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>
  5 *
  6 *
  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.
 11 *
 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.
 16 *
 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
 20 *
 21 */
 22  
 23#if 0
 24#define PLUGIN_DEBUG
 25#endif
 26
 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"
 34
 35#define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
 36#define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
 37
 38/*
 39 *  because some cards might have rates "very close", we ignore
 40 *  all "resampling" requests within +-5%
 41 */
 42static int rate_match(unsigned int src_rate, unsigned int dst_rate)
 43{
 44	unsigned int low = (src_rate * 95) / 100;
 45	unsigned int high = (src_rate * 105) / 100;
 46	return dst_rate >= low && dst_rate <= high;
 47}
 48
 49static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
 50{
 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;
 56
 57	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 58		format = &plugin->src_format;
 59	} else {
 60		format = &plugin->dst_format;
 61	}
 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		kvfree(plugin->buf);
 70		plugin->buf = kvzalloc(size, GFP_KERNEL);
 71		plugin->buf_frames = frames;
 72	}
 73	if (!plugin->buf) {
 74		plugin->buf_frames = 0;
 75		return -ENOMEM;
 76	}
 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;
 86		}
 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;
 98		}
 99	} else
100		return -EINVAL;
101	return 0;
102}
103
104int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
105{
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_pcm_sframes_t)frames <= 0)
115				return -ENXIO;
116			plugin = plugin->next;
117			err = snd_pcm_plugin_alloc(plugin, frames);
118			if (err < 0)
119				return err;
120		}
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_pcm_sframes_t)frames <= 0)
127				return -ENXIO;
128			plugin = plugin->prev;
129			err = snd_pcm_plugin_alloc(plugin, frames);
130			if (err < 0)
131				return err;
132		}
133	}
134	return 0;
135}
136
137
138snd_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)
141{
142	*channels = plugin->buf_channels;
143	return frames;
144}
145
146int 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)
152{
153	struct snd_pcm_plugin *plugin;
154	unsigned int channels;
155	
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;
181	}
182	plugin->client_channels = snd_pcm_plugin_client_channels;
183	*ret = plugin;
184	return 0;
185}
186
187int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
188{
189	if (! plugin)
190		return 0;
191	if (plugin->private_free)
192		plugin->private_free(plugin);
193	kfree(plugin->buf_channels);
194	kvfree(plugin->buf);
195	kfree(plugin);
196	return 0;
197}
198
199static snd_pcm_sframes_t calc_dst_frames(struct snd_pcm_substream *plug,
200					 snd_pcm_sframes_t frames,
201					 bool check_size)
202{
203	struct snd_pcm_plugin *plugin, *plugin_next;
204
205	plugin = snd_pcm_plug_first(plug);
206	while (plugin && frames > 0) {
207		plugin_next = plugin->next;
208		if (check_size && plugin->buf_frames &&
209		    frames > plugin->buf_frames)
210			frames = plugin->buf_frames;
211		if (plugin->dst_frames) {
212			frames = plugin->dst_frames(plugin, frames);
213			if (frames < 0)
214				return frames;
215		}
216		plugin = plugin_next;
217	}
218	return frames;
219}
220
221static snd_pcm_sframes_t calc_src_frames(struct snd_pcm_substream *plug,
222					 snd_pcm_sframes_t frames,
223					 bool check_size)
224{
225	struct snd_pcm_plugin *plugin, *plugin_prev;
226
227	plugin = snd_pcm_plug_last(plug);
228	while (plugin && frames > 0) {
229		plugin_prev = plugin->prev;
230		if (plugin->src_frames) {
231			frames = plugin->src_frames(plugin, frames);
232			if (frames < 0)
233				return frames;
234		}
235		if (check_size && plugin->buf_frames &&
236		    frames > plugin->buf_frames)
237			frames = plugin->buf_frames;
238		plugin = plugin_prev;
239	}
240	return frames;
241}
242
243snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
244{
 
 
 
245	if (snd_BUG_ON(!plug))
246		return -ENXIO;
247	switch (snd_pcm_plug_stream(plug)) {
248	case SNDRV_PCM_STREAM_PLAYBACK:
249		return calc_src_frames(plug, drv_frames, false);
250	case SNDRV_PCM_STREAM_CAPTURE:
251		return calc_dst_frames(plug, drv_frames, false);
252	default:
 
