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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
24#include <linux/slab.h>
25#include <linux/time.h>
26#include <linux/vmalloc.h>
27#include <sound/core.h>
28#include <sound/pcm.h>
29#include <sound/pcm_params.h>
30#include "pcm_plugin.h"
31
32#define snd_pcm_plug_first(plug) ((plug)->runtime->oss.plugin_first)
33#define snd_pcm_plug_last(plug) ((plug)->runtime->oss.plugin_last)
34
35/*
36 *  because some cards might have rates "very close", we ignore
37 *  all "resampling" requests within +-5%
38 */
39static int rate_match(unsigned int src_rate, unsigned int dst_rate)
40{
41	unsigned int low = (src_rate * 95) / 100;
42	unsigned int high = (src_rate * 105) / 100;
43	return dst_rate >= low && dst_rate <= high;
44}
45
46static int snd_pcm_plugin_alloc(struct snd_pcm_plugin *plugin, snd_pcm_uframes_t frames)
47{
48	struct snd_pcm_plugin_format *format;
49	ssize_t width;
50	size_t size;
51	unsigned int channel;
52	struct snd_pcm_plugin_channel *c;
53
54	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK) {
55		format = &plugin->src_format;
56	} else {
57		format = &plugin->dst_format;
58	}
59	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
60		return width;
61	size = frames * format->channels * width;
62	if (snd_BUG_ON(size % 8))
63		return -ENXIO;
64	size /= 8;
65	if (plugin->buf_frames < frames) {
66		vfree(plugin->buf);
67		plugin->buf = vmalloc(size);
68		plugin->buf_frames = frames;
69	}
70	if (!plugin->buf) {
71		plugin->buf_frames = 0;
72		return -ENOMEM;
73	}
74	c = plugin->buf_channels;
75	if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
76		for (channel = 0; channel < format->channels; channel++, c++) {
77			c->frames = frames;
78			c->enabled = 1;
79			c->wanted = 0;
80			c->area.addr = plugin->buf;
81			c->area.first = channel * width;
82			c->area.step = format->channels * width;
83		}
84	} else if (plugin->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) {
85		if (snd_BUG_ON(size % format->channels))
86			return -EINVAL;
87		size /= format->channels;
88		for (channel = 0; channel < format->channels; channel++, c++) {
89			c->frames = frames;
90			c->enabled = 1;
91			c->wanted = 0;
92			c->area.addr = plugin->buf + (channel * size);
93			c->area.first = 0;
94			c->area.step = width;
95		}
96	} else
97		return -EINVAL;
98	return 0;
99}
100
101int snd_pcm_plug_alloc(struct snd_pcm_substream *plug, snd_pcm_uframes_t frames)
102{
103	int err;
104	if (snd_BUG_ON(!snd_pcm_plug_first(plug)))
105		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			if (snd_BUG_ON(frames <= 0))
112				return -ENXIO;
113			plugin = plugin->next;
114			err = snd_pcm_plugin_alloc(plugin, frames);
115			if (err < 0)
116				return err;
117		}
118	} else {
119		struct snd_pcm_plugin *plugin = snd_pcm_plug_last(plug);
120		while (plugin->prev) {
121			if (plugin->src_frames)
122				frames = plugin->src_frames(plugin, frames);
123			if (snd_BUG_ON(frames <= 0))
124				return -ENXIO;
125			plugin = plugin->prev;
126			err = snd_pcm_plugin_alloc(plugin, frames);
127			if (err < 0)
128				return err;
129		}
130	}
131	return 0;
132}
133
134
135snd_pcm_sframes_t snd_pcm_plugin_client_channels(struct snd_pcm_plugin *plugin,
136				       snd_pcm_uframes_t frames,
137				       struct snd_pcm_plugin_channel **channels)
138{
139	*channels = plugin->buf_channels;
140	return frames;
141}
142
143int snd_pcm_plugin_build(struct snd_pcm_substream *plug,
144			 const char *name,
145			 struct snd_pcm_plugin_format *src_format,
146			 struct snd_pcm_plugin_format *dst_format,
147			 size_t extra,
148			 struct snd_pcm_plugin **ret)
149{
150	struct snd_pcm_plugin *plugin;
