feeder_chain.c revision 267985
1/*-
2 * Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifdef HAVE_KERNEL_OPTION_HEADERS
28#include "opt_snd.h"
29#endif
30
31#include <dev/sound/pcm/sound.h>
32
33#include "feeder_if.h"
34
35SND_DECLARE_FILE("$FreeBSD: head/sys/dev/sound/pcm/feeder_chain.c 267985 2014-06-27 22:05:21Z gjb $");
36
37/* chain state */
38struct feeder_chain_state {
39	uint32_t afmt;				/* audio format */
40	uint32_t rate;				/* sampling rate */
41	struct pcmchan_matrix *matrix;		/* matrix map */
42};
43
44/*
45 * chain descriptor that will be passed around from the beginning until the
46 * end of chain process.
47 */
48struct feeder_chain_desc {
49	struct feeder_chain_state origin;	/* original state */
50	struct feeder_chain_state current;	/* current state */
51	struct feeder_chain_state target;	/* target state */
52	struct pcm_feederdesc desc;		/* feeder descriptor */
53	uint32_t afmt_ne;			/* prefered native endian */
54	int mode;				/* chain mode */
55	int use_eq;				/* need EQ? */
56	int use_matrix;				/* need channel matrixing? */
57	int use_volume;				/* need softpcmvol? */
58	int dummy;				/* dummy passthrough */
59	int expensive;				/* possibly expensive */
60};
61
62#define FEEDER_CHAIN_LEAN		0
63#define FEEDER_CHAIN_16			1
64#define FEEDER_CHAIN_32			2
65#define FEEDER_CHAIN_MULTI		3
66#define FEEDER_CHAIN_FULLMULTI		4
67#define FEEDER_CHAIN_LAST		5
68
69#if defined(SND_FEEDER_FULL_MULTIFORMAT)
70#define FEEDER_CHAIN_DEFAULT		FEEDER_CHAIN_FULLMULTI
71#elif defined(SND_FEEDER_MULTIFORMAT)
72#define FEEDER_CHAIN_DEFAULT		FEEDER_CHAIN_MULTI
73#else
74#define FEEDER_CHAIN_DEFAULT		FEEDER_CHAIN_LEAN
75#endif
76
77/*
78 * List of prefered formats that might be required during
79 * processing. It will be decided through snd_fmtbest().
80 */
81
82/* 'Lean' mode, signed 16 or 32 bit native endian. */
83static uint32_t feeder_chain_formats_lean[] = {
84	AFMT_S16_NE, AFMT_S32_NE,
85	0
86};
87
88/* Force everything to signed 16 bit native endian. */
89static uint32_t feeder_chain_formats_16[] = {
90	AFMT_S16_NE,
91	0
92};
93
94/* Force everything to signed 32 bit native endian. */
95static uint32_t feeder_chain_formats_32[] = {
96	AFMT_S32_NE,
97	0
98};
99
100/* Multiple choices, all except 8 bit. */
101static uint32_t feeder_chain_formats_multi[] = {
102	AFMT_S16_LE, AFMT_S16_BE, AFMT_U16_LE, AFMT_U16_BE,
103	AFMT_S24_LE, AFMT_S24_BE, AFMT_U24_LE, AFMT_U24_BE,
104	AFMT_S32_LE, AFMT_S32_BE, AFMT_U32_LE, AFMT_U32_BE,
105	0
106};
107
108/* Everything that is convertible. */
109static uint32_t feeder_chain_formats_fullmulti[] = {
110	AFMT_S8, AFMT_U8,
111	AFMT_S16_LE, AFMT_S16_BE, AFMT_U16_LE, AFMT_U16_BE,
112	AFMT_S24_LE, AFMT_S24_BE, AFMT_U24_LE, AFMT_U24_BE,
113	AFMT_S32_LE, AFMT_S32_BE, AFMT_U32_LE, AFMT_U32_BE,
114	0
115};
116
117static uint32_t *feeder_chain_formats[FEEDER_CHAIN_LAST] = {
118	[FEEDER_CHAIN_LEAN]      = feeder_chain_formats_lean,
119	[FEEDER_CHAIN_16]        = feeder_chain_formats_16,
120	[FEEDER_CHAIN_32]        = feeder_chain_formats_32,
121	[FEEDER_CHAIN_MULTI]     = feeder_chain_formats_multi,
122	[FEEDER_CHAIN_FULLMULTI] = feeder_chain_formats_fullmulti
123};
124
125static int feeder_chain_mode = FEEDER_CHAIN_DEFAULT;
126
127#if defined(_KERNEL) && defined(SND_DEBUG) && defined(SND_FEEDER_FULL_MULTIFORMAT)
128TUNABLE_INT("hw.snd.feeder_chain_mode", &feeder_chain_mode);
129SYSCTL_INT(_hw_snd, OID_AUTO, feeder_chain_mode, CTLFLAG_RW,
130    &feeder_chain_mode, 0,
131    "feeder chain mode "
132    "(0=lean, 1=16bit, 2=32bit, 3=multiformat, 4=fullmultiformat)");
133#endif
134
135/*
136 * feeder_build_format(): Chain any format converter.
