Linux 2.6.31.8
[linux/fpc-iii.git] / sound / core / oss / pcm_plugin.c
blob6751daa3bb507fe9dd3007e2013dff63a4a701ee
1 /*
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
23 #if 0
24 #define PLUGIN_DEBUG
25 #endif
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;
52 ssize_t width;
53 size_t size;
54 unsigned int channel;
55 struct snd_pcm_plugin_channel *c;
57 if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
58 format = &plugin->src_format;
59 } else {
60 format = &plugin->dst_format;
62 if ((width = snd_pcm_format_physical_width(format->format)) < 0)
63 return width;
64 size = frames * format->channels * width;
65 if (snd_BUG_ON(size % 8))
66 return -ENXIO;
67 size /= 8;
68 if (plugin->buf_frames < frames) {
69 vfree(plugin->buf);
70 plugin->buf = vmalloc(size);
71 plugin->buf_frames = frames;
73 if (!plugin->buf) {
74 plugin->buf_frames = 0;
75 return -ENOMEM;
77 c = plugin->buf_channels;
78 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
79 for (channel = 0; channel < format->channels; channel++, c++) {
80 c->frames = frames;
81 c->enabled = 1;
82 c->wanted = 0;
83 c->area.addr = plugin->buf;
84 c->area.first = channel * width;
85 c->area.step = format->channels * width;
87 } else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
88 if (snd_BUG_ON(size % format->channels))
89 return -EINVAL;
90 size /= format->channels;
91 for (channel = 0; channel < format->channels; channel++, c++) {
92 c->frames = frames;
93 c->enabled = 1;
94 c->wanted = 0;
95 c->area.addr = plugin->buf + (channel * size);
96 c->area.first = 0;
97 c->area.step = width;
99 } else
100 return -EINVAL;
101 return 0;
104 int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
106 int err;
107 if (snd_BUG_ON(!snd_pcm_plug_first(plug)))
108 return -ENXIO;
109 if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
110 struct snd_pcm_plugin *plugin = snd_pcm_plug_first(plug);
111 while (plugin->next) {
112 if (plugin->dst_frames)
113 frames = plugin->dst_frames(plugin, frames);
114 if (snd_BUG_ON(frames <= 0))
115 return -ENXIO;
116 plugin = plugin->next;
117 err = snd_pcm_plugin_alloc(plugin, frames);
118 if (err < 0)
119 return err;
121 } else {
122 struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
123 while (plugin->prev) {
124 if (plugin->src_frames)
125 frames = plugin->src_frames(plugin, frames);
126 if (snd_BUG_ON(frames <= 0))
127 return -ENXIO;
128 plugin = plugin->prev;
129 err = snd_pcm_plugin_alloc(plugin, frames);
130 if (err < 0)
131 return err;
134 return 0;
138 snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
139 snd_pcm_uframes_t frames,
140 struct snd_pcm_plugin_channel **channels)
142 *channels = plugin->buf_channels;
143 return frames;
146 int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
147 const char *name,
148 struct snd_pcm_plugin_format *src_format,
149 struct snd_pcm_plugin_format *dst_format,
150 size_t extra,
151 struct snd_pcm_plugin **ret)
153 struct snd_pcm_plugin *plugin;
154 unsigned int channels;
156 if (snd_BUG_ON(!plug))
157 return -ENXIO;
158 if (snd_BUG_ON(!src_format || !dst_format))
159 return -ENXIO;
160 plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
161 if (plugin == NULL)
162 return -ENOMEM;
163 plugin->name = name;
164 plugin->plug = plug;
165 plugin->stream = snd_pcm_plug_stream(plug);
166 plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
167 plugin->src_format = *src_format;
168 plugin->src_width = snd_pcm_format_physical_width(src_format->format);
169 snd_BUG_ON(plugin->src_width <= 0);
170 plugin->dst_format = *dst_format;
171 plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
172 snd_BUG_ON(plugin->dst_width <= 0);
173 if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
174 channels = src_format->channels;
175 else
176 channels = dst_format->channels;
177 plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
178 if (plugin->buf_channels == NULL) {
179 snd_pcm_plugin_free(plugin);
180 return -ENOMEM;
