2 * PCM Plug-In shared (kernel/library) code
3 * Copyright (c) 1999 by Jaroslav Kysela <perex@suse.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 <sound/driver.h>
28 #include <linux/slab.h>
29 #include <linux/time.h>
30 #include <linux/vmalloc.h>
31 #include <sound/core.h>
32 #include <sound/pcm.h>
33 #include <sound/pcm_params.h>
34 #include "pcm_plugin.h"
36 #define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
37 #define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
39 static int snd_pcm_plugin_src_channels_mask(snd_pcm_plugin_t *plugin,
43 bitset_t *vmask = plugin->src_vmask;
44 bitset_copy(vmask, dst_vmask, plugin->src_format.channels);
49 static int snd_pcm_plugin_dst_channels_mask(snd_pcm_plugin_t *plugin,
53 bitset_t *vmask = plugin->dst_vmask;
54 bitset_copy(vmask, src_vmask, plugin->dst_format.channels);
60 * because some cards might have rates "very close", we ignore
61 * all "resampling" requests within +-5%
63 static int rate_match(unsigned int src_rate, unsigned int dst_rate)
65 unsigned int low = (src_rate * 95) / 100;
66 unsigned int high = (src_rate * 105) / 100;
67 return dst_rate >= low && dst_rate <= high;
70 static int snd_pcm_plugin_alloc(snd_pcm_plugin_t *plugin, snd_pcm_uframes_t frames)
72 snd_pcm_plugin_format_t *format;
76 snd_pcm_plugin_channel_t *c;
78 if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
79 format = &plugin->src_format;
81 format = &plugin->dst_format;
83 if ((width = snd_pcm_format_physical_width(format->format)) < 0)
85 size = frames * format->channels * width;
86 snd_assert((size % 8) == 0, return -ENXIO);
88 if (plugin->buf_frames < frames) {
90 plugin->buf = vmalloc(size);
91 plugin->buf_frames = frames;
94 plugin->buf_frames = 0;
97 c = plugin->buf_channels;
98 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
99 for (channel = 0; channel < format->channels; channel++, c++) {
103 c->area.addr = plugin->buf;
104 c->area.first = channel * width;
105 c->area.step = format->channels * width;
107 } else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
108 snd_assert((size % format->channels) == 0,);
109 size /= format->channels;
110 for (channel = 0; channel < format->channels; channel++, c++) {
114 c->area.addr = plugin->buf + (channel * size);
116 c->area.step = width;
123 int snd_pcm_plug_alloc(snd_pcm_plug_t *plug, snd_pcm_uframes_t frames)
126 snd_assert(snd_pcm_plug_first(plug) != NULL, return -ENXIO);
127 if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
128 snd_pcm_plugin_t *plugin = snd_pcm_plug_first(plug);
129 while (plugin->next) {
130 if (plugin->dst_frames)
131 frames = plugin->dst_frames(plugin, frames);
132 snd_assert(frames > 0, return -ENXIO);
133 plugin = plugin->next;
134 err = snd_pcm_plugin_alloc(plugin, frames);
139 snd_pcm_plugin_t *plugin = snd_pcm_plug_last(plug);
140 while (plugin->prev) {
141 if (plugin->src_frames)
142 frames = plugin->src_frames(plugin, frames);
143 snd_assert(frames > 0, return -ENXIO);
144 plugin = plugin->prev;
145 err = snd_pcm_plugin_alloc(plugin, frames);
154 snd_pcm_sframes_t snd_pcm_plugin_client_channels(snd_pcm_plugin_t *plugin,
155 snd_pcm_uframes_t frames,
156 snd_pcm_plugin_channel_t **channels)
158 *channels = plugin->buf_channels;
162 int snd_pcm_plugin_build(snd_pcm_plug_t *plug,
164 snd_pcm_plugin_format_t *src_format,
165 snd_pcm_plugin_format_t *dst_format,
167 snd_pcm_plugin_t **ret)
169 snd_pcm_plugin_t *plugin;
170 unsigned int channels;
