2 * PCM Plug-In shared (kernel/library) code
3 * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
4 * Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Library General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU Library General Public License for more details.
17 * You should have received a copy of the GNU Library General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 #include <linux/slab.h>
28 #include <linux/time.h>
29 #include <linux/vmalloc.h>
30 #include <sound/core.h>
31 #include <sound/pcm.h>
32 #include <sound/pcm_params.h>
33 #include "pcm_plugin.h"
35 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
36 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
39 * because some cards might have rates "very close", we ignore
40 * all "resampling" requests within +-5%
42 static int rate_match(unsigned int src_rate
, unsigned int dst_rate
)
44 unsigned int low
= (src_rate
* 95) / 100;
45 unsigned int high
= (src_rate
* 105) / 100;
46 return dst_rate
>= low
&& dst_rate
<= high
;
49 static int snd_pcm_plugin_alloc(struct snd_pcm_plugin
*plugin
, snd_pcm_uframes_t frames
)
51 struct snd_pcm_plugin_format
*format
;
55 struct snd_pcm_plugin_channel
*c
;
57 if (plugin
->stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
58 format
= &plugin
->src_format
;
60 format
= &plugin
->dst_format
;
62 if ((width
= snd_pcm_format_physical_width(format
->format
)) < 0)
64 size
= frames
* format
->channels
* width
;
65 snd_assert((size
% 8) == 0, return -ENXIO
);
67 if (plugin
->buf_frames
< frames
) {
69 plugin
->buf
= vmalloc(size
);
70 plugin
->buf_frames
= frames
;
73 plugin
->buf_frames
= 0;
76 c
= plugin
->buf_channels
;
77 if (plugin
->access
== SNDRV_PCM_ACCESS_RW_INTERLEAVED
) {
78 for (channel
= 0; channel
< format
->channels
; channel
++, c
++) {
82 c
->area
.addr
= plugin
->buf
;
83 c
->area
.first
= channel
* width
;
84 c
->area
.step
= format
->channels
* width
;
86 } else if (plugin
->access
== SNDRV_PCM_ACCESS_RW_NONINTERLEAVED
) {
87 snd_assert((size
% format
->channels
) == 0,);
88 size
/= format
->channels
;
89 for (channel
= 0; channel
< format
->channels
; channel
++, c
++) {
93 c
->area
.addr
= plugin
->buf
+ (channel
* size
);
102 int snd_pcm_plug_alloc(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t frames
)
105 snd_assert(snd_pcm_plug_first(plug
) != NULL
, return -ENXIO
);
106 if (snd_pcm_plug_stream(plug
) == SNDRV_PCM_STREAM_PLAYBACK
) {
107 struct snd_pcm_plugin
*plugin
= snd_pcm_plug_first(plug
);
108 while (plugin
->next
) {
109 if (plugin
->dst_frames
)
110 frames
= plugin
->dst_frames(plugin
, frames
);
111 snd_assert(frames
> 0, return -ENXIO
);
112 plugin
= plugin
->next
;
113 err
= snd_pcm_plugin_alloc(plugin
, frames
);
118 struct snd_pcm_plugin
*plugin
= snd_pcm_plug_last(plug
);
119 while (plugin
->prev
) {
120 if (plugin
->src_frames
)
121 frames
= plugin
->src_frames(plugin
, frames
);
122 snd_assert(frames
> 0, return -ENXIO
);
123 plugin
= plugin
->prev
;
124 err
= snd_pcm_plugin_alloc(plugin
, frames
);
133 snd_pcm_sframes_t
snd_pcm_plugin_client_channels(struct snd_pcm_plugin
