xref: /freebsd/sys/dev/sound/pcm/feeder_chain.c (revision 92dcd20222a2674ba31ae09865da19d948992994)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008-2009 Ariff Abdullah <ariff@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #ifdef HAVE_KERNEL_OPTION_HEADERS
30 #include "opt_snd.h"
31 #endif
32 
33 #include <dev/sound/pcm/sound.h>
34 
35 #include "feeder_if.h"
36 
37 /* chain state */
38 struct 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  */
48 struct 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;			/* preferred 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 preferred 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. */
83 static 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. */
89 static uint32_t feeder_chain_formats_16[] = {
90 	AFMT_S16_NE,
91 	0
92 };
93 
94 /* Force everything to signed 32 bit native endian. */
95 static uint32_t feeder_chain_formats_32[] = {
96 	AFMT_S32_NE,
97 	0
98 };
99 
100 /* Multiple choices, all except 8 bit. */
101 static 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 	AFMT_F32_LE, AFMT_F32_BE,
106 	0
107 };
108 
109 /* Everything that is convertible. */
110 static uint32_t feeder_chain_formats_fullmulti[] = {
111 	AFMT_S8, AFMT_U8,
112 	AFMT_S16_LE, AFMT_S16_BE, AFMT_U16_LE, AFMT_U16_BE,
113 	AFMT_S24_LE, AFMT_S24_BE, AFMT_U24_LE, AFMT_U24_BE,
114 	AFMT_S32_LE, AFMT_S32_BE, AFMT_U32_LE, AFMT_U32_BE,
115 	AFMT_F32_LE, AFMT_F32_BE,
116 	0
117 };
118 
119 static uint32_t *feeder_chain_formats[FEEDER_CHAIN_LAST] = {
120 	[FEEDER_CHAIN_LEAN]      = feeder_chain_formats_lean,
121 	[FEEDER_CHAIN_16]        = feeder_chain_formats_16,
122 	[FEEDER_CHAIN_32]        = feeder_chain_formats_32,
123 	[FEEDER_CHAIN_MULTI]     = feeder_chain_formats_multi,
124 	[FEEDER_CHAIN_FULLMULTI] = feeder_chain_formats_fullmulti
125 };
126 
127 static int feeder_chain_mode = FEEDER_CHAIN_DEFAULT;
128 
129 #if defined(_KERNEL) && defined(SND_DEBUG) && defined(SND_FEEDER_FULL_MULTIFORMAT)
130 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_chain_mode, CTLFLAG_RWTUN,
131     &feeder_chain_mode, 0,
132     "feeder chain mode "
133     "(0=lean, 1=16bit, 2=32bit, 3=multiformat, 4=fullmultiformat)");
134 #endif
135 
136 /*
137  * feeder_build_format(): Chain any format converter.
138  */
139 static int
feeder_build_format(struct pcm_channel * c,struct feeder_chain_desc * cdesc)140 feeder_build_format(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
141 {
142 	struct feeder_class *fc;
143 	struct pcm_feederdesc *desc;
144 	int ret;
145 
146 	desc = &(cdesc->desc);
147 	desc->in = 0;
148 	desc->out = 0;
149 
150 	fc = feeder_getclass(FEEDER_FORMAT);
151 	if (fc == NULL) {
152 		device_printf(c->dev,
153 		    "%s(): can't find feeder_format\n", __func__);
154 		return (ENOTSUP);
155 	}
156 
157 	desc->in = cdesc->current.afmt;
158 	desc->out = cdesc->target.afmt;
159 
160 	ret = feeder_add(c, fc, desc);
161 	if (ret != 0) {
162 		device_printf(c->dev,
163 		    "%s(): can't add feeder_format\n", __func__);
164 		return (ret);
165 	}
166 
167 	c->feederflags |= 1 << FEEDER_FORMAT;
168 
169 	cdesc->current.afmt = cdesc->target.afmt;
170 
171 	return (0);
172 }
173 
174 /*
175  * feeder_build_formatne(): Chain format converter that suite best for native
176  *                          endian format.