182 plugin->client_channels = snd_pcm_plugin_client_channels;
183 *ret = plugin;
184 return 0;
187 int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
189 if (! plugin)
190 return 0;
191 if (plugin->private_free)
192 plugin->private_free(plugin);
193 kfree(plugin->buf_channels);
194 vfree(plugin->buf);
195 kfree(plugin);
196 return 0;
199 snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
201 struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
202 int stream = snd_pcm_plug_stream(plug);
204 if (snd_BUG_ON(!plug))
205 return -ENXIO;
206 if (drv_frames == 0)
207 return 0;
208 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
209 plugin = snd_pcm_plug_last(plug);
210 while (plugin && drv_frames > 0) {
211 plugin_prev = plugin->prev;
212 if (plugin->src_frames)
213 drv_frames = plugin->src_frames(plugin, drv_frames);
214 plugin = plugin_prev;
216 } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
217 plugin = snd_pcm_plug_first(plug);
218 while (plugin && drv_frames > 0) {
219 plugin_next = plugin->next;
220 if (plugin->dst_frames)
221 drv_frames = plugin->dst_frames(plugin, drv_frames);
222 plugin = plugin_next;
224 } else
225 snd_BUG();
226 return drv_frames;
229 snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
231 struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
232 snd_pcm_sframes_t frames;
233 int stream = snd_pcm_plug_stream(plug);
235 if (snd_BUG_ON(!plug))
236 return -ENXIO;
237 if (clt_frames == 0)
238 return 0;
239 frames = clt_frames;
240 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
241 plugin = snd_pcm_plug_first(plug);
242 while (plugin && frames > 0) {
243 plugin_next = plugin->next;
244 if (plugin->dst_frames) {
245 frames = plugin->dst_frames(plugin, frames);
246 if (frames < 0)
247 return frames;
249 plugin = plugin_next;
251 } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
252 plugin = snd_pcm_plug_last(plug);
253 while (plugin) {
254 plugin_prev = plugin->prev;
255 if (plugin->src_frames) {
256 frames = plugin->src_frames(plugin, frames);
257 if (frames < 0)
258 return frames;
260 plugin = plugin_prev;
262 } else
263 snd_BUG();
264 return frames;
267 static int snd_pcm_plug_formats(struct snd_mask *mask, int format)
269 struct snd_mask formats = *mask;
270 u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
271 SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
272 SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
273 SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
274 SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
275 SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
276 SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
277 SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
278 SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
279 snd_mask_set(&formats, SNDRV_PCM_FORMAT_MU_LAW);
281 if (formats.bits[0] & (u32)linfmts)
282 formats.bits[0] |= (u32)linfmts;
283 if (formats.bits[1] & (u32)(linfmts >> 32))
284 formats.bits[1] |= (u32)(linfmts >> 32);
285 return snd_mask_test(&formats, format);
288 static int preferred_formats[] = {
289 SNDRV_PCM_FORMAT_S16_LE,
290 SNDRV_PCM_FORMAT_S16_BE,
291 SNDRV_PCM_FORMAT_U16_LE,
292 SNDRV_PCM_FORMAT_U16_BE,
293 SNDRV_PCM_FORMAT_S24_3LE,
294 SNDRV_PCM_FORMAT_S24_3BE,
295 SNDRV_PCM_FORMAT_U24_3LE,
296 SNDRV_PCM_FORMAT_U24_3BE,
297 SNDRV_PCM_FORMAT_S24_LE,
298 SNDRV_PCM_FORMAT_S24_BE,
299 SNDRV_PCM_FORMAT_U24_LE,
300 SNDRV_PCM_FORMAT_U24_BE,
301 SNDRV_PCM_FORMAT_S32_LE,
302 SNDRV_PCM_FORMAT_S32_BE,
303 SNDRV_PCM_FORMAT_U32_LE,
304 SNDRV_PCM_FORMAT_U32_BE,
305 SNDRV_PCM_FORMAT_S8,
306 SNDRV_PCM_FORMAT_U8
309 int snd_pcm_plug_slave_format(int format, struct snd_mask *format_mask)
311 int i;
313 if (snd_mask_test(format_mask, format))
314 return format;
315 if (! snd_pcm_plug_formats(format_mask, format))
316 return -EINVAL;
317 if (snd_pcm_format_linear(format)) {
318 unsigned int width = snd_pcm_format_width(format);
319 int unsignd = snd_pcm_format_unsigned(format) > 0;