 
 
 
 
 
 
 
 
 
 
 
 
253		snd_BUG();
254		return -EINVAL;
255	}
256}
257
258snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
259{
 
 
 
 
260	if (snd_BUG_ON(!plug))
261		return -ENXIO;
262	switch (snd_pcm_plug_stream(plug)) {
263	case SNDRV_PCM_STREAM_PLAYBACK:
264		return calc_dst_frames(plug, clt_frames, false);
265	case SNDRV_PCM_STREAM_CAPTURE:
266		return calc_src_frames(plug, clt_frames, false);
267	default:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
268		snd_BUG();
269		return -EINVAL;
270	}
271}
272
273static int snd_pcm_plug_formats(const struct snd_mask *mask,
274				snd_pcm_format_t format)
275{
276	struct snd_mask formats = *mask;
277	u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
278		       SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
279		       SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
280		       SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
281		       SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
282		       SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
283		       SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
284		       SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
285		       SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
286	snd_mask_set(&formats, (__force int)SNDRV_PCM_FORMAT_MU_LAW);
287	
288	if (formats.bits[0] & lower_32_bits(linfmts))
289		formats.bits[0] |= lower_32_bits(linfmts);
290	if (formats.bits[1] & upper_32_bits(linfmts))
291		formats.bits[1] |= upper_32_bits(linfmts);
292	return snd_mask_test(&formats, (__force int)format);
293}
294
295static const snd_pcm_format_t preferred_formats[] = {
296	SNDRV_PCM_FORMAT_S16_LE,
297	SNDRV_PCM_FORMAT_S16_BE,
298	SNDRV_PCM_FORMAT_U16_LE,
299	SNDRV_PCM_FORMAT_U16_BE,
300	SNDRV_PCM_FORMAT_S24_3LE,
301	SNDRV_PCM_FORMAT_S24_3BE,
302	SNDRV_PCM_FORMAT_U24_3LE,
303	SNDRV_PCM_FORMAT_U24_3BE,
304	SNDRV_PCM_FORMAT_S24_LE,
305	SNDRV_PCM_FORMAT_S24_BE,
306	SNDRV_PCM_FORMAT_U24_LE,
307	SNDRV_PCM_FORMAT_U24_BE,
308	SNDRV_PCM_FORMAT_S32_LE,
309	SNDRV_PCM_FORMAT_S32_BE,
310	SNDRV_PCM_FORMAT_U32_LE,
311	SNDRV_PCM_FORMAT_U32_BE,
312	SNDRV_PCM_FORMAT_S8,
313	SNDRV_PCM_FORMAT_U8
314};
315
316snd_pcm_format_t snd_pcm_plug_slave_format(snd_pcm_format_t format,
317					   const struct snd_mask *format_mask)
318{
319	int i;
320
321	if (snd_mask_test(format_mask, (__force int)format))
322		return format;
323	if (!snd_pcm_plug_formats(format_mask, format))
324		return (__force snd_pcm_format_t)-EINVAL;
325	if (snd_pcm_format_linear(format)) {
326		unsigned int width = snd_pcm_format_width(format);
327		int unsignd = snd_pcm_format_unsigned(format) > 0;
328		int big = snd_pcm_format_big_endian(format) > 0;
329		unsigned int badness, best = -1;
330		snd_pcm_format_t best_format = (__force snd_pcm_format_t)-1;
331		for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
332			snd_pcm_format_t f = preferred_formats[i];
333			unsigned int w;
334			if (!snd_mask_test(format_mask, (__force int)f))
335				continue;
336			w = snd_pcm_format_width(f);
337			if (w >= width)
338				badness = w - width;
339			else
340				badness = width - w + 32;
341			badness += snd_pcm_format_unsigned(f) != unsignd;
342			badness += snd_pcm_format_big_endian(f) != big;
343			if (badness < best) {
344				best_format = f;
345				best = badness;
346			}
347		}
348		if ((__force int)best_format >= 0)
349			return best_format;
350		else
351			return (__force snd_pcm_format_t)-EINVAL;
352	} else {
353		switch (format) {
354		case SNDRV_PCM_FORMAT_MU_LAW:
355			for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
356				snd_pcm_format_t format1 = preferred_formats[i];
357				if (snd_mask_test(format_mask, (__force int)format1))
358					return format1;
359			}
360			fallthrough;
361		default:
362			return (__force snd_pcm_format_t)-EINVAL;
363		}
364	}
365}
366
367int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
368				struct snd_pcm_hw_params *params,
369				struct snd_pcm_hw_params *slave_params)
