feeder_rate.c revision 195689
1/*-
2 * Copyright (c) 2005-2009 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/*
28 * feeder_rate: (Codename: Z Resampler), which means any effort to create
29 *              future replacement for this resampler are simply absurd unless
30 *              the world decide to add new alphabet after Z.
31 *
32 * FreeBSD bandlimited sinc interpolator, technically based on
33 * "Digital Audio Resampling" by Julius O. Smith III
34 *  - http://ccrma.stanford.edu/~jos/resample/
35 *
36 * The Good:
37 * + all out fixed point integer operations, no soft-float or anything like
38 *   that.
39 * + classic polyphase converters with high quality coefficient's polynomial
40 *   interpolators.
41 * + fast, faster, or the fastest of its kind.
42 * + compile time configurable.
43 * + etc etc..
44 *
45 * The Bad:
46 * - The z, z_, and Z_ . Due to mental block (or maybe just 0x7a69), I
47 *   couldn't think of anything simpler than that (feeder_rate_xxx is just
48 *   too long). Expect possible clashes with other zitizens (any?).
49 */
50
51#ifdef _KERNEL
52#ifdef HAVE_KERNEL_OPTION_HEADERS
53#include "opt_snd.h"
54#endif
55#include <dev/sound/pcm/sound.h>
56#include <dev/sound/pcm/pcm.h>
57#include "feeder_if.h"
58
59#define SND_USE_FXDIV
60#include "snd_fxdiv_gen.h"
61
62SND_DECLARE_FILE("$FreeBSD: head/sys/dev/sound/pcm/feeder_rate.c 195689 2009-07-14 18:53:34Z ariff $");
63#endif
64
65#include "feeder_rate_gen.h"
66
67#if !defined(_KERNEL) && defined(SND_DIAGNOSTIC)
68#undef Z_DIAGNOSTIC
69#define Z_DIAGNOSTIC		1
70#elif defined(_KERNEL)
71#undef Z_DIAGNOSTIC
72#endif
73
74#ifndef Z_QUALITY_DEFAULT
75#define Z_QUALITY_DEFAULT	Z_QUALITY_LINEAR
76#endif
77
78#define Z_RESERVOIR		2048
79#define Z_RESERVOIR_MAX		131072
80
81#define Z_SINC_MAX		0x3fffff
82#define Z_SINC_DOWNMAX		48		/* 384000 / 8000 */
83
84#ifdef _KERNEL
85#define Z_POLYPHASE_MAX		183040		/* 286 taps, 640 phases */
86#else
87#define Z_POLYPHASE_MAX		1464320		/* 286 taps, 5120 phases */
88#endif
89
90#define Z_RATE_DEFAULT		48000
91
92#define Z_RATE_MIN		FEEDRATE_RATEMIN
93#define Z_RATE_MAX		FEEDRATE_RATEMAX
94#define Z_ROUNDHZ		FEEDRATE_ROUNDHZ
95#define Z_ROUNDHZ_MIN		FEEDRATE_ROUNDHZ_MIN
96#define Z_ROUNDHZ_MAX		FEEDRATE_ROUNDHZ_MAX
97
98#define Z_RATE_SRC		FEEDRATE_SRC
99#define Z_RATE_DST		FEEDRATE_DST
100#define Z_RATE_QUALITY		FEEDRATE_QUALITY
101#define Z_RATE_CHANNELS		FEEDRATE_CHANNELS
102
103#define Z_PARANOID		1
104
105#define Z_MULTIFORMAT		1
106
107#ifdef _KERNEL
108#undef Z_USE_ALPHADRIFT
109#define Z_USE_ALPHADRIFT	1
110#endif
111
112#define Z_FACTOR_MIN		1
113#define Z_FACTOR_MAX		Z_MASK
114#define Z_FACTOR_SAFE(v)	(!((v) < Z_FACTOR_MIN || (v) > Z_FACTOR_MAX))
115
116struct z_info;
117
118typedef void (*z_resampler_t)(struct z_info *, uint8_t *);
119
120struct z_info {
121	int32_t rsrc, rdst;	/* original source / destination rates */
122	int32_t src, dst;	/* rounded source / destination rates */
123	int32_t channels;	/* total channels */
124	int32_t bps;		/* bytes-per-sample */
125	int32_t quality;	/* resampling quality */