320 int big = snd_pcm_format_big_endian(format) > 0;
321 unsigned int badness, best = -1;
322 int best_format = -1;
323 for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
324 int f = preferred_formats[i];
325 unsigned int w;
326 if (!snd_mask_test(format_mask, f))
327 continue;
328 w = snd_pcm_format_width(f);
329 if (w >= width)
330 badness = w - width;
331 else
332 badness = width - w + 32;
333 badness += snd_pcm_format_unsigned(f) != unsignd;
334 badness += snd_pcm_format_big_endian(f) != big;
335 if (badness < best) {
336 best_format = f;
337 best = badness;
340 return best_format >= 0 ? best_format : -EINVAL;
341 } else {
342 switch (format) {
343 case SNDRV_PCM_FORMAT_MU_LAW:
344 for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
345 int format1 = preferred_formats[i];
346 if (snd_mask_test(format_mask, format1))
347 return format1;
349 default:
350 return -EINVAL;
355 int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
356 struct snd_pcm_hw_params *params,
357 struct snd_pcm_hw_params *slave_params)
359 struct snd_pcm_plugin_format tmpformat;
360 struct snd_pcm_plugin_format dstformat;
361 struct snd_pcm_plugin_format srcformat;
362 int src_access, dst_access;
363 struct snd_pcm_plugin *plugin = NULL;
364 int err;
365 int stream = snd_pcm_plug_stream(plug);
366 int slave_interleaved = (params_channels(slave_params) == 1 ||
367 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
369 switch (stream) {
370 case SNDRV_PCM_STREAM_PLAYBACK:
371 dstformat.format = params_format(slave_params);
372 dstformat.rate = params_rate(slave_params);
373 dstformat.channels = params_channels(slave_params);
374 srcformat.format = params_format(params);
375 srcformat.rate = params_rate(params);
376 srcformat.channels = params_channels(params);
377 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
378 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
379 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
380 break;
381 case SNDRV_PCM_STREAM_CAPTURE:
382 dstformat.format = params_format(params);
383 dstformat.rate = params_rate(params);
384 dstformat.channels = params_channels(params);
385 srcformat.format = params_format(slave_params);
386 srcformat.rate = params_rate(slave_params);
387 srcformat.channels = params_channels(slave_params);
388 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
389 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
390 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
391 break;
392 default:
393 snd_BUG();
394 return -EINVAL;
396 tmpformat = srcformat;
398 pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
399 srcformat.format,
400 srcformat.rate,
401 srcformat.channels);
402 pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
403 dstformat.format,
404 dstformat.rate,
405 dstformat.channels);
407 /* Format change (linearization) */
408 if (! rate_match(srcformat.rate, dstformat.rate) &&
409 ! snd_pcm_format_linear(srcformat.format)) {
410 if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
411 return -EINVAL;
412 tmpformat.format = SNDRV_PCM_FORMAT_S16;
413 err = snd_pcm_plugin_build_mulaw(plug,
414 &srcformat, &tmpformat,
415 &plugin);
416 if (err < 0)
417 return err;
418 err = snd_pcm_plugin_append(plugin);
419 if (err < 0) {
420 snd_pcm_plugin_free(plugin);
421 return err;
423 srcformat = tmpformat;
424 src_access = dst_access;
427 /* channels reduction */
428 if (srcformat.channels > dstformat.channels) {
429 tmpformat.channels = dstformat.channels;
430 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
431 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
432 if (err < 0)
433 return err;
434 err = snd_pcm_plugin_append(plugin);
435 if (err < 0) {
436 snd_pcm_plugin_free(plugin);
437 return err;
439 srcformat = tmpformat;
440 src_access = dst_access;
443 /* rate resampling */
444 if (!rate_match(srcformat.rate, dstformat.rate)) {
445 if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
446 /* convert to S16 for resampling */