151	unsigned int channels;
152
153	if (snd_BUG_ON(!plug))
154		return -ENXIO;
155	if (snd_BUG_ON(!src_format || !dst_format))
156		return -ENXIO;
157	plugin = kzalloc(sizeof(*plugin) + extra, GFP_KERNEL);
158	if (plugin == NULL)
159		return -ENOMEM;
160	plugin->name = name;
161	plugin->plug = plug;
162	plugin->stream = snd_pcm_plug_stream(plug);
163	plugin->access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
164	plugin->src_format = *src_format;
165	plugin->src_width = snd_pcm_format_physical_width(src_format->format);
166	snd_BUG_ON(plugin->src_width <= 0);
167	plugin->dst_format = *dst_format;
168	plugin->dst_width = snd_pcm_format_physical_width(dst_format->format);
169	snd_BUG_ON(plugin->dst_width <= 0);
170	if (plugin->stream == SNDRV_PCM_STREAM_PLAYBACK)
171		channels = src_format->channels;
172	else
173		channels = dst_format->channels;
174	plugin->buf_channels = kcalloc(channels, sizeof(*plugin->buf_channels), GFP_KERNEL);
175	if (plugin->buf_channels == NULL) {
176		snd_pcm_plugin_free(plugin);
177		return -ENOMEM;
178	}
179	plugin->client_channels = snd_pcm_plugin_client_channels;
180	*ret = plugin;
181	return 0;
182}
183
184int snd_pcm_plugin_free(struct snd_pcm_plugin *plugin)
185{
186	if (! plugin)
187		return 0;
188	if (plugin->private_free)
189		plugin->private_free(plugin);
190	kfree(plugin->buf_channels);
191	vfree(plugin->buf);
192	kfree(plugin);
193	return 0;
194}
195
196snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t drv_frames)
197{
198	struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
199	int stream = snd_pcm_plug_stream(plug);
200
201	if (snd_BUG_ON(!plug))
202		return -ENXIO;
203	if (drv_frames == 0)
204		return 0;
205	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
206		plugin = snd_pcm_plug_last(plug);
207		while (plugin && drv_frames > 0) {
208			plugin_prev = plugin->prev;
209			if (plugin->src_frames)
210				drv_frames = plugin->src_frames(plugin, drv_frames);
211			plugin = plugin_prev;
212		}
213	} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
214		plugin = snd_pcm_plug_first(plug);
215		while (plugin && drv_frames > 0) {
216			plugin_next = plugin->next;
217			if (plugin->dst_frames)
218				drv_frames = plugin->dst_frames(plugin, drv_frames);
219			plugin = plugin_next;
220		}
221	} else
222		snd_BUG();
223	return drv_frames;
224}
225
226snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pcm_uframes_t clt_frames)
227{
228	struct snd_pcm_plugin *plugin, *plugin_prev, *plugin_next;
229	snd_pcm_sframes_t frames;
230	int stream = snd_pcm_plug_stream(plug);
231
232	if (snd_BUG_ON(!plug))
233		return -ENXIO;
234	if (clt_frames == 0)
235		return 0;
236	frames = clt_frames;
237	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
238		plugin = snd_pcm_plug_first(plug);
239		while (plugin && frames > 0) {
240			plugin_next = plugin->next;
241			if (plugin->dst_frames) {
242				frames = plugin->dst_frames(plugin, frames);
243				if (frames < 0)
244					return frames;
245			}
246			plugin = plugin_next;
247		}
248	} else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
249		plugin = snd_pcm_plug_last(plug);
250		while (plugin) {
251			plugin_prev = plugin->prev;
252			if (plugin->src_frames) {
253				frames = plugin->src_frames(plugin, frames);
254				if (frames < 0)
255					return frames;
256			}
257			plugin = plugin_prev;
258		}
259	} else
260		snd_BUG();
261	return frames;
262}
263
264static int snd_pcm_plug_formats(struct snd_mask *mask, int format)
265{
266	struct snd_mask formats = *mask;
267	u64 linfmts = (SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S8 |
268		       SNDRV_PCM_FMTBIT_U16_LE | SNDRV_PCM_FMTBIT_S16_LE |