126
127	int32_t z_gx, z_gy;	/* interpolation / decimation ratio */
128	int32_t z_alpha;	/* output sample time phase / drift */
129	uint8_t *z_delay;	/* FIR delay line / linear buffer */
130	int32_t *z_coeff;	/* FIR coefficients */
131	int32_t *z_dcoeff;	/* FIR coefficients differences */
132	int32_t *z_pcoeff;	/* FIR polyphase coefficients */
133	int32_t z_scale;	/* output scaling */
134	int32_t z_dx;		/* input sample drift increment */
135	int32_t z_dy;		/* output sample drift increment */
136#ifdef Z_USE_ALPHADRIFT
137	int32_t z_alphadrift;	/* alpha drift rate */
138	int32_t z_startdrift;	/* buffer start position drift rate */
139#endif
140	int32_t z_mask;		/* delay line full length mask */
141	int32_t z_size;		/* half width of FIR taps */
142	int32_t z_full;		/* full size of delay line */
143	int32_t z_alloc;	/* largest allocated full size of delay line */
144	int32_t z_start;	/* buffer processing start position */
145	int32_t z_pos;		/* current position for the next feed */
146#ifdef Z_DIAGNOSTIC
147	uint32_t z_cycle;	/* output cycle, purely for statistical */
148#endif
149	int32_t z_maxfeed;	/* maximum feed to avoid 32bit overflow */
150
151	z_resampler_t z_resample;
152};
153
154int feeder_rate_min = Z_RATE_MIN;
155int feeder_rate_max = Z_RATE_MAX;
156int feeder_rate_round = Z_ROUNDHZ;
157int feeder_rate_quality = Z_QUALITY_DEFAULT;
158
159static int feeder_rate_polyphase_max = Z_POLYPHASE_MAX;
160
161#ifdef _KERNEL
162static const char feeder_rate_presets[] = FEEDER_RATE_PRESETS;
163SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_rate_presets, CTLFLAG_RD,
164    &feeder_rate_presets, 0, "compile-time rate presets");
165
166TUNABLE_INT("hw.snd.feeder_rate_min", &feeder_rate_min);
167TUNABLE_INT("hw.snd.feeder_rate_max", &feeder_rate_max);
168TUNABLE_INT("hw.snd.feeder_rate_round", &feeder_rate_round);
169TUNABLE_INT("hw.snd.feeder_rate_quality", &feeder_rate_quality);
170
171TUNABLE_INT("hw.snd.feeder_rate_polyphase_max", &feeder_rate_polyphase_max);
172SYSCTL_INT(_hw_snd, OID_AUTO, feeder_rate_polyphase_max, CTLFLAG_RW,
173    &feeder_rate_polyphase_max, 0, "maximum allowable polyphase entries");
174
175static int
176sysctl_hw_snd_feeder_rate_min(SYSCTL_HANDLER_ARGS)
177{
178	int err, val;
179
180	val = feeder_rate_min;
181	err = sysctl_handle_int(oidp, &val, 0, req);
182
183	if (err != 0 || req->newptr == NULL || val == feeder_rate_min)
184		return (err);
185
186	if (!(Z_FACTOR_SAFE(val) && val < feeder_rate_max))
187		return (EINVAL);
188
189	feeder_rate_min = val;
190
191	return (0);
192}
193SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_min, CTLTYPE_INT | CTLFLAG_RW,
194    0, sizeof(int), sysctl_hw_snd_feeder_rate_min, "I",
195    "minimum allowable rate");
196
197static int
198sysctl_hw_snd_feeder_rate_max(SYSCTL_HANDLER_ARGS)
199{
200	int err, val;
201
202	val = feeder_rate_max;
203	err = sysctl_handle_int(oidp, &val, 0, req);
204
205	if (err != 0 || req->newptr == NULL || val == feeder_rate_max)
206		return (err);
207
208	if (!(Z_FACTOR_SAFE(val) && val > feeder_rate_min))
