encoding</entry>
1396 </row><row><entry spanname="descr">MPEG Video encoding
1397 method. This control is specific to multiplexed MPEG streams.
1398 Possible values are:</entry>
1399 </row>
1400 <row>
1401 <entrytbl spanname="descr" cols="2">
1402 <tbody valign="top">
1403 <row>
1404 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant> </entry>
1405 <entry>MPEG-1 Video encoding</entry>
1406 </row>
1407 <row>
1408 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant> </entry>
1409 <entry>MPEG-2 Video encoding</entry>
1410 </row>
1411 <row>
1412 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant> </entry>
1413 <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1414 </row>
1415 </tbody>
1416 </entrytbl>
1417 </row>
1418 <row><entry></entry></row>
1419 <row id="v4l2-mpeg-video-aspect">
1420 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant> </entry>
1421 <entry>enum v4l2_mpeg_video_aspect</entry>
1422 </row><row><entry spanname="descr">Video aspect.
1423 Possible values are:</entry>
1424 </row>
1425 <row>
1426 <entrytbl spanname="descr" cols="2">
1427 <tbody valign="top">
1428 <row>
1429 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant> </entry>
1430 </row>
1431 <row>
1432 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant> </entry>
1433 </row>
1434 <row>
1435 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant> </entry>
1436 </row>
1437 <row>
1438 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant> </entry>
1439 </row>
1440 </tbody>
1441 </entrytbl>
1442 </row>
1443 <row><entry></entry></row>
1444 <row>
1445 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant> </entry>
1446 <entry>integer</entry>
1447 </row><row><entry spanname="descr">Number of B-Frames
1448 (default 2)</entry>
1449 </row>
1450 <row><entry></entry></row>
1451 <row>
1452 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant> </entry>
1453 <entry>integer</entry>
1454 </row><row><entry spanname="descr">GOP size (default
1455 12)</entry>
1456 </row>
1457 <row><entry></entry></row>
1458 <row>
1459 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant> </entry>
1460 <entry>boolean</entry>
1461 </row><row><entry spanname="descr">GOP closure (default
1462 1)</entry>
1463 </row>
1464 <row><entry></entry></row>
1465 <row>
1466 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant> </entry>
1467 <entry>boolean</entry>
1468 </row><row><entry spanname="descr">Enable 3:2 pulldown
1469 (default 0)</entry>
1470 </row>
1471 <row><entry></entry></row>
1472 <row id="v4l2-mpeg-video-bitrate-mode">
1473 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant> </entry>
1474 <entry>enum v4l2_mpeg_video_bitrate_mode</entry>
1475 </row><row><entry spanname="descr">Video bitrate mode.
1476 Possible values are:</entry>
1477 </row>
1478 <row>
1479 <entrytbl spanname="descr" cols="2">
1480 <tbody valign="top">
1481 <row>
1482 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant> </entry>
1483 <entry>Variable bitrate</entry>
1484 </row>
1485 <row>
1486 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant> </entry>
1487 <entry>Constant bitrate</entry>
1488 </row>
1489 </tbody>
1490 </entrytbl>
1491 </row>
1492 <row><entry></entry></row>
1493 <row>
1494 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant> </entry>
1495 <entry>integer</entry>
1496 </row><row><entry spanname="descr">Video bitrate in bits
1497 per second.</entry>
1498 </row>
1499 <row><entry></entry></row>
1500 <row>
1501 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant> </entry>
1502 <entry>integer</entry>
1503 </row><row><entry spanname="descr">Peak video bitrate in
1504 bits per second. Must be larger or equal to the average video bitrate.
1505 It is ignored if the video bitrate mode is set to constant
1506 bitrate.</entry>
1507 </row>
1508 <row><entry></entry></row>
1509 <row>
1510 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant> </entry>
1511 <entry>integer</entry>
1512 </row><row><entry spanname="descr">For every captured
1513 frame, skip this many subsequent frames (default 0).</entry>
1514 </row>
1515 <row><entry></entry></row>
1516 <row>
1517 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant> </entry>
1518 <entry>boolean</entry>
1519 </row>
1520 <row><entry spanname="descr">"Mutes" the video to a
1521 fixed color when capturing. This is useful for testing, to produce a
1522 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1523 </row>
1524 <row><entry></entry></row>
1525 <row>
1526 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant> </entry>
1527 <entry>integer</entry>
1528 </row><row><entry spanname="descr">Sets the "mute" color
1529 of the video. The supplied 32-bit integer is interpreted as follows (bit
1530 0 = least significant bit):</entry>
1531 </row>
1532 <row>
1533 <entrytbl spanname="descr" cols="2">
1534 <tbody valign="top">
1535 <row>
1536 <entry>Bit 0:7</entry>
1537 <entry>V chrominance information</entry>
1538 </row>
1539 <row>
1540 <entry>Bit 8:15</entry>
1541 <entry>U chrominance information</entry>
1542 </row>
1543 <row>
1544 <entry>Bit 16:23</entry>
1545 <entry>Y luminance information</entry>
1546 </row>
1547 <row>
1548 <entry>Bit 24:31</entry>
1549 <entry>Must be zero.</entry>
1550 </row>
1551 </tbody>
1552 </entrytbl>
1553 </row>
1554 <row><entry></entry></row>
1555 <row id="v4l2-mpeg-video-dec-pts">
1556 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_PTS</constant> </entry>
1557 <entry>integer64</entry>
1558 </row><row><entry spanname="descr">This read-only control returns the
1559 33-bit video Presentation Time Stamp as defined in ITU T-REC-H.222.0 and ISO/IEC 13818-1 of
1560 the currently displayed frame. This is the same PTS as is used in &VIDIOC-DECODER-CMD;.</entry>
1561 </row>
1562 <row><entry></entry></row>
1563 <row id="v4l2-mpeg-video-dec-frame">
1564 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DEC_FRAME</constant> </entry>
1565 <entry>integer64</entry>
1566 </row><row><entry spanname="descr">This read-only control returns the
1567 frame counter of the frame that is currently displayed (decoded). This value is reset to 0 whenever
1568 the decoder is started.</entry>
1569 </row>
1571 <row><entry></entry></row>
1572 <row>
1573 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant> </entry>
1574 <entry>boolean</entry>
1575 </row>
1576 <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1577 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1578 </entry>
1579 </row>
1581 <row><entry></entry></row>
1582 <row>
1583 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant> </entry>
1584 <entry>boolean</entry>
1585 </row>
1586 <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1587 Applicable to the H264 encoder.</entry>
1588 </row>
1590 <row><entry></entry></row>
1591 <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1592 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant> </entry>
1593 <entry>enum v4l2_mpeg_video_h264_vui_sar_idc</entry>
1594 </row>
1595 <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1596 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1597 </row>
1598 <row>
1599 <entrytbl spanname="descr" cols="2">
1600 <tbody valign="top">
1602 <row>
1603 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant> </entry>
1604 <entry>Unspecified</entry>
1605 </row>
1606 <row>
1607 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant> </entry>
1608 <entry>1x1</entry>
1609 </row>
1610 <row>
1611 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant> </entry>
1612 <entry>12x11</entry>
1613 </row>
1614 <row>
1615 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant> </entry>
1616 <entry>10x11</entry>
1617 </row>
1618 <row>
1619 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant> </entry>
1620 <entry>16x11</entry>
1621 </row>
1622 <row>
1623 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant> </entry>
1624 <entry>40x33</entry>
1625 </row>
1626 <row>
1627 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant> </entry>
1628 <entry>24x11</entry>
1629 </row>
1630 <row>
1631 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant> </entry>
1632 <entry>20x11</entry>
1633 </row>
1634 <row>
1635 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant> </entry>
1636 <entry>32x11</entry>
1637 </row>
1638 <row>
1639 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant> </entry>
1640 <entry>80x33</entry>
1641 </row>
1642 <row>
1643 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant> </entry>
1644 <entry>18x11</entry>
1645 </row>
1646 <row>
1647 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant> </entry>
1648 <entry>15x11</entry>
1649 </row>
1650 <row>
1651 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant> </entry>
1652 <entry>64x33</entry>
1653 </row>
1654 <row>
1655 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant> </entry>
1656 <entry>160x99</entry>
1657 </row>
1658 <row>
1659 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant> </entry>
1660 <entry>4x3</entry>
1661 </row>
1662 <row>
1663 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant> </entry>
1664 <entry>3x2</entry>
1665 </row>
1666 <row>
1667 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant> </entry>
1668 <entry>2x1</entry>
1669 </row>
1670 <row>
1671 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant> </entry>
1672 <entry>Extended SAR</entry>
1673 </row>
1674 </tbody>
1675 </entrytbl>
1676 </row>
1678 <row><entry></entry></row>
1679 <row>
1680 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant> </entry>
1681 <entry>integer</entry>
1682 </row>
1683 <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1684 Applicable to the H264 encoder.</entry>
1685 </row>
1687 <row><entry></entry></row>
1688 <row>
1689 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant> </entry>
1690 <entry>integer</entry>
1691 </row>
1692 <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1693 Applicable to the H264 encoder.</entry>
1694 </row>
1696 <row><entry></entry></row>
1697 <row id="v4l2-mpeg-video-h264-level">
1698 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant> </entry>
1699 <entry>enum v4l2_mpeg_video_h264_level</entry>
1700 </row>
1701 <row><entry spanname="descr">The level information for the H264 video elementary stream.
1702 Applicable to the H264 encoder.
1703 Possible values are:</entry>
1704 </row>
1705 <row>
1706 <entrytbl spanname="descr" cols="2">
1707 <tbody valign="top">
1708 <row>
1709 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant> </entry>
1710 <entry>Level 1.0</entry>
1711 </row>
1712 <row>
1713 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant> </entry>
1714 <entry>Level 1B</entry>
1715 </row>
1716 <row>
1717 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant> </entry>
1718 <entry>Level 1.1</entry>
1719 </row>
1720 <row>
1721 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant> </entry>
1722 <entry>Level 1.2</entry>
1723 </row>
1724 <row>
1725 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant> </entry>
1726 <entry>Level 1.3</entry>
1727 </row>
1728 <row>
1729 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant> </entry>
1730 <entry>Level 2.0</entry>
1731 </row>
1732 <row>
1733 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant> </entry>
1734 <entry>Level 2.1</entry>
1735 </row>
1736 <row>
1737 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant> </entry>
1738 <entry>Level 2.2</entry>
1739 </row>
1740 <row>
1741 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant> </entry>
1742 <entry>Level 3.0</entry>
1743 </row>
1744 <row>
1745 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant> </entry>
1746 <entry>Level 3.1</entry>
1747 </row>
1748 <row>
1749 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant> </entry>
1750 <entry>Level 3.2</entry>
1751 </row>
1752 <row>
1753 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant> </entry>
1754 <entry>Level 4.0</entry>
1755 </row>
1756 <row>
1757 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant> </entry>
1758 <entry>Level 4.1</entry>
1759 </row>
1760 <row>
1761 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant> </entry>
1762 <entry>Level 4.2</entry>
1763 </row>
1764 <row>
1765 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant> </entry>
1766 <entry>Level 5.0</entry>
1767 </row>
1768 <row>
1769 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant> </entry>
1770 <entry>Level 5.1</entry>
1771 </row>
1772 </tbody>
1773 </entrytbl>
1774 </row>
1776 <row><entry></entry></row>
1777 <row id="v4l2-mpeg-video-mpeg4-level">
1778 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant> </entry>
1779 <entry>enum v4l2_mpeg_video_mpeg4_level</entry>
1780 </row>
1781 <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1782 Applicable to the MPEG4 encoder.
1783 Possible values are:</entry>
1784 </row>
1785 <row>
1786 <entrytbl spanname="descr" cols="2">
1787 <tbody valign="top">
1788 <row>
1789 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant> </entry>
1790 <entry>Level 0</entry>
1791 </row>
1792 <row>
1793 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant> </entry>
1794 <entry>Level 0b</entry>
1795 </row>
1796 <row>
1797 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant> </entry>
1798 <entry>Level 1</entry>
1799 </row>
1800 <row>
1801 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant> </entry>
1802 <entry>Level 2</entry>
1803 </row>
1804 <row>
1805 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant> </entry>
1806 <entry>Level 3</entry>
1807 </row>
1808 <row>
1809 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant> </entry>
1810 <entry>Level 3b</entry>
1811 </row>
1812 <row>
1813 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant> </entry>
1814 <entry>Level 4</entry>
1815 </row>
1816 <row>
1817 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant> </entry>
1818 <entry>Level 5</entry>
1819 </row>
1820 </tbody>
1821 </entrytbl>
1822 </row>
1824 <row><entry></entry></row>
1825 <row id="v4l2-mpeg-video-h264-profile">
1826 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant> </entry>
1827 <entry>enum v4l2_mpeg_video_h264_profile</entry>
1828 </row>
1829 <row><entry spanname="descr">The profile information for H264.
1830 Applicable to the H264 encoder.
1831 Possible values are:</entry>
1832 </row>
1833 <row>
1834 <entrytbl spanname="descr" cols="2">
1835 <tbody valign="top">
1836 <row>
1837 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant> </entry>
1838 <entry>Baseline profile</entry>
1839 </row>
1840 <row>
1841 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant> </entry>
1842 <entry>Constrained Baseline profile</entry>
1843 </row>
1844 <row>
1845 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant> </entry>
1846 <entry>Main profile</entry>
1847 </row>
1848 <row>
1849 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant> </entry>
1850 <entry>Extended profile</entry>
1851 </row>
1852 <row>
1853 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant> </entry>
1854 <entry>High profile</entry>
1855 </row>
1856 <row>
1857 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant> </entry>
1858 <entry>High 10 profile</entry>
1859 </row>
1860 <row>
1861 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant> </entry>
1862 <entry>High 422 profile</entry>
1863 </row>
1864 <row>
1865 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant> </entry>
1866 <entry>High 444 Predictive profile</entry>
1867 </row>
1868 <row>
1869 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant> </entry>
1870 <entry>High 10 Intra profile</entry>
1871 </row>
1872 <row>
1873 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant> </entry>
1874 <entry>High 422 Intra profile</entry>
1875 </row>
1876 <row>
1877 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant> </entry>
1878 <entry>High 444 Intra profile</entry>
1879 </row>
1880 <row>
1881 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant> </entry>
1882 <entry>CAVLC 444 Intra profile</entry>
1883 </row>
1884 <row>
1885 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant> </entry>
1886 <entry>Scalable Baseline profile</entry>
1887 </row>
1888 <row>
1889 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant> </entry>
1890 <entry>Scalable High profile</entry>
1891 </row>
1892 <row>
1893 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant> </entry>
1894 <entry>Scalable High Intra profile</entry>
1895 </row>
1896 <row>
1897 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant> </entry>
1898 <entry>Stereo High profile</entry>
1899 </row>
1900 <row>
1901 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant> </entry>
1902 <entry>Multiview High profile</entry>
1903 </row>
1905 </tbody>
1906 </entrytbl>
1907 </row>
1909 <row><entry></entry></row>
1910 <row id="v4l2-mpeg-video-mpeg4-profile">
1911 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant> </entry>
1912 <entry>enum v4l2_mpeg_video_mpeg4_profile</entry>
1913 </row>
1914 <row><entry spanname="descr">The profile information for MPEG4.