177  */
178 static int
feeder_build_formatne(struct pcm_channel * c,struct feeder_chain_desc * cdesc)179 feeder_build_formatne(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
180 {
181 	struct feeder_chain_state otarget;
182 	int ret;
183 
184 	if (cdesc->afmt_ne == 0 ||
185 	    AFMT_ENCODING(cdesc->current.afmt) == cdesc->afmt_ne)
186 		return (0);
187 
188 	otarget = cdesc->target;
189 	cdesc->target = cdesc->current;
190 	cdesc->target.afmt = SND_FORMAT(cdesc->afmt_ne,
191 	    cdesc->current.matrix->channels, cdesc->current.matrix->ext);
192 
193 	ret = feeder_build_format(c, cdesc);
194 	if (ret != 0)
195 		return (ret);
196 
197 	cdesc->target = otarget;
198 
199 	return (0);
200 }
201 
202 /*
203  * feeder_build_rate(): Chain sample rate converter.
204  */
205 static int
feeder_build_rate(struct pcm_channel * c,struct feeder_chain_desc * cdesc)206 feeder_build_rate(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
207 {
208 	struct feeder_class *fc;
209 	struct pcm_feeder *f;
210 	struct pcm_feederdesc *desc;
211 	int ret;
212 
213 	ret = feeder_build_formatne(c, cdesc);
214 	if (ret != 0)
215 		return (ret);
216 
217 	desc = &(cdesc->desc);
218 	desc->in = 0;
219 	desc->out = 0;
220 
221 	fc = feeder_getclass(FEEDER_RATE);
222 	if (fc == NULL) {
223 		device_printf(c->dev,
224 		    "%s(): can't find feeder_rate\n", __func__);
225 		return (ENOTSUP);
226 	}
227 
228 	desc->in = cdesc->current.afmt;
229 	desc->out = desc->in;
230 
231 	ret = feeder_add(c, fc, desc);
232 	if (ret != 0) {
233 		device_printf(c->dev,
234 		    "%s(): can't add feeder_rate\n", __func__);
235 		return (ret);
236 	}
237 
238 	f = c->feeder;
239 
240 	/*
241 	 * If in 'dummy' mode (possibly due to passthrough mode), set the
242 	 * conversion quality to the lowest possible (should be fastest) since
243 	 * listener won't be hearing anything. Theoretically we can just
244 	 * disable it, but that will cause weird runtime behaviour:
245 	 * application appear to play something that is either too fast or too
246 	 * slow.
247 	 */
248 	if (cdesc->dummy != 0) {
249 		ret = FEEDER_SET(f, FEEDRATE_QUALITY, 0);
250 		if (ret != 0) {
251 			device_printf(c->dev,
252 			    "%s(): can't set resampling quality\n", __func__);
253 			return (ret);
254 		}
255 	}
256 
257 	ret = FEEDER_SET(f, FEEDRATE_SRC, cdesc->current.rate);
258 	if (ret != 0) {
259 		device_printf(c->dev,
260 		    "%s(): can't set source rate\n", __func__);
261 		return (ret);
262 	}
263 
264 	ret = FEEDER_SET(f, FEEDRATE_DST, cdesc->target.rate);
265 	if (ret != 0) {
266 		device_printf(c->dev,
267 		    "%s(): can't set destination rate\n", __func__);
268 		return (ret);
269 	}
270 
271 	c->feederflags |= 1 << FEEDER_RATE;
272 
273 	cdesc->current.rate = cdesc->target.rate;
274 
275 	return (0);
276 }
277 
278 /*
279  * feeder_build_matrix(): Chain channel matrixing converter.