*plugin
,
134 snd_pcm_uframes_t frames
,
135 struct snd_pcm_plugin_channel
**channels
)
137 *channels
= plugin
->buf_channels
;
141 int snd_pcm_plugin_build(struct snd_pcm_substream
*plug
,
143 struct snd_pcm_plugin_format
*src_format
,
144 struct snd_pcm_plugin_format
*dst_format
,
146 struct snd_pcm_plugin
**ret
)
148 struct snd_pcm_plugin
*plugin
;
149 unsigned int channels
;
151 snd_assert(plug
!= NULL
, return -ENXIO
);
152 snd_assert(src_format
!= NULL
&& dst_format
!= NULL
, return -ENXIO
);
153 plugin
= kzalloc(sizeof(*plugin
) + extra
, GFP_KERNEL
);
158 plugin
->stream
= snd_pcm_plug_stream(plug
);
159 plugin
->access
= SNDRV_PCM_ACCESS_RW_INTERLEAVED
;
160 plugin
->src_format
= *src_format
;
161 plugin
->src_width
= snd_pcm_format_physical_width(src_format
->format
);
162 snd_assert(plugin
->src_width
> 0, );
163 plugin
->dst_format
= *dst_format
;
164 plugin
->dst_width
= snd_pcm_format_physical_width(dst_format
->format
);
165 snd_assert(plugin
->dst_width
> 0, );
166 if (plugin
->stream
== SNDRV_PCM_STREAM_PLAYBACK
)
167 channels
= src_format
->channels
;
169 channels
= dst_format
->channels
;
170 plugin
->buf_channels
= kcalloc(channels
, sizeof(*plugin
->buf_channels
), GFP_KERNEL
);
171 if (plugin
->buf_channels
== NULL
) {
172 snd_pcm_plugin_free(plugin
);
175 plugin
->client_channels
= snd_pcm_plugin_client_channels
;
180 int snd_pcm_plugin_free(struct snd_pcm_plugin
*plugin
)
184 if (plugin
->private_free
)
185 plugin
->private_free(plugin
);
186 kfree(plugin
->buf_channels
);
192 snd_pcm_sframes_t
snd_pcm_plug_client_size(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t drv_frames
)
194 struct snd_pcm_plugin
*plugin
, *plugin_prev
, *plugin_next
;
195 int stream
= snd_pcm_plug_stream(plug
);
197 snd_assert(plug
!= NULL
, return -ENXIO
);
200 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
201 plugin
= snd_pcm_plug_last(plug
);
202 while (plugin
&& drv_frames
> 0) {
203 plugin_prev
= plugin
->prev
;
204 if (plugin
->src_frames
)
205 drv_frames
= plugin
->src_frames(plugin
, drv_frames
);
206 plugin
= plugin_prev
;
208 } else if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
209 plugin
= snd_pcm_plug_first(plug
);
210 while (plugin
&& drv_frames
> 0) {
211 plugin_next
= plugin
->next
;
212 if (plugin
->dst_frames
)
213 drv_frames
= plugin
->dst_frames(plugin
, drv_frames
);
214 plugin
= plugin_next
;
221 snd_pcm_sframes_t
snd_pcm_plug_slave_size(struct snd_pcm_substream
*plug
, snd_pcm_uframes_t clt_frames
)
223 struct snd_pcm_plugin
*plugin
, *plugin_prev
, *plugin_next
;
224 snd_pcm_sframes_t frames
;
225 int stream
= snd_pcm_plug_stream(plug
);
227 snd_assert(plug
!= NULL
, return -ENXIO
);
231 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
232 plugin
= snd_pcm_plug_first(plug
);
233 while (plugin
&& frames
> 0) {
234 plugin_next
= plugin
->next
;
235 if (plugin
->dst_frames
) {
236 frames
= plugin
->dst_frames(plugin
, frames
);
240 plugin
= plugin_next
;
242 } else if (stream
== SNDRV_PCM_STREAM_CAPTURE
) {
243 plugin
= snd_pcm_plug_last(plug
);
245 plugin_prev