1915 Applicable to the MPEG4 encoder.
1916 Possible values are:</entry>
1917 </row>
1918 <row>
1919 <entrytbl spanname="descr" cols="2">
1920 <tbody valign="top">
1921 <row>
1922 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant> </entry>
1923 <entry>Simple profile</entry>
1924 </row>
1925 <row>
1926 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant> </entry>
1927 <entry>Advanced Simple profile</entry>
1928 </row>
1929 <row>
1930 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant> </entry>
1931 <entry>Core profile</entry>
1932 </row>
1933 <row>
1934 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant> </entry>
1935 <entry>Simple Scalable profile</entry>
1936 </row>
1937 <row>
1938 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant> </entry>
1939 <entry></entry>
1940 </row>
1941 </tbody>
1942 </entrytbl>
1943 </row>
1945 <row><entry></entry></row>
1946 <row>
1947 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant> </entry>
1948 <entry>integer</entry>
1949 </row>
1950 <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1951 Applicable to the encoder.
1952 </entry>
1953 </row>
1955 <row><entry></entry></row>
1956 <row id="v4l2-mpeg-video-multi-slice-mode">
1957 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> </entry>
1958 <entry>enum v4l2_mpeg_video_multi_slice_mode</entry>
1959 </row>
1960 <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1961 Applicable to the encoder.
1962 Possible values are:</entry>
1963 </row>
1964 <row>
1965 <entrytbl spanname="descr" cols="2">
1966 <tbody valign="top">
1967 <row>
1968 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant> </entry>
1969 <entry>Single slice per frame.</entry>
1970 </row>
1971 <row>
1972 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant> </entry>
1973 <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1974 </row>
1975 <row>
1976 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant> </entry>
1977 <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1978 </row>
1979 </tbody>
1980 </entrytbl>
1981 </row>
1983 <row><entry></entry></row>
1984 <row>
1985 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant> </entry>
1986 <entry>integer</entry>
1987 </row>
1988 <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
1989 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
1990 Applicable to the encoder.</entry>
1991 </row>
1993 <row><entry></entry></row>
1994 <row>
1995 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant> </entry>
1996 <entry>integer</entry>
1997 </row>
1998 <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
1999 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
2000 Applicable to the encoder.</entry>
2001 </row>
2003 <row><entry></entry></row>
2004 <row id="v4l2-mpeg-video-h264-loop-filter-mode">
2005 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant> </entry>
2006 <entry>enum v4l2_mpeg_video_h264_loop_filter_mode</entry>
2007 </row>
2008 <row><entry spanname="descr">Loop filter mode for H264 encoder.
2009 Possible values are:</entry>
2010 </row>
2011 <row>
2012 <entrytbl spanname="descr" cols="2">
2013 <tbody valign="top">
2014 <row>
2015 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant> </entry>
2016 <entry>Loop filter is enabled.</entry>
2017 </row>
2018 <row>
2019 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant> </entry>
2020 <entry>Loop filter is disabled.</entry>
2021 </row>
2022 <row>
2023 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant> </entry>
2024 <entry>Loop filter is disabled at the slice boundary.</entry>
2025 </row>
2026 </tbody>
2027 </entrytbl>
2028 </row>
2030 <row><entry></entry></row>
2031 <row>
2032 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant> </entry>
2033 <entry>integer</entry>
2034 </row>
2035 <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
2036 Applicable to the H264 encoder.</entry>
2037 </row>
2039 <row><entry></entry></row>
2040 <row>
2041 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant> </entry>
2042 <entry>integer</entry>
2043 </row>
2044 <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
2045 Applicable to the H264 encoder.</entry>
2046 </row>
2048 <row><entry></entry></row>
2049 <row id="v4l2-mpeg-video-h264-entropy-mode">
2050 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant> </entry>
2051 <entry>enum v4l2_mpeg_video_h264_entropy_mode</entry>
2052 </row>
2053 <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
2054 Applicable to the H264 encoder.
2055 Possible values are:</entry>
2056 </row>
2057 <row>
2058 <entrytbl spanname="descr" cols="2">
2059 <tbody valign="top">
2060 <row>
2061 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant> </entry>
2062 <entry>Use CAVLC entropy coding.</entry>
2063 </row>
2064 <row>
2065 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant> </entry>
2066 <entry>Use CABAC entropy coding.</entry>
2067 </row>
2068 </tbody>
2069 </entrytbl>
2070 </row>
2072 <row><entry></entry></row>
2073 <row>
2074 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant> </entry>
2075 <entry>boolean</entry>
2076 </row>
2077 <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
2078 </row>
2080 <row><entry></entry></row>
2081 <row>
2082 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant> </entry>
2083 <entry>integer</entry>
2084 </row>
2085 <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
2086 refreshed every frame. Each frame a successive set of macroblocks is refreshed until the cycle completes and starts from the
2087 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
2088 </row>
2090 <row><entry></entry></row>
2091 <row>
2092 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant> </entry>
2093 <entry>boolean</entry>
2094 </row>
2095 <row><entry spanname="descr">Frame level rate control enable.
2096 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
2097 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
2098 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
2099 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
2100 Applicable to encoders.</entry>
2101 </row>
2103 <row><entry></entry></row>
2104 <row>
2105 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant> </entry>
2106 <entry>boolean</entry>
2107 </row>
2108 <row><entry spanname="descr">Macroblock level rate control enable.
2109 Applicable to the MPEG4 and H264 encoders.</entry>
2110 </row>
2112 <row><entry></entry></row>
2113 <row>
2114 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant> </entry>
2115 <entry>boolean</entry>
2116 </row>
2117 <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
2118 </row>
2120 <row><entry></entry></row>
2121 <row>
2122 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant> </entry>
2123 <entry>integer</entry>
2124 </row>
2125 <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
2126 </row>
2128 <row><entry></entry></row>
2129 <row>
2130 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant> </entry>
2131 <entry>integer</entry>
2132 </row>
2133 <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2134 </row>
2136 <row><entry></entry></row>
2137 <row>
2138 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant> </entry>
2139 <entry>integer</entry>
2140 </row>
2141 <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2142 </row>
2144 <row><entry></entry></row>
2145 <row>
2146 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant> </entry>
2147 <entry>integer</entry>
2148 </row>
2149 <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2150 </row>
2152 <row><entry></entry></row>
2153 <row>
2154 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant> </entry>
2155 <entry>integer</entry>
2156 </row>
2157 <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2158 </row>
2160 <row><entry></entry></row>
2161 <row>
2162 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant> </entry>
2163 <entry>integer</entry>
2164 </row>
2165 <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2166 </row>
2168 <row><entry></entry></row>
2169 <row>
2170 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant> </entry>
2171 <entry>integer</entry>
2172 </row>
2173 <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2174 </row>
2176 <row><entry></entry></row>
2177 <row>
2178 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant> </entry>
2179 <entry>integer</entry>
2180 </row>
2181 <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2182 </row>
2184 <row><entry></entry></row>
2185 <row>
2186 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant> </entry>
2187 <entry>integer</entry>
2188 </row>
2189 <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2190 </row>
2192 <row><entry></entry></row>
2193 <row>
2194 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant> </entry>
2195 <entry>integer</entry>
2196 </row>
2197 <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2198 </row>
2200 <row><entry></entry></row>
2201 <row>
2202 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant> </entry>
2203 <entry>integer</entry>
2204 </row>
2205 <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2206 </row>
2208 <row><entry></entry></row>
2209 <row>
2210 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant> </entry>
2211 <entry>integer</entry>
2212 </row>
2213 <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2214 </row>
2216 <row><entry></entry></row>
2217 <row>
2218 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant> </entry>
2219 <entry>integer</entry>
2220 </row>
2221 <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2222 </row>
2224 <row><entry></entry></row>
2225 <row>
2226 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant> </entry>
2227 <entry>integer</entry>
2228 </row>
2229 <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2230 </row>
2232 <row><entry></entry></row>
2233 <row>
2234 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant> </entry>
2235 <entry>integer</entry>
2236 </row>
2237 <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2238 </row>
2240 <row><entry></entry></row>
2241 <row>
2242 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant> </entry>
2243 <entry>integer</entry>
2244 </row>
2245 <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2246 The VBV is defined in the standard as a mean to verify that the produced stream will be successfully decoded.
2247 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2248 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2249 encoder or editing process may produce.".
2250 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2251 </row>
2253 <row><entry></entry></row>
2254 <row id="v4l2-mpeg-video-vbv-delay">
2255 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_DELAY</constant> </entry>
2256 <entry>integer</entry>
2257 </row><row><entry spanname="descr">Sets the initial delay in milliseconds for
2258 VBV buffer control.</entry>
2259 </row>
2261 <row><entry></entry></row>
2262 <row>
2263 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant> </entry>
2264 <entry>integer</entry>
2265 </row>
2266 <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2267 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be successfully decoded.
2268 Applicable to the H264 encoder.</entry>
2269 </row>
2271 <row><entry></entry></row>
2272 <row>
2273 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant> </entry>
2274 <entry>integer</entry>
2275 </row>
2276 <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2277 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2278 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2279 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2280 previous frames. Applicable to the H264 encoder.</entry>
2281 </row>
2283 <row><entry></entry></row>
2284 <row id="v4l2-mpeg-video-header-mode">
2285 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant> </entry>
2286 <entry>enum v4l2_mpeg_video_header_mode</entry>
2287 </row>
2288 <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2289 it returned together with the first frame. Applicable to encoders.
2290 Possible values are:</entry>
2291 </row>
2292 <row>
2293 <entrytbl spanname="descr" cols="2">
2294 <tbody valign="top">
2295 <row>
2296 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant> </entry>
2297 <entry>The stream header is returned separately in the first buffer.</entry>
2298 </row>
2299 <row>
2300 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant> </entry>
2301 <entry>The stream header is returned together with the first encoded frame.</entry>
2302 </row>
2303 </tbody>
2304 </entrytbl>
2305 </row>
2306 <row><entry></entry></row>
2307 <row>
2308 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_REPEAT_SEQ_HEADER</constant> </entry>
2309 <entry>boolean</entry>
2310 </row><row><entry spanname="descr">Repeat the video sequence headers. Repeating these
2311 headers makes random access to the video stream easier. Applicable to the MPEG1, 2 and 4 encoder.</entry>
2312 </row>
2313 <row>
2314 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant> </entry>
2315 <entry>boolean</entry>
2316 </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2317 Applicable to the MPEG4 decoder.</entry>
2318 </row>
2319 <row><entry></entry></row>
2320 <row>
2321 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant> </entry>
2322 <entry>integer</entry>
2323 </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2324 </row>
2325 <row><entry></entry></row>
2326 <row>
2327 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant> </entry>
2328 <entry>integer</entry>
2329 </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2330 </row>
2332 <row><entry></entry></row>
2333 <row>
2334 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FRAME_PACKING</constant> </entry>
2335 <entry>boolean</entry>
2336 </row>
2337 <row><entry spanname="descr">Enable generation of frame packing supplemental enhancement information in the encoded bitstream.
2338 The frame packing SEI message contains the arrangement of L and R planes for 3D viewing. Applicable to the H264 encoder.</entry>
2339 </row>
2341 <row><entry></entry></row>
2342 <row>
2343 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_CURRENT_FRAME_0</constant> </entry>
2344 <entry>boolean</entry>
2345 </row>
2346 <row><entry spanname="descr">Sets current frame as frame0 in frame packing SEI.
2347 Applicable to the H264 encoder.</entry>
2348 </row>
2350 <row><entry></entry></row>
2351 <row id="v4l2-mpeg-video-h264-sei-fp-arrangement-type">
2352 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE</constant> </entry>
2353 <entry>enum v4l2_mpeg_video_h264_sei_fp_arrangement_type</entry>
2354 </row>
2355 <row><entry spanname="descr">Frame packing arrangement type for H264 SEI.
2356 Applicable to the H264 encoder.
2357 Possible values are:</entry>
2358 </row>
2359 <row>
2360 <entrytbl spanname="descr" cols="2">
2361 <tbody valign="top">
2362 <row>
2363 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_CHEKERBOARD</constant> </entry>
2364 <entry>Pixels are alternatively from L and R.</entry>
2365 </row>
2366 <row>
2367 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_COLUMN</constant> </entry>
2368 <entry>L and R are interlaced by column.</entry>
2369 </row>
2370 <row>
2371 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_ROW</constant> </entry>
2372 <entry>L and R are interlaced by row.</entry>
2373 </row>
2374 <row>
2375 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_SIDE_BY_SIDE</constant> </entry>
2376 <entry>L is on the left, R on the right.</entry>
2377 </row>
2378 <row>
2379 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TOP_BOTTOM</constant> </entry>
2380 <entry>L is on top, R on bottom.</entry>
2381 </row>
2382 <row>
2383 <entry><constant>V4L2_MPEG_VIDEO_H264_SEI_FP_ARRANGEMENT_TYPE_TEMPORAL</constant> </entry>
2384 <entry>One view per frame.</entry>
2385 </row>
2386 </tbody>
2387 </entrytbl>
2388 </row>
2390 <row><entry></entry></row>
2391 <row>
2392 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO</constant> </entry>
2393 <entry>boolean</entry>
2394 </row>
2395 <row><entry spanname="descr">Enables flexible macroblock ordering in the encoded bitstream. It is a technique
2396 used for restructuring the ordering of macroblocks in pictures. Applicable to the H264 encoder.</entry>
2397 </row>
2399 <row><entry></entry></row>
2400 <row id="v4l2-mpeg-video-h264-fmo-map-type">
2401 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_MAP_TYPE</constant> </entry>
2402 <entry>enum v4l2_mpeg_video_h264_fmo_map_type</entry>
2403 </row>
2404 <row><entry spanname="descr">When using FMO, the map type divides the image in different scan patterns of macroblocks.
2405 Applicable to the H264 encoder.
2406 Possible values are:</entry>
2407 </row>
2408 <row>
2409 <entrytbl spanname="descr" cols="2">
2410 <tbody valign="top">
2411 <row>
2412 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_INTERLEAVED_SLICES</constant> </entry>
2413 <entry>Slices are interleaved one after other with macroblocks in run length order.</entry>
2414 </row>
2415 <row>
2416 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_SCATTERED_SLICES</constant> </entry>
2417 <entry>Scatters the macroblocks based on a mathematical function known to both encoder and decoder.</entry>
2418 </row>
2419 <row>
2420 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_FOREGROUND_WITH_LEFT_OVER</constant> </entry>
2421 <entry>Macroblocks arranged in rectangular areas or regions of interest.</entry>
2422 </row>
2423 <row>
2424 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_BOX_OUT</constant> </entry>
2425 <entry>Slice groups grow in a cyclic way from centre to outwards.</entry>
2426 </row>
2427 <row>
2428 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_RASTER_SCAN</constant> </entry>
2429 <entry>Slice groups grow in raster scan pattern from left to right.</entry>
2430 </row>
2431 <row>
2432 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_WIPE_SCAN</constant> </entry>
2433 <entry>Slice groups grow in wipe scan pattern from top to bottom.</entry>
2434 </row>
2435 <row>
2436 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_MAP_TYPE_EXPLICIT</constant> </entry>
2437 <entry>User defined map type.</entry>
2438 </row>
2439 </tbody>
2440 </entrytbl>
2441 </row>
2443 <row><entry></entry></row>
2444 <row>
2445 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_SLICE_GROUP</constant> </entry>
2446 <entry>integer</entry>
2447 </row>
2448 <row><entry spanname="descr">Number of slice groups in FMO.
2449 Applicable to the H264 encoder.</entry>
2450 </row>
2452 <row><entry></entry></row>
2453 <row id="v4l2-mpeg-video-h264-fmo-change-direction">
2454 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_DIRECTION</constant> </entry>
2455 <entry>enum v4l2_mpeg_video_h264_fmo_change_dir</entry>
2456 </row>
2457 <row><entry spanname="descr">Specifies a direction of the slice group change for raster and wipe maps.