447 tmpformat.format = SNDRV_PCM_FORMAT_S16;
448 err = snd_pcm_plugin_build_linear(plug,
449 &srcformat, &tmpformat,
450 &plugin);
451 if (err < 0)
452 return err;
453 err = snd_pcm_plugin_append(plugin);
454 if (err < 0) {
455 snd_pcm_plugin_free(plugin);
456 return err;
458 srcformat = tmpformat;
459 src_access = dst_access;
461 tmpformat.rate = dstformat.rate;
462 err = snd_pcm_plugin_build_rate(plug,
463 &srcformat, &tmpformat,
464 &plugin);
465 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
466 if (err < 0)
467 return err;
468 err = snd_pcm_plugin_append(plugin);
469 if (err < 0) {
470 snd_pcm_plugin_free(plugin);
471 return err;
473 srcformat = tmpformat;
474 src_access = dst_access;
477 /* format change */
478 if (srcformat.format != dstformat.format) {
479 tmpformat.format = dstformat.format;
480 if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
481 tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
482 err = snd_pcm_plugin_build_mulaw(plug,
483 &srcformat, &tmpformat,
484 &plugin);
486 else if (snd_pcm_format_linear(srcformat.format) &&
487 snd_pcm_format_linear(tmpformat.format)) {
488 err = snd_pcm_plugin_build_linear(plug,
489 &srcformat, &tmpformat,
490 &plugin);
492 else
493 return -EINVAL;
494 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
495 if (err < 0)
496 return err;
497 err = snd_pcm_plugin_append(plugin);
498 if (err < 0) {
499 snd_pcm_plugin_free(plugin);
500 return err;
502 srcformat = tmpformat;
503 src_access = dst_access;
506 /* channels extension */
507 if (srcformat.channels < dstformat.channels) {
508 tmpformat.channels = dstformat.channels;
509 err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
510 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
511 if (err < 0)
512 return err;
513 err = snd_pcm_plugin_append(plugin);
514 if (err < 0) {
515 snd_pcm_plugin_free(plugin);
516 return err;
518 srcformat = tmpformat;
519 src_access = dst_access;
522 /* de-interleave */
523 if (src_access != dst_access) {
524 err = snd_pcm_plugin_build_copy(plug,
525 &srcformat,
526 &tmpformat,
527 &plugin);
528 pdprintf("interleave change (copy: returns %i)\n", err);
529 if (err < 0)
530 return err;
531 err = snd_pcm_plugin_append(plugin);
532 if (err < 0) {
533 snd_pcm_plugin_free(plugin);
534 return err;
538 return 0;
541 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
542 char *buf,
543 snd_pcm_uframes_t count,
544 struct snd_pcm_plugin_channel **channels)
546 struct snd_pcm_plugin *plugin;
547 struct snd_pcm_plugin_channel *v;
548 struct snd_pcm_plugin_format *format;
549 int width, nchannels, channel;
550 int stream = snd_pcm_plug_stream(plug);
552 if (snd_BUG_ON(!buf))
553 return -ENXIO;
554 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
555 plugin = snd_pcm_plug_first(plug);
556 format = &plugin->src_format;
557 } else {
558 plugin = snd_pcm_plug_last(plug);
559 format = &plugin->dst_format;
561 v = plugin->buf_channels;
562 *channels = v;
563 if ((width = snd_pcm_format_physical_width(format->format)) < 0)
564 return width;
565 nchannels = format->channels;
566 if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
567 format->channels > 1))
568 return -ENXIO;
569 for (channel = 0; channel < nchannels; channel++, v++) {
570 v->frames = count;
571 v->enabled = 1;
572 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
573 v->area.addr = buf;
574 v->area.first = channel * width;
575 v->area.step = nchannels * width;
577 return count;
580 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)
582 struct snd_pcm_plugin *plugin, *next;
583 struct snd_pcm_plugin_channel *dst_channels;
584 int err;
585 snd_pcm_sframes_t frames = size;
587 plugin = snd_pcm_plug_first(plug);
588 while (plugin && frames > 0) {
589 if ((next = plugin->next) != NULL) {
590 snd_pcm_sframes_t frames1 = frames;
591 if (plugin->dst_frames)
592 frames1 = plugin->dst_frames(plugin, frames);
593 if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