= plugin
->prev
;
246 if (plugin
->src_frames
) {
247 frames
= plugin
->src_frames(plugin
, frames
);
251 plugin
= plugin_prev
;
258 static int snd_pcm_plug_formats(struct snd_mask
*mask
, int format
)
260 struct snd_mask formats
= *mask
;
261 u64 linfmts
= (SNDRV_PCM_FMTBIT_U8
| SNDRV_PCM_FMTBIT_S8
|
262 SNDRV_PCM_FMTBIT_U16_LE
| SNDRV_PCM_FMTBIT_S16_LE
|
263 SNDRV_PCM_FMTBIT_U16_BE
| SNDRV_PCM_FMTBIT_S16_BE
|
264 SNDRV_PCM_FMTBIT_U24_LE
| SNDRV_PCM_FMTBIT_S24_LE
|
265 SNDRV_PCM_FMTBIT_U24_BE
| SNDRV_PCM_FMTBIT_S24_BE
|
266 SNDRV_PCM_FMTBIT_U24_3LE
| SNDRV_PCM_FMTBIT_S24_3LE
|
267 SNDRV_PCM_FMTBIT_U24_3BE
| SNDRV_PCM_FMTBIT_S24_3BE
|
268 SNDRV_PCM_FMTBIT_U32_LE
| SNDRV_PCM_FMTBIT_S32_LE
|
269 SNDRV_PCM_FMTBIT_U32_BE
| SNDRV_PCM_FMTBIT_S32_BE
);
270 snd_mask_set(&formats
, SNDRV_PCM_FORMAT_MU_LAW
);
272 if (formats
.bits
[0] & (u32
)linfmts
)
273 formats
.bits
[0] |= (u32
)linfmts
;
274 if (formats
.bits
[1] & (u32
)(linfmts
>> 32))
275 formats
.bits
[1] |= (u32
)(linfmts
>> 32);
276 return snd_mask_test(&formats
, format
);
279 static int preferred_formats
[] = {
280 SNDRV_PCM_FORMAT_S16_LE
,
281 SNDRV_PCM_FORMAT_S16_BE
,
282 SNDRV_PCM_FORMAT_U16_LE
,
283 SNDRV_PCM_FORMAT_U16_BE
,
284 SNDRV_PCM_FORMAT_S24_3LE
,
285 SNDRV_PCM_FORMAT_S24_3BE
,
286 SNDRV_PCM_FORMAT_U24_3LE
,
287 SNDRV_PCM_FORMAT_U24_3BE
,
288 SNDRV_PCM_FORMAT_S24_LE
,
289 SNDRV_PCM_FORMAT_S24_BE
,
290 SNDRV_PCM_FORMAT_U24_LE
,
291 SNDRV_PCM_FORMAT_U24_BE
,
292 SNDRV_PCM_FORMAT_S32_LE
,
293 SNDRV_PCM_FORMAT_S32_BE
,
294 SNDRV_PCM_FORMAT_U32_LE
,
295 SNDRV_PCM_FORMAT_U32_BE
,
300 int snd_pcm_plug_slave_format(int format
, struct snd_mask
*format_mask
)
304 if (snd_mask_test(format_mask
, format
))
306 if (! snd_pcm_plug_formats(format_mask
, format
))
308 if (snd_pcm_format_linear(format
)) {
309 unsigned int width
= snd_pcm_format_width(format
);
310 int unsignd
= snd_pcm_format_unsigned(format
) > 0;
311 int big
= snd_pcm_format_big_endian(format
) > 0;
312 unsigned int badness
, best
= -1;
313 int best_format
= -1;
314 for (i
= 0; i
< ARRAY_SIZE(preferred_formats
); i
++) {
315 int f
= preferred_formats
[i
];
317 if (!snd_mask_test(format_mask
, f
))
319 w
= snd_pcm_format_width(f
);
323 badness
= width
- w
+ 32;
324 badness
+= snd_pcm_format_unsigned(f
) != unsignd
;
325 badness
+= snd_pcm_format_big_endian(f
) != big
;
326 if (badness
< best
) {
331 return best_format
>= 0 ? best_format
: -EINVAL
;
334 case SNDRV_PCM_FORMAT_MU_LAW
:
335 for (i
= 0; i
< ARRAY_SIZE(preferred_formats
); ++i
) {
336 int format1
= preferred_formats
[i
];
337 if (snd_mask_test(format_mask
, format1
))
346 int snd_pcm_plug_format_plugins(struct snd_pcm_substream
*plug
,
347 struct snd_pcm_hw_params
*params
,
348 struct snd_pcm_hw_params
*slave_params
)
350 struct snd_pcm_plugin_format tmpformat
;
351 struct snd_pcm_plugin_format dstformat
;
352 struct snd_pcm_plugin_format srcformat
;
353 int src_access
, dst_access
;
354 struct snd_pcm_plugin
*plugin
= NULL
;
356 int stream
= snd_pcm_plug_stream(plug
);
357 int slave_interleaved
= (params_channels(slave_params
) == 1 ||