280  */
281 static int
feeder_build_matrix(struct pcm_channel * c,struct feeder_chain_desc * cdesc)282 feeder_build_matrix(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
283 {
284 	struct feeder_class *fc;
285 	struct pcm_feeder *f;
286 	struct pcm_feederdesc *desc;
287 	int ret;
288 
289 	ret = feeder_build_formatne(c, cdesc);
290 	if (ret != 0)
291 		return (ret);
292 
293 	desc = &(cdesc->desc);
294 	desc->in = 0;
295 	desc->out = 0;
296 
297 	fc = feeder_getclass(FEEDER_MATRIX);
298 	if (fc == NULL) {
299 		device_printf(c->dev,
300 		    "%s(): can't find feeder_matrix\n", __func__);
301 		return (ENOTSUP);
302 	}
303 
304 	desc->in = cdesc->current.afmt;
305 	desc->out = SND_FORMAT(cdesc->current.afmt,
306 	    cdesc->target.matrix->channels, cdesc->target.matrix->ext);
307 
308 	ret = feeder_add(c, fc, desc);
309 	if (ret != 0) {
310 		device_printf(c->dev,
311 		    "%s(): can't add feeder_matrix\n", __func__);
312 		return (ret);
313 	}
314 
315 	f = c->feeder;
316 	ret = feeder_matrix_setup(f, cdesc->current.matrix,
317 	    cdesc->target.matrix);
318 	if (ret != 0) {
319 		device_printf(c->dev,
320 		    "%s(): feeder_matrix_setup() failed\n", __func__);
321 		return (ret);
322 	}
323 
324 	c->feederflags |= 1 << FEEDER_MATRIX;
325 
326 	cdesc->current.afmt = desc->out;
327 	cdesc->current.matrix = cdesc->target.matrix;
328 	cdesc->use_matrix = 0;
329 
330 	return (0);
331 }
332 
333 /*
334  * feeder_build_volume(): Chain soft volume.
335  */
336 static int
feeder_build_volume(struct pcm_channel * c,struct feeder_chain_desc * cdesc)337 feeder_build_volume(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
338 {
339 	struct feeder_class *fc;
340 	struct pcm_feeder *f;
341 	struct pcm_feederdesc *desc;
342 	int ret;
343 
344 	ret = feeder_build_formatne(c, cdesc);
345 	if (ret != 0)
346 		return (ret);
347 
348 	desc = &(cdesc->desc);
349 	desc->in = 0;
350 	desc->out = 0;
351 
352 	fc = feeder_getclass(FEEDER_VOLUME);
353 	if (fc == NULL) {
354 		device_printf(c->dev,
355 		    "%s(): can't find feeder_volume\n", __func__);
356 		return (ENOTSUP);
357 	}
358 
359 	desc->in = cdesc->current.afmt;
360 	desc->out = desc->in;
361 
362 	ret = feeder_add(c, fc, desc);
363 	if (ret != 0) {
364 		device_printf(c->dev,
365 		    "%s(): can't add feeder_volume\n", __func__);
366 		return (ret);
367 	}
368 
369 	f = c->feeder;
370 
371 	/*
372 	 * If in 'dummy' mode (possibly due to passthrough mode), set BYPASS
373 	 * mode since listener won't be hearing anything. Theoretically we can
374 	 * just disable it, but that will confuse volume per channel mixer.
375 	 */
376 	if (cdesc->dummy != 0) {
377 		ret = FEEDER_SET(f, FEEDVOLUME_STATE, FEEDVOLUME_BYPASS);
378 		if (ret != 0) {
379 			device_printf(c->dev,
380 			    "%s(): can't set volume bypass\n", __func__);
381 			return (ret);
382 		}
383 	}
384 
385 	ret = feeder_volume_apply_matrix(f, cdesc->current.matrix);
386 	if (ret != 0) {
387 		device_printf(c->dev,
388 		    "%s(): feeder_volume_apply_matrix() failed\n", __func__);
389 		return (ret);
390 	}
391 
392 	c->feederflags |= 1 << FEEDER_VOLUME;
393 
394 	cdesc->use_volume = 0;
395 
396 	return (0);
397 }
398 
399 /*
400  * feeder_build_eq(): Chain parametric software equalizer.