370{
371	struct snd_pcm_plugin_format tmpformat;
372	struct snd_pcm_plugin_format dstformat;
373	struct snd_pcm_plugin_format srcformat;
374	snd_pcm_access_t src_access, dst_access;
375	struct snd_pcm_plugin *plugin = NULL;
376	int err;
377	int stream = snd_pcm_plug_stream(plug);
378	int slave_interleaved = (params_channels(slave_params) == 1 ||
379				 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
380
381	switch (stream) {
382	case SNDRV_PCM_STREAM_PLAYBACK:
383		dstformat.format = params_format(slave_params);
384		dstformat.rate = params_rate(slave_params);
385		dstformat.channels = params_channels(slave_params);
386		srcformat.format = params_format(params);
387		srcformat.rate = params_rate(params);
388		srcformat.channels = params_channels(params);
389		src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
390		dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
391						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
392		break;
393	case SNDRV_PCM_STREAM_CAPTURE:
394		dstformat.format = params_format(params);
395		dstformat.rate = params_rate(params);
396		dstformat.channels = params_channels(params);
397		srcformat.format = params_format(slave_params);
398		srcformat.rate = params_rate(slave_params);
399		srcformat.channels = params_channels(slave_params);
400		src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
401						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
402		dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
403		break;
404	default:
405		snd_BUG();
406		return -EINVAL;
407	}
408	tmpformat = srcformat;
409		
410	pdprintf("srcformat: format=%i, rate=%i, channels=%i\n", 
411		 srcformat.format,
412		 srcformat.rate,
413		 srcformat.channels);
414	pdprintf("dstformat: format=%i, rate=%i, channels=%i\n", 
415		 dstformat.format,
416		 dstformat.rate,
417		 dstformat.channels);
418
419	/* Format change (linearization) */
420	if (! rate_match(srcformat.rate, dstformat.rate) &&
421	    ! snd_pcm_format_linear(srcformat.format)) {
422		if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
423			return -EINVAL;
424		tmpformat.format = SNDRV_PCM_FORMAT_S16;
425		err = snd_pcm_plugin_build_mulaw(plug,
426						 &srcformat, &tmpformat,
427						 &plugin);
428		if (err < 0)
429			return err;
430		err = snd_pcm_plugin_append(plugin);
431		if (err < 0) {
432			snd_pcm_plugin_free(plugin);
433			return err;
434		}
435		srcformat = tmpformat;
436		src_access = dst_access;
437	}
438
439	/* channels reduction */
440	if (srcformat.channels > dstformat.channels) {
441		tmpformat.channels = dstformat.channels;
442		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
443		pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
444		if (err < 0)
445			return err;
446		err = snd_pcm_plugin_append(plugin);
447		if (err < 0) {
448			snd_pcm_plugin_free(plugin);
449			return err;
450		}
451		srcformat = tmpformat;
452		src_access = dst_access;
453	}
454
455	/* rate resampling */
456	if (!rate_match(srcformat.rate, dstformat.rate)) {
457		if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
458			/* convert to S16 for resampling */
459			tmpformat.format = SNDRV_PCM_FORMAT_S16;
460			err = snd_pcm_plugin_build_linear(plug,
461							  &srcformat, &tmpformat,
462							  &plugin);
463			if (err < 0)
464				return err;
465			err = snd_pcm_plugin_append(plugin);
466			if (err < 0) {
467				snd_pcm_plugin_free(plugin);
468				return err;
469			}
470			srcformat = tmpformat;
471			src_access = dst_access;
472		}
473		tmpformat.rate = dstformat.rate;
474        	err = snd_pcm_plugin_build_rate(plug,
475        					&srcformat, &tmpformat,
476						&plugin);
477		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
478		if (err < 0)
479			return err;
480		err = snd_pcm_plugin_append(plugin);
481		if (err < 0) {
482			snd_pcm_plugin_free(plugin);
483			return err;
484		}
485		srcformat = tmpformat;
486		src_access = dst_access;
487        }
488
489	/* format change */