358 params_access(slave_params
) == SNDRV_PCM_ACCESS_RW_INTERLEAVED
);
361 case SNDRV_PCM_STREAM_PLAYBACK
:
362 dstformat
.format
= params_format(slave_params
);
363 dstformat
.rate
= params_rate(slave_params
);
364 dstformat
.channels
= params_channels(slave_params
);
365 srcformat
.format
= params_format(params
);
366 srcformat
.rate
= params_rate(params
);
367 srcformat
.channels
= params_channels(params
);
368 src_access
= SNDRV_PCM_ACCESS_RW_INTERLEAVED
;
369 dst_access
= (slave_interleaved
? SNDRV_PCM_ACCESS_RW_INTERLEAVED
:
370 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED
);
372 case SNDRV_PCM_STREAM_CAPTURE
:
373 dstformat
.format
= params_format(params
);
374 dstformat
.rate
= params_rate(params
);
375 dstformat
.channels
= params_channels(params
);
376 srcformat
.format
= params_format(slave_params
);
377 srcformat
.rate
= params_rate(slave_params
);
378 srcformat
.channels
= params_channels(slave_params
);
379 src_access
= (slave_interleaved
? SNDRV_PCM_ACCESS_RW_INTERLEAVED
:
380 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED
);
381 dst_access
= SNDRV_PCM_ACCESS_RW_INTERLEAVED
;
387 tmpformat
= srcformat
;
389 pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
393 pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
398 /* Format change (linearization) */
399 if (! rate_match(srcformat
.rate
, dstformat
.rate
) &&
400 ! snd_pcm_format_linear(srcformat
.format
)) {
401 if (srcformat
.format
!= SNDRV_PCM_FORMAT_MU_LAW
)
403 tmpformat
.format
= SNDRV_PCM_FORMAT_S16
;
404 err
= snd_pcm_plugin_build_mulaw(plug
,
405 &srcformat
, &tmpformat
,
409 err
= snd_pcm_plugin_append(plugin
);
411 snd_pcm_plugin_free(plugin
);
414 srcformat
= tmpformat
;
415 src_access
= dst_access
;
418 /* channels reduction */
419 if (srcformat
.channels
> dstformat
.channels
) {
420 tmpformat
.channels
= dstformat
.channels
;
421 err
= snd_pcm_plugin_build_route(plug
, &srcformat
, &tmpformat
, &plugin
);
422 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat
.channels
, tmpformat
.channels
, err
);
425 err
= snd_pcm_plugin_append(plugin
);
427 snd_pcm_plugin_free(plugin
);
430 srcformat
= tmpformat
;
431 src_access
= dst_access
;
434 /* rate resampling */
435 if (!rate_match(srcformat
.rate
, dstformat
.rate
)) {
436 if (srcformat
.format
!= SNDRV_PCM_FORMAT_S16
) {
437 /* convert to S16 for resampling */
438 tmpformat
.format
= SNDRV_PCM_FORMAT_S16
;
439 err
= snd_pcm_plugin_build_linear(plug
,
440 &srcformat
, &tmpformat
,
444 err
= snd_pcm_plugin_append(plugin
);
446 snd_pcm_plugin_free(plugin
);
449 srcformat
= tmpformat
;
450 src_access
= dst_access
;
452 tmpformat
.rate
= dstformat
.rate
;
453 err
= snd_pcm_plugin_build_rate(plug
,
454 &srcformat
, &tmpformat
,
456 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat
.rate
, tmpformat
.rate
, err
);
459 err
= snd_pcm_plugin_append(plugin
);
461 snd_pcm_plugin_free(plugin
);
464 srcformat
= tmpformat
;
465 src_access
= dst_access
;
469 if (srcformat
.format
!= dstformat
.format
) {
470 tmpformat
.format
= dstformat
.format
;
471 if (srcformat
.format