137 */
138static int
139feeder_build_format(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
140{
141	struct feeder_class *fc;
142	struct pcm_feederdesc *desc;
143	int ret;
144
145	desc = &(cdesc->desc);
146	desc->type = FEEDER_FORMAT;
147	desc->in = 0;
148	desc->out = 0;
149	desc->flags = 0;
150
151	fc = feeder_getclass(desc);
152	if (fc == NULL) {
153		device_printf(c->dev,
154		    "%s(): can't find feeder_format\n", __func__);
155		return (ENOTSUP);
156	}
157
158	desc->in = cdesc->current.afmt;
159	desc->out = cdesc->target.afmt;
160
161	ret = chn_addfeeder(c, fc, desc);
162	if (ret != 0) {
163		device_printf(c->dev,
164		    "%s(): can't add feeder_format\n", __func__);
165		return (ret);
166	}
167
168	c->feederflags |= 1 << FEEDER_FORMAT;
169
170	cdesc->current.afmt = cdesc->target.afmt;
171
172	return (0);
173}
174
175/*
176 * feeder_build_formatne(): Chain format converter that suite best for native
177 *                          endian format.
178 */
179static int
180feeder_build_formatne(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
181{
182	struct feeder_chain_state otarget;
183	int ret;
184
185	if (cdesc->afmt_ne == 0 ||
186	    AFMT_ENCODING(cdesc->current.afmt) == cdesc->afmt_ne)
187		return (0);
188
189	otarget = cdesc->target;
190	cdesc->target = cdesc->current;
191	cdesc->target.afmt = SND_FORMAT(cdesc->afmt_ne,
192	    cdesc->current.matrix->channels, cdesc->current.matrix->ext);
193
194	ret = feeder_build_format(c, cdesc);
195	if (ret != 0)
196		return (ret);
197
198	cdesc->target = otarget;
199
200	return (0);
201}
202
203/*
204 * feeder_build_rate(): Chain sample rate converter.
205 */
206static int
207feeder_build_rate(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
208{
209	struct feeder_class *fc;
210	struct pcm_feeder *f;
211	struct pcm_feederdesc *desc;
212	int ret;
213
214	ret = feeder_build_formatne(c, cdesc);
215	if (ret != 0)
216		return (ret);
217
218	desc = &(cdesc->desc);
219	desc->type = FEEDER_RATE;
220	desc->in = 0;
221	desc->out = 0;
222	desc->flags = 0;
223
224	fc = feeder_getclass(desc);
225	if (fc == NULL) {
226		device_printf(c->dev,
227		    "%s(): can't find feeder_rate\n", __func__);
228		return (ENOTSUP);
229	}
230
231	desc->in = cdesc->current.afmt;
232	desc->out = desc->in;
233
234	ret = chn_addfeeder(c, fc, desc);
235	if (ret != 0) {
236		device_printf(c->dev,
237		    "%s(): can't add feeder_rate\n", __func__);
238		return (ret);
239	}
240
241	f = c->feeder;
242
243	/*
244	 * If in 'dummy' mode (possibly due to passthrough mode), set the
245	 * conversion quality to the lowest possible (should be fastest) since
246	 * listener won't be hearing anything. Theoretically we can just
247	 * disable it, but that will cause weird runtime behaviour:
248	 * application appear to play something that is either too fast or too
249	 * slow.