401  */
402 static int
feeder_build_eq(struct pcm_channel * c,struct feeder_chain_desc * cdesc)403 feeder_build_eq(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
404 {
405 	struct feeder_class *fc;
406 	struct pcm_feeder *f;
407 	struct pcm_feederdesc *desc;
408 	int ret;
409 
410 	ret = feeder_build_formatne(c, cdesc);
411 	if (ret != 0)
412 		return (ret);
413 
414 	desc = &(cdesc->desc);
415 	desc->in = 0;
416 	desc->out = 0;
417 
418 	fc = feeder_getclass(FEEDER_EQ);
419 	if (fc == NULL) {
420 		device_printf(c->dev,
421 		    "%s(): can't find feeder_eq\n", __func__);
422 		return (ENOTSUP);
423 	}
424 
425 	desc->in = cdesc->current.afmt;
426 	desc->out = desc->in;
427 
428 	ret = feeder_add(c, fc, desc);
429 	if (ret != 0) {
430 		device_printf(c->dev,
431 		    "%s(): can't add feeder_eq\n", __func__);
432 		return (ret);
433 	}
434 
435 	f = c->feeder;
436 
437 	ret = FEEDER_SET(f, FEEDEQ_RATE, cdesc->current.rate);
438 	if (ret != 0) {
439 		device_printf(c->dev,
440 		    "%s(): can't set rate on feeder_eq\n", __func__);
441 		return (ret);
442 	}
443 
444 	c->feederflags |= 1 << FEEDER_EQ;
445 
446 	cdesc->use_eq = 0;
447 
448 	return (0);
449 }
450 
451 /*
452  * feeder_build_root(): Chain root feeder, the top, father of all.
453  */
454 static int
feeder_build_root(struct pcm_channel * c,struct feeder_chain_desc * cdesc)455 feeder_build_root(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
456 {
457 	struct feeder_class *fc;
458 	int ret;
459 
460 	fc = feeder_getclass(FEEDER_ROOT);
461 	if (fc == NULL) {
462 		device_printf(c->dev,
463 		    "%s(): can't find feeder_root\n", __func__);
464 		return (ENOTSUP);
465 	}
466 
467 	ret = feeder_add(c, fc, NULL);
468 	if (ret != 0) {
469 		device_printf(c->dev,
470 		    "%s(): can't add feeder_root\n", __func__);
471 		return (ret);
472 	}
473 
474 	c->feederflags |= 1 << FEEDER_ROOT;
475 
476 	c->feeder->desc->in = cdesc->current.afmt;
477 	c->feeder->desc->out = cdesc->current.afmt;
478 
479 	return (0);
480 }
481 
482 /*
483  * feeder_build_mixer(): Chain software mixer for virtual channels.
484  */
485 static int
feeder_build_mixer(struct pcm_channel * c,struct feeder_chain_desc * cdesc)486 feeder_build_mixer(struct pcm_channel *c, struct feeder_chain_desc *cdesc)
487 {
488 	struct feeder_class *fc;
489 	struct pcm_feederdesc *desc;
490 	int ret;
491 
492 	desc = &(cdesc->desc);
493 	desc->in = 0;
494 	desc->out = 0;
495 
496 	fc = feeder_getclass(FEEDER_MIXER);
497 	if (fc == NULL) {
498 		device_printf(c->dev,
499 		    "%s(): can't find feeder_mixer\n", __func__);
500 		return (ENOTSUP);
501 	}
502 
503 	desc->in = cdesc->current.afmt;
504 	desc->out = desc->in;
505 
506 	ret = feeder_add(c, fc, desc);
507 	if (ret != 0) {
508 		device_printf(c->dev,
509 		    "%s(): can't add feeder_mixer\n", __func__);
510 		return (ret);
511 	}
512 
513 	c->feederflags |= 1 << FEEDER_MIXER;
514 
515 	return (0);
516 }
517 
518 /* Macrosses to ease our job doing stuffs later. */
519 #define FEEDER_BW(c, t)		((c)->t.matrix->channels * (c)->t.rate)
520 