209		return (EINVAL);
210
211	feeder_rate_max = val;
212
213	return (0);
214}
215SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_max, CTLTYPE_INT | CTLFLAG_RW,
216    0, sizeof(int), sysctl_hw_snd_feeder_rate_max, "I",
217    "maximum allowable rate");
218
219static int
220sysctl_hw_snd_feeder_rate_round(SYSCTL_HANDLER_ARGS)
221{
222	int err, val;
223
224	val = feeder_rate_round;
225	err = sysctl_handle_int(oidp, &val, 0, req);
226
227	if (err != 0 || req->newptr == NULL || val == feeder_rate_round)
228		return (err);
229
230	if (val < Z_ROUNDHZ_MIN || val > Z_ROUNDHZ_MAX)
231		return (EINVAL);
232
233	feeder_rate_round = val - (val % Z_ROUNDHZ);
234
235	return (0);
236}
237SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_round, CTLTYPE_INT | CTLFLAG_RW,
238    0, sizeof(int), sysctl_hw_snd_feeder_rate_round, "I",
239    "sample rate converter rounding threshold");
240
241static int
242sysctl_hw_snd_feeder_rate_quality(SYSCTL_HANDLER_ARGS)
243{
244	struct snddev_info *d;
245	struct pcm_channel *c;
246	struct pcm_feeder *f;
247	int i, err, val;
248
249	val = feeder_rate_quality;
250	err = sysctl_handle_int(oidp, &val, 0, req);
251
252	if (err != 0 || req->newptr == NULL || val == feeder_rate_quality)
253		return (err);
254
255	if (val < Z_QUALITY_MIN || val > Z_QUALITY_MAX)
256		return (EINVAL);
257
258	feeder_rate_quality = val;
259
260	/*
261	 * Traverse all available channels on each device and try to
262	 * set resampler quality if and only if it is exist as
263	 * part of feeder chains and the channel is idle.
264	 */
265	for (i = 0; pcm_devclass != NULL &&
266	    i < devclass_get_maxunit(pcm_devclass); i++) {
267		d = devclass_get_softc(pcm_devclass, i);
268		if (!PCM_REGISTERED(d))
269			continue;
270		PCM_LOCK(d);
271		PCM_WAIT(d);
272		PCM_ACQUIRE(d);
273		CHN_FOREACH(c, d, channels.pcm) {
274			CHN_LOCK(c);
275			f = chn_findfeeder(c, FEEDER_RATE);
276			if (f == NULL || f->data == NULL || CHN_STARTED(c)) {
277				CHN_UNLOCK(c);
278				continue;
279			}
280			(void)FEEDER_SET(f, FEEDRATE_QUALITY, val);
281			CHN_UNLOCK(c);
282		}
283		PCM_RELEASE(d);
284		PCM_UNLOCK(d);
285	}
286
287	return (0);
288}
289SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_quality, CTLTYPE_INT | CTLFLAG_RW,
290    0, sizeof(int), sysctl_hw_snd_feeder_rate_quality, "I",
291    "sample rate converter quality ("__XSTRING(Z_QUALITY_MIN)"=low .. "
292    __XSTRING(Z_QUALITY_MAX)"=high)");
293#endif	/* _KERNEL */
294
295
296/*
297 * Resampler type.
298 */
299#define Z_IS_ZOH(i)		((i)->quality == Z_QUALITY_ZOH)
300#define Z_IS_LINEAR(i)		((i)->quality == Z_QUALITY_LINEAR)
301#define Z_IS_SINC(i)		((i)->quality > Z_QUALITY_LINEAR)
302
303/*
304 * Macroses for accurate sample time drift calculations.
305 *
306 * gy2gx : given the amount of output, return the _exact_ required amount of
307 *         input.
308 * gx2gy : given the amount of input, return the _maximum_ amount of output
309 *         that will be generated.
310 * drift : given the amount of input and output, return the elapsed
311 *         sample-time.