172 snd_assert(plug != NULL, return -ENXIO);
173 snd_assert(src_format != NULL && dst_format != NULL, return -ENXIO);
174 plugin = kcalloc(1, sizeof(*plugin) + extra, GFP_KERNEL);
179 plugin->stream = snd_pcm_plug_stream(plug);
180 plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
181 plugin->src_format = *src_format;
182 plugin->src_width = snd_pcm_format_physical_width(src_format->format);
183 snd_assert(plugin->src_width > 0, );
184 plugin->dst_format = *dst_format;
185 plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
186 snd_assert(plugin->dst_width > 0, );
187 if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
188 channels = src_format->channels;
190 channels = dst_format->channels;
191 plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
192 if (plugin->buf_channels == NULL) {
193 snd_pcm_plugin_free(plugin);
196 plugin->src_vmask = bitset_alloc(src_format->channels);
197 if (plugin->src_vmask == NULL) {
198 snd_pcm_plugin_free(plugin);
201 plugin->dst_vmask = bitset_alloc(dst_format->channels);
202 if (plugin->dst_vmask == NULL) {
203 snd_pcm_plugin_free(plugin);
206 plugin->client_channels = snd_pcm_plugin_client_channels;
207 plugin->src_channels_mask = snd_pcm_plugin_src_channels_mask;
208 plugin->dst_channels_mask = snd_pcm_plugin_dst_channels_mask;
213 int snd_pcm_plugin_free(snd_pcm_plugin_t *plugin)
217 if (plugin->private_free)
218 plugin->private_free(plugin);
219 kfree(plugin->buf_channels);
221 kfree(plugin->src_vmask);
222 kfree(plugin->dst_vmask);
227 snd_pcm_sframes_t snd_pcm_plug_client_size(snd_pcm_plug_t *plug, snd_pcm_uframes_t drv_frames)
229 snd_pcm_plugin_t *plugin, *plugin_prev, *plugin_next;
230 int stream = snd_pcm_plug_stream(plug);
232 snd_assert(plug != NULL, return -ENXIO);
235 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
236 plugin = snd_pcm_plug_last(plug);
237 while (plugin && drv_frames > 0) {
238 plugin_prev = plugin->prev;
239 if (plugin->src_frames)
240 drv_frames = plugin->src_frames(plugin, drv_frames);
241 plugin = plugin_prev;
243 } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
244 plugin = snd_pcm_plug_first(plug);
245 while (plugin && drv_frames > 0) {
246 plugin_next = plugin->next;
247 if (plugin->dst_frames)
248 drv_frames = plugin->dst_frames(plugin, drv_frames);
249 plugin = plugin_next;
256 snd_pcm_sframes_t snd_pcm_plug_slave_size(snd_pcm_plug_t *plug, snd_pcm_uframes_t clt_frames)
258 snd_pcm_plugin_t *plugin, *plugin_prev, *plugin_next;
259 snd_pcm_sframes_t frames;
260 int stream = snd_pcm_plug_stream(plug);
262 snd_assert(plug != NULL, return -ENXIO);
266 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
267 plugin = snd_pcm_plug_first(plug);
268 while (plugin && frames > 0) {
269 plugin_next = plugin->next;
270 if (plugin->dst_frames) {
271 frames = plugin->dst_frames(plugin, frames);
275 plugin = plugin_next;
277 } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
278 plugin = snd_pcm_plug_last(plug);
280 plugin_prev = plugin->prev;
281 if (plugin->src_frames) {
282 frames = plugin->src_frames(plugin, frames);
286 plugin = plugin_prev;
293 static int snd_pcm_plug_formats(snd_mask_t *mask, int format)
295 snd_mask_t formats = *mask;
296 u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
297 SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
298 SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
299 SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