2458 Applicable to the H264 encoder.
2459 Possible values are:</entry>
2460 </row>
2461 <row>
2462 <entrytbl spanname="descr" cols="2">
2463 <tbody valign="top">
2464 <row>
2465 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_RIGHT</constant> </entry>
2466 <entry>Raster scan or wipe right.</entry>
2467 </row>
2468 <row>
2469 <entry><constant>V4L2_MPEG_VIDEO_H264_FMO_CHANGE_DIR_LEFT</constant> </entry>
2470 <entry>Reverse raster scan or wipe left.</entry>
2471 </row>
2472 </tbody>
2473 </entrytbl>
2474 </row>
2476 <row><entry></entry></row>
2477 <row>
2478 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_CHANGE_RATE</constant> </entry>
2479 <entry>integer</entry>
2480 </row>
2481 <row><entry spanname="descr">Specifies the size of the first slice group for raster and wipe map.
2482 Applicable to the H264 encoder.</entry>
2483 </row>
2485 <row><entry></entry></row>
2486 <row>
2487 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_FMO_RUN_LENGTH</constant> </entry>
2488 <entry>integer</entry>
2489 </row>
2490 <row><entry spanname="descr">Specifies the number of consecutive macroblocks for the interleaved map.
2491 Applicable to the H264 encoder.</entry>
2492 </row>
2494 <row><entry></entry></row>
2495 <row>
2496 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO</constant> </entry>
2497 <entry>boolean</entry>
2498 </row>
2499 <row><entry spanname="descr">Enables arbitrary slice ordering in encoded bitstream.
2500 Applicable to the H264 encoder.</entry>
2501 </row>
2503 <row><entry></entry></row>
2504 <row>
2505 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ASO_SLICE_ORDER</constant> </entry>
2506 <entry>integer</entry>
2507 </row><row><entry spanname="descr">Specifies the slice order in ASO. Applicable to the H264 encoder.
2508 The supplied 32-bit integer is interpreted as follows (bit
2509 0 = least significant bit):</entry>
2510 </row>
2511 <row>
2512 <entrytbl spanname="descr" cols="2">
2513 <tbody valign="top">
2514 <row>
2515 <entry>Bit 0:15</entry>
2516 <entry>Slice ID</entry>
2517 </row>
2518 <row>
2519 <entry>Bit 16:32</entry>
2520 <entry>Slice position or order</entry>
2521 </row>
2522 </tbody>
2523 </entrytbl>
2524 </row>
2526 <row><entry></entry></row>
2527 <row>
2528 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING</constant> </entry>
2529 <entry>boolean</entry>
2530 </row>
2531 <row><entry spanname="descr">Enables H264 hierarchical coding.
2532 Applicable to the H264 encoder.</entry>
2533 </row>
2535 <row><entry></entry></row>
2536 <row id="v4l2-mpeg-video-h264-hierarchical-coding-type">
2537 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_TYPE</constant> </entry>
2538 <entry>enum v4l2_mpeg_video_h264_hierarchical_coding_type</entry>
2539 </row>
2540 <row><entry spanname="descr">Specifies the hierarchical coding type.
2541 Applicable to the H264 encoder.
2542 Possible values are:</entry>
2543 </row>
2544 <row>
2545 <entrytbl spanname="descr" cols="2">
2546 <tbody valign="top">
2547 <row>
2548 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_B</constant> </entry>
2549 <entry>Hierarchical B coding.</entry>
2550 </row>
2551 <row>
2552 <entry><constant>V4L2_MPEG_VIDEO_H264_HIERARCHICAL_CODING_P</constant> </entry>
2553 <entry>Hierarchical P coding.</entry>
2554 </row>
2555 </tbody>
2556 </entrytbl>
2557 </row>
2559 <row><entry></entry></row>
2560 <row>
2561 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER</constant> </entry>
2562 <entry>integer</entry>
2563 </row>
2564 <row><entry spanname="descr">Specifies the number of hierarchical coding layers.
2565 Applicable to the H264 encoder.</entry>
2566 </row>
2568 <row><entry></entry></row>
2569 <row>
2570 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_HIERARCHICAL_CODING_LAYER_QP</constant> </entry>
2571 <entry>integer</entry>
2572 </row><row><entry spanname="descr">Specifies a user defined QP for each layer. Applicable to the H264 encoder.
2573 The supplied 32-bit integer is interpreted as follows (bit
2574 0 = least significant bit):</entry>
2575 </row>
2576 <row>
2577 <entrytbl spanname="descr" cols="2">
2578 <tbody valign="top">
2579 <row>
2580 <entry>Bit 0:15</entry>
2581 <entry>QP value</entry>
2582 </row>
2583 <row>
2584 <entry>Bit 16:32</entry>
2585 <entry>Layer number</entry>
2586 </row>
2587 </tbody>
2588 </entrytbl>
2589 </row>
2591 </tbody>
2592 </tgroup>
2593 </table>
2594 </section>
2596 <section>
2597 <title>MFC 5.1 MPEG Controls</title>
2599 <para>The following MPEG class controls deal with MPEG
2600 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2601 in the S5P family of SoCs by Samsung.
2602 </para>
2604 <table pgwide="1" frame="none" id="mfc51-control-id">
2605 <title>MFC 5.1 Control IDs</title>
2606 <tgroup cols="4">
2607 <colspec colname="c1" colwidth="1*" />
2608 <colspec colname="c2" colwidth="6*" />
2609 <colspec colname="c3" colwidth="2*" />
2610 <colspec colname="c4" colwidth="6*" />
2611 <spanspec namest="c1" nameend="c2" spanname="id" />
2612 <spanspec namest="c2" nameend="c4" spanname="descr" />
2613 <thead>
2614 <row>
2615 <entry spanname="id" align="left">ID</entry>
2616 <entry align="left">Type</entry>
2617 </row><row><entry spanname="descr" align="left">Description</entry>
2618 </row>
2619 </thead>
2620 <tbody valign="top">
2621 <row><entry></entry></row>
2622 <row>
2623 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant> </entry>
2624 <entry>integer</entry>
2625 </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2626 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2627 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2628 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2629 Applicable to the H264 decoder.
2630 </entry>
2631 </row>
2632 <row><entry></entry></row>
2633 <row>
2634 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant> </entry>
2635 <entry>integer</entry>
2636 </row><row><entry spanname="descr">Display delay value for H264 decoder.
2637 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2638 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2639 as a reference picture for subsequent frames.
2640 </entry>
2641 </row>
2642 <row><entry></entry></row>
2643 <row>
2644 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant> </entry>
2645 <entry>integer</entry>
2646 </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2647 Applicable to the H264 encoder.</entry>
2648 </row>
2649 <row><entry></entry></row>
2650 <row>
2651 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant> </entry>
2652 <entry>boolean</entry>
2653 </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2654 Applicable to encoders.</entry>
2655 </row>
2656 <row><entry></entry></row>
2657 <row>
2658 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant> </entry>
2659 <entry>integer</entry>
2660 </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2661 0 = least significant bit):</entry>
2662 </row>
2663 <row>
2664 <entrytbl spanname="descr" cols="2">
2665 <tbody valign="top">
2666 <row>
2667 <entry>Bit 0:7</entry>
2668 <entry>V chrominance information</entry>
2669 </row>
2670 <row>
2671 <entry>Bit 8:15</entry>
2672 <entry>U chrominance information</entry>
2673 </row>
2674 <row>
2675 <entry>Bit 16:23</entry>
2676 <entry>Y luminance information</entry>
2677 </row>
2678 <row>
2679 <entry>Bit 24:31</entry>
2680 <entry>Must be zero.</entry>
2681 </row>
2682 </tbody>
2683 </entrytbl>
2684 </row>
2685 <row><entry></entry></row>
2686 <row>
2687 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant> </entry>
2688 <entry>integer</entry>
2689 </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2690 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2691 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2692 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2693 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2694 </entry>
2695 </row>
2696 <row><entry></entry></row>
2697 <row>
2698 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant> </entry>
2699 <entry>boolean</entry>
2700 </row><row><entry spanname="descr">Adaptive rate control for dark region.
2701 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2702 Applicable to the H264 encoder.</entry>
2703 </row>
2704 <row><entry></entry></row>
2705 <row>
2706 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant> </entry>
2707 <entry>boolean</entry>
2708 </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2709 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2710 Applicable to the H264 encoder.</entry>
2711 </row>
2712 <row><entry></entry></row>
2713 <row>
2714 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant> </entry>
2715 <entry>boolean</entry>
2716 </row><row><entry spanname="descr">Adaptive rate control for static region.
2717 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2718 Applicable to the H264 encoder.</entry>
2719 </row>
2720 <row><entry></entry></row>
2721 <row>
2722 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant> </entry>
2723 <entry>boolean</entry>
2724 </row><row><entry spanname="descr">Adaptive rate control for activity region.
2725 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2726 Applicable to the H264 encoder.</entry>
2727 </row>
2728 <row><entry></entry></row>
2729 <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2730 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant> </entry>
2731 <entry>enum v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2732 </row>
2733 <row><entry spanname="descr">
2734 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2735 a chosen data limit then the frame will be skipped.
2736 Possible values are:</entry>
2737 </row>
2738 <row>
2739 <entrytbl spanname="descr" cols="2">
2740 <tbody valign="top">
2741 <row>
2742 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant> </entry>
2743 <entry>Frame skip mode is disabled.</entry>
2744 </row>
2745 <row>
2746 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant> </entry>
2747 <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2748 </row>
2749 <row>
2750 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant> </entry>
2751 <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2752 </row>
2753 </tbody>
2754 </entrytbl>
2755 </row>
2756 <row><entry></entry></row>
2757 <row>
2758 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant> </entry>
2759 <entry>integer</entry>
2760 </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2761 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2762 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2763 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2764 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2765 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2766 the stream will meet tight bandwidth contraints. Applicable to encoders.
2767 </entry>
2768 </row>
2769 <row><entry></entry></row>
2770 <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2771 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant> </entry>
2772 <entry>enum v4l2_mpeg_mfc51_video_force_frame_type</entry>
2773 </row>
2774 <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2775 Possible values are:</entry>
2776 </row>
2777 <row>
2778 <entrytbl spanname="descr" cols="2">
2779 <tbody valign="top">
2780 <row>
2781 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant> </entry>
2782 <entry>Forcing a specific frame type disabled.</entry>
2783 </row>
2784 <row>
2785 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant> </entry>
2786 <entry>Force an I-frame.</entry>
2787 </row>
2788 <row>
2789 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant> </entry>
2790 <entry>Force a non-coded frame.</entry>
2791 </row>
2792 </tbody>
2793 </entrytbl>
2794 </row>
2795 </tbody>
2796 </tgroup>
2797 </table>
2798 </section>
2800 <section>
2801 <title>CX2341x MPEG Controls</title>
2803 <para>The following MPEG class controls deal with MPEG
2804 encoding settings that are specific to the Conexant CX23415 and
2805 CX23416 MPEG encoding chips.</para>
2807 <table pgwide="1" frame="none" id="cx2341x-control-id">
2808 <title>CX2341x Control IDs</title>
2809 <tgroup cols="4">
2810 <colspec colname="c1" colwidth="1*" />
2811 <colspec colname="c2" colwidth="6*" />
2812 <colspec colname="c3" colwidth="2*" />
2813 <colspec colname="c4" colwidth="6*" />
2814 <spanspec namest="c1" nameend="c2" spanname="id" />
2815 <spanspec namest="c2" nameend="c4" spanname="descr" />
2816 <thead>
2817 <row>
2818 <entry spanname="id" align="left">ID</entry>
2819 <entry align="left">Type</entry>
2820 </row><row><entry spanname="descr" align="left">Description</entry>
2821 </row>
2822 </thead>
2823 <tbody valign="top">
2824 <row><entry></entry></row>
2825 <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2826 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant> </entry>
2827 <entry>enum v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2828 </row><row><entry spanname="descr">Sets the Spatial
2829 Filter mode (default <constant>MANUAL</constant>). Possible values
2830 are:</entry>
2831 </row>
2832 <row>
2833 <entrytbl spanname="descr" cols="2">
2834 <tbody valign="top">
2835 <row>
2836 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant> </entry>
2837 <entry>Choose the filter manually</entry>
2838 </row>
2839 <row>
2840 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant> </entry>
2841 <entry>Choose the filter automatically</entry>
2842 </row>
2843 </tbody>
2844 </entrytbl>
2845 </row>
2846 <row><entry></entry></row>
2847 <row>
2848 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant> </entry>
2849 <entry>integer (0-15)</entry>
2850 </row><row><entry spanname="descr">The setting for the
2851 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2852 </row>
2853 <row><entry></entry></row>
2854 <row id="luma-spatial-filter-type">
2855 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant> </entry>
2856 <entry>enum v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2857 </row><row><entry spanname="descr">Select the algorithm
2858 to use for the Luma Spatial Filter (default
2859 <constant>1D_HOR</constant>). Possible values:</entry>
2860 </row>
2861 <row>
2862 <entrytbl spanname="descr" cols="2">
2863 <tbody valign="top">
2864 <row>
2865 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2866 <entry>No filter</entry>
2867 </row>
2868 <row>
2869 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2870 <entry>One-dimensional horizontal</entry>
2871 </row>
2872 <row>
2873 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant> </entry>
2874 <entry>One-dimensional vertical</entry>
2875 </row>
2876 <row>
2877 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant> </entry>
2878 <entry>Two-dimensional separable</entry>
2879 </row>
2880 <row>
2881 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant> </entry>
2882 <entry>Two-dimensional symmetrical
2883 non-separable</entry>
2884 </row>
2885 </tbody>
2886 </entrytbl>
2887 </row>
2888 <row><entry></entry></row>
2889 <row id="chroma-spatial-filter-type">
2890 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant> </entry>
2891 <entry>enum v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2892 </row><row><entry spanname="descr">Select the algorithm
2893 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2894 Possible values are:</entry>
2895 </row>
2896 <row>
2897 <entrytbl spanname="descr" cols="2">
2898 <tbody valign="top">
2899 <row>
2900 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2901 <entry>No filter</entry>
2902 </row>
2903 <row>
2904 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2905 <entry>One-dimensional horizontal</entry>
2906 </row>
2907 </tbody>
2908 </entrytbl>
2909 </row>
2910 <row><entry></entry></row>
2911 <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2912 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant> </entry>
2913 <entry>enum v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2914 </row><row><entry spanname="descr">Sets the Temporal
2915 Filter mode (default <constant>MANUAL</constant>). Possible values
2916 are:</entry>
2917 </row>
2918 <row>
2919 <entrytbl spanname="descr" cols="2">
2920 <tbody valign="top">
2921 <row>
2922 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant> </entry>
2923 <entry>Choose the filter manually</entry>
2924 </row>
2925 <row>
2926 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant> </entry>
2927 <entry>Choose the filter automatically</entry>
2928 </row>
2929 </tbody>
2930 </entrytbl>
2931 </row>
2932 <row><entry></entry></row>
2933 <row>
2934 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant> </entry>
2935 <entry>integer (0-31)</entry>
2936 </row><row><entry spanname="descr">The setting for the
2937 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2938 capturing and 0 for scaled capturing.)</entry>
2939 </row>
2940 <row><entry></entry></row>
2941 <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2942 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant> </entry>
2943 <entry>enum v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2944 </row><row><entry spanname="descr">Median Filter Type
2945 (default <constant>OFF</constant>). Possible values are:</entry>
2946 </row>
2947 <row>
2948 <entrytbl spanname="descr" cols="2">
2949 <tbody valign="top">
2950 <row>
2951 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant> </entry>
2952 <entry>No filter</entry>
2953 </row>
2954 <row>
2955 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant> </entry>
2956 <entry>Horizontal filter</entry>
2957 </row>
2958 <row>
2959 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant> </entry>
2960 <entry>Vertical filter</entry>
2961 </row>
2962 <row>
2963 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant> </entry>
2964 <entry>Horizontal and vertical filter</entry>
2965 </row>
2966 <row>
2967 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant> </entry>
2968 <entry>Diagonal filter</entry>
2969 </row>
2970 </tbody>
2971 </entrytbl>
2972 </row>
2973 <row><entry></entry></row>
2974 <row>
2975 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2976 <entry>integer (0-255)</entry>
2977 </row><row><entry spanname="descr">Threshold above which
2978 the luminance median filter is enabled (default 0)</entry>
2979 </row>
2980 <row><entry></entry></row>
2981 <row>
2982 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant> </entry>
2983 <entry>integer (0-255)</entry>
2984 </row><row><entry spanname="descr">Threshold below which
2985 the luminance median filter is enabled (default 255)</entry>
2986 </row>
2987 <row><entry></entry></row>
2988 <row>
2989 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2990 <entry>integer (0-255)</entry>
2991 </row><row><entry spanname="descr">Threshold above which
2992 the chroma median filter is enabled (default 0)</entry>
2993 </row>
2994 <row><entry></entry></row>
2995 <row>
2996 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant> </entry>
2997 <entry>integer (0-255)</entry>
2998 </row><row><entry spanname="descr">Threshold below which
2999 the chroma median filter is enabled (default 255)</entry>
3000 </row>
3001 <row><entry></entry></row>
3002 <row>
3003 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant> </entry>
3004 <entry>boolean</entry>
3005 </row>
3006 <row><entry spanname="descr">The CX2341X MPEG encoder
3007 can insert one empty MPEG-2 PES packet into the stream between every
3008 four video frames. The packet size is 2048 bytes, including the
3009 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
3010 (private stream 2). The payload consists of 0x00 bytes, to be filled
3011 in by the application. 0 = do not insert, 1 = insert packets.</entry>
3012 </row>
3013 </tbody>
3014 </tgroup>
3015 </table>
3016 </section>
3018 <section>
3019 <title>VPX Control Reference</title>
3021 <para>The VPX controls include controls for encoding parameters
3022 of VPx video codec.</para>
3024 <table pgwide="1" frame="none" id="vpx-control-id">
3025 <title>VPX Control IDs</title>
3027 <tgroup cols="4">
3028 <colspec colname="c1" colwidth="1*" />
3029 <colspec colname="c2" colwidth="6*" />
3030 <colspec colname="c3" colwidth="2*" />
3031 <colspec colname="c4" colwidth="6*" />
3032 <spanspec namest="c1" nameend="c2" spanname="id" />
3033 <spanspec namest="c2" nameend="c4" spanname="descr" />
3034 <thead>
3035 <row>
3036 <entry spanname="id" align="left">ID</entry>
3037 <entry align="left">Type</entry>
3038 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3039 </row>
3040 </thead>
3041 <tbody valign="top">
3042 <row><entry></entry></row>
3044 <row><entry></entry></row>
3045 <row id="v4l2-vpx-num-partitions">
3046 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS</constant></entry>
3047 <entry>enum v4l2_vp8_num_partitions</entry>
3048 </row>
3049 <row><entry spanname="descr">The number of token partitions to use in VP8 encoder.