250	 */
251	if (cdesc->dummy != 0) {
252		ret = FEEDER_SET(f, FEEDRATE_QUALITY, 0);
253		if (ret != 0) {
254			device_printf(c->dev,
255			    "%s(): can't set resampling quality\n", __func__);
256			return (ret);
257		}
258	}
259
260	ret = FEEDER_SET(f, FEEDRATE_SRC, cdesc->current.rate);
261	if (ret != 0) {
262		device_printf(c->dev,
263		    "%s(): can't set source rate\n", __func__);
264		return (ret);
265	}
266
267	ret = FEEDER_SET(f, FEEDRATE_DST, cdesc->target.rate);
268	if (ret != 0) {
269		device_printf(c->dev,
270		    "%s(): can't set destination rate\n", __func__);
271		return (ret);
272	}
273
274	c->feederflags |= 1 << FEEDER_RATE;
275
276	cdesc->current.rate = cdesc->target.rate;
277
278	return (0);
279}
280
281/*
282 * feeder_build_matrix(): Chain channel matrixing converter.
283 */
284static int
285feeder_build_matrix(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
286{
287	struct feeder_class *fc;
288	struct pcm_feeder *f;
289	struct pcm_feederdesc *desc;
290	int ret;
291
292	ret = feeder_build_formatne(c, cdesc);
293	if (ret != 0)
294		return (ret);
295
296	desc = &(cdesc->desc);
297	desc->type = FEEDER_MATRIX;
298	desc->in = 0;
299	desc->out = 0;
300	desc->flags = 0;
301
302	fc = feeder_getclass(desc);
303	if (fc == NULL) {
304		device_printf(c->dev,
305		    "%s(): can't find feeder_matrix\n", __func__);
306		return (ENOTSUP);
307	}
308
309	desc->in = cdesc->current.afmt;
310	desc->out = SND_FORMAT(cdesc->current.afmt,
311	    cdesc->target.matrix->channels, cdesc->target.matrix->ext);
312
313	ret = chn_addfeeder(c, fc, desc);
314	if (ret != 0) {
315		device_printf(c->dev,
316		    "%s(): can't add feeder_matrix\n", __func__);
317		return (ret);
318	}
319
320	f = c->feeder;
321	ret = feeder_matrix_setup(f, cdesc->current.matrix,
322	    cdesc->target.matrix);
323	if (ret != 0) {
324		device_printf(c->dev,
325		    "%s(): feeder_matrix_setup() failed\n", __func__);
326		return (ret);
327	}
328
329	c->feederflags |= 1 << FEEDER_MATRIX;
330
331	cdesc->current.afmt = desc->out;
332	cdesc->current.matrix = cdesc->target.matrix;
333	cdesc->use_matrix = 0;
334
335	return (0);
336}
337
338/*
339 * feeder_build_volume(): Chain soft volume.