== SNDRV_PCM_FORMAT_MU_LAW
||
472 tmpformat
.format
== SNDRV_PCM_FORMAT_MU_LAW
) {
473 err
= snd_pcm_plugin_build_mulaw(plug
,
474 &srcformat
, &tmpformat
,
477 else if (snd_pcm_format_linear(srcformat
.format
) &&
478 snd_pcm_format_linear(tmpformat
.format
)) {
479 err
= snd_pcm_plugin_build_linear(plug
,
480 &srcformat
, &tmpformat
,
485 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat
.format
, tmpformat
.format
, err
);
488 err
= snd_pcm_plugin_append(plugin
);
490 snd_pcm_plugin_free(plugin
);
493 srcformat
= tmpformat
;
494 src_access
= dst_access
;
497 /* channels extension */
498 if (srcformat
.channels
< dstformat
.channels
) {
499 tmpformat
.channels
= dstformat
.channels
;
500 err
= snd_pcm_plugin_build_route(plug
, &srcformat
, &tmpformat
, &plugin
);
501 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat
.channels
, tmpformat
.channels
, err
);
504 err
= snd_pcm_plugin_append(plugin
);
506 snd_pcm_plugin_free(plugin
);
509 srcformat
= tmpformat
;
510 src_access
= dst_access
;
514 if (src_access
!= dst_access
) {
515 err
= snd_pcm_plugin_build_copy(plug
,
519 pdprintf("interleave change (copy: returns %i)\n", err
);
522 err
= snd_pcm_plugin_append(plugin
);
524 snd_pcm_plugin_free(plugin
);
532 snd_pcm_sframes_t
snd_pcm_plug_client_channels_buf(struct snd_pcm_substream
*plug
,
534 snd_pcm_uframes_t count
,
535 struct snd_pcm_plugin_channel
**channels
)
537 struct snd_pcm_plugin
*plugin
;
538 struct snd_pcm_plugin_channel
*v
;
539 struct snd_pcm_plugin_format
*format
;
540 int width
, nchannels
, channel
;
541 int stream
= snd_pcm_plug_stream(plug
);
543 snd_assert(buf
!= NULL
, return -ENXIO
);
544 if (stream
== SNDRV_PCM_STREAM_PLAYBACK
) {
545 plugin
= snd_pcm_plug_first(plug
);
546 format
= &plugin
->src_format
;
548 plugin
= snd_pcm_plug_last(plug
);
549 format
= &plugin
->dst_format
;
551 v
= plugin
->buf_channels
;
553 if ((width
= snd_pcm_format_physical_width(format
->format
)) < 0)
555 nchannels
= format
->channels
;
556 snd_assert(plugin
->access
== SNDRV_PCM_ACCESS_RW_INTERLEAVED
|| format
->channels
<= 1, return -ENXIO
);
557 for (channel
= 0; channel
< nchannels
; channel
++, v
++) {
560 v
->wanted
= (stream
== SNDRV_PCM_STREAM_CAPTURE
);
562 v
->area
.first
= channel
* width
;
563 v
->area
.step
= nchannels
* width
;
568 snd_pcm_sframes_t
snd_pcm_plug_write_transfer(struct snd_pcm_substream
*plug
, struct snd_pcm_plugin_channel
*src_channels
, snd_pcm_uframes_t size
)
570 struct snd_pcm_plugin
*plugin
, *next
;
571 struct snd_pcm_plugin_channel
*dst_channels
;
573 snd_pcm_sframes_t frames
= size
;
575 plugin
= snd_pcm_plug_first(plug
);
576 while (plugin
&& frames
> 0) {
577 if ((next
= plugin
->next
) != NULL
) {
578 snd_pcm_sframes_t frames1
= frames
;
579 if (plugin
->dst_frames
)
580 frames1
= plugin
->dst_frames(plugin
, frames
);
581 if ((err
= next
->client_channels(next
, frames1
, &dst_channels
)) < 0) {
584 if (err
!= frames1
) {
586 if (plugin
->src_frames
)
587 frames
= plugin
->src_frames(plugin
, frames1
);
591 pdprintf("write plugin: %s, %li\n", plugin
->name
, frames