300 SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
301 SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
302 SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
303 snd_mask_set(&formats, SNDRV_PCM_FORMAT_MU_LAW);
305 if (formats.bits[0] & (u32)linfmts)
306 formats.bits[0] |= (u32)linfmts;
307 if (formats.bits[1] & (u32)(linfmts >> 32))
308 formats.bits[1] |= (u32)(linfmts >> 32);
309 return snd_mask_test(&formats, format);
312 static int preferred_formats[] = {
313 SNDRV_PCM_FORMAT_S16_LE,
314 SNDRV_PCM_FORMAT_S16_BE,
315 SNDRV_PCM_FORMAT_U16_LE,
316 SNDRV_PCM_FORMAT_U16_BE,
317 SNDRV_PCM_FORMAT_S24_LE,
318 SNDRV_PCM_FORMAT_S24_BE,
319 SNDRV_PCM_FORMAT_U24_LE,
320 SNDRV_PCM_FORMAT_U24_BE,
321 SNDRV_PCM_FORMAT_S32_LE,
322 SNDRV_PCM_FORMAT_S32_BE,
323 SNDRV_PCM_FORMAT_U32_LE,
324 SNDRV_PCM_FORMAT_U32_BE,
329 int snd_pcm_plug_slave_format(int format, snd_mask_t *format_mask)
331 if (snd_mask_test(format_mask, format))
333 if (! snd_pcm_plug_formats(format_mask, format))
335 if (snd_pcm_format_linear(format)) {
336 int width = snd_pcm_format_width(format);
337 int unsignd = snd_pcm_format_unsigned(format);
338 int big = snd_pcm_format_big_endian(format);
340 int wid, width1=width;
342 for (wid = 0; wid < 4; ++wid) {
344 for (end = 0; end < 2; ++end) {
345 int sgn, unsignd1 = unsignd;
346 for (sgn = 0; sgn < 2; ++sgn) {
347 format1 = snd_pcm_build_linear_format(width1, unsignd1, big1);
349 snd_mask_test(format_mask, format1))
351 unsignd1 = !unsignd1;
367 case SNDRV_PCM_FORMAT_MU_LAW:
368 for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
369 int format1 = preferred_formats[i];
370 if (snd_mask_test(format_mask, format1))
379 int snd_pcm_plug_format_plugins(snd_pcm_plug_t *plug,
380 snd_pcm_hw_params_t *params,
381 snd_pcm_hw_params_t *slave_params)
383 snd_pcm_plugin_format_t tmpformat;
384 snd_pcm_plugin_format_t dstformat;
385 snd_pcm_plugin_format_t srcformat;
386 int src_access, dst_access;
387 snd_pcm_plugin_t *plugin = NULL;
389 int stream = snd_pcm_plug_stream(plug);
390 int slave_interleaved = (params_channels(slave_params) == 1 ||
391 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
394 case SNDRV_PCM_STREAM_PLAYBACK:
395 dstformat.format = params_format(slave_params);
396 dstformat.rate = params_rate(slave_params);
397 dstformat.channels = params_channels(slave_params);
398 srcformat.format = params_format(params);
399 srcformat.rate = params_rate(params);
400 srcformat.channels = params_channels(params);
401 src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
402 dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
403 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
405 case SNDRV_PCM_STREAM_CAPTURE:
406 dstformat.format = params_format(params);
407 dstformat.rate = params_rate(params);
408 dstformat.channels = params_channels(params);
409 srcformat.format = params_format(slave_params);
410 srcformat.rate = params_rate(slave_params);
411 srcformat.channels = params_channels(slave_params);
412 src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
413 SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
414 dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
420 tmpformat = srcformat;
422 pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
426 pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
431 /* Format change (linearization) */
432 if ((srcformat.format != dstformat.format ||
433 !rate_match(srcformat.rate, dstformat.rate) ||