490	if (srcformat.format != dstformat.format) {
491		tmpformat.format = dstformat.format;
492		if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
493		    tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
494			err = snd_pcm_plugin_build_mulaw(plug,
495							 &srcformat, &tmpformat,
496							 &plugin);
497		}
498		else if (snd_pcm_format_linear(srcformat.format) &&
499			 snd_pcm_format_linear(tmpformat.format)) {
500			err = snd_pcm_plugin_build_linear(plug,
501							  &srcformat, &tmpformat,
502							  &plugin);
503		}
504		else
505			return -EINVAL;
506		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
507		if (err < 0)
508			return err;
509		err = snd_pcm_plugin_append(plugin);
510		if (err < 0) {
511			snd_pcm_plugin_free(plugin);
512			return err;
513		}
514		srcformat = tmpformat;
515		src_access = dst_access;
516	}
517
518	/* channels extension */
519	if (srcformat.channels < dstformat.channels) {
520		tmpformat.channels = dstformat.channels;
521		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
522		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
523		if (err < 0)
524			return err;
525		err = snd_pcm_plugin_append(plugin);
526		if (err < 0) {
527			snd_pcm_plugin_free(plugin);
528			return err;
529		}
530		srcformat = tmpformat;
531		src_access = dst_access;
532	}
533
534	/* de-interleave */
535	if (src_access != dst_access) {
536		err = snd_pcm_plugin_build_copy(plug,
537						&srcformat,
538						&tmpformat,
539						&plugin);
540		pdprintf("interleave change (copy: returns %i)\n", err);
541		if (err < 0)
542			return err;
543		err = snd_pcm_plugin_append(plugin);
544		if (err < 0) {
545			snd_pcm_plugin_free(plugin);
546			return err;
547		}
548	}
549
550	return 0;
551}
552
553snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
554					 char *buf,
555					 snd_pcm_uframes_t count,
556					 struct snd_pcm_plugin_channel **channels)
557{
558	struct snd_pcm_plugin *plugin;
559	struct snd_pcm_plugin_channel *v;
560	struct snd_pcm_plugin_format *format;
561	int width, nchannels, channel;
562	int stream = snd_pcm_plug_stream(plug);
563
564	if (snd_BUG_ON(!buf))
565		return -ENXIO;
566	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
567		plugin = snd_pcm_plug_first(plug);
568		format = &plugin->src_format;
569	} else {
570		plugin = snd_pcm_plug_last(plug);
571		format = &plugin->dst_format;
572	}
573	v = plugin->buf_channels;
574	*channels = v;
575	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
576		return width;
577	nchannels = format->channels;
578	if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
579		       format->channels > 1))
580		return -ENXIO;
581	for (channel = 0; channel < nchannels; channel++, v++) {
582		v->frames = count;
583		v->enabled = 1;
584		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
585		v->area.addr = buf;
586		v->area.first = channel * width;
587		v->area.step = nchannels * width;
588	}
589	return count;
590}
591
592snd_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)
593{
594	struct snd_pcm_plugin *plugin, *next;
595	struct snd_pcm_plugin_channel *dst_channels;
596	int err;
597	snd_pcm_sframes_t frames = size;
598
599	plugin = snd_pcm_plug_first(plug);
600	while (plugin) {
601		if (frames <= 0)
602			return frames;
603		if ((next = plugin->next) != NULL) {
604			snd_pcm_sframes_t frames1 = frames;
605			if (plugin->dst_frames) {
606				frames1 = plugin->dst_frames(plugin, frames);
607				if (frames1 <= 0)
608					return frames1;
609			}
610			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
611				return err;
612			}
613			if (err != frames1) {
614				frames = err;
615				if (plugin->src_frames) {
616					frames = plugin->src_frames(plugin, frames1);
617					if (frames <= 0)
618						return frames;
619				}
620			}
621		} else
622			dst_channels = NULL;
623		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
624		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
625			return frames;