3050 Possible values are:</entry>
3051 </row>
3052 <row>
3053 <entrytbl spanname="descr" cols="2">
3054 <tbody valign="top">
3055 <row>
3056 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_PARTITION</constant></entry>
3057 <entry>1 coefficient partition</entry>
3058 </row>
3059 <row>
3060 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_PARTITIONS</constant></entry>
3061 <entry>2 coefficient partitions</entry>
3062 </row>
3063 <row>
3064 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_4_PARTITIONS</constant></entry>
3065 <entry>4 coefficient partitions</entry>
3066 </row>
3067 <row>
3068 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_8_PARTITIONS</constant></entry>
3069 <entry>8 coefficient partitions</entry>
3070 </row>
3071 </tbody>
3072 </entrytbl>
3073 </row>
3075 <row><entry></entry></row>
3076 <row>
3077 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_IMD_DISABLE_4X4</constant></entry>
3078 <entry>boolean</entry>
3079 </row>
3080 <row><entry spanname="descr">Setting this prevents intra 4x4 mode in the intra mode decision.</entry>
3081 </row>
3083 <row><entry></entry></row>
3084 <row id="v4l2-vpx-num-ref-frames">
3085 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_NUM_REF_FRAMES</constant></entry>
3086 <entry>enum v4l2_vp8_num_ref_frames</entry>
3087 </row>
3088 <row><entry spanname="descr">The number of reference pictures for encoding P frames.
3089 Possible values are:</entry>
3090 </row>
3091 <row>
3092 <entrytbl spanname="descr" cols="2">
3093 <tbody valign="top">
3094 <row>
3095 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_1_REF_FRAME</constant></entry>
3096 <entry>Last encoded frame will be searched</entry>
3097 </row>
3098 <row>
3099 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_2_REF_FRAME</constant></entry>
3100 <entry>Two frames will be searched among the last encoded frame, the golden frame
3101 and the alternate reference (altref) frame. The encoder implementation will decide which two are chosen.</entry>
3102 </row>
3103 <row>
3104 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_3_REF_FRAME</constant></entry>
3105 <entry>The last encoded frame, the golden frame and the altref frame will be searched.</entry>
3106 </row>
3107 </tbody>
3108 </entrytbl>
3109 </row>
3111 <row><entry></entry></row>
3112 <row>
3113 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_LEVEL</constant></entry>
3114 <entry>integer</entry>
3115 </row>
3116 <row><entry spanname="descr">Indicates the loop filter level. The adjustment of the loop
3117 filter level is done via a delta value against a baseline loop filter value.</entry>
3118 </row>
3120 <row><entry></entry></row>
3121 <row>
3122 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_FILTER_SHARPNESS</constant></entry>
3123 <entry>integer</entry>
3124 </row>
3125 <row><entry spanname="descr">This parameter affects the loop filter. Anything above
3126 zero weakens the deblocking effect on the loop filter.</entry>
3127 </row>
3129 <row><entry></entry></row>
3130 <row>
3131 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD</constant></entry>
3132 <entry>integer</entry>
3133 </row>
3134 <row><entry spanname="descr">Sets the refresh period for the golden frame. The period is defined
3135 in number of frames. For a value of 'n', every nth frame starting from the first key frame will be taken as a golden frame.
3136 For eg. for encoding sequence of 0, 1, 2, 3, 4, 5, 6, 7 where the golden frame refresh period is set as 4, the frames
3137 0, 4, 8 etc will be taken as the golden frames as frame 0 is always a key frame.</entry>
3138 </row>
3140 <row><entry></entry></row>
3141 <row id="v4l2-vpx-golden-frame-sel">
3142 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_SEL</constant></entry>
3143 <entry>enum v4l2_vp8_golden_frame_sel</entry>
3144 </row>
3145 <row><entry spanname="descr">Selects the golden frame for encoding.
3146 Possible values are:</entry>
3147 </row>
3148 <row>
3149 <entrytbl spanname="descr" cols="2">
3150 <tbody valign="top">
3151 <row>
3152 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_PREV</constant></entry>
3153 <entry>Use the (n-2)th frame as a golden frame, current frame index being 'n'.</entry>
3154 </row>
3155 <row>
3156 <entry><constant>V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_USE_REF_PERIOD</constant></entry>
3157 <entry>Use the previous specific frame indicated by
3158 V4L2_CID_MPEG_VIDEO_VPX_GOLDEN_FRAME_REF_PERIOD as a golden frame.</entry>
3159 </row>
3160 </tbody>
3161 </entrytbl>
3162 </row>
3164 <row><entry></entry></row>
3165 <row>
3166 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MIN_QP</constant></entry>
3167 <entry>integer</entry>
3168 </row>
3169 <row><entry spanname="descr">Minimum quantization parameter for VP8.</entry>
3170 </row>
3172 <row><entry></entry></row>
3173 <row>
3174 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_MAX_QP</constant></entry>
3175 <entry>integer</entry>
3176 </row>
3177 <row><entry spanname="descr">Maximum quantization parameter for VP8.</entry>
3178 </row>
3180 <row><entry></entry></row>
3181 <row>
3182 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_I_FRAME_QP</constant> </entry>
3183 <entry>integer</entry>
3184 </row>
3185 <row><entry spanname="descr">Quantization parameter for an I frame for VP8.</entry>
3186 </row>
3188 <row><entry></entry></row>
3189 <row>
3190 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_P_FRAME_QP</constant> </entry>
3191 <entry>integer</entry>
3192 </row>
3193 <row><entry spanname="descr">Quantization parameter for a P frame for VP8.</entry>
3194 </row>
3196 <row><entry></entry></row>
3197 <row>
3198 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VPX_PROFILE</constant> </entry>
3199 <entry>integer</entry>
3200 </row>
3201 <row><entry spanname="descr">Select the desired profile for VPx encoder.
3202 Acceptable values are 0, 1, 2 and 3 corresponding to encoder profiles 0, 1, 2 and 3.</entry>
3203 </row>
3205 <row><entry></entry></row>
3206 </tbody>
3207 </tgroup>
3208 </table>
3210 </section>
3211 </section>
3213 <section id="camera-controls">
3214 <title>Camera Control Reference</title>
3216 <para>The Camera class includes controls for mechanical (or
3217 equivalent digital) features of a device such as controllable lenses
3218 or sensors.</para>
3220 <table pgwide="1" frame="none" id="camera-control-id">
3221 <title>Camera Control IDs</title>
3222 <tgroup cols="4">
3223 <colspec colname="c1" colwidth="1*" />
3224 <colspec colname="c2" colwidth="6*" />
3225 <colspec colname="c3" colwidth="2*" />
3226 <colspec colname="c4" colwidth="6*" />
3227 <spanspec namest="c1" nameend="c2" spanname="id" />
3228 <spanspec namest="c2" nameend="c4" spanname="descr" />
3229 <thead>
3230 <row>
3231 <entry spanname="id" align="left">ID</entry>
3232 <entry align="left">Type</entry>
3233 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3234 </row>
3235 </thead>
3236 <tbody valign="top">
3237 <row><entry></entry></row>
3238 <row>
3239 <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant> </entry>
3240 <entry>class</entry>
3241 </row><row><entry spanname="descr">The Camera class
3242 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3243 description of this control class.</entry>
3244 </row>
3245 <row><entry></entry></row>
3247 <row id="v4l2-exposure-auto-type">
3248 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant> </entry>
3249 <entry>enum v4l2_exposure_auto_type</entry>
3250 </row><row><entry spanname="descr">Enables automatic
3251 adjustments of the exposure time and/or iris aperture. The effect of
3252 manual changes of the exposure time or iris aperture while these
3253 features are enabled is undefined, drivers should ignore such
3254 requests. Possible values are:</entry>
3255 </row>
3256 <row>
3257 <entrytbl spanname="descr" cols="2">
3258 <tbody valign="top">
3259 <row>
3260 <entry><constant>V4L2_EXPOSURE_AUTO</constant> </entry>
3261 <entry>Automatic exposure time, automatic iris
3262 aperture.</entry>
3263 </row>
3264 <row>
3265 <entry><constant>V4L2_EXPOSURE_MANUAL</constant> </entry>
3266 <entry>Manual exposure time, manual iris.</entry>
3267 </row>
3268 <row>
3269 <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant> </entry>
3270 <entry>Manual exposure time, auto iris.</entry>
3271 </row>
3272 <row>
3273 <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant> </entry>
3274 <entry>Auto exposure time, manual iris.</entry>
3275 </row>
3276 </tbody>
3277 </entrytbl>
3278 </row>
3279 <row><entry></entry></row>
3281 <row>
3282 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant> </entry>
3283 <entry>integer</entry>
3284 </row><row><entry spanname="descr">Determines the exposure
3285 time of the camera sensor. The exposure time is limited by the frame
3286 interval. Drivers should interpret the values as 100 µs units,
3287 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
3288 and 100000 for 10 seconds.</entry>
3289 </row>
3290 <row><entry></entry></row>
3292 <row>
3293 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant> </entry>
3294 <entry>boolean</entry>
3295 </row><row><entry spanname="descr">When
3296 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
3297 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
3298 this control determines if the device may dynamically vary the frame
3299 rate. By default this feature is disabled (0) and the frame rate must
3300 remain constant.</entry>
3301 </row>
3302 <row><entry></entry></row>
3304 <row>
3305 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_BIAS</constant> </entry>
3306 <entry>integer menu</entry>
3307 </row><row><entry spanname="descr"> Determines the automatic
3308 exposure compensation, it is effective only when <constant>V4L2_CID_EXPOSURE_AUTO</constant>
3309 control is set to <constant>AUTO</constant>, <constant>SHUTTER_PRIORITY </constant>
3310 or <constant>APERTURE_PRIORITY</constant>.
3311 It is expressed in terms of EV, drivers should interpret the values as 0.001 EV
3312 units, where the value 1000 stands for +1 EV.
3313 <para>Increasing the exposure compensation value is equivalent to decreasing
3314 the exposure value (EV) and will increase the amount of light at the image
3315 sensor. The camera performs the exposure compensation by adjusting absolute
3316 exposure time and/or aperture.</para></entry>
3317 </row>
3318 <row><entry></entry></row>
3320 <row id="v4l2-exposure-metering">
3321 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_METERING</constant> </entry>
3322 <entry>enum v4l2_exposure_metering</entry>
3323 </row><row><entry spanname="descr">Determines how the camera measures
3324 the amount of light available for the frame exposure. Possible values are:</entry>
3325 </row>
3326 <row>
3327 <entrytbl spanname="descr" cols="2">
3328 <tbody valign="top">
3329 <row>
3330 <entry><constant>V4L2_EXPOSURE_METERING_AVERAGE</constant> </entry>
3331 <entry>Use the light information coming from the entire frame
3332 and average giving no weighting to any particular portion of the metered area.