434 srcformat.channels != dstformat.channels) &&
435 !snd_pcm_format_linear(srcformat.format)) {
436 if (snd_pcm_format_linear(dstformat.format))
437 tmpformat.format = dstformat.format;
439 tmpformat.format = SNDRV_PCM_FORMAT_S16;
440 switch (srcformat.format) {
441 case SNDRV_PCM_FORMAT_MU_LAW:
442 err = snd_pcm_plugin_build_mulaw(plug,
443 &srcformat, &tmpformat,
449 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
452 err = snd_pcm_plugin_append(plugin);
454 snd_pcm_plugin_free(plugin);
457 srcformat = tmpformat;
458 src_access = dst_access;
461 /* channels reduction */
462 if (srcformat.channels > dstformat.channels) {
463 int sv = srcformat.channels;
464 int dv = dstformat.channels;
465 route_ttable_entry_t *ttable = kcalloc(dv * sv, sizeof(*ttable), GFP_KERNEL);
469 if (sv == 2 && dv == 1) {
476 for (v = 0; v < dv; ++v)
477 ttable[v * sv + v] = FULL;
479 tmpformat.channels = dstformat.channels;
480 if (rate_match(srcformat.rate, dstformat.rate) &&
481 snd_pcm_format_linear(dstformat.format))
482 tmpformat.format = dstformat.format;
483 err = snd_pcm_plugin_build_route(plug,
484 &srcformat, &tmpformat,
487 pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
489 snd_pcm_plugin_free(plugin);
492 err = snd_pcm_plugin_append(plugin);
494 snd_pcm_plugin_free(plugin);
497 srcformat = tmpformat;
498 src_access = dst_access;
501 /* rate resampling */
502 if (!rate_match(srcformat.rate, dstformat.rate)) {
503 tmpformat.rate = dstformat.rate;
504 if (srcformat.channels == dstformat.channels &&
505 snd_pcm_format_linear(dstformat.format))
506 tmpformat.format = dstformat.format;
507 err = snd_pcm_plugin_build_rate(plug,
508 &srcformat, &tmpformat,
510 pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
512 snd_pcm_plugin_free(plugin);
515 err = snd_pcm_plugin_append(plugin);
517 snd_pcm_plugin_free(plugin);
520 srcformat = tmpformat;
521 src_access = dst_access;
524 /* channels extension */
525 if (srcformat.channels < dstformat.channels) {
526 int sv = srcformat.channels;
527 int dv = dstformat.channels;
528 route_ttable_entry_t *ttable = kcalloc(dv * sv, sizeof(*ttable), GFP_KERNEL);
534 for (v = 0; v < sv; ++v)
535 ttable[v * sv + v] = FULL;
539 /* Playback is spreaded on all channels */
541 for (vd = 0, vs = 0; vd < dv; ++vd) {
542 ttable[vd * sv + vs] = FULL;
549 tmpformat.channels = dstformat.channels;
550 if (snd_pcm_format_linear(dstformat.format))
551 tmpformat.format = dstformat.format;
552 err = snd_pcm_plugin_build_route(plug,
553 &srcformat, &tmpformat,
556 pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
558 snd_pcm_plugin_free(plugin);
561 err = snd_pcm_plugin_append(plugin);
563 snd_pcm_plugin_free(plugin);
566 srcformat = tmpformat;
567 src_access = dst_access;
571 if (srcformat.format != dstformat.format) {
572 tmpformat.format = dstformat.format;
573 if (tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
574 err = snd_pcm_plugin_build_mulaw(plug,
575 &srcformat, &tmpformat,
578 else if (snd_pcm_format_linear(srcformat.format) &&
579 snd_pcm_format_linear(tmpformat.format)) {
580 err = snd_pcm_plugin_build_linear(plug,
581 &srcformat, &tmpformat,
586 pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
589 err = snd_pcm_plugin_append(plugin);
591 snd_pcm_plugin_free(plugin);
594 srcformat = tmpformat;
595 src_access = dst_access;
599 if (src_access != dst_access) {
600 err = snd_pcm_plugin_build_copy(plug,
604 pdprintf("interleave change (copy: returns %i)\n", err);