340 */
341static int
342feeder_build_volume(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
343{
344	struct feeder_class *fc;
345	struct pcm_feeder *f;
346	struct pcm_feederdesc *desc;
347	int ret;
348
349	ret = feeder_build_formatne(c, cdesc);
350	if (ret != 0)
351		return (ret);
352
353	desc = &(cdesc->desc);
354	desc->type = FEEDER_VOLUME;
355	desc->in = 0;
356	desc->out = 0;
357	desc->flags = 0;
358
359	fc = feeder_getclass(desc);
360	if (fc == NULL) {
361		device_printf(c->dev,
362		    "%s(): can't find feeder_volume\n", __func__);
363		return (ENOTSUP);
364	}
365
366	desc->in = cdesc->current.afmt;
367	desc->out = desc->in;
368
369	ret = chn_addfeeder(c, fc, desc);
370	if (ret != 0) {
371		device_printf(c->dev,
372		    "%s(): can't add feeder_volume\n", __func__);
373		return (ret);
374	}
375
376	f = c->feeder;
377
378	/*
379	 * If in 'dummy' mode (possibly due to passthrough mode), set BYPASS
380	 * mode since listener won't be hearing anything. Theoretically we can
381	 * just disable it, but that will confuse volume per channel mixer.
382	 */
383	if (cdesc->dummy != 0) {
384		ret = FEEDER_SET(f, FEEDVOLUME_STATE, FEEDVOLUME_BYPASS);
385		if (ret != 0) {
386			device_printf(c->dev,
387			    "%s(): can't set volume bypass\n", __func__);
388			return (ret);
389		}
390	}
391
392	ret = feeder_volume_apply_matrix(f, cdesc->current.matrix);
393	if (ret != 0) {
394		device_printf(c->dev,
395		    "%s(): feeder_volume_apply_matrix() failed\n", __func__);
396		return (ret);
397	}
398
399	c->feederflags |= 1 << FEEDER_VOLUME;
400
401	cdesc->use_volume = 0;
402
403	return (0);
404}
405
406/*
407 * feeder_build_eq(): Chain parametric software equalizer.
408 */
409static int
410feeder_build_eq(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
411{
412	struct feeder_class *fc;
413	struct pcm_feeder *f;
414	struct pcm_feederdesc *desc;
415	int ret;
416
417	ret = feeder_build_formatne(c, cdesc);
418	if (ret != 0)
419		return (ret);
420
421	desc = &(cdesc->desc);
422	desc->type = FEEDER_EQ;
423	desc->in = 0;
424	desc->out = 0;
425	desc->flags = 0;
426
427	fc = feeder_getclass(desc);
428	if (fc == NULL) {
429		device_printf(c->dev,
430		    "%s(): can't find feeder_eq\n", __func__);
431		return (ENOTSUP);
432	}
433
434	desc->in = cdesc->current.afmt;
435	desc->out = desc->in;
436
437	ret = chn_addfeeder(c, fc, desc);
438	if (ret != 0) {
439		device_printf(c->dev,
440		    "%s(): can't add feeder_eq\n", __func__);
441		return (ret);
442	}
443
444	f = c->feeder;
445
446	ret = FEEDER_SET(f, FEEDEQ_RATE, cdesc->current.rate);
447	if (ret != 0) {
448		device_printf(c->dev,
449		    "%s(): can't set rate on feeder_eq\n", __func__);
450		return (ret);
451	}
452
453	c->feederflags |= 1 << FEEDER_EQ;
454
455	cdesc->use_eq = 0;
456
457	return (0);
458}
459
460/*
461 * feeder_build_root(): Chain root feeder, the top, father of all.
462 */
463static int
464feeder_build_root(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
465{
466	struct feeder_class *fc;
467	int ret;
468
469	fc = feeder_getclass(NULL);
470	if (fc == NULL) {
471		device_printf(c->dev,
472		    "%s(): can't find feeder_root\n", __func__);
473		return (ENOTSUP);
474	}
475
476	ret = chn_addfeeder(c, fc, NULL);
477	if (ret != 0) {
478		device_printf(c->dev,
479		    "%s(): can't add feeder_root\n", __func__);
480		return (ret);
481	}
482
483	c->feederflags |= 1 << FEEDER_ROOT;
484
485	c->feeder->desc->in = cdesc->current.afmt;
486	c->feeder->desc->out = cdesc->current.afmt;
487
488	return (0);
489}
490
491/*
492 * feeder_build_mixer(): Chain software mixer for virtual channels.