521 #define FEEDRATE_UP(c)		((c)->target.rate > (c)->current.rate)
522 #define FEEDRATE_DOWN(c)	((c)->target.rate < (c)->current.rate)
523 #define FEEDRATE_REQUIRED(c)	(FEEDRATE_UP(c) || FEEDRATE_DOWN(c))
524 
525 #define FEEDMATRIX_UP(c)	((c)->target.matrix->channels >		\
526 				 (c)->current.matrix->channels)
527 #define FEEDMATRIX_DOWN(c)	((c)->target.matrix->channels <		\
528 				 (c)->current.matrix->channels)
529 #define FEEDMATRIX_REQUIRED(c)	(FEEDMATRIX_UP(c) ||			\
530 				 FEEDMATRIX_DOWN(c) || (c)->use_matrix != 0)
531 
532 #define FEEDFORMAT_REQUIRED(c)	(AFMT_ENCODING((c)->current.afmt) !=	\
533 				 AFMT_ENCODING((c)->target.afmt))
534 
535 #define FEEDVOLUME_REQUIRED(c)	((c)->use_volume != 0)
536 
537 #define FEEDEQ_VALIDRATE(c, t)	(feeder_eq_validrate((c)->t.rate) != 0)
538 #define FEEDEQ_ECONOMY(c)	(FEEDER_BW(c, current) < FEEDER_BW(c, target))
539 #define FEEDEQ_REQUIRED(c)	((c)->use_eq != 0 &&			\
540 				 FEEDEQ_VALIDRATE(c, current))
541 
542 #define FEEDFORMAT_NE_REQUIRED(c)					\
543 	((c)->afmt_ne != AFMT_S32_NE &&					\
544 	(((c)->mode == FEEDER_CHAIN_16 &&				\
545 	AFMT_ENCODING((c)->current.afmt) != AFMT_S16_NE) ||		\
546 	((c)->mode == FEEDER_CHAIN_32 &&				\
547 	AFMT_ENCODING((c)->current.afmt) != AFMT_S32_NE) ||		\
548 	(c)->mode == FEEDER_CHAIN_FULLMULTI ||				\
549 	((c)->mode == FEEDER_CHAIN_MULTI &&				\
550 	((c)->current.afmt & AFMT_8BIT)) ||				\
551 	((c)->mode == FEEDER_CHAIN_LEAN &&				\
552 	!((c)->current.afmt & (AFMT_S16_NE | AFMT_S32_NE)))))
553 
554 static void
feeder_default_matrix(struct pcmchan_matrix * m,uint32_t fmt,int id)555 feeder_default_matrix(struct pcmchan_matrix *m, uint32_t fmt, int id)
556 {
557 	int x;
558 
559 	memset(m, 0, sizeof(*m));
560 
561 	m->id = id;
562 	m->channels = AFMT_CHANNEL(fmt);
563 	m->ext = AFMT_EXTCHANNEL(fmt);
564 	for (x = 0; x != SND_CHN_T_MAX; x++)
565 		m->offset[x] = -1;
566 }
567 
568 int
feeder_chain(struct pcm_channel * c)569 feeder_chain(struct pcm_channel *c)
570 {
571 	struct snddev_info *d;
572 	struct pcmchan_caps *caps;
573 	struct feeder_chain_desc cdesc;
574 	struct pcmchan_matrix *hwmatrix, *softmatrix;
575 	uint32_t hwfmt, softfmt;
576 	int ret;
577 
578 	CHN_LOCKASSERT(c);
579 
580 	/* Remove everything first. */
581 	feeder_remove(c);
582 
583 	KASSERT(c->feeder == NULL, ("feeder chain not empty"));
584 
585 	/* clear and populate chain descriptor. */
586 	bzero(&cdesc, sizeof(cdesc));
587 
588 	switch (feeder_chain_mode) {
589 	case FEEDER_CHAIN_LEAN:
590 	case FEEDER_CHAIN_16:
591 	case FEEDER_CHAIN_32:
592 #if defined(SND_FEEDER_MULTIFORMAT) || defined(SND_FEEDER_FULL_MULTIFORMAT)
593 	case FEEDER_CHAIN_MULTI:
594 #endif
595 #if defined(SND_FEEDER_FULL_MULTIFORMAT)
596 	case FEEDER_CHAIN_FULLMULTI:
597 #endif
598 		break;
599 	default:
600 		feeder_chain_mode = FEEDER_CHAIN_DEFAULT;
601 		break;
602 	}
603 
604 	cdesc.mode = feeder_chain_mode;
605 	cdesc.expensive = 1;	/* XXX faster.. */
606 
607 #define VCHAN_PASSTHROUGH(c)	(((c)->flags & (CHN_F_VIRTUAL |		\
608 				 CHN_F_PASSTHROUGH)) ==			\