594 return err;
596 if (err != frames1) {
597 frames = err;
598 if (plugin->src_frames)
599 frames = plugin->src_frames(plugin, frames1);
601 } else
602 dst_channels = NULL;
603 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
604 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
605 return frames;
606 src_channels = dst_channels;
607 plugin = next;
609 return snd_pcm_plug_client_size(plug, frames);
612 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)
614 struct snd_pcm_plugin *plugin, *next;
615 struct snd_pcm_plugin_channel *src_channels, *dst_channels;
616 snd_pcm_sframes_t frames = size;
617 int err;
619 frames = snd_pcm_plug_slave_size(plug, frames);
620 if (frames < 0)
621 return frames;
623 src_channels = NULL;
624 plugin = snd_pcm_plug_first(plug);
625 while (plugin && frames > 0) {
626 if ((next = plugin->next) != NULL) {
627 if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
628 return err;
630 frames = err;
631 } else {
632 dst_channels = dst_channels_final;
634 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
635 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
636 return frames;
637 plugin = next;
638 src_channels = dst_channels;
640 return frames;
643 int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
644 size_t samples, int format)
646 /* FIXME: sub byte resolution and odd dst_offset */
647 unsigned char *dst;
648 unsigned int dst_step;
649 int width;
650 const unsigned char *silence;
651 if (!dst_area->addr)
652 return 0;
653 dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
654 width = snd_pcm_format_physical_width(format);
655 if (width <= 0)
656 return -EINVAL;
657 if (dst_area->step == (unsigned int) width && width >= 8)
658 return snd_pcm_format_set_silence(format, dst, samples);
659 silence = snd_pcm_format_silence_64(format);
660 if (! silence)
661 return -EINVAL;
662 dst_step = dst_area->step / 8;
663 if (width == 4) {
664 /* Ima ADPCM */
665 int dstbit = dst_area->first % 8;
666 int dstbit_step = dst_area->step % 8;
667 while (samples-- > 0) {
668 if (dstbit)
669 *dst &= 0xf0;
670 else
671 *dst &= 0x0f;
672 dst += dst_step;
673 dstbit += dstbit_step;
674 if (dstbit == 8) {
675 dst++;
676 dstbit = 0;
679 } else {
680 width /= 8;
681 while (samples-- > 0) {
682 memcpy(dst, silence, width);
683 dst += dst_step;
686 return 0;
689 int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
690 const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
691 size_t samples, int format)
693 /* FIXME: sub byte resolution and odd dst_offset */
694 char *src, *dst;
695 int width;
696 int src_step, dst_step;
697 src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
698 if (!src_area->addr)
699 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
700 dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
701 if (!dst_area->addr)
702 return 0;
703 width = snd_pcm_format_physical_width(format);
704 if (width <= 0)
705 return -EINVAL;
706 if (src_area->step == (unsigned int) width &&
707 dst_area->step == (unsigned int) width && width >= 8) {
708 size_t bytes = samples * width / 8;
709 memcpy(dst, src, bytes);
710 return 0;
712 src_step = src_area->step / 8;
713 dst_step = dst_area->step / 8;
714 if (width == 4) {
715 /* Ima ADPCM */
716 int srcbit = src_area->first % 8;
717 int srcbit_step = src_area->step % 8;
718 int dstbit = dst_area->first % 8;
719 int dstbit_step = dst_area->step % 8;
720 while (samples-- > 0) {
721 unsigned char srcval;
722 if (srcbit)
723 srcval = *src & 0x0f;
724 else
725 srcval = (*src & 0xf0) >> 4;
726 if (dstbit)
727 *dst = (*dst & 0xf0) | srcval;
728 else
729 *dst = (*dst & 0x0f) | (srcval << 4);
730 src += src_step;
731 srcbit += srcbit_step;
732 if (srcbit == 8) {
733 src++;
734 srcbit = 0;
736 dst += dst_step;
737 dstbit += dstbit_step;
738 if (dstbit == 8) {
739 dst++;
740 dstbit = 0;
743 } else {
744 width /= 8;
745 while (samples-- > 0) {
746 memcpy(dst, src, width);
747 src += src_step;
748 dst += dst_step;
751 return 0;