493 */
494static int
495feeder_build_mixer(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
496{
497	struct feeder_class *fc;
498	struct pcm_feederdesc *desc;
499	int ret;
500
501	desc = &(cdesc->desc);
502	desc->type = FEEDER_MIXER;
503	desc->in = 0;
504	desc->out = 0;
505	desc->flags = 0;
506
507	fc = feeder_getclass(desc);
508	if (fc == NULL) {
509		device_printf(c->dev,
510		    "%s(): can't find feeder_mixer\n", __func__);
511		return (ENOTSUP);
512	}
513
514	desc->in = cdesc->current.afmt;
515	desc->out = desc->in;
516
517	ret = chn_addfeeder(c, fc, desc);
518	if (ret != 0) {
519		device_printf(c->dev,
520		    "%s(): can't add feeder_mixer\n", __func__);
521		return (ret);
522	}
523
524	c->feederflags |= 1 << FEEDER_MIXER;
525
526	return (0);
527}
528
529/* Macrosses to ease our job doing stuffs later. */
530#define FEEDER_BW(c, t)		((c)->t.matrix->channels * (c)->t.rate)
531
532#define FEEDRATE_UP(c)		((c)->target.rate > (c)->current.rate)
533#define FEEDRATE_DOWN(c)	((c)->target.rate < (c)->current.rate)
534#define FEEDRATE_REQUIRED(c)	(FEEDRATE_UP(c) || FEEDRATE_DOWN(c))
535
536#define FEEDMATRIX_UP(c)	((c)->target.matrix->channels >		\
537				 (c)->current.matrix->channels)
538#define FEEDMATRIX_DOWN(c)	((c)->target.matrix->channels <		\
539				 (c)->current.matrix->channels)
540#define FEEDMATRIX_REQUIRED(c)	(FEEDMATRIX_UP(c) ||			\
541				 FEEDMATRIX_DOWN(c) || (c)->use_matrix != 0)
542
543#define FEEDFORMAT_REQUIRED(c)	(AFMT_ENCODING((c)->current.afmt) !=	\
544				 AFMT_ENCODING((c)->target.afmt))
545
546#define FEEDVOLUME_REQUIRED(c)	((c)->use_volume != 0)
547
548#define FEEDEQ_VALIDRATE(c, t)	(feeder_eq_validrate((c)->t.rate) != 0)
549#define FEEDEQ_ECONOMY(c)	(FEEDER_BW(c, current) < FEEDER_BW(c, target))
550#define FEEDEQ_REQUIRED(c)	((c)->use_eq != 0 &&			\
551				 FEEDEQ_VALIDRATE(c, current))
552
553#define FEEDFORMAT_NE_REQUIRED(c)					\
554	((c)->afmt_ne != AFMT_S32_NE &&					\
555	(((c)->mode == FEEDER_CHAIN_16 &&				\
556	AFMT_ENCODING((c)->current.afmt) != AFMT_S16_NE) ||		\
557	((c)->mode == FEEDER_CHAIN_32 &&				\
558	AFMT_ENCODING((c)->current.afmt) != AFMT_S32_NE) ||		\
559	(c)->mode == FEEDER_CHAIN_FULLMULTI ||				\
560	((c)->mode == FEEDER_CHAIN_MULTI &&				\
561	((c)->current.afmt & AFMT_8BIT)) ||				\
562	((c)->mode == FEEDER_CHAIN_LEAN &&				\
563	!((c)->current.afmt & (AFMT_S16_NE | AFMT_S32_NE)))))
564
565int
566feeder_chain(struct pcm_channel *c)
567{
568	struct snddev_info *d;
569	struct pcmchan_caps *caps;
570	struct feeder_chain_desc cdesc;
571	struct pcmchan_matrix *hwmatrix, *softmatrix;
572	uint32_t hwfmt, softfmt;
573	int ret;
574
575	CHN_LOCKASSERT(c);
576
577	/* Remove everything first. */
578	while (chn_removefeeder(c) == 0)
579		;
580
581	KASSERT(c->feeder == NULL, ("feeder chain not empty"));
582
583	/* clear and populate chain descriptor. */