607 err = snd_pcm_plugin_append(plugin);
609 snd_pcm_plugin_free(plugin);
617 snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(snd_pcm_plug_t *plug,
619 snd_pcm_uframes_t count,
620 snd_pcm_plugin_channel_t **channels)
622 snd_pcm_plugin_t *plugin;
623 snd_pcm_plugin_channel_t *v;
624 snd_pcm_plugin_format_t *format;
625 int width, nchannels, channel;
626 int stream = snd_pcm_plug_stream(plug);
628 snd_assert(buf != NULL, return -ENXIO);
629 if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
630 plugin = snd_pcm_plug_first(plug);
631 format = &plugin->src_format;
633 plugin = snd_pcm_plug_last(plug);
634 format = &plugin->dst_format;
636 v = plugin->buf_channels;
638 if ((width = snd_pcm_format_physical_width(format->format)) < 0)
640 nchannels = format->channels;
641 snd_assert(plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED || format->channels <= 1, return -ENXIO);
642 for (channel = 0; channel < nchannels; channel++, v++) {
645 v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
647 v->area.first = channel * width;
648 v->area.step = nchannels * width;
653 static int snd_pcm_plug_playback_channels_mask(snd_pcm_plug_t *plug,
654 bitset_t *client_vmask)
656 snd_pcm_plugin_t *plugin = snd_pcm_plug_last(plug);
657 if (plugin == NULL) {
660 int schannels = plugin->dst_format.channels;
661 bitset_t bs[bitset_size(schannels)];
663 bitset_t *dstmask = bs;
665 bitset_one(dstmask, schannels);
668 err = plugin->src_channels_mask(plugin, dstmask, &srcmask);
672 if (plugin->prev == NULL)
674 plugin = plugin->prev;
676 bitset_and(client_vmask, dstmask, plugin->src_format.channels);
681 static int snd_pcm_plug_playback_disable_useless_channels(snd_pcm_plug_t *plug,
682 snd_pcm_plugin_channel_t *src_channels)
684 snd_pcm_plugin_t *plugin = snd_pcm_plug_first(plug);
685 unsigned int nchannels = plugin->src_format.channels;
686 bitset_t bs[bitset_size(nchannels)];
687 bitset_t *srcmask = bs;
689 unsigned int channel;
690 for (channel = 0; channel < nchannels; channel++) {
691 if (src_channels[channel].enabled)
692 bitset_set(srcmask, channel);
694 bitset_reset(srcmask, channel);
696 err = snd_pcm_plug_playback_channels_mask(plug, srcmask);
699 for (channel = 0; channel < nchannels; channel++) {
700 if (!bitset_get(srcmask, channel))
701 src_channels[channel].enabled = 0;
706 static int snd_pcm_plug_capture_disable_useless_channels(snd_pcm_plug_t *plug,
707 snd_pcm_plugin_channel_t *src_channels,
708 snd_pcm_plugin_channel_t *client_channels)
710 snd_pcm_plugin_t *plugin = snd_pcm_plug_last(plug);
711 unsigned int nchannels = plugin->dst_format.channels;
712 bitset_t bs[bitset_size(nchannels)];
713 bitset_t *dstmask = bs;
716 unsigned int channel;
717 for (channel = 0; channel < nchannels; channel++) {
718 if (client_channels[channel].enabled)
719 bitset_set(dstmask, channel);
721 bitset_reset(dstmask, channel);
724 err = plugin->src_channels_mask(plugin, dstmask, &srcmask);
728 plugin = plugin->prev;
730 plugin = snd_pcm_plug_first(plug);
731 nchannels = plugin->src_format.channels;
732 for (channel = 0; channel < nchannels; channel++) {
733 if (!bitset_get(dstmask, channel))
734 src_channels[channel].enabled = 0;
739 snd_pcm_sframes_t snd_pcm_plug_write_transfer(snd_pcm_plug_t *plug, snd_pcm_plugin_channel_t *src_channels, snd_pcm_uframes_t size)
741 snd_pcm_plugin_t *plugin, *next;
742 snd_pcm_plugin_channel_t *dst_channels;
744 snd_pcm_sframes_t frames = size;