609 				 (CHN_F_VIRTUAL | CHN_F_PASSTHROUGH))
610 
611 	/* Get the best possible hardware format. */
612 	if (VCHAN_PASSTHROUGH(c))
613 		hwfmt = c->parentchannel->format;
614 	else {
615 		caps = chn_getcaps(c);
616 		if (caps == NULL || caps->fmtlist == NULL) {
617 			device_printf(c->dev,
618 			    "%s(): failed to get channel caps\n", __func__);
619 			return (ENODEV);
620 		}
621 
622 		if ((c->format & AFMT_PASSTHROUGH) &&
623 		    !snd_fmtvalid(c->format, caps->fmtlist))
624 			return (ENODEV);
625 
626 		hwfmt = snd_fmtbest(c->format, caps->fmtlist);
627 		if (hwfmt == 0 || !snd_fmtvalid(hwfmt, caps->fmtlist)) {
628 			device_printf(c->dev,
629 			    "%s(): invalid hardware format 0x%08x\n",
630 			    __func__, hwfmt);
631 			{
632 				int i;
633 				for (i = 0; caps->fmtlist[i] != 0; i++)
634 					printf("0x%08x\n", caps->fmtlist[i]);
635 				printf("Req: 0x%08x\n", c->format);
636 			}
637 			return (ENODEV);
638 		}
639 	}
640 
641 	/*
642 	 * The 'hardware' possibly have different interpretation of channel
643 	 * matrixing, so get it first .....
644 	 */
645 	hwmatrix = CHANNEL_GETMATRIX(c->methods, c->devinfo, hwfmt);
646 	if (hwmatrix == NULL) {
647 		/* setup a default matrix */
648 		hwmatrix = &c->matrix_scratch;
649 		feeder_default_matrix(hwmatrix, hwfmt,
650 		    SND_CHN_MATRIX_UNKNOWN);
651 	}
652 	/* ..... and rebuild hwfmt. */
653 	hwfmt = SND_FORMAT(hwfmt, hwmatrix->channels, hwmatrix->ext);
654 
655 	/* Reset and rebuild default channel format/matrix map. */
656 	softfmt = c->format;
657 	softmatrix = &c->matrix;
658 	if (softmatrix->channels != AFMT_CHANNEL(softfmt) ||
659 	    softmatrix->ext != AFMT_EXTCHANNEL(softfmt)) {
660 		softmatrix = feeder_matrix_format_map(softfmt);
661 		if (softmatrix == NULL) {
662 			/* setup a default matrix */
663 		  	softmatrix = &c->matrix;
664 			feeder_default_matrix(softmatrix, softfmt,
665 			    SND_CHN_MATRIX_PCMCHANNEL);
666 		} else {
667 			c->matrix = *softmatrix;
668 			c->matrix.id = SND_CHN_MATRIX_PCMCHANNEL;
669 		}
670 	}
671 	softfmt = SND_FORMAT(softfmt, softmatrix->channels, softmatrix->ext);
672 	if (softfmt != c->format)
673 		device_printf(c->dev,
674 		    "%s(): WARNING: %s Soft format 0x%08x -> 0x%08x\n",
675 		    __func__, CHN_DIRSTR(c), c->format, softfmt);
676 
677 	/*
678 	 * PLAY and REC are opposite.
679 	 */
680 	if (c->direction == PCMDIR_PLAY) {
681 		cdesc.origin.afmt    = softfmt;
682 		cdesc.origin.matrix  = softmatrix;
683 		cdesc.origin.rate    = c->speed;
684 		cdesc.target.afmt    = hwfmt;
685 		cdesc.target.matrix  = hwmatrix;
686 		cdesc.target.rate    = c->bufhard->spd;
687 	} else {
688 		cdesc.origin.afmt    = hwfmt;
689 		cdesc.origin.matrix  = hwmatrix;
690 		cdesc.origin.rate    = c->bufhard->spd;
691 		cdesc.target.afmt    = softfmt;
692 		cdesc.target.matrix  = softmatrix;
693 		cdesc.target.rate    = c->speed;
694 	}
695 
696 	d = c->parentsnddev;
697 
698 	/*
699 	 * If channel is in bitperfect or passthrough mode, make it appear
700 	 * that 'origin' and 'target' identical, skipping mostly chain
701 	 * procedures.