584	bzero(&cdesc, sizeof(cdesc));
585
586	switch (feeder_chain_mode) {
587	case FEEDER_CHAIN_LEAN:
588	case FEEDER_CHAIN_16:
589	case FEEDER_CHAIN_32:
590#if defined(SND_FEEDER_MULTIFORMAT) || defined(SND_FEEDER_FULL_MULTIFORMAT)
591	case FEEDER_CHAIN_MULTI:
592#endif
593#if defined(SND_FEEDER_FULL_MULTIFORMAT)
594	case FEEDER_CHAIN_FULLMULTI:
595#endif
596		break;
597	default:
598		feeder_chain_mode = FEEDER_CHAIN_DEFAULT;
599		break;
600	}
601
602	cdesc.mode = feeder_chain_mode;
603	cdesc.expensive = 1;	/* XXX faster.. */
604
605#define VCHAN_PASSTHROUGH(c)	(((c)->flags & (CHN_F_VIRTUAL |		\
606				 CHN_F_PASSTHROUGH)) ==			\
607				 (CHN_F_VIRTUAL | CHN_F_PASSTHROUGH))
608
609	/* Get the best possible hardware format. */
610	if (VCHAN_PASSTHROUGH(c))
611		hwfmt = c->parentchannel->format;
612	else {
613		caps = chn_getcaps(c);
614		if (caps == NULL || caps->fmtlist == NULL) {
615			device_printf(c->dev,
616			    "%s(): failed to get channel caps\n", __func__);
617			return (ENODEV);
618		}
619
620		if ((c->format & AFMT_PASSTHROUGH) &&
621		    !snd_fmtvalid(c->format, caps->fmtlist))
622			return (ENODEV);
623
624		hwfmt = snd_fmtbest(c->format, caps->fmtlist);
625		if (hwfmt == 0 || !snd_fmtvalid(hwfmt, caps->fmtlist)) {
626			device_printf(c->dev,
627			    "%s(): invalid hardware format 0x%08x\n",
628			    __func__, hwfmt);
629			{
630				int i;
631				for (i = 0; caps->fmtlist[i] != 0; i++)
632					printf("0x%08x\n", caps->fmtlist[i]);
633				printf("Req: 0x%08x\n", c->format);
634			}
635			return (ENODEV);
636		}
637	}
638
639	/*
640	 * The 'hardware' possibly have different intepretation of channel
641	 * matrixing, so get it first .....
642	 */
643	hwmatrix = CHANNEL_GETMATRIX(c->methods, c->devinfo, hwfmt);
644	if (hwmatrix == NULL) {
645		device_printf(c->dev,
646		    "%s(): failed to acquire hw matrix [0x%08x]\n",
647		    __func__, hwfmt);
648		return (ENODEV);
649	}
650	/* ..... and rebuild hwfmt. */
651	hwfmt = SND_FORMAT(hwfmt, hwmatrix->channels, hwmatrix->ext);
652
653	/* Reset and rebuild default channel format/matrix map. */
654	softfmt = c->format;
655	softmatrix = &c->matrix;
656	if (softmatrix->channels != AFMT_CHANNEL(softfmt) ||
657	    softmatrix->ext != AFMT_EXTCHANNEL(softfmt)) {
658		softmatrix = feeder_matrix_format_map(softfmt);
659		if (softmatrix == NULL) {
660			device_printf(c->dev,
661			    "%s(): failed to acquire soft matrix [0x%08x]\n",
662			    __func__, softfmt);
663			return (ENODEV);
664		}
665		c->matrix = *softmatrix;
666		c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
667	}
668	softfmt = SND_FORMAT(softfmt, softmatrix->channels, softmatrix->ext);
669	if (softfmt != c->format)
670		device_printf(c->dev,
671		    "%s(): WARNING: %s Soft format 0x%08x -> 0x%08x\n",
672		    __func__, CHN_DIRSTR(c), c->format, softfmt);
673
674	/*
675	 * PLAY and REC are opposite.