3333 </entry>
3334 </row>
3335 <row>
3336 <entry><constant>V4L2_EXPOSURE_METERING_CENTER_WEIGHTED</constant> </entry>
3337 <entry>Average the light information coming from the entire frame
3338 giving priority to the center of the metered area.</entry>
3339 </row>
3340 <row>
3341 <entry><constant>V4L2_EXPOSURE_METERING_SPOT</constant> </entry>
3342 <entry>Measure only very small area at the center of the frame.</entry>
3343 </row>
3344 <row>
3345 <entry><constant>V4L2_EXPOSURE_METERING_MATRIX</constant> </entry>
3346 <entry>A multi-zone metering. The light intensity is measured
3347 in several points of the frame and the the results are combined. The
3348 algorithm of the zones selection and their significance in calculating the
3349 final value is device dependent.</entry>
3350 </row>
3351 </tbody>
3352 </entrytbl>
3353 </row>
3354 <row><entry></entry></row>
3356 <row>
3357 <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant> </entry>
3358 <entry>integer</entry>
3359 </row><row><entry spanname="descr">This control turns the
3360 camera horizontally by the specified amount. The unit is undefined. A
3361 positive value moves the camera to the right (clockwise when viewed
3362 from above), a negative value to the left. A value of zero does not
3363 cause motion. This is a write-only control.</entry>
3364 </row>
3365 <row><entry></entry></row>
3367 <row>
3368 <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant> </entry>
3369 <entry>integer</entry>
3370 </row><row><entry spanname="descr">This control turns the
3371 camera vertically by the specified amount. The unit is undefined. A
3372 positive value moves the camera up, a negative value down. A value of
3373 zero does not cause motion. This is a write-only control.</entry>
3374 </row>
3375 <row><entry></entry></row>
3377 <row>
3378 <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant> </entry>
3379 <entry>button</entry>
3380 </row><row><entry spanname="descr">When this control is set,
3381 the camera moves horizontally to the default position.</entry>
3382 </row>
3383 <row><entry></entry></row>
3385 <row>
3386 <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant> </entry>
3387 <entry>button</entry>
3388 </row><row><entry spanname="descr">When this control is set,
3389 the camera moves vertically to the default position.</entry>
3390 </row>
3391 <row><entry></entry></row>
3393 <row>
3394 <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant> </entry>
3395 <entry>integer</entry>
3396 </row><row><entry spanname="descr">This control
3397 turns the camera horizontally to the specified position. Positive
3398 values move the camera to the right (clockwise when viewed from above),
3399 negative values to the left. Drivers should interpret the values as arc
3400 seconds, with valid values between -180 * 3600 and +180 * 3600
3401 inclusive.</entry>
3402 </row>
3403 <row><entry></entry></row>
3405 <row>
3406 <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant> </entry>
3407 <entry>integer</entry>
3408 </row><row><entry spanname="descr">This control
3409 turns the camera vertically to the specified position. Positive values
3410 move the camera up, negative values down. Drivers should interpret the
3411 values as arc seconds, with valid values between -180 * 3600 and +180
3412 * 3600 inclusive.</entry>
3413 </row>
3414 <row><entry></entry></row>
3416 <row>
3417 <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant> </entry>
3418 <entry>integer</entry>
3419 </row><row><entry spanname="descr">This control sets the
3420 focal point of the camera to the specified position. The unit is
3421 undefined. Positive values set the focus closer to the camera,
3422 negative values towards infinity.</entry>
3423 </row>
3424 <row><entry></entry></row>
3426 <row>
3427 <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant> </entry>
3428 <entry>integer</entry>
3429 </row><row><entry spanname="descr">This control moves the
3430 focal point of the camera by the specified amount. The unit is
3431 undefined. Positive values move the focus closer to the camera,
3432 negative values towards infinity. This is a write-only control.</entry>
3433 </row>
3434 <row><entry></entry></row>
3436 <row>
3437 <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant> </entry>
3438 <entry>boolean</entry>
3439 </row><row><entry spanname="descr">Enables continuous automatic
3440 focus adjustments. The effect of manual focus adjustments while this feature
3441 is enabled is undefined, drivers should ignore such requests.</entry>
3442 </row>
3443 <row><entry></entry></row>
3445 <row>
3446 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_START</constant> </entry>
3447 <entry>button</entry>
3448 </row><row><entry spanname="descr">Starts single auto focus process.
3449 The effect of setting this control when <constant>V4L2_CID_FOCUS_AUTO</constant>
3450 is set to <constant>TRUE</constant> (1) is undefined, drivers should ignore
3451 such requests.</entry>
3452 </row>
3453 <row><entry></entry></row>
3455 <row>
3456 <entry spanname="id"><constant>V4L2_CID_AUTO_FOCUS_STOP</constant> </entry>
3457 <entry>button</entry>
3458 </row><row><entry spanname="descr">Aborts automatic focusing
3459 started with <constant>V4L2_CID_AUTO_FOCUS_START</constant> control. It is
3460 effective only when the continuous autofocus is disabled, that is when
3461 <constant>V4L2_CID_FOCUS_AUTO</constant> control is set to <constant>FALSE
3462 </constant> (0).</entry>
3463 </row>
3464 <row><entry></entry></row>
3466 <row id="v4l2-auto-focus-status">
3467 <entry spanname="id">
3468 <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant> </entry>
3469 <entry>bitmask</entry>
3470 </row>
3471 <row><entry spanname="descr">The automatic focus status. This is a read-only
3472 control.</entry>
3473 </row>
3474 <row>
3475 <entrytbl spanname="descr" cols="2">
3476 <tbody valign="top">
3477 <row>
3478 <entry><constant>V4L2_AUTO_FOCUS_STATUS_IDLE</constant> </entry>
3479 <entry>Automatic focus is not active.</entry>
3480 </row>
3481 <row>
3482 <entry><constant>V4L2_AUTO_FOCUS_STATUS_BUSY</constant> </entry>
3483 <entry>Automatic focusing is in progress.</entry>
3484 </row>
3485 <row>
3486 <entry><constant>V4L2_AUTO_FOCUS_STATUS_REACHED</constant> </entry>
3487 <entry>Focus has been reached.</entry>
3488 </row>
3489 <row>
3490 <entry><constant>V4L2_AUTO_FOCUS_STATUS_FAILED</constant> </entry>
3491 <entry>Automatic focus has failed, the driver will not
3492 transition from this state until another action is
3493 performed by an application.</entry>
3494 </row>
3495 </tbody>
3496 </entrytbl>
3497 </row>
3498 <row><entry spanname="descr">
3499 Setting <constant>V4L2_LOCK_FOCUS</constant> lock bit of the <constant>V4L2_CID_3A_LOCK
3500 </constant> control may stop updates of the <constant>V4L2_CID_AUTO_FOCUS_STATUS</constant>
3501 control value.</entry>
3502 </row>
3503 <row><entry></entry></row>
3505 <row id="v4l2-auto-focus-range">
3506 <entry spanname="id">
3507 <constant>V4L2_CID_AUTO_FOCUS_RANGE</constant> </entry>
3508 <entry>enum v4l2_auto_focus_range</entry>
3509 </row>
3510 <row><entry spanname="descr">Determines auto focus distance range
3511 for which lens may be adjusted. </entry>
3512 </row>
3513 <row>
3514 <entrytbl spanname="descr" cols="2">
3515 <tbody valign="top">
3516 <row>
3517 <entry><constant>V4L2_AUTO_FOCUS_RANGE_AUTO</constant> </entry>
3518 <entry>The camera automatically selects the focus range.</entry>
3519 </row>
3520 <row>
3521 <entry><constant>V4L2_AUTO_FOCUS_RANGE_NORMAL</constant> </entry>
3522 <entry>Normal distance range, limited for best automatic focus
3523 performance.</entry>
3524 </row>
3525 <row>
3526 <entry><constant>V4L2_AUTO_FOCUS_RANGE_MACRO</constant> </entry>
3527 <entry>Macro (close-up) auto focus. The camera will
3528 use its minimum possible distance for auto focus.</entry>
3529 </row>
3530 <row>
3531 <entry><constant>V4L2_AUTO_FOCUS_RANGE_INFINITY</constant> </entry>
3532 <entry>The lens is set to focus on an object at infinite distance.</entry>
3533 </row>
3534 </tbody>
3535 </entrytbl>
3536 </row>
3537 <row><entry></entry></row>
3539 <row>
3540 <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant> </entry>
3541 <entry>integer</entry>
3542 </row><row><entry spanname="descr">Specify the objective lens
3543 focal length as an absolute value. The zoom unit is driver-specific and its
3544 value should be a positive integer.</entry>
3545 </row>
3546 <row><entry></entry></row>
3548 <row>
3549 <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant> </entry>
3550 <entry>integer</entry>
3551 </row><row><entry spanname="descr">Specify the objective lens
3552 focal length relatively to the current value. Positive values move the zoom
3553 lens group towards the telephoto direction, negative values towards the
3554 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
3555 </row>
3556 <row><entry></entry></row>
3558 <row>
3559 <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant> </entry>
3560 <entry>integer</entry>
3561 </row><row><entry spanname="descr">Move the objective lens group
3562 at the specified speed until it reaches physical device limits or until an
3563 explicit request to stop the movement. A positive value moves the zoom lens
3564 group towards the telephoto direction. A value of zero stops the zoom lens
3565 group movement. A negative value moves the zoom lens group towards the
3566 wide-angle direction. The zoom speed unit is driver-specific.</entry>
3567 </row>
3568 <row><entry></entry></row>
3570 <row>
3571 <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant> </entry>
3572 <entry>integer</entry>
3573 </row><row><entry spanname="descr">This control sets the
3574 camera's aperture to the specified value. The unit is undefined.
3575 Larger values open the iris wider, smaller values close it.</entry>
3576 </row>
3577 <row><entry></entry></row>
3579 <row>
3580 <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant> </entry>
3581 <entry>integer</entry>
3582 </row><row><entry spanname="descr">This control modifies the
3583 camera's aperture by the specified amount. The unit is undefined.
3584 Positive values open the iris one step further, negative values close
3585 it one step further. This is a write-only control.</entry>
3586 </row>
3587 <row><entry></entry></row>
3589 <row>
3590 <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant> </entry>
3591 <entry>boolean</entry>
3592 </row><row><entry spanname="descr">Prevent video from being acquired
3593 by the camera. When this control is set to <constant>TRUE</constant> (1), no
3594 image can be captured by the camera. Common means to enforce privacy are
3595 mechanical obturation of the sensor and firmware image processing, but the
3596 device is not restricted to these methods. Devices that implement the privacy
3597 control must support read access and may support write access.</entry>
3598 </row>
3600 <row>
3601 <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant> </entry>
3602 <entry>integer</entry>
3603 </row><row><entry spanname="descr">Switch the band-stop filter of a
3604 camera sensor on or off, or specify its strength. Such band-stop filters can
3605 be used, for example, to filter out the fluorescent light component.</entry>
3606 </row>
3607 <row><entry></entry></row>
3609 <row id="v4l2-auto-n-preset-white-balance">
3610 <entry spanname="id"><constant>V4L2_CID_AUTO_N_PRESET_WHITE_BALANCE</constant> </entry>
3611 <entry>enum v4l2_auto_n_preset_white_balance</entry>
3612 </row><row><entry spanname="descr">Sets white balance to automatic,
3613 manual or a preset. The presets determine color temperature of the light as
3614 a hint to the camera for white balance adjustments resulting in most accurate
3615 color representation. The following white balance presets are listed in order
3616 of increasing color temperature.</entry>
3617 </row>
3618 <row>
3619 <entrytbl spanname="descr" cols="2">
3620 <tbody valign="top">
3621 <row>
3622 <entry><constant>V4L2_WHITE_BALANCE_MANUAL</constant> </entry>
3623 <entry>Manual white balance.</entry>
3624 </row>
3625 <row>
3626 <entry><constant>V4L2_WHITE_BALANCE_AUTO</constant> </entry>
3627 <entry>Automatic white balance adjustments.</entry>
3628 </row>
3629 <row>
3630 <entry><constant>V4L2_WHITE_BALANCE_INCANDESCENT</constant> </entry>
3631 <entry>White balance setting for incandescent (tungsten) lighting.
3632 It generally cools down the colors and corresponds approximately to 2500...3500 K
3633 color temperature range.</entry>
3634 </row>
3635 <row>
3636 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT</constant> </entry>
3637 <entry>White balance preset for fluorescent lighting.
3638 It corresponds approximately to 4000...5000 K color temperature.</entry>
3639 </row>
3640 <row>
3641 <entry><constant>V4L2_WHITE_BALANCE_FLUORESCENT_H</constant> </entry>
3642 <entry>With this setting the camera will compensate for
3643 fluorescent H lighting.</entry>
3644 </row>
3645 <row>
3646 <entry><constant>V4L2_WHITE_BALANCE_HORIZON</constant> </entry>
3647 <entry>White balance setting for horizon daylight.
3648 It corresponds approximately to 5000 K color temperature.</entry>
3649 </row>
3650 <row>
3651 <entry><constant>V4L2_WHITE_BALANCE_DAYLIGHT</constant> </entry>
3652 <entry>White balance preset for daylight (with clear sky).
3653 It corresponds approximately to 5000...6500 K color temperature.</entry>
3654 </row>
3655 <row>
3656 <entry><constant>V4L2_WHITE_BALANCE_FLASH</constant> </entry>
3657 <entry>With this setting the camera will compensate for the flash
3658 light. It slightly warms up the colors and corresponds roughly to 5000...5500 K
3659 color temperature.</entry>
3660 </row>
3661 <row>
3662 <entry><constant>V4L2_WHITE_BALANCE_CLOUDY</constant> </entry>
3663 <entry>White balance preset for moderately overcast sky.
3664 This option corresponds approximately to 6500...8000 K color temperature
3665 range.</entry>
3666 </row>
3667 <row>
3668 <entry><constant>V4L2_WHITE_BALANCE_SHADE</constant> </entry>
3669 <entry>White balance preset for shade or heavily overcast
3670 sky. It corresponds approximately to 9000...10000 K color temperature.
3671 </entry>
3672 </row>
3673 </tbody>
3674 </entrytbl>
3675 </row>
3676 <row><entry></entry></row>
3678 <row id="v4l2-wide-dynamic-range">
3679 <entry spanname="id"><constant>V4L2_CID_WIDE_DYNAMIC_RANGE</constant></entry>
3680 <entry>boolean</entry>
3681 </row>
3682 <row>
3683 <entry spanname="descr">Enables or disables the camera's wide dynamic
3684 range feature. This feature allows to obtain clear images in situations where
3685 intensity of the illumination varies significantly throughout the scene, i.e.
3686 there are simultaneously very dark and very bright areas. It is most commonly
3687 realized in cameras by combining two subsequent frames with different exposure
3688 times. <footnote id="ctypeconv"><para> This control may be changed to a menu
3689 control in the future, if more options are required.</para></footnote></entry>
3690 </row>
3691 <row><entry></entry></row>
3693 <row id="v4l2-image-stabilization">
3694 <entry spanname="id"><constant>V4L2_CID_IMAGE_STABILIZATION</constant></entry>
3695 <entry>boolean</entry>
3696 </row>
3697 <row>
3698 <entry spanname="descr">Enables or disables image stabilization.
3699 <footnoteref linkend="ctypeconv"/></entry>
3700 </row>
3701 <row><entry></entry></row>
3703 <row>
3704 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY</constant> </entry>
3705 <entry>integer menu</entry>
3706 </row><row><entry spanname="descr">Determines ISO equivalent of an
3707 image sensor indicating the sensor's sensitivity to light. The numbers are
3708 expressed in arithmetic scale, as per <xref linkend="iso12232" /> standard,
3709 where doubling the sensor sensitivity is represented by doubling the numerical
3710 ISO value. Applications should interpret the values as standard ISO values
3711 multiplied by 1000, e.g. control value 800 stands for ISO 0.8. Drivers will
3712 usually support only a subset of standard ISO values. The effect of setting
3713 this control while the <constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant>
3714 control is set to a value other than <constant>V4L2_CID_ISO_SENSITIVITY_MANUAL
3715 </constant> is undefined, drivers should ignore such requests.</entry>
3716 </row>
3717 <row><entry></entry></row>
3719 <row id="v4l2-iso-sensitivity-auto-type">
3720 <entry spanname="id"><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant> </entry>
3721 <entry>enum v4l2_iso_sensitivity_type</entry>
3722 </row><row><entry spanname="descr">Enables or disables automatic ISO
3723 sensitivity adjustments.</entry>
3724 </row>
3725 <row>
3726 <entrytbl spanname="descr" cols="2">
3727 <tbody valign="top">
3728 <row>
3729 <entry><constant>V4L2_CID_ISO_SENSITIVITY_MANUAL</constant> </entry>
3730 <entry>Manual ISO sensitivity.</entry>
3731 </row>
3732 <row>
3733 <entry><constant>V4L2_CID_ISO_SENSITIVITY_AUTO</constant> </entry>
3734 <entry>Automatic ISO sensitivity adjustments.</entry>
3735 </row>
3736 </tbody>
3737 </entrytbl>
3738 </row>
3739 <row><entry></entry></row>
3741 <row id="v4l2-scene-mode">
3742 <entry spanname="id"><constant>V4L2_CID_SCENE_MODE</constant> </entry>
3743 <entry>enum v4l2_scene_mode</entry>
3744 </row><row><entry spanname="descr">This control allows to select
3745 scene programs as the camera automatic modes optimized for common shooting
3746 scenes. Within these modes the camera determines best exposure, aperture,
3747 focusing, light metering, white balance and equivalent sensitivity. The
3748 controls of those parameters are influenced by the scene mode control.