269		       SNDRV_PCM_FMTBIT_U16_BE | SNDRV_PCM_FMTBIT_S16_BE |
270		       SNDRV_PCM_FMTBIT_U24_LE | SNDRV_PCM_FMTBIT_S24_LE |
271		       SNDRV_PCM_FMTBIT_U24_BE | SNDRV_PCM_FMTBIT_S24_BE |
272		       SNDRV_PCM_FMTBIT_U24_3LE | SNDRV_PCM_FMTBIT_S24_3LE |
273		       SNDRV_PCM_FMTBIT_U24_3BE | SNDRV_PCM_FMTBIT_S24_3BE |
274		       SNDRV_PCM_FMTBIT_U32_LE | SNDRV_PCM_FMTBIT_S32_LE |
275		       SNDRV_PCM_FMTBIT_U32_BE | SNDRV_PCM_FMTBIT_S32_BE);
276	snd_mask_set(&formats, SNDRV_PCM_FORMAT_MU_LAW);
277
278	if (formats.bits[0] & (u32)linfmts)
279		formats.bits[0] |= (u32)linfmts;
280	if (formats.bits[1] & (u32)(linfmts >> 32))
281		formats.bits[1] |= (u32)(linfmts >> 32);
282	return snd_mask_test(&formats, format);
283}
284
285static int preferred_formats[] = {
286	SNDRV_PCM_FORMAT_S16_LE,
287	SNDRV_PCM_FORMAT_S16_BE,
288	SNDRV_PCM_FORMAT_U16_LE,
289	SNDRV_PCM_FORMAT_U16_BE,
290	SNDRV_PCM_FORMAT_S24_3LE,
291	SNDRV_PCM_FORMAT_S24_3BE,
292	SNDRV_PCM_FORMAT_U24_3LE,
293	SNDRV_PCM_FORMAT_U24_3BE,
294	SNDRV_PCM_FORMAT_S24_LE,
295	SNDRV_PCM_FORMAT_S24_BE,
296	SNDRV_PCM_FORMAT_U24_LE,
297	SNDRV_PCM_FORMAT_U24_BE,
298	SNDRV_PCM_FORMAT_S32_LE,
299	SNDRV_PCM_FORMAT_S32_BE,
300	SNDRV_PCM_FORMAT_U32_LE,
301	SNDRV_PCM_FORMAT_U32_BE,
302	SNDRV_PCM_FORMAT_S8,
303	SNDRV_PCM_FORMAT_U8
304};
305
306int snd_pcm_plug_slave_format(int format, struct snd_mask *format_mask)
307{
308	int i;
309
310	if (snd_mask_test(format_mask, format))
311		return format;
312	if (! snd_pcm_plug_formats(format_mask, format))
313		return -EINVAL;
314	if (snd_pcm_format_linear(format)) {
315		unsigned int width = snd_pcm_format_width(format);
316		int unsignd = snd_pcm_format_unsigned(format) > 0;
317		int big = snd_pcm_format_big_endian(format) > 0;
318		unsigned int badness, best = -1;
319		int best_format = -1;
320		for (i = 0; i < ARRAY_SIZE(preferred_formats); i++) {
321			int f = preferred_formats[i];
322			unsigned int w;
323			if (!snd_mask_test(format_mask, f))
324				continue;
325			w = snd_pcm_format_width(f);
326			if (w >= width)
327				badness = w - width;
328			else
329				badness = width - w + 32;
330			badness += snd_pcm_format_unsigned(f) != unsignd;
331			badness += snd_pcm_format_big_endian(f) != big;
332			if (badness < best) {
333				best_format = f;
334				best = badness;
335			}
336		}
337		return best_format >= 0 ? best_format : -EINVAL;
338	} else {
339		switch (format) {
340		case SNDRV_PCM_FORMAT_MU_LAW:
341			for (i = 0; i < ARRAY_SIZE(preferred_formats); ++i) {
342				int format1 = preferred_formats[i];
343				if (snd_mask_test(format_mask, format1))
344					return format1;
345			}
346		default:
347			return -EINVAL;
348		}
349	}
350}
351
352int snd_pcm_plug_format_plugins(struct snd_pcm_substream *plug,
353				struct snd_pcm_hw_params *params,
354				struct snd_pcm_hw_params *slave_params)
355{
356	struct snd_pcm_plugin_format tmpformat;
357	struct snd_pcm_plugin_format dstformat;
358	struct snd_pcm_plugin_format srcformat;
359	int src_access, dst_access;
360	struct snd_pcm_plugin *plugin = NULL;
361	int err;
362	int stream = snd_pcm_plug_stream(plug);
363	int slave_interleaved = (params_channels(slave_params) == 1 ||
364				 params_access(slave_params) == SNDRV_PCM_ACCESS_RW_INTERLEAVED);
365
366	switch (stream) {
367	case SNDRV_PCM_STREAM_PLAYBACK:
368		dstformat.format = params_format(slave_params);
369		dstformat.rate = params_rate(slave_params);
370		dstformat.channels = params_channels(slave_params);
371		srcformat.format = params_format(params);
372		srcformat.rate = params_rate(params);
373		srcformat.channels = params_channels(params);
374		src_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