676	 */
677	if (c->direction == PCMDIR_PLAY) {
678		cdesc.origin.afmt    = softfmt;
679		cdesc.origin.matrix  = softmatrix;
680		cdesc.origin.rate    = c->speed;
681		cdesc.target.afmt    = hwfmt;
682		cdesc.target.matrix  = hwmatrix;
683		cdesc.target.rate    = sndbuf_getspd(c->bufhard);
684	} else {
685		cdesc.origin.afmt    = hwfmt;
686		cdesc.origin.matrix  = hwmatrix;
687		cdesc.origin.rate    = sndbuf_getspd(c->bufhard);
688		cdesc.target.afmt    = softfmt;
689		cdesc.target.matrix  = softmatrix;
690		cdesc.target.rate    = c->speed;
691	}
692
693	d = c->parentsnddev;
694
695	/*
696	 * If channel is in bitperfect or passthrough mode, make it appear
697	 * that 'origin' and 'target' identical, skipping mostly chain
698	 * procedures.
699	 */
700	if (CHN_BITPERFECT(c) || (c->format & AFMT_PASSTHROUGH)) {
701		if (c->direction == PCMDIR_PLAY)
702			cdesc.origin = cdesc.target;
703		else
704			cdesc.target = cdesc.origin;
705		c->format = cdesc.target.afmt;
706		c->speed  = cdesc.target.rate;
707	} else {
708		/* hwfmt is not convertible, so 'dummy' it. */
709		if (hwfmt & AFMT_PASSTHROUGH)
710			cdesc.dummy = 1;
711
712		if ((softfmt & AFMT_CONVERTIBLE) &&
713		    (((d->flags & SD_F_VPC) && !(c->flags & CHN_F_HAS_VCHAN)) ||
714		    (!(d->flags & SD_F_VPC) && (d->flags & SD_F_SOFTPCMVOL) &&
715		    !(c->flags & CHN_F_VIRTUAL))))
716			cdesc.use_volume = 1;
717
718		if (feeder_matrix_compare(cdesc.origin.matrix,
719		    cdesc.target.matrix) != 0)
720			cdesc.use_matrix = 1;
721
722		/* Soft EQ only applicable for PLAY. */
723		if (cdesc.dummy == 0 &&
724		    c->direction == PCMDIR_PLAY && (d->flags & SD_F_EQ) &&
725		    (((d->flags & SD_F_EQ_PC) &&
726		    !(c->flags & CHN_F_HAS_VCHAN)) ||
727		    (!(d->flags & SD_F_EQ_PC) && !(c->flags & CHN_F_VIRTUAL))))
728			cdesc.use_eq = 1;
729
730		if (FEEDFORMAT_NE_REQUIRED(&cdesc)) {
731			cdesc.afmt_ne =
732			    (cdesc.dummy != 0) ?
733			    snd_fmtbest(AFMT_ENCODING(softfmt),
734			    feeder_chain_formats[cdesc.mode]) :
735			    snd_fmtbest(AFMT_ENCODING(cdesc.target.afmt),
736			    feeder_chain_formats[cdesc.mode]);
737			if (cdesc.afmt_ne == 0) {
738				device_printf(c->dev,
739				    "%s(): snd_fmtbest failed!\n", __func__);
740				cdesc.afmt_ne =
741				    (((cdesc.dummy != 0) ? softfmt :
742				    cdesc.target.afmt) &
743				    (AFMT_24BIT | AFMT_32BIT)) ?
744				    AFMT_S32_NE : AFMT_S16_NE;
745			}
746		}
747	}
748
749	cdesc.current = cdesc.origin;
750
751	/* Build everything. */
752
753	c->feederflags = 0;
754
755#define FEEDER_BUILD(t)	do {						\
756	ret = feeder_build_##t(c, &cdesc);				\
757	if (ret != 0)							\
758		return (ret);						\
759	} while (0)
760
761	if (!(c->flags & CHN_F_HAS_VCHAN) || c->direction == PCMDIR_REC)
762		FEEDER_BUILD(root);
763	else if (c->direction == PCMDIR_PLAY && (c->flags & CHN_F_HAS_VCHAN))
764		FEEDER_BUILD(mixer);
765	else
766		return (ENOTSUP);
767
768	/*
769	 * The basic idea is: The smaller the bandwidth, the cheaper the
770	 * conversion process, with following constraints:-
771	 *
772	 * 1) Almost all feeders work best in 16/32 native endian.