626		src_channels = dst_channels;
627		plugin = next;
628	}
629	return calc_src_frames(plug, frames, true);
630}
631
632snd_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)
633{
634	struct snd_pcm_plugin *plugin, *next;
635	struct snd_pcm_plugin_channel *src_channels, *dst_channels;
636	snd_pcm_sframes_t frames = size;
637	int err;
638
639	frames = calc_src_frames(plug, frames, true);
640	if (frames < 0)
641		return frames;
642
643	src_channels = NULL;
644	plugin = snd_pcm_plug_first(plug);
645	while (plugin && frames > 0) {
646		if ((next = plugin->next) != NULL) {
647			if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
648				return err;
649			}
650			frames = err;
651		} else {
652			dst_channels = dst_channels_final;
653		}
654		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
655		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
656			return frames;
657		plugin = next;
658		src_channels = dst_channels;
659	}
660	return frames;
661}
662
663int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
664			 size_t samples, snd_pcm_format_t format)
665{
666	/* FIXME: sub byte resolution and odd dst_offset */
667	unsigned char *dst;
668	unsigned int dst_step;
669	int width;
670	const unsigned char *silence;
671	if (!dst_area->addr)
672		return 0;
673	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
674	width = snd_pcm_format_physical_width(format);
675	if (width <= 0)
676		return -EINVAL;
677	if (dst_area->step == (unsigned int) width && width >= 8)
678		return snd_pcm_format_set_silence(format, dst, samples);
679	silence = snd_pcm_format_silence_64(format);
680	if (! silence)
681		return -EINVAL;
682	dst_step = dst_area->step / 8;
683	if (width == 4) {
684		/* Ima ADPCM */
685		int dstbit = dst_area->first % 8;
686		int dstbit_step = dst_area->step % 8;
687		while (samples-- > 0) {
688			if (dstbit)
689				*dst &= 0xf0;
690			else
691				*dst &= 0x0f;
692			dst += dst_step;
693			dstbit += dstbit_step;
694			if (dstbit == 8) {
695				dst++;
696				dstbit = 0;
697			}
698		}
699	} else {
700		width /= 8;
701		while (samples-- > 0) {
702			memcpy(dst, silence, width);
703			dst += dst_step;
704		}
705	}
706	return 0;
707}
708
709int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
710		      const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
711		      size_t samples, snd_pcm_format_t format)
712{
713	/* FIXME: sub byte resolution and odd dst_offset */
714	char *src, *dst;
715	int width;
716	int src_step, dst_step;
717	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
718	if (!src_area->addr)
719		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
720	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
721	if (!dst_area->addr)
722		return 0;
723	width = snd_pcm_format_physical_width(format);
724	if (width <= 0)
725		return -EINVAL;
726	if (src_area->step == (unsigned int) width &&
727	    dst_area->step == (unsigned int) width && width >= 8) {
728		size_t bytes = samples * width / 8;
729		memcpy(dst, src, bytes);
730		return 0;
731	}
732	src_step = src_area->step / 8;
733	dst_step = dst_area->step / 8;
734	if (width == 4) {
735		/* Ima ADPCM */
736		int srcbit = src_area->first % 8;
737		int srcbit_step = src_area->step % 8;
738		int dstbit = dst_area->first % 8;
739		int dstbit_step = dst_area->step % 8;
740		while (samples-- > 0) {
741			unsigned char srcval;
742			if (srcbit)
743				srcval = *src & 0x0f;
744			else
745				srcval = (*src & 0xf0) >> 4;
746			if (dstbit)
747				*dst = (*dst & 0xf0) | srcval;
748			else
749				*dst = (*dst & 0x0f) | (srcval << 4);
750			src += src_step;
751			srcbit += srcbit_step;
752			if (srcbit == 8) {
753				src++;
754				srcbit = 0;
755			}
756			dst += dst_step;
757			dstbit += dstbit_step;
758			if (dstbit == 8) {
759				dst++;
760				dstbit = 0;
761			}
762		}
763	} else {
764		width /= 8;
765		while (samples-- > 0) {
766			memcpy(dst, src, width);
767			src += src_step;
768			dst += dst_step;
769		}
770	}
771	return 0;
772}