312 */
313#define _Z_GCAST(x)		((uint64_t)(x))
314
315#if defined(__GNUCLIKE_ASM) && defined(__i386__)
316/*
317 * This is where i386 being beaten to a pulp. Fortunately this function is
318 * rarely being called and if it is, it will decide the best (hopefully)
319 * fastest way to do the division. If we can ensure that everything is dword
320 * aligned, letting the compiler to call udivdi3 to do the division can be
321 * faster compared to this.
322 *
323 * amd64 is the clear winner here, no question about it.
324 */
325static __inline uint32_t
326Z_DIV(uint64_t v, uint32_t d)
327{
328	uint32_t hi, lo, quo, rem;
329
330	hi = v >> 32;
331	lo = v & 0xffffffff;
332
333	/*
334	 * As much as we can, try to avoid long division like a plague.
335	 */
336	if (hi == 0)
337		quo = lo / d;
338	else
339		__asm("divl %2"
340		    : "=a" (quo), "=d" (rem)
341		    : "r" (d), "0" (lo), "1" (hi));
342
343	return (quo);
344}
345#else
346#define Z_DIV(x, y)		((x) / (y))
347#endif
348
349#define _Z_GY2GX(i, a, v)						\
350	Z_DIV(((_Z_GCAST((i)->z_gx) * (v)) + ((i)->z_gy - (a) - 1)),	\
351	(i)->z_gy)
352
353#define _Z_GX2GY(i, a, v)						\
354	Z_DIV(((_Z_GCAST((i)->z_gy) * (v)) + (a)), (i)->z_gx)
355
356#define _Z_DRIFT(i, x, y)						\
357	((_Z_GCAST((i)->z_gy) * (x)) - (_Z_GCAST((i)->z_gx) * (y)))
358
359#define z_gy2gx(i, v)		_Z_GY2GX(i, (i)->z_alpha, v)
360#define z_gx2gy(i, v)		_Z_GX2GY(i, (i)->z_alpha, v)
361#define z_drift(i, x, y)	_Z_DRIFT(i, x, y)
362
363/*
364 * Macroses for SINC coefficients table manipulations.. whatever.
365 */
366#define Z_SINC_COEFF_IDX(i)	((i)->quality - Z_QUALITY_LINEAR - 1)
367
368#define Z_SINC_LEN(i)							\
369	((int32_t)(((uint64_t)z_coeff_tab[Z_SINC_COEFF_IDX(i)].len <<	\
370	    Z_SHIFT) / (i)->z_dy))
371
372#define Z_SINC_BASE_LEN(i)						\
373	((z_coeff_tab[Z_SINC_COEFF_IDX(i)].len - 1) >> (Z_DRIFT_SHIFT - 1))
374
375/*
376 * Macroses for linear delay buffer operations. Alignment is not
377 * really necessary since we're not using true circular buffer, but it
378 * will help us guard against possible trespasser. To be honest,
379 * the linear block operations does not need guarding at all due to
380 * accurate drifting!
381 */
382#define z_align(i, v)		((v) & (i)->z_mask)
383#define z_next(i, o, v)		z_align(i, (o) + (v))
384#define z_prev(i, o, v)		z_align(i, (o) - (v))
385#define z_fetched(i)		(z_align(i, (i)->z_pos - (i)->z_start) - 1)
386#define z_free(i)		((i)->z_full - (i)->z_pos)
387
388/*
389 * Macroses for Bla Bla .. :)
390 */
391#define z_copy(src, dst, sz)	(void)memcpy(dst, src, sz)
392#define z_feed(...)		FEEDER_FEED(__VA_ARGS__)
393
394static __inline uint32_t
395z_min(uint32_t x, uint32_t y)
396{
397
398	return ((x < y) ? x : y);
399}
400
401static int32_t
402z_gcd(int32_t x, int32_t y)
403{
404	int32_t w;
405
406	while (y != 0) {
407		w = x % y;
408		x = y;
409		y = w;
410	}
411
412	return (x);
413}
414
415static int32_t
416z_roundpow2(int32_t v)
417{
418	int32_t i;
419
420	i = 1;
421
422	/*
423	 * Let it overflow at will..