);
592 if ((frames
= plugin
->transfer(plugin
, src_channels
, dst_channels
, frames
)) < 0)
594 src_channels
= dst_channels
;
597 return snd_pcm_plug_client_size(plug
, frames
);
600 snd_pcm_sframes_t
snd_pcm_plug_read_transfer(struct snd_pcm_substream
*plug
, struct snd_pcm_plugin_channel
*dst_channels_final
, snd_pcm_uframes_t size
)
602 struct snd_pcm_plugin
*plugin
, *next
;
603 struct snd_pcm_plugin_channel
*src_channels
, *dst_channels
;
604 snd_pcm_sframes_t frames
= size
;
607 frames
= snd_pcm_plug_slave_size(plug
, frames
);
612 plugin
= snd_pcm_plug_first(plug
);
613 while (plugin
&& frames
> 0) {
614 if ((next
= plugin
->next
) != NULL
) {
615 if ((err
= plugin
->client_channels(plugin
, frames
, &dst_channels
)) < 0) {
620 dst_channels
= dst_channels_final
;
622 pdprintf("read plugin: %s, %li\n", plugin
->name
, frames
);
623 if ((frames
= plugin
->transfer(plugin
, src_channels
, dst_channels
, frames
)) < 0)
626 src_channels
= dst_channels
;
631 int snd_pcm_area_silence(const struct snd_pcm_channel_area
*dst_area
, size_t dst_offset
,
632 size_t samples
, int format
)
634 /* FIXME: sub byte resolution and odd dst_offset */
636 unsigned int dst_step
;
638 const unsigned char *silence
;
641 dst
= dst_area
->addr
+ (dst_area
->first
+ dst_area
->step
* dst_offset
) / 8;
642 width
= snd_pcm_format_physical_width(format
);
645 if (dst_area
->step
== (unsigned int) width
&& width
>= 8)
646 return snd_pcm_format_set_silence(format
, dst
, samples
);
647 silence
= snd_pcm_format_silence_64(format
);
650 dst_step
= dst_area
->step
/ 8;
653 int dstbit
= dst_area
->first
% 8;
654 int dstbit_step
= dst_area
->step
% 8;
655 while (samples
-- > 0) {
661 dstbit
+= dstbit_step
;
669 while (samples
-- > 0) {
670 memcpy(dst
, silence
, width
);
677 int snd_pcm_area_copy(const struct snd_pcm_channel_area
*src_area
, size_t src_offset
,
678 const struct snd_pcm_channel_area
*dst_area
, size_t dst_offset
,
679 size_t samples
, int format
)
681 /* FIXME: sub byte resolution and odd dst_offset */
684 int src_step
, dst_step
;
685 src
= src_area
->addr
+ (src_area
->first
+ src_area
->step
* src_offset
) / 8;
687 return snd_pcm_area_silence(dst_area
, dst_offset
, samples
, format
);
688 dst
= dst_area
->addr
+ (dst_area
->first
+ dst_area
->step
* dst_offset
) / 8;
691 width
= snd_pcm_format_physical_width(format
);
694 if (src_area
->step
== (unsigned int) width
&&
695 dst_area
->step
== (unsigned int) width
&& width
>= 8) {
696 size_t bytes
= samples
* width
/ 8;
697 memcpy(dst
, src
, bytes
);
700 src_step
= src_area
->step
/ 8;
701 dst_step
= dst_area
->step
/ 8;
704 int srcbit
= src_area
->first
% 8;
705 int srcbit_step
= src_area
->step
% 8;
706 int dstbit
= dst_area
->first
% 8;
707 int dstbit_step
= dst_area
->step
% 8;
708 while (samples
-- > 0) {
709 unsigned char srcval
;
711 srcval
= *src
& 0x0f;
713 srcval
= (*src
& 0xf0) >> 4;
715 *dst
= (*dst
& 0xf0) | srcval
;
717 *dst
= (*dst
& 0x0f) | (srcval
<< 4);
719 srcbit
+= srcbit_step
;
725 dstbit
+= dstbit_step
;
733 while (samples
-- > 0) {
734 memcpy(dst
, src
, width
);