375		dst_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
376						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
377		break;
378	case SNDRV_PCM_STREAM_CAPTURE:
379		dstformat.format = params_format(params);
380		dstformat.rate = params_rate(params);
381		dstformat.channels = params_channels(params);
382		srcformat.format = params_format(slave_params);
383		srcformat.rate = params_rate(slave_params);
384		srcformat.channels = params_channels(slave_params);
385		src_access = (slave_interleaved ? SNDRV_PCM_ACCESS_RW_INTERLEAVED :
386						  SNDRV_PCM_ACCESS_RW_NONINTERLEAVED);
387		dst_access = SNDRV_PCM_ACCESS_RW_INTERLEAVED;
388		break;
389	default:
390		snd_BUG();
391		return -EINVAL;
392	}
393	tmpformat = srcformat;
394
395	pdprintf("srcformat: format=%i, rate=%i, channels=%i\n",
396		 srcformat.format,
397		 srcformat.rate,
398		 srcformat.channels);
399	pdprintf("dstformat: format=%i, rate=%i, channels=%i\n",
400		 dstformat.format,
401		 dstformat.rate,
402		 dstformat.channels);
403
404	/* Format change (linearization) */
405	if (! rate_match(srcformat.rate, dstformat.rate) &&
406	    ! snd_pcm_format_linear(srcformat.format)) {
407		if (srcformat.format != SNDRV_PCM_FORMAT_MU_LAW)
408			return -EINVAL;
409		tmpformat.format = SNDRV_PCM_FORMAT_S16;
410		err = snd_pcm_plugin_build_mulaw(plug,
411						 &srcformat, &tmpformat,
412						 &plugin);
413		if (err < 0)
414			return err;
415		err = snd_pcm_plugin_append(plugin);
416		if (err < 0) {
417			snd_pcm_plugin_free(plugin);
418			return err;
419		}
420		srcformat = tmpformat;
421		src_access = dst_access;
422	}
423
424	/* channels reduction */
425	if (srcformat.channels > dstformat.channels) {
426		tmpformat.channels = dstformat.channels;
427		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
428		pdprintf("channels reduction: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
429		if (err < 0)
430			return err;
431		err = snd_pcm_plugin_append(plugin);
432		if (err < 0) {
433			snd_pcm_plugin_free(plugin);
434			return err;
435		}
436		srcformat = tmpformat;
437		src_access = dst_access;
438	}
439
440	/* rate resampling */
441	if (!rate_match(srcformat.rate, dstformat.rate)) {
442		if (srcformat.format != SNDRV_PCM_FORMAT_S16) {
443			/* convert to S16 for resampling */
444			tmpformat.format = SNDRV_PCM_FORMAT_S16;
445			err = snd_pcm_plugin_build_linear(plug,
446							  &srcformat, &tmpformat,
447							  &plugin);
448			if (err < 0)
449				return err;
450			err = snd_pcm_plugin_append(plugin);
451			if (err < 0) {
452				snd_pcm_plugin_free(plugin);
453				return err;
454			}
455			srcformat = tmpformat;
456			src_access = dst_access;
457		}
458		tmpformat.rate = dstformat.rate;
459        	err = snd_pcm_plugin_build_rate(plug,
460        					&srcformat, &tmpformat,
461						&plugin);
462		pdprintf("rate down resampling: src=%i, dst=%i returns %i\n", srcformat.rate, tmpformat.rate, err);
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
474	/* format change */
475	if (srcformat.format != dstformat.format) {
476		tmpformat.format = dstformat.format;
477		if (srcformat.format == SNDRV_PCM_FORMAT_MU_LAW ||
478		    tmpformat.format == SNDRV_PCM_FORMAT_MU_LAW) {
479			err = snd_pcm_plugin_build_mulaw(plug,
480							 &srcformat, &tmpformat,
481							 &plugin);
482		}
483		else if (snd_pcm_format_linear(srcformat.format) &&
484			 snd_pcm_format_linear(tmpformat.format)) {
485			err = snd_pcm_plugin_build_linear(plug,
486							  &srcformat, &tmpformat,
487							  &plugin);
488		}
489		else
490			return -EINVAL;
491		pdprintf("format change: src=%i, dst=%i returns %i\n", srcformat.format, tmpformat.format, err);