3749 An exact behavior in each mode is subject to the camera specification.
3751 <para>When the scene mode feature is not used, this control should be set to
3752 <constant>V4L2_SCENE_MODE_NONE</constant> to make sure the other possibly
3753 related controls are accessible. The following scene programs are defined:
3754 </para>
3755 </entry>
3756 </row>
3757 <row>
3758 <entrytbl spanname="descr" cols="2">
3759 <tbody valign="top">
3760 <row>
3761 <entry><constant>V4L2_SCENE_MODE_NONE</constant> </entry>
3762 <entry>The scene mode feature is disabled.</entry>
3763 </row>
3764 <row>
3765 <entry><constant>V4L2_SCENE_MODE_BACKLIGHT</constant> </entry>
3766 <entry>Backlight. Compensates for dark shadows when light is
3767 coming from behind a subject, also by automatically turning
3768 on the flash.</entry>
3769 </row>
3770 <row>
3771 <entry><constant>V4L2_SCENE_MODE_BEACH_SNOW</constant> </entry>
3772 <entry>Beach and snow. This mode compensates for all-white or
3773 bright scenes, which tend to look gray and low contrast, when camera's automatic
3774 exposure is based on an average scene brightness. To compensate, this mode
3775 automatically slightly overexposes the frames. The white balance may also be
3776 adjusted to compensate for the fact that reflected snow looks bluish rather
3777 than white.</entry>
3778 </row>
3779 <row>
3780 <entry><constant>V4L2_SCENE_MODE_CANDLELIGHT</constant> </entry>
3781 <entry>Candle light. The camera generally raises the ISO
3782 sensitivity and lowers the shutter speed. This mode compensates for relatively
3783 close subject in the scene. The flash is disabled in order to preserve the
3784 ambiance of the light.</entry>
3785 </row>
3786 <row>
3787 <entry><constant>V4L2_SCENE_MODE_DAWN_DUSK</constant> </entry>
3788 <entry>Dawn and dusk. Preserves the colors seen in low
3789 natural light before dusk and after down. The camera may turn off the flash,
3790 and automatically focus at infinity. It will usually boost saturation and
3791 lower the shutter speed.</entry>
3792 </row>
3793 <row>
3794 <entry><constant>V4L2_SCENE_MODE_FALL_COLORS</constant> </entry>
3795 <entry>Fall colors. Increases saturation and adjusts white
3796 balance for color enhancement. Pictures of autumn leaves get saturated reds
3797 and yellows.</entry>
3798 </row>
3799 <row>
3800 <entry><constant>V4L2_SCENE_MODE_FIREWORKS</constant> </entry>
3801 <entry>Fireworks. Long exposure times are used to capture
3802 the expanding burst of light from a firework. The camera may invoke image
3803 stabilization.</entry>
3804 </row>
3805 <row>
3806 <entry><constant>V4L2_SCENE_MODE_LANDSCAPE</constant> </entry>
3807 <entry>Landscape. The camera may choose a small aperture to
3808 provide deep depth of field and long exposure duration to help capture detail
3809 in dim light conditions. The focus is fixed at infinity. Suitable for distant
3810 and wide scenery.</entry>
3811 </row>
3812 <row>
3813 <entry><constant>V4L2_SCENE_MODE_NIGHT</constant> </entry>
3814 <entry>Night, also known as Night Landscape. Designed for low
3815 light conditions, it preserves detail in the dark areas without blowing out bright
3816 objects. The camera generally sets itself to a medium-to-high ISO sensitivity,
3817 with a relatively long exposure time, and turns flash off. As such, there will be
3818 increased image noise and the possibility of blurred image.</entry>
3819 </row>
3820 <row>
3821 <entry><constant>V4L2_SCENE_MODE_PARTY_INDOOR</constant> </entry>
3822 <entry>Party and indoor. Designed to capture indoor scenes
3823 that are lit by indoor background lighting as well as the flash. The camera
3824 usually increases ISO sensitivity, and adjusts exposure for the low light
3825 conditions.</entry>
3826 </row>
3827 <row>
3828 <entry><constant>V4L2_SCENE_MODE_PORTRAIT</constant> </entry>
3829 <entry>Portrait. The camera adjusts the aperture so that the
3830 depth of field is reduced, which helps to isolate the subject against a smooth
3831 background. Most cameras recognize the presence of faces in the scene and focus
3832 on them. The color hue is adjusted to enhance skin tones. The intensity of the
3833 flash is often reduced.</entry>
3834 </row>
3835 <row>
3836 <entry><constant>V4L2_SCENE_MODE_SPORTS</constant> </entry>
3837 <entry>Sports. Significantly increases ISO and uses a fast
3838 shutter speed to freeze motion of rapidly-moving subjects. Increased image
3839 noise may be seen in this mode.</entry>
3840 </row>
3841 <row>
3842 <entry><constant>V4L2_SCENE_MODE_SUNSET</constant> </entry>
3843 <entry>Sunset. Preserves deep hues seen in sunsets and
3844 sunrises. It bumps up the saturation.</entry>
3845 </row>
3846 <row>
3847 <entry><constant>V4L2_SCENE_MODE_TEXT</constant> </entry>
3848 <entry>Text. It applies extra contrast and sharpness, it is
3849 typically a black-and-white mode optimized for readability. Automatic focus
3850 may be switched to close-up mode and this setting may also involve some
3851 lens-distortion correction.</entry>
3852 </row>
3853 </tbody>
3854 </entrytbl>
3855 </row>
3856 <row><entry></entry></row>
3858 <row>
3859 <entry spanname="id"><constant>V4L2_CID_3A_LOCK</constant></entry>
3860 <entry>bitmask</entry>
3861 </row>
3862 <row>
3863 <entry spanname="descr">This control locks or unlocks the automatic
3864 focus, exposure and white balance. The automatic adjustments can be paused
3865 independently by setting the corresponding lock bit to 1. The camera then retains
3866 the settings until the lock bit is cleared. The following lock bits are defined:
3867 </entry>
3868 </row>
3869 <row>
3870 <entrytbl spanname="descr" cols="2">
3871 <tbody valign="top">
3872 <row>
3873 <entry><constant>V4L2_LOCK_EXPOSURE</constant></entry>
3874 <entry>Automatic exposure adjustments lock.</entry>
3875 </row>
3876 <row>
3877 <entry><constant>V4L2_LOCK_WHITE_BALANCE</constant></entry>
3878 <entry>Automatic white balance adjustments lock.</entry>
3879 </row>
3880 <row>
3881 <entry><constant>V4L2_LOCK_FOCUS</constant></entry>
3882 <entry>Automatic focus lock.</entry>
3883 </row>
3884 </tbody>
3885 </entrytbl>
3886 </row>
3887 <row><entry spanname="descr">
3888 When a given algorithm is not enabled, drivers should ignore requests
3889 to lock it and should return no error. An example might be an application
3890 setting bit <constant>V4L2_LOCK_WHITE_BALANCE</constant> when the
3891 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant> control is set to
3892 <constant>FALSE</constant>. The value of this control may be changed
3893 by exposure, white balance or focus controls.</entry>
3894 </row>
3895 <row><entry></entry></row>
3897 </tbody>
3898 </tgroup>
3899 </table>
3900 </section>
3902 <section id="fm-tx-controls">
3903 <title>FM Transmitter Control Reference</title>
3905 <para>The FM Transmitter (FM_TX) class includes controls for common features of
3906 FM transmissions capable devices. Currently this class includes parameters for audio
3907 compression, pilot tone generation, audio deviation limiter, RDS transmission and
3908 tuning power features.</para>
3910 <table pgwide="1" frame="none" id="fm-tx-control-id">
3911 <title>FM_TX Control IDs</title>
3913 <tgroup cols="4">
3914 <colspec colname="c1" colwidth="1*" />
3915 <colspec colname="c2" colwidth="6*" />
3916 <colspec colname="c3" colwidth="2*" />
3917 <colspec colname="c4" colwidth="6*" />
3918 <spanspec namest="c1" nameend="c2" spanname="id" />
3919 <spanspec namest="c2" nameend="c4" spanname="descr" />
3920 <thead>
3921 <row>
3922 <entry spanname="id" align="left">ID</entry>
3923 <entry align="left">Type</entry>
3924 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3925 </row>
3926 </thead>
3927 <tbody valign="top">
3928 <row><entry></entry></row>
3929 <row>
3930 <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant> </entry>
3931 <entry>class</entry>
3932 </row><row><entry spanname="descr">The FM_TX class
3933 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
3934 description of this control class.</entry>
3935 </row>
3936 <row>
3937 <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant> </entry>
3938 <entry>integer</entry>
3939 </row>
3940 <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
3941 The range and step are driver-specific.</entry>
3942 </row>
3943 <row>
3944 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant> </entry>
3945 <entry>integer</entry>
3946 </row>
3947 <row><entry spanname="descr">Sets the RDS Programme Identification field
3948 for transmission.</entry>
3949 </row>
3950 <row>
3951 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant> </entry>
3952 <entry>integer</entry>
3953 </row>
3954 <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
3955 This encodes up to 31 pre-defined programme types.</entry>
3956 </row>
3957 <row>
3958 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant> </entry>
3959 <entry>string</entry>
3960 </row>
3961 <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
3962 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
3963 identification and selection. In Annex E of <xref linkend="iec62106" />, the RDS specification,
3964 there is a full description of the correct character encoding for Programme Service name strings.
3965 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
3966 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
3967 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
3968 </row>
3969 <row>
3970 <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant> </entry>
3971 <entry>string</entry>
3972 </row>
3973 <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
3974 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
3975 programme-related information or any other text. In these cases, RadioText should be used in addition to
3976 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
3977 in Annex E of <xref linkend="iec62106" />. The length of Radio Text strings depends on which RDS Block is being
3978 used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible
3979 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
3980 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
3981 </row>
3982 <row>
3983 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant> </entry>
3984 <entry>boolean</entry>
3985 </row>
3986 <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
3987 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
3988 distortion and prevent overmodulation.
3989 </entry>
3990 </row>
3991 <row>
3992 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant> </entry>
3993 <entry>integer</entry>
3994 </row>
3995 <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
3996 Unit is in useconds. Step and range are driver-specific.</entry>
3997 </row>
3998 <row>
3999 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant> </entry>
4000 <entry>integer</entry>
4001 </row>
4002 <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
4003 The range and step are driver-specific.</entry>
4004 </row>
4005 <row>
4006 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant> </entry>
4007 <entry>boolean</entry>
4008 </row>
4009 <row><entry spanname="descr">Enables or disables the audio compression feature.
4010 This feature amplifies signals below the threshold by a fixed gain and compresses audio
4011 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
4012 </row>
4013 <row>
4014 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant> </entry>
4015 <entry>integer</entry>
4016 </row>
4017 <row><entry spanname="descr">Sets the gain for audio compression feature. It is
4018 a dB value. The range and step are driver-specific.</entry>
4019 </row>
4020 <row>
4021 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant> </entry>
4022 <entry>integer</entry>
4023 </row>
4024 <row><entry spanname="descr">Sets the threshold level for audio compression freature.
4025 It is a dB value. The range and step are driver-specific.</entry>
4026 </row>
4027 <row>
4028 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant> </entry>
4029 <entry>integer</entry>
4030 </row>
4031 <row><entry spanname="descr">Sets the attack time for audio compression feature.
4032 It is a useconds value. The range and step are driver-specific.</entry>
4033 </row>
4034 <row>
4035 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant> </entry>
4036 <entry>integer</entry>
4037 </row>
4038 <row><entry spanname="descr">Sets the release time for audio compression feature.
4039 It is a useconds value. The range and step are driver-specific.</entry>
4040 </row>
4041 <row>
4042 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant> </entry>
4043 <entry>boolean</entry>
4044 </row>
4045 <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
4046 </row>
4047 <row>
4048 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant> </entry>
4049 <entry>integer</entry>
4050 </row>
4051 <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
4052 in Hz. The range and step are driver-specific.</entry>
4053 </row>
4054 <row>
4055 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant> </entry>
4056 <entry>integer</entry>
4057 </row>
4058 <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
4059 in Hz. The range and step are driver-specific.</entry>
4060 </row>
4061 <row>
4062 <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant> </entry>
4063 <entry>enum v4l2_preemphasis</entry>
4064 </row>
4065 <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
4066 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4067 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_preemphasis
4068 defines possible values for pre-emphasis. Here they are:</entry>
4069 </row><row>
4070 <entrytbl spanname="descr" cols="2">
4071 <tbody valign="top">
4072 <row>
4073 <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant> </entry>
4074 <entry>No pre-emphasis is applied.</entry>
4075 </row>
4076 <row>
4077 <entry><constant>V4L2_PREEMPHASIS_50_uS</constant> </entry>
4078 <entry>A pre-emphasis of 50 uS is used.</entry>
4079 </row>
4080 <row>
4081 <entry><constant>V4L2_PREEMPHASIS_75_uS</constant> </entry>
4082 <entry>A pre-emphasis of 75 uS is used.</entry>
4083 </row>
4084 </tbody>
4085 </entrytbl>
4087 </row>
4088 <row>
4089 <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant> </entry>
4090 <entry>integer</entry>
4091 </row>
4092 <row><entry spanname="descr">Sets the output power level for signal transmission.
4093 Unit is in dBuV. Range and step are driver-specific.</entry>
4094 </row>
4095 <row>
4096 <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant> </entry>
4097 <entry>integer</entry>
4098 </row>
4099 <row><entry spanname="descr">This selects the value of antenna tuning capacitor
4100 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
4101 </row>
4102 <row><entry></entry></row>
4103 </tbody>
4104 </tgroup>
4105 </table>
4107 <para>For more details about RDS specification, refer to
4108 <xref linkend="iec62106" /> document, from CENELEC.</para>
4109 </section>
4111 <section id="flash-controls">
4112 <title>Flash Control Reference</title>
4114 <note>
4115 <title>Experimental</title>
4117 <para>This is an <link linkend="experimental">experimental</link>
4118 interface and may change in the future.</para>
4119 </note>
4121 <para>
4122 The V4L2 flash controls are intended to provide generic access
4123 to flash controller devices. Flash controller devices are
4124 typically used in digital cameras.
4125 </para>
4127 <para>
4128 The interface can support both LED and xenon flash devices. As
4129 of writing this, there is no xenon flash driver using this
4130 interface.
4131 </para>
4133 <section id="flash-controls-use-cases">
4134 <title>Supported use cases</title>
4136 <section>
4137 <title>Unsynchronised LED flash (software strobe)</title>
4139 <para>
4140 Unsynchronised LED flash is controlled directly by the
4141 host as the sensor. The flash must be enabled by the host
4142 before the exposure of the image starts and disabled once
4143 it ends. The host is fully responsible for the timing of
4144 the flash.