702 	 */
703 	if (CHN_BITPERFECT(c) || (c->format & AFMT_PASSTHROUGH)) {
704 		if (c->direction == PCMDIR_PLAY)
705 			cdesc.origin = cdesc.target;
706 		else
707 			cdesc.target = cdesc.origin;
708 		c->format = cdesc.target.afmt;
709 		c->speed  = cdesc.target.rate;
710 	} else {
711 		/*
712 		 * Bail out early if we do not support either of those formats.
713 		 */
714 		if ((cdesc.origin.afmt & AFMT_CONVERTIBLE) == 0 ||
715 		    (cdesc.target.afmt & AFMT_CONVERTIBLE) == 0) {
716 			device_printf(c->dev,
717 			    "%s(): unsupported formats: in=0x%08x, out=0x%08x\n",
718 			    __func__, cdesc.origin.afmt, cdesc.target.afmt);
719 			return (ENODEV);
720 		}
721 
722 		/* hwfmt is not convertible, so 'dummy' it. */
723 		if (hwfmt & AFMT_PASSTHROUGH)
724 			cdesc.dummy = 1;
725 
726 		if ((softfmt & AFMT_CONVERTIBLE) &&
727 		    (((d->flags & SD_F_VPC) && !(c->flags & CHN_F_HAS_VCHAN)) ||
728 		    (!(d->flags & SD_F_VPC) && (d->flags & SD_F_SOFTPCMVOL) &&
729 		    !(c->flags & CHN_F_VIRTUAL))))
730 			cdesc.use_volume = 1;
731 
732 		if (feeder_matrix_compare(cdesc.origin.matrix,
733 		    cdesc.target.matrix) != 0)
734 			cdesc.use_matrix = 1;
735 
736 		/* Soft EQ only applicable for PLAY. */
737 		if (cdesc.dummy == 0 &&
738 		    c->direction == PCMDIR_PLAY && (d->flags & SD_F_EQ) &&
739 		    (((d->flags & SD_F_EQ_PC) &&
740 		    !(c->flags & CHN_F_HAS_VCHAN)) ||
741 		    (!(d->flags & SD_F_EQ_PC) && !(c->flags & CHN_F_VIRTUAL))))
742 			cdesc.use_eq = 1;
743 
744 		if (FEEDFORMAT_NE_REQUIRED(&cdesc)) {
745 			cdesc.afmt_ne =
746 			    (cdesc.dummy != 0) ?
747 			    snd_fmtbest(AFMT_ENCODING(softfmt),
748 			    feeder_chain_formats[cdesc.mode]) :
749 			    snd_fmtbest(AFMT_ENCODING(cdesc.target.afmt),
750 			    feeder_chain_formats[cdesc.mode]);
751 			if (cdesc.afmt_ne == 0) {
752 				device_printf(c->dev,
753 				    "%s(): snd_fmtbest failed!\n", __func__);
754 				cdesc.afmt_ne =
755 				    (((cdesc.dummy != 0) ? softfmt :
756 				    cdesc.target.afmt) &
757 				    (AFMT_24BIT | AFMT_32BIT)) ?
758 				    AFMT_S32_NE : AFMT_S16_NE;
759 			}
760 		}
761 	}
762 
763 	cdesc.current = cdesc.origin;
764 
765 	/* Build everything. */
766 
767 	c->feederflags = 0;
768 
769 #define FEEDER_BUILD(t)	do {						\
770 	ret = feeder_build_##t(c, &cdesc);				\
771 	if (ret != 0)							\
772 		return (ret);						\
773 	} while (0)
774 
775 	if (!(c->flags & CHN_F_HAS_VCHAN) || c->direction == PCMDIR_REC)
776 		FEEDER_BUILD(root);
777 	else if (c->direction == PCMDIR_PLAY && (c->flags & CHN_F_HAS_VCHAN))
778 		FEEDER_BUILD(mixer);
779 	else
780 		return (ENOTSUP);
781 
782 	/*
783 	 * The basic idea is: The smaller the bandwidth, the cheaper the
784 	 * conversion process, with following constraints:-
785 	 *
786 	 * 1) Almost all feeders work best in 16/32 native endian.