492		if (err < 0)
493			return err;
494		err = snd_pcm_plugin_append(plugin);
495		if (err < 0) {
496			snd_pcm_plugin_free(plugin);
497			return err;
498		}
499		srcformat = tmpformat;
500		src_access = dst_access;
501	}
502
503	/* channels extension */
504	if (srcformat.channels < dstformat.channels) {
505		tmpformat.channels = dstformat.channels;
506		err = snd_pcm_plugin_build_route(plug, &srcformat, &tmpformat, &plugin);
507		pdprintf("channels extension: src=%i, dst=%i returns %i\n", srcformat.channels, tmpformat.channels, err);
508		if (err < 0)
509			return err;
510		err = snd_pcm_plugin_append(plugin);
511		if (err < 0) {
512			snd_pcm_plugin_free(plugin);
513			return err;
514		}
515		srcformat = tmpformat;
516		src_access = dst_access;
517	}
518
519	/* de-interleave */
520	if (src_access != dst_access) {
521		err = snd_pcm_plugin_build_copy(plug,
522						&srcformat,
523						&tmpformat,
524						&plugin);
525		pdprintf("interleave change (copy: returns %i)\n", err);
526		if (err < 0)
527			return err;
528		err = snd_pcm_plugin_append(plugin);
529		if (err < 0) {
530			snd_pcm_plugin_free(plugin);
531			return err;
532		}
533	}
534
535	return 0;
536}
537
538snd_pcm_sframes_t snd_pcm_plug_client_channels_buf(struct snd_pcm_substream *plug,
539					 char *buf,
540					 snd_pcm_uframes_t count,
541					 struct snd_pcm_plugin_channel **channels)
542{
543	struct snd_pcm_plugin *plugin;
544	struct snd_pcm_plugin_channel *v;
545	struct snd_pcm_plugin_format *format;
546	int width, nchannels, channel;
547	int stream = snd_pcm_plug_stream(plug);
548
549	if (snd_BUG_ON(!buf))
550		return -ENXIO;
551	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
552		plugin = snd_pcm_plug_first(plug);
553		format = &plugin->src_format;
554	} else {
555		plugin = snd_pcm_plug_last(plug);
556		format = &plugin->dst_format;
557	}
558	v = plugin->buf_channels;
559	*channels = v;
560	if ((width = snd_pcm_format_physical_width(format->format)) < 0)
561		return width;
562	nchannels = format->channels;
563	if (snd_BUG_ON(plugin->access != SNDRV_PCM_ACCESS_RW_INTERLEAVED &&
564		       format->channels > 1))
565		return -ENXIO;
566	for (channel = 0; channel < nchannels; channel++, v++) {
567		v->frames = count;
568		v->enabled = 1;
569		v->wanted = (stream == SNDRV_PCM_STREAM_CAPTURE);
570		v->area.addr = buf;
571		v->area.first = channel * width;
572		v->area.step = nchannels * width;
573	}
574	return count;
575}
576
577snd_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)
578{
579	struct snd_pcm_plugin *plugin, *next;
580	struct snd_pcm_plugin_channel *dst_channels;
581	int err;
582	snd_pcm_sframes_t frames = size;
583
584	plugin = snd_pcm_plug_first(plug);
585	while (plugin && frames > 0) {
586		if ((next = plugin->next) != NULL) {
587			snd_pcm_sframes_t frames1 = frames;
588			if (plugin->dst_frames)
589				frames1 = plugin->dst_frames(plugin, frames);
590			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
591				return err;
592			}
593			if (err != frames1) {
594				frames = err;
595				if (plugin->src_frames)
596					frames = plugin->src_frames(plugin, frames1);
597			}
598		} else
599			dst_channels = NULL;
600		pdprintf("write plugin: %s, %li\n", plugin->name, frames);
601		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
602			return frames;
603		src_channels = dst_channels;
604		plugin = next;
605	}
606	return snd_pcm_plug_client_size(plug, frames);
607}
608
609snd_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)
610{
611	struct snd_pcm_plugin *plugin, *next;
612	struct snd_pcm_plugin_channel *src_channels, *dst_channels;
613	snd_pcm_sframes_t frames = size;
614	int err;
615