4145 </para>
4147 <para>Example of such device: Nokia N900.</para>
4148 </section>
4150 <section>
4151 <title>Synchronised LED flash (hardware strobe)</title>
4153 <para>
4154 The synchronised LED flash is pre-programmed by the host
4155 (power and timeout) but controlled by the sensor through a
4156 strobe signal from the sensor to the flash.
4157 </para>
4159 <para>
4160 The sensor controls the flash duration and timing. This
4161 information typically must be made available to the
4162 sensor.
4163 </para>
4165 </section>
4167 <section>
4168 <title>LED flash as torch</title>
4170 <para>
4171 LED flash may be used as torch in conjunction with another
4172 use case involving camera or individually.
4173 </para>
4176 <table pgwide="1" frame="none" id="flash-control-id">
4177 <title>Flash Control IDs</title>
4179 <tgroup cols="4">
4180 <colspec colname="c1" colwidth="1*" />
4181 <colspec colname="c2" colwidth="6*" />
4182 <colspec colname="c3" colwidth="2*" />
4183 <colspec colname="c4" colwidth="6*" />
4184 <spanspec namest="c1" nameend="c2" spanname="id" />
4185 <spanspec namest="c2" nameend="c4" spanname="descr" />
4186 <thead>
4187 <row>
4188 <entry spanname="id" align="left">ID</entry>
4189 <entry align="left">Type</entry>
4190 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4191 </row>
4192 </thead>
4193 <tbody valign="top">
4194 <row><entry></entry></row>
4195 <row>
4196 <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
4197 <entry>class</entry>
4198 </row>
4199 <row>
4200 <entry spanname="descr">The FLASH class descriptor.</entry>
4201 </row>
4202 <row>
4203 <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
4204 <entry>menu</entry>
4205 </row>
4206 <row id="v4l2-flash-led-mode">
4207 <entry spanname="descr">Defines the mode of the flash LED,
4208 the high-power white LED attached to the flash controller.
4209 Setting this control may not be possible in presence of
4210 some faults. See V4L2_CID_FLASH_FAULT.</entry>
4211 </row>
4212 <row>
4213 <entrytbl spanname="descr" cols="2">
4214 <tbody valign="top">
4215 <row>
4216 <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
4217 <entry>Off.</entry>
4218 </row>
4219 <row>
4220 <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
4221 <entry>Flash mode.</entry>
4222 </row>
4223 <row>
4224 <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
4225 <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
4226 </row>
4227 </tbody>
4228 </entrytbl>
4229 </row>
4230 <row>
4231 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
4232 <entry>menu</entry>
4233 </row>
4234 <row id="v4l2-flash-strobe-source"><entry
4235 spanname="descr">Defines the source of the flash LED
4236 strobe.</entry>
4237 </row>
4238 <row>
4239 <entrytbl spanname="descr" cols="2">
4240 <tbody valign="top">
4241 <row>
4242 <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
4243 <entry>The flash strobe is triggered by using
4244 the V4L2_CID_FLASH_STROBE control.</entry>
4245 </row>
4246 <row>
4247 <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
4248 <entry>The flash strobe is triggered by an
4249 external source. Typically this is a sensor,
4250 which makes it possible to synchronises the
4251 flash strobe start to exposure start.</entry>
4252 </row>
4253 </tbody>
4254 </entrytbl>
4255 </row>
4256 <row>
4257 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
4258 <entry>button</entry>
4259 </row>
4260 <row>
4261 <entry spanname="descr">Strobe flash. Valid when
4262 V4L2_CID_FLASH_LED_MODE is set to
4263 V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
4264 is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
4265 control may not be possible in presence of some faults.
4266 See V4L2_CID_FLASH_FAULT.</entry>
4267 </row>
4268 <row>
4269 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
4270 <entry>button</entry>
4271 </row>
4272 <row><entry spanname="descr">Stop flash strobe immediately.</entry>
4273 </row>
4274 <row>
4275 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
4276 <entry>boolean</entry>
4277 </row>
4278 <row>
4279 <entry spanname="descr">Strobe status: whether the flash
4280 is strobing at the moment or not. This is a read-only
4281 control.</entry>
4282 </row>
4283 <row>
4284 <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
4285 <entry>integer</entry>
4286 </row>
4287 <row>
4288 <entry spanname="descr">Hardware timeout for flash. The
4289 flash strobe is stopped after this period of time has
4290 passed from the start of the strobe.</entry>
4291 </row>
4292 <row>
4293 <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
4294 <entry>integer</entry>
4295 </row>
4296 <row>
4297 <entry spanname="descr">Intensity of the flash strobe when
4298 the flash LED is in flash mode
4299 (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
4300 (mA) if possible.</entry>
4301 </row>
4302 <row>
4303 <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
4304 <entry>integer</entry>
4305 </row>
4306 <row>
4307 <entry spanname="descr">Intensity of the flash LED in
4308 torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
4309 milliamps (mA) if possible. Setting this control may not
4310 be possible in presence of some faults. See
4311 V4L2_CID_FLASH_FAULT.</entry>
4312 </row>
4313 <row>
4314 <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
4315 <entry>integer</entry>
4316 </row>
4317 <row>
4318 <entry spanname="descr">Intensity of the indicator LED.
4319 The indicator LED may be fully independent of the flash
4320 LED. The unit should be microamps (uA) if possible.</entry>
4321 </row>
4322 <row>
4323 <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
4324 <entry>bitmask</entry>
4325 </row>
4326 <row>
4327 <entry spanname="descr">Faults related to the flash. The
4328 faults tell about specific problems in the flash chip
4329 itself or the LEDs attached to it. Faults may prevent
4330 further use of some of the flash controls. In particular,
4331 V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
4332 if the fault affects the flash LED. Exactly which faults
4333 have such an effect is chip dependent. Reading the faults
4334 resets the control and returns the chip to a usable state
4335 if possible.</entry>
4336 </row>
4337 <row>
4338 <entrytbl spanname="descr" cols="2">
4339 <tbody valign="top">
4340 <row>
4341 <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
4342 <entry>Flash controller voltage to the flash LED
4343 has exceeded the limit specific to the flash
4344 controller.</entry>
4345 </row>
4346 <row>
4347 <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
4348 <entry>The flash strobe was still on when
4349 the timeout set by the user ---
4350 V4L2_CID_FLASH_TIMEOUT control --- has expired.
4351 Not all flash controllers may set this in all
4352 such conditions.</entry>
4353 </row>
4354 <row>
4355 <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
4356 <entry>The flash controller has overheated.</entry>
4357 </row>
4358 <row>
4359 <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
4360 <entry>The short circuit protection of the flash
4361 controller has been triggered.</entry>
4362 </row>
4363 <row>
4364 <entry><constant>V4L2_FLASH_FAULT_OVER_CURRENT</constant></entry>
4365 <entry>Current in the LED power supply has exceeded the limit
4366 specific to the flash controller.</entry>
4367 </row>
4368 <row>
4369 <entry><constant>V4L2_FLASH_FAULT_INDICATOR</constant></entry>
4370 <entry>The flash controller has detected a short or open
4371 circuit condition on the indicator LED.</entry>
4372 </row>
4373 </tbody>
4374 </entrytbl>
4375 </row>
4376 <row>
4377 <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
4378 <entry>boolean</entry>
4379 </row>
4380 <row><entry spanname="descr">Enable or disable charging of the xenon
4381 flash capacitor.</entry>
4382 </row>
4383 <row>
4384 <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
4385 <entry>boolean</entry>
4386 </row>
4387 <row>
4388 <entry spanname="descr">Is the flash ready to strobe?
4389 Xenon flashes require their capacitors charged before
4390 strobing. LED flashes often require a cooldown period
4391 after strobe during which another strobe will not be
4392 possible. This is a read-only control.</entry>
4393 </row>
4394 <row><entry></entry></row>
4395 </tbody>
4396 </tgroup>
4397 </table>
4398 </section>
4399 </section>
4400 </section>
4402 <section id="jpeg-controls">
4403 <title>JPEG Control Reference</title>
4404 <para>The JPEG class includes controls for common features of JPEG
4405 encoders and decoders. Currently it includes features for codecs
4406 implementing progressive baseline DCT compression process with
4407 Huffman entrophy coding.</para>
4408 <table pgwide="1" frame="none" id="jpeg-control-id">
4409 <title>JPEG Control IDs</title>
4411 <tgroup cols="4">
4412 <colspec colname="c1" colwidth="1*" />
4413 <colspec colname="c2" colwidth="6*" />
4414 <colspec colname="c3" colwidth="2*" />
4415 <colspec colname="c4" colwidth="6*" />
4416 <spanspec namest="c1" nameend="c2" spanname="id" />
4417 <spanspec namest="c2" nameend="c4" spanname="descr" />
4418 <thead>
4419 <row>
4420 <entry spanname="id" align="left">ID</entry>
4421 <entry align="left">Type</entry>
4422 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4423 </row>
4424 </thead>
4425 <tbody valign="top">
4426 <row><entry></entry></row>
4427 <row>
4428 <entry spanname="id"><constant>V4L2_CID_JPEG_CLASS</constant> </entry>
4429 <entry>class</entry>
4430 </row><row><entry spanname="descr">The JPEG class descriptor. Calling
4431 &VIDIOC-QUERYCTRL; for this control will return a description of this
4432 control class.
4434 </entry>
4435 </row>
4436 <row>
4437 <entry spanname="id"><constant>V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant></entry>
4438 <entry>menu</entry>
4439 </row>
4440 <row id="v4l2-jpeg-chroma-subsampling">
4441 <entry spanname="descr">The chroma subsampling factors describe how
4442 each component of an input image is sampled, in respect to maximum
4443 sample rate in each spatial dimension. See <xref linkend="itu-t81"/>,
4444 clause A.1.1. for more details. The <constant>
4445 V4L2_CID_JPEG_CHROMA_SUBSAMPLING</constant> control determines how
4446 Cb and Cr components are downsampled after coverting an input image
4447 from RGB to Y'CbCr color space.
4448 </entry>
4449 </row>
4450 <row>
4451 <entrytbl spanname="descr" cols="2">
4452 <tbody valign="top">
4453 <row>
4454 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_444</constant>
4455 </entry><entry>No chroma subsampling, each pixel has
4456 Y, Cr and Cb values.</entry>
4457 </row>
4458 <row>
4459 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_422</constant>
4460 </entry><entry>Horizontally subsample Cr, Cb components
4461 by a factor of 2.</entry>
4462 </row>
4463 <row>
4464 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_420</constant>
4465 </entry><entry>Subsample Cr, Cb components horizontally
4466 and vertically by 2.</entry>
4467 </row>
4468 <row>
4469 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_411</constant>
4470 </entry><entry>Horizontally subsample Cr, Cb components
4471 by a factor of 4.</entry>
4472 </row>
4473 <row>
4474 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_410</constant>
4475 </entry><entry>Subsample Cr, Cb components horizontally
4476 by 4 and vertically by 2.</entry>
4477 </row>
4478 <row>
4479 <entry><constant>V4L2_JPEG_CHROMA_SUBSAMPLING_GRAY</constant>
4480 </entry><entry>Use only luminance component.</entry>
4481 </row>
4482 </tbody>
4483 </entrytbl>
4484 </row>
4485 <row>
4486 <entry spanname="id"><constant>V4L2_CID_JPEG_RESTART_INTERVAL</constant>
4487 </entry><entry>integer</entry>
4488 </row>
4489 <row><entry spanname="descr">
4490 The restart interval determines an interval of inserting RSTm
4491 markers (m = 0..7). The purpose of these markers is to additionally
4492 reinitialize the encoder process, in order to process blocks of
4493 an image independently.
4494 For the lossy compression processes the restart interval unit is
4495 MCU (Minimum Coded Unit) and its value is contained in DRI
4496 (Define Restart Interval) marker. If <constant>
4497 V4L2_CID_JPEG_RESTART_INTERVAL</constant> control is set to 0,
4498 DRI and RSTm markers will not be inserted.
4499 </entry>
4500 </row>
4501 <row id="jpeg-quality-control">
4502 <entry spanname="id"><constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant></entry>
4503 <entry>integer</entry>
4504 </row>
4505 <row>
4506 <entry spanname="descr">
4507 <constant>V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control
4508 determines trade-off between image quality and size.
4509 It provides simpler method for applications to control image quality,
4510 without a need for direct reconfiguration of luminance and chrominance
4511 quantization tables.
4513 In cases where a driver uses quantization tables configured directly
4514 by an application, using interfaces defined elsewhere, <constant>
4515 V4L2_CID_JPEG_COMPRESSION_QUALITY</constant> control should be set
4516 by driver to 0.
4518 <para>The value range of this control is driver-specific. Only
4519 positive, non-zero values are meaningful. The recommended range
4520 is 1 - 100, where larger values correspond to better image quality.
4521 </para>
4522 </entry>
4523 </row>
4524 <row id="jpeg-active-marker-control">
4525 <entry spanname="id"><constant>V4L2_CID_JPEG_ACTIVE_MARKER</constant></entry>
4526 <entry>bitmask</entry>
4527 </row>
4528 <row>
4529 <entry spanname="descr">Specify which JPEG markers are included
4530 in compressed stream. This control is valid only for encoders.
4531 </entry>
4532 </row>
4533 <row>
4534 <entrytbl spanname="descr" cols="2">
4535 <tbody valign="top">
4536 <row>
4537 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP0</constant></entry>
4538 <entry>Application data segment APP<subscript>0</subscript>.</entry>
4539 </row><row>
4540 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_APP1</constant></entry>
4541 <entry>Application data segment APP<subscript>1</subscript>.</entry>
4542 </row><row>
4543 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_COM</constant></entry>
4544 <entry>Comment segment.</entry>
4545 </row><row>
4546 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DQT</constant></entry>
4547 <entry>Quantization tables segment.</entry>
4548 </row><row>
4549 <entry><constant>V4L2_JPEG_ACTIVE_MARKER_DHT</constant></entry>
4550 <entry>Huffman tables segment.</entry>
4551 </row>
4552 </tbody>
4553 </entrytbl>
4554 </row>
4555 <row><entry></entry></row>
4556 </tbody>
4557 </tgroup>
4558 </table>
4559 <para>For more details about JPEG specification, refer
4560 to <xref linkend="itu-t81"/>, <xref linkend="jfif"/>,
4561 <xref linkend="w3c-jpeg-jfif"/>.</para>
4562 </section>
4564 <section id="image-source-controls">
4565 <title>Image Source Control Reference</title>
4567 <note>
4568 <title>Experimental</title>
4570 <para>This is an <link
4571 linkend="experimental">experimental</link> interface and may
4572 change in the future.</para>
4573 </note>
4575 <para>
4576 The Image Source control class is intended for low-level
4577 control of image source devices such as image sensors. The
4578 devices feature an analogue to digital converter and a bus
4579 transmitter to transmit the image data out of the device.
4580 </para>
4582 <table pgwide="1" frame="none" id="image-source-control-id">
4583 <title>Image Source Control IDs</title>
4585 <tgroup cols="4">
4586 <colspec colname="c1" colwidth="1*" />
4587 <colspec colname="c2" colwidth="6*" />
4588 <colspec colname="c3" colwidth="2*" />
4589 <colspec colname="c4" colwidth="6*" />
4590 <spanspec namest="c1" nameend="c2" spanname="id" />
4591 <spanspec namest="c2" nameend="c4" spanname="descr" />
4592 <thead>
4593 <row>
4594 <entry spanname="id" align="left">ID</entry>
4595 <entry align="left">Type</entry>
4596 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4597 </row>
4598 </thead>
4599 <tbody valign="top">
4600 <row><entry></entry></row>
4601 <row>
4602 <entry spanname="id"><constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant></entry>
4603 <entry>class</entry>
4604 </row>
4605 <row>
4606 <entry spanname="descr">The IMAGE_SOURCE class descriptor.</entry>
4607 </row>
4608 <row>
4609 <entry spanname="id"><constant>V4L2_CID_VBLANK</constant></entry>
4610 <entry>integer</entry>
4611 </row>
4612 <row>
4613 <entry spanname="descr">Vertical blanking. The idle period
4614 after every frame during which no image data is produced.