787 	 * 2) Try to avoid 8bit feeders due to poor dynamic range.
788 	 * 3) Avoid volume, format, matrix and rate in BITPERFECT or
789 	 *    PASSTHROUGH mode.
790 	 * 4) Try putting volume before EQ or rate. Should help to
791 	 *    avoid/reduce possible clipping.
792 	 * 5) EQ require specific, valid rate, unless it allow sloppy
793 	 *    conversion.
794 	 */
795 	if (FEEDMATRIX_UP(&cdesc)) {
796 		if (FEEDEQ_REQUIRED(&cdesc) &&
797 		    (!FEEDEQ_VALIDRATE(&cdesc, target) ||
798 		    (cdesc.expensive == 0 && FEEDEQ_ECONOMY(&cdesc))))
799 			FEEDER_BUILD(eq);
800 		if (FEEDRATE_REQUIRED(&cdesc))
801 			FEEDER_BUILD(rate);
802 		FEEDER_BUILD(matrix);
803 		if (FEEDVOLUME_REQUIRED(&cdesc))
804 			FEEDER_BUILD(volume);
805 		if (FEEDEQ_REQUIRED(&cdesc))
806 			FEEDER_BUILD(eq);
807 	} else if (FEEDMATRIX_DOWN(&cdesc)) {
808 		FEEDER_BUILD(matrix);
809 		if (FEEDVOLUME_REQUIRED(&cdesc))
810 			FEEDER_BUILD(volume);
811 		if (FEEDEQ_REQUIRED(&cdesc) &&
812 		    (!FEEDEQ_VALIDRATE(&cdesc, target) ||
813 		    FEEDEQ_ECONOMY(&cdesc)))
814 			FEEDER_BUILD(eq);
815 		if (FEEDRATE_REQUIRED(&cdesc))
816 			FEEDER_BUILD(rate);
817 		if (FEEDEQ_REQUIRED(&cdesc))
818 			FEEDER_BUILD(eq);
819 	} else {
820 		if (FEEDRATE_DOWN(&cdesc)) {
821 			if (FEEDEQ_REQUIRED(&cdesc) &&
822 			    !FEEDEQ_VALIDRATE(&cdesc, target)) {
823 				if (FEEDVOLUME_REQUIRED(&cdesc))
824 					FEEDER_BUILD(volume);
825 				FEEDER_BUILD(eq);
826 			}
827 			FEEDER_BUILD(rate);
828 		}
829 		if (FEEDMATRIX_REQUIRED(&cdesc))
830 			FEEDER_BUILD(matrix);
831 		if (FEEDVOLUME_REQUIRED(&cdesc))
832 			FEEDER_BUILD(volume);
833 		if (FEEDRATE_UP(&cdesc)) {
834 			if (FEEDEQ_REQUIRED(&cdesc) &&
835 			    !FEEDEQ_VALIDRATE(&cdesc, target))
836 				FEEDER_BUILD(eq);
837 			FEEDER_BUILD(rate);
838 		}
839 		if (FEEDEQ_REQUIRED(&cdesc))
840 			FEEDER_BUILD(eq);
841 	}
842 
843 	if (FEEDFORMAT_REQUIRED(&cdesc))
844 		FEEDER_BUILD(format);
845 
846 	if (c->direction == PCMDIR_REC && (c->flags & CHN_F_HAS_VCHAN))
847 		FEEDER_BUILD(mixer);
848 
849 	sndbuf_setfmt(c->bufsoft, c->format);
850 	sndbuf_setspd(c->bufsoft, c->speed);
851 
852 	sndbuf_setfmt(c->bufhard, hwfmt);
853 
854 	chn_syncstate(c);
855 
856 	return (0);
857 }
858