773	 * 2) Try to avoid 8bit feeders due to poor dynamic range.
774	 * 3) Avoid volume, format, matrix and rate in BITPERFECT or
775	 *    PASSTHROUGH mode.
776	 * 4) Try putting volume before EQ or rate. Should help to
777	 *    avoid/reduce possible clipping.
778	 * 5) EQ require specific, valid rate, unless it allow sloppy
779	 *    conversion.
780	 */
781	if (FEEDMATRIX_UP(&cdesc)) {
782		if (FEEDEQ_REQUIRED(&cdesc) &&
783		    (!FEEDEQ_VALIDRATE(&cdesc, target) ||
784		    (cdesc.expensive == 0 && FEEDEQ_ECONOMY(&cdesc))))
785			FEEDER_BUILD(eq);
786		if (FEEDRATE_REQUIRED(&cdesc))
787			FEEDER_BUILD(rate);
788		FEEDER_BUILD(matrix);
789		if (FEEDVOLUME_REQUIRED(&cdesc))
790			FEEDER_BUILD(volume);
791		if (FEEDEQ_REQUIRED(&cdesc))
792			FEEDER_BUILD(eq);
793	} else if (FEEDMATRIX_DOWN(&cdesc)) {
794		FEEDER_BUILD(matrix);
795		if (FEEDVOLUME_REQUIRED(&cdesc))
796			FEEDER_BUILD(volume);
797		if (FEEDEQ_REQUIRED(&cdesc) &&
798		    (!FEEDEQ_VALIDRATE(&cdesc, target) ||
799		    FEEDEQ_ECONOMY(&cdesc)))
800			FEEDER_BUILD(eq);
801		if (FEEDRATE_REQUIRED(&cdesc))
802			FEEDER_BUILD(rate);
803		if (FEEDEQ_REQUIRED(&cdesc))
804			FEEDER_BUILD(eq);
805	} else {
806		if (FEEDRATE_DOWN(&cdesc)) {
807			if (FEEDEQ_REQUIRED(&cdesc) &&
808			    !FEEDEQ_VALIDRATE(&cdesc, target)) {
809				if (FEEDVOLUME_REQUIRED(&cdesc))
810					FEEDER_BUILD(volume);
811				FEEDER_BUILD(eq);
812			}
813			FEEDER_BUILD(rate);
814		}
815		if (FEEDMATRIX_REQUIRED(&cdesc))
816			FEEDER_BUILD(matrix);
817		if (FEEDVOLUME_REQUIRED(&cdesc))
818			FEEDER_BUILD(volume);
819		if (FEEDRATE_UP(&cdesc)) {
820			if (FEEDEQ_REQUIRED(&cdesc) &&
821			    !FEEDEQ_VALIDRATE(&cdesc, target))
822				FEEDER_BUILD(eq);
823			FEEDER_BUILD(rate);
824		}
825		if (FEEDEQ_REQUIRED(&cdesc))
826			FEEDER_BUILD(eq);
827	}
828
829	if (FEEDFORMAT_REQUIRED(&cdesc))
830		FEEDER_BUILD(format);
831
832	if (c->direction == PCMDIR_REC && (c->flags & CHN_F_HAS_VCHAN))
833		FEEDER_BUILD(mixer);
834
835	sndbuf_setfmt(c->bufsoft, c->format);
836	sndbuf_setspd(c->bufsoft, c->speed);
837
838	sndbuf_setfmt(c->bufhard, hwfmt);
839
840	chn_syncstate(c);
841
842	return (0);
843}
844