616	frames = snd_pcm_plug_slave_size(plug, frames);
617	if (frames < 0)
618		return frames;
619
620	src_channels = NULL;
621	plugin = snd_pcm_plug_first(plug);
622	while (plugin && frames > 0) {
623		if ((next = plugin->next) != NULL) {
624			if ((err = plugin->client_channels(plugin, frames, &dst_channels)) < 0) {
625				return err;
626			}
627			frames = err;
628		} else {
629			dst_channels = dst_channels_final;
630		}
631		pdprintf("read plugin: %s, %li\n", plugin->name, frames);
632		if ((frames = plugin->transfer(plugin, src_channels, dst_channels, frames)) < 0)
633			return frames;
634		plugin = next;
635		src_channels = dst_channels;
636	}
637	return frames;
638}
639
640int snd_pcm_area_silence(const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
641			 size_t samples, int format)
642{
643	unsigned char *dst;
644	unsigned int dst_step;
645	int width;
646	const unsigned char *silence;
647	if (!dst_area->addr)
648		return 0;
649	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
650	width = snd_pcm_format_physical_width(format);
651	if (width <= 0)
652		return -EINVAL;
653	if (dst_area->step == (unsigned int) width && width >= 8)
654		return snd_pcm_format_set_silence(format, dst, samples);
655	silence = snd_pcm_format_silence_64(format);
656	if (! silence)
657		return -EINVAL;
658	dst_step = dst_area->step / 8;
659	if (width == 4) {
660		/* Ima ADPCM */
661		int dstbit = dst_area->first % 8;
662		int dstbit_step = dst_area->step % 8;
663		while (samples-- > 0) {
664			if (dstbit)
665				*dst &= 0xf0;
666			else
667				*dst &= 0x0f;
668			dst += dst_step;
669			dstbit += dstbit_step;
670			if (dstbit == 8) {
671				dst++;
672				dstbit = 0;
673			}
674		}
675	} else {
676		width /= 8;
677		while (samples-- > 0) {
678			memcpy(dst, silence, width);
679			dst += dst_step;
680		}
681	}
682	return 0;
683}
684
685int snd_pcm_area_copy(const struct snd_pcm_channel_area *src_area, size_t src_offset,
686		      const struct snd_pcm_channel_area *dst_area, size_t dst_offset,
687		      size_t samples, int format)
688{
689	char *src, *dst;
690	int width;
691	int src_step, dst_step;
692	src = src_area->addr + (src_area->first + src_area->step * src_offset) / 8;
693	if (!src_area->addr)
694		return snd_pcm_area_silence(dst_area, dst_offset, samples, format);
695	dst = dst_area->addr + (dst_area->first + dst_area->step * dst_offset) / 8;
696	if (!dst_area->addr)
697		return 0;
698	width = snd_pcm_format_physical_width(format);
699	if (width <= 0)
700		return -EINVAL;
701	if (src_area->step == (unsigned int) width &&
702	    dst_area->step == (unsigned int) width && width >= 8) {
703		size_t bytes = samples * width / 8;
704		memcpy(dst, src, bytes);
705		return 0;
706	}
707	src_step = src_area->step / 8;
708	dst_step = dst_area->step / 8;
709	if (width == 4) {
710		/* Ima ADPCM */
711		int srcbit = src_area->first % 8;
712		int srcbit_step = src_area->step % 8;
713		int dstbit = dst_area->first % 8;
714		int dstbit_step = dst_area->step % 8;
715		while (samples-- > 0) {
716			unsigned char srcval;
717			if (srcbit)
718				srcval = *src & 0x0f;
719			else
720				srcval = (*src & 0xf0) >> 4;
721			if (dstbit)
722				*dst = (*dst & 0xf0) | srcval;
723			else
724				*dst = (*dst & 0x0f) | (srcval << 4);
725			src += src_step;
726			srcbit += srcbit_step;
727			if (srcbit == 8) {
728				src++;
729				srcbit = 0;
730			}
731			dst += dst_step;
732			dstbit += dstbit_step;
733			if (dstbit == 8) {
734				dst++;
735				dstbit = 0;
736			}
737		}
738	} else {
739		width /= 8;
740		while (samples-- > 0) {
741			memcpy(dst, src, width);
742			src += src_step;
743			dst += dst_step;
744		}
745	}
746	return 0;
747}
748