4615 The unit of vertical blanking is a line. Every line has
4616 length of the image width plus horizontal blanking at the
4617 pixel rate defined by
4618 <constant>V4L2_CID_PIXEL_RATE</constant> control in the
4619 same sub-device.</entry>
4620 </row>
4621 <row>
4622 <entry spanname="id"><constant>V4L2_CID_HBLANK</constant></entry>
4623 <entry>integer</entry>
4624 </row>
4625 <row>
4626 <entry spanname="descr">Horizontal blanking. The idle
4627 period after every line of image data during which no
4628 image data is produced. The unit of horizontal blanking is
4629 pixels.</entry>
4630 </row>
4631 <row>
4632 <entry spanname="id"><constant>V4L2_CID_ANALOGUE_GAIN</constant></entry>
4633 <entry>integer</entry>
4634 </row>
4635 <row>
4636 <entry spanname="descr">Analogue gain is gain affecting
4637 all colour components in the pixel matrix. The gain
4638 operation is performed in the analogue domain before A/D
4639 conversion.
4640 </entry>
4641 </row>
4642 <row><entry></entry></row>
4643 </tbody>
4644 </tgroup>
4645 </table>
4647 </section>
4649 <section id="image-process-controls">
4650 <title>Image Process Control Reference</title>
4652 <note>
4653 <title>Experimental</title>
4655 <para>This is an <link
4656 linkend="experimental">experimental</link> interface and may
4657 change in the future.</para>
4658 </note>
4660 <para>
4661 The Image Source control class is intended for low-level control of
4662 image processing functions. Unlike
4663 <constant>V4L2_CID_IMAGE_SOURCE_CLASS</constant>, the controls in
4664 this class affect processing the image, and do not control capturing
4665 of it.
4666 </para>
4668 <table pgwide="1" frame="none" id="image-process-control-id">
4669 <title>Image Source Control IDs</title>
4671 <tgroup cols="4">
4672 <colspec colname="c1" colwidth="1*" />
4673 <colspec colname="c2" colwidth="6*" />
4674 <colspec colname="c3" colwidth="2*" />
4675 <colspec colname="c4" colwidth="6*" />
4676 <spanspec namest="c1" nameend="c2" spanname="id" />
4677 <spanspec namest="c2" nameend="c4" spanname="descr" />
4678 <thead>
4679 <row>
4680 <entry spanname="id" align="left">ID</entry>
4681 <entry align="left">Type</entry>
4682 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4683 </row>
4684 </thead>
4685 <tbody valign="top">
4686 <row><entry></entry></row>
4687 <row>
4688 <entry spanname="id"><constant>V4L2_CID_IMAGE_PROC_CLASS</constant></entry>
4689 <entry>class</entry>
4690 </row>
4691 <row>
4692 <entry spanname="descr">The IMAGE_PROC class descriptor.</entry>
4693 </row>
4694 <row>
4695 <entry spanname="id"><constant>V4L2_CID_LINK_FREQ</constant></entry>
4696 <entry>integer menu</entry>
4697 </row>
4698 <row>
4699 <entry spanname="descr">Data bus frequency. Together with the
4700 media bus pixel code, bus type (clock cycles per sample), the
4701 data bus frequency defines the pixel rate
4702 (<constant>V4L2_CID_PIXEL_RATE</constant>) in the
4703 pixel array (or possibly elsewhere, if the device is not an
4704 image sensor). The frame rate can be calculated from the pixel
4705 clock, image width and height and horizontal and vertical
4706 blanking. While the pixel rate control may be defined elsewhere
4707 than in the subdev containing the pixel array, the frame rate
4708 cannot be obtained from that information. This is because only
4709 on the pixel array it can be assumed that the vertical and
4710 horizontal blanking information is exact: no other blanking is
4711 allowed in the pixel array. The selection of frame rate is
4712 performed by selecting the desired horizontal and vertical
4713 blanking. The unit of this control is Hz. </entry>
4714 </row>
4715 <row>
4716 <entry spanname="id"><constant>V4L2_CID_PIXEL_RATE</constant></entry>
4717 <entry>64-bit integer</entry>
4718 </row>
4719 <row>
4720 <entry spanname="descr">Pixel rate in the source pads of
4721 the subdev. This control is read-only and its unit is
4722 pixels / second.
4723 </entry>
4724 </row>
4725 <row>
4726 <entry spanname="id"><constant>V4L2_CID_TEST_PATTERN</constant></entry>
4727 <entry>menu</entry>
4728 </row>
4729 <row id="v4l2-test-pattern">
4730 <entry spanname="descr"> Some capture/display/sensor devices have
4731 the capability to generate test pattern images. These hardware
4732 specific test patterns can be used to test if a device is working
4733 properly.</entry>
4734 </row>
4735 <row><entry></entry></row>
4736 </tbody>
4737 </tgroup>
4738 </table>
4740 </section>
4742 <section id="dv-controls">
4743 <title>Digital Video Control Reference</title>
4745 <note>
4746 <title>Experimental</title>
4748 <para>This is an <link
4749 linkend="experimental">experimental</link> interface and may
4750 change in the future.</para>
4751 </note>
4753 <para>
4754 The Digital Video control class is intended to control receivers
4755 and transmitters for <ulink url="http://en.wikipedia.org/wiki/Vga">VGA</ulink>,
4756 <ulink url="http://en.wikipedia.org/wiki/Digital_Visual_Interface">DVI</ulink>
4757 (Digital Visual Interface), HDMI (<xref linkend="hdmi" />) and DisplayPort (<xref linkend="dp" />).
4758 These controls are generally expected to be private to the receiver or transmitter
4759 subdevice that implements them, so they are only exposed on the
4760 <filename>/dev/v4l-subdev*</filename> device node.
4761 </para>
4763 <para>Note that these devices can have multiple input or output pads which are
4764 hooked up to e.g. HDMI connectors. Even though the subdevice will receive or
4765 transmit video from/to only one of those pads, the other pads can still be
4766 active when it comes to EDID (Extended Display Identification Data,
4767 <xref linkend="vesaedid" />) and HDCP (High-bandwidth Digital Content
4768 Protection System, <xref linkend="hdcp" />) processing, allowing the device
4769 to do the fairly slow EDID/HDCP handling in advance. This allows for quick
4770 switching between connectors.</para>
4772 <para>These pads appear in several of the controls in this section as
4773 bitmasks, one bit for each pad. Bit 0 corresponds to pad 0, bit 1 to pad 1,
4774 etc. The maximum value of the control is the set of valid pads.</para>
4776 <table pgwide="1" frame="none" id="dv-control-id">
4777 <title>Digital Video Control IDs</title>
4779 <tgroup cols="4">
4780 <colspec colname="c1" colwidth="1*" />
4781 <colspec colname="c2" colwidth="6*" />
4782 <colspec colname="c3" colwidth="2*" />
4783 <colspec colname="c4" colwidth="6*" />
4784 <spanspec namest="c1" nameend="c2" spanname="id" />
4785 <spanspec namest="c2" nameend="c4" spanname="descr" />
4786 <thead>
4787 <row>
4788 <entry spanname="id" align="left">ID</entry>
4789 <entry align="left">Type</entry>
4790 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4791 </row>
4792 </thead>
4793 <tbody valign="top">
4794 <row><entry></entry></row>
4795 <row>
4796 <entry spanname="id"><constant>V4L2_CID_DV_CLASS</constant></entry>
4797 <entry>class</entry>
4798 </row>
4799 <row>
4800 <entry spanname="descr">The Digital Video class descriptor.</entry>
4801 </row>
4802 <row>
4803 <entry spanname="id"><constant>V4L2_CID_DV_TX_HOTPLUG</constant></entry>
4804 <entry>bitmask</entry>
4805 </row>
4806 <row>
4807 <entry spanname="descr">Many connectors have a hotplug pin which is high
4808 if EDID information is available from the source. This control shows the
4809 state of the hotplug pin as seen by the transmitter.
4810 Each bit corresponds to an output pad on the transmitter. If an output pad
4811 does not have an associated hotplug pin, then the bit for that pad will be 0.
4812 This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4813 </entry>
4814 </row>
4815 <row>
4816 <entry spanname="id"><constant>V4L2_CID_DV_TX_RXSENSE</constant></entry>
4817 <entry>bitmask</entry>
4818 </row>
4819 <row>
4820 <entry spanname="descr">Rx Sense is the detection of pull-ups on the TMDS
4821 clock lines. This normally means that the sink has left/entered standby (i.e.
4822 the transmitter can sense that the receiver is ready to receive video).
4823 Each bit corresponds to an output pad on the transmitter. If an output pad
4824 does not have an associated Rx Sense, then the bit for that pad will be 0.
4825 This read-only control is applicable to DVI-D and HDMI devices.
4826 </entry>
4827 </row>
4828 <row>
4829 <entry spanname="id"><constant>V4L2_CID_DV_TX_EDID_PRESENT</constant></entry>
4830 <entry>bitmask</entry>
4831 </row>
4832 <row>
4833 <entry spanname="descr">When the transmitter sees the hotplug signal from the
4834 receiver it will attempt to read the EDID. If set, then the transmitter has read
4835 at least the first block (= 128 bytes).
4836 Each bit corresponds to an output pad on the transmitter. If an output pad
4837 does not support EDIDs, then the bit for that pad will be 0.
4838 This read-only control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4839 </entry>
4840 </row>
4841 <row>
4842 <entry spanname="id"><constant>V4L2_CID_DV_TX_MODE</constant></entry>
4843 <entry id="v4l2-dv-tx-mode">enum v4l2_dv_tx_mode</entry>
4844 </row>
4845 <row>
4846 <entry spanname="descr">HDMI transmitters can transmit in DVI-D mode (just video)
4847 or in HDMI mode (video + audio + auxiliary data). This control selects which mode
4848 to use: V4L2_DV_TX_MODE_DVI_D or V4L2_DV_TX_MODE_HDMI.
4849 This control is applicable to HDMI connectors.
4850 </entry>
4851 </row>
4852 <row>
4853 <entry spanname="id"><constant>V4L2_CID_DV_TX_RGB_RANGE</constant></entry>
4854 <entry id="v4l2-dv-rgb-range">enum v4l2_dv_rgb_range</entry>
4855 </row>
4856 <row>
4857 <entry spanname="descr">Select the quantization range for RGB output. V4L2_DV_RANGE_AUTO
4858 follows the RGB quantization range specified in the standard for the video interface
4859 (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4860 to be compatible with sinks that have not implemented the standard correctly
4861 (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4862 used whereas limited range sets the range to (16 << (N-8)) - (235 << (N-8))
4863 where N is the number of bits per component.
4864 This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4865 </entry>
4866 </row>
4867 <row>
4868 <entry spanname="id"><constant>V4L2_CID_DV_RX_POWER_PRESENT</constant></entry>
4869 <entry>bitmask</entry>
4870 </row>
4871 <row>
4872 <entry spanname="descr">Detects whether the receiver receives power from the source
4873 (e.g. HDMI carries 5V on one of the pins). This is often used to power an eeprom
4874 which contains EDID information, such that the source can read the EDID even if
4875 the sink is in standby/power off.
4876 Each bit corresponds to an input pad on the transmitter. If an input pad
4877 cannot detect whether power is present, then the bit for that pad will be 0.
4878 This read-only control is applicable to DVI-D, HDMI and DisplayPort connectors.
4879 </entry>
4880 </row>
4881 <row>
4882 <entry spanname="id"><constant>V4L2_CID_DV_RX_RGB_RANGE</constant></entry>
4883 <entry>enum v4l2_dv_rgb_range</entry>
4884 </row>
4885 <row>
4886 <entry spanname="descr">Select the quantization range for RGB input. V4L2_DV_RANGE_AUTO
4887 follows the RGB quantization range specified in the standard for the video interface
4888 (ie. <xref linkend="cea861" /> for HDMI). V4L2_DV_RANGE_LIMITED and V4L2_DV_RANGE_FULL override the standard
4889 to be compatible with sources that have not implemented the standard correctly
4890 (unfortunately quite common for HDMI and DVI-D). Full range allows all possible values to be
4891 used whereas limited range sets the range to (16 << (N-8)) - (235 << (N-8))
4892 where N is the number of bits per component.
4893 This control is applicable to VGA, DVI-A/D, HDMI and DisplayPort connectors.
4894 </entry>
4895 </row>
4896 <row><entry></entry></row>
4897 </tbody>
4898 </tgroup>
4899 </table>
4901 </section>
4903 <section id="fm-rx-controls">
4904 <title>FM Receiver Control Reference</title>
4906 <para>The FM Receiver (FM_RX) class includes controls for common features of
4907 FM Reception capable devices.</para>
4909 <table pgwide="1" frame="none" id="fm-rx-control-id">
4910 <title>FM_RX Control IDs</title>
4912 <tgroup cols="4">
4913 <colspec colname="c1" colwidth="1*" />
4914 <colspec colname="c2" colwidth="6*" />
4915 <colspec colname="c3" colwidth="2*" />
4916 <colspec colname="c4" colwidth="6*" />
4917 <spanspec namest="c1" nameend="c2" spanname="id" />
4918 <spanspec namest="c2" nameend="c4" spanname="descr" />
4919 <thead>
4920 <row>
4921 <entry spanname="id" align="left">ID</entry>
4922 <entry align="left">Type</entry>
4923 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
4924 </row>
4925 </thead>
4926 <tbody valign="top">
4927 <row><entry></entry></row>
4928 <row>
4929 <entry spanname="id"><constant>V4L2_CID_FM_RX_CLASS</constant> </entry>
4930 <entry>class</entry>
4931 </row><row><entry spanname="descr">The FM_RX class
4932 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
4933 description of this control class.</entry>
4934 </row>
4935 <row>
4936 <entry spanname="id"><constant>V4L2_CID_RDS_RECEPTION</constant> </entry>
4937 <entry>boolean</entry>
4938 </row><row><entry spanname="descr">Enables/disables RDS
4939 reception by the radio tuner</entry>
4940 </row>
4941 <row>
4942 <entry spanname="id"><constant>V4L2_CID_TUNE_DEEMPHASIS</constant> </entry>
4943 <entry>enum v4l2_deemphasis</entry>
4944 </row>
4945 <row id="v4l2-deemphasis"><entry spanname="descr">Configures the de-emphasis value for reception.
4946 A de-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
4947 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_deemphasis
4948 defines possible values for de-emphasis. Here they are:</entry>
4949 </row><row>
4950 <entrytbl spanname="descr" cols="2">
4951 <tbody valign="top">
4952 <row>
4953 <entry><constant>V4L2_DEEMPHASIS_DISABLED</constant> </entry>
4954 <entry>No de-emphasis is applied.</entry>
4955 </row>
4956 <row>
4957 <entry><constant>V4L2_DEEMPHASIS_50_uS</constant> </entry>
4958 <entry>A de-emphasis of 50 uS is used.</entry>
4959 </row>
4960 <row>
4961 <entry><constant>V4L2_DEEMPHASIS_75_uS</constant> </entry>
4962 <entry>A de-emphasis of 75 uS is used.</entry>
4963 </row>
4964 </tbody>
4965 </entrytbl>
4967 </row>
4968 <row><entry></entry></row>
4969 </tbody>
4970 </tgroup>
4971 </table>
4973 </section>
4974 </section>