746 if ((err = snd_pcm_plug_playback_disable_useless_channels(plug, src_channels)) < 0)
749 plugin = snd_pcm_plug_first(plug);
750 while (plugin && frames > 0) {
751 if ((next = plugin->next) != NULL) {
752 snd_pcm_sframes_t frames1 = frames;
753 if (plugin->dst_frames)
754 frames1 = plugin->dst_frames(plugin, frames);
755 if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
758 if (err != frames1) {
760 if (plugin->src_frames)
761 frames = plugin->src_frames(plugin, frames1);
765 pdprintf("write plugin: %s, %li\n", plugin->name, frames);
766 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
768 src_channels = dst_channels;
771 return snd_pcm_plug_client_size(plug, frames);
774 snd_pcm_sframes_t snd_pcm_plug_read_transfer(snd_pcm_plug_t *plug, snd_pcm_plugin_channel_t *dst_channels_final, snd_pcm_uframes_t size)
776 snd_pcm_plugin_t *plugin, *next;
777 snd_pcm_plugin_channel_t *src_channels, *dst_channels;
778 snd_pcm_sframes_t frames = size;
781 frames = snd_pcm_plug_slave_size(plug, frames);
786 plugin = snd_pcm_plug_first(plug);
787 while (plugin && frames > 0) {
788 if ((next = plugin->next) != NULL) {
789 if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
794 if ((err = snd_pcm_plug_capture_disable_useless_channels(plug, dst_channels, dst_channels_final)) < 0)
798 dst_channels = dst_channels_final;
800 pdprintf("read plugin: %s, %li\n", plugin->name, frames);
801 if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
804 src_channels = dst_channels;
809 int snd_pcm_area_silence(const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
810 size_t samples, int format)
812 /* FIXME: sub byte resolution and odd dst_offset */
814 unsigned int dst_step;
816 const unsigned char *silence;
819 dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
820 width = snd_pcm_format_physical_width(format);
823 if (dst_area->step == (unsigned int) width && width >= 8)
824 return snd_pcm_format_set_silence(format, dst, samples);
825 silence = snd_pcm_format_silence_64(format);
828 dst_step = dst_area->step / 8;
831 int dstbit = dst_area->first % 8;
832 int dstbit_step = dst_area->step % 8;
833 while (samples-- > 0) {
839 dstbit += dstbit_step;
847 while (samples-- > 0) {
848 memcpy(dst, silence, width);
855 int snd_pcm_area_copy(const snd_pcm_channel_area_t *src_area, size_t src_offset,
856 const snd_pcm_channel_area_t *dst_area, size_t dst_offset,
857 size_t samples, int format)
859 /* FIXME: sub byte resolution and odd dst_offset */
862 int src_step, dst_step;
863 src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
865 return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
866 dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
869 width = snd_pcm_format_physical_width(format);
872 if (src_area->step == (unsigned int) width &&
873 dst_area->step == (unsigned int) width && width >= 8) {
874 size_t bytes = samples * width / 8;
875 memcpy(dst, src, bytes);
878 src_step = src_area->step / 8;
879 dst_step = dst_area->step / 8;
882 int srcbit = src_area->first % 8;
883 int srcbit_step = src_area->step % 8;
884 int dstbit = dst_area->first % 8;
885 int dstbit_step = dst_area->step % 8;
886 while (samples-- > 0) {
887 unsigned char srcval;
889 srcval = *src & 0x0f;
891 srcval = (*src & 0xf0) >> 4;
893 *dst = (*dst & 0xf0) | srcval;
895 *dst = (*dst & 0x0f) | (srcval << 4);
897 srcbit += srcbit_step;
903 dstbit += dstbit_step;
911 while (samples-- > 0) {
912 memcpy(dst, src, width);