424	 */
425	while (i > 0 && i < v)
426		i <<= 1;
427
428	return (i);
429}
430
431/*
432 * Zero Order Hold, the worst of the worst, an insult against quality,
433 * but super fast.
434 */
435static void
436z_feed_zoh(struct z_info *info, uint8_t *dst)
437{
438#if 0
439	z_copy(info->z_delay +
440	    (info->z_start * info->channels * info->bps), dst,
441	    info->channels * info->bps);
442#else
443	uint32_t cnt;
444	uint8_t *src;
445
446	cnt = info->channels * info->bps;
447	src = info->z_delay + (info->z_start * cnt);
448
449	/*
450	 * This is a bit faster than doing bcopy() since we're dealing
451	 * with possible unaligned samples.
452	 */
453	do {
454		*dst++ = *src++;
455	} while (--cnt != 0);
456#endif
457}
458
459/*
460 * Linear Interpolation. This at least sounds better (perceptually) and fast,
461 * but without any proper filtering which means aliasing still exist and
462 * could become worst with a right sample. Interpolation centered within
463 * Z_LINEAR_ONE between the present and previous sample and everything is
464 * done with simple 32bit scaling arithmetic.
465 */
466#define Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)					\
467static void									\
468z_feed_linear_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)		\
469{										\
470	int32_t z;								\
471	intpcm_t x, y;								\
472	uint32_t ch;								\
473	uint8_t *sx, *sy;							\
474										\
475	z = ((uint32_t)info->z_alpha * info->z_dx) >> Z_LINEAR_UNSHIFT;		\
476										\
477	sx = info->z_delay + (info->z_start * info->channels *			\
478	    PCM_##BIT##_BPS);							\
479	sy = sx - (info->channels * PCM_##BIT##_BPS);				\
480										\
481	ch = info->channels;							\
482										\
483	do {									\
484		x = _PCM_READ_##SIGN##BIT##_##ENDIAN(sx);			\
485		y = _PCM_READ_##SIGN##BIT##_##ENDIAN(sy);			\
486		x = Z_LINEAR_INTERPOLATE_##BIT(z, x, y);			\
487		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, x);			\
488		sx += PCM_##BIT##_BPS;						\
489		sy += PCM_##BIT##_BPS;						\
490		dst += PCM_##BIT##_BPS;						\
491	} while (--ch != 0);							\
492}
493
494/*
495 * Userland clipping diagnostic check, not enabled in kernel compilation.
496 * While doing sinc interpolation, unrealistic samples like full scale sine
497 * wav will clip, but for other things this will not make any noise at all.
498 * Everybody should learn how to normalized perceived loudness of their own
499 * music/sounds/samples (hint: ReplayGain).
500 */
501#ifdef Z_DIAGNOSTIC
502#define Z_CLIP_CHECK(v, BIT)	do {					\
503	if ((v) > PCM_S##BIT##_MAX) {					\
504		fprintf(stderr, "Overflow: v=%jd, max=%jd\n",		\
505		    (intmax_t)(v), (intmax_t)PCM_S##BIT##_MAX);		\
506	} else if ((v) < PCM_S##BIT##_MIN) {				\
507		fprintf(stderr, "Underflow: v=%jd, min=%jd\n",		\
508		    (intmax_t)(v), (intmax_t)PCM_S##BIT##_MIN);		\
509	}								\
510} while (0)
511#else
512#define Z_CLIP_CHECK(...)
513#endif
514
515#define Z_CLAMP(v, BIT)							\
516	(((v) > PCM_S##BIT##_MAX) ? PCM_S##BIT##_MAX :			\
517	(((v) < PCM_S##BIT##_MIN) ? PCM_S##BIT##_MIN : (v)))
518
519/*
520 * Sine Cardinal (SINC) Interpolation. Scaling is done in 64 bit, so
521 * there's no point to hold the plate any longer. All samples will be
522 * shifted to a full 32 bit, scaled and restored during write for
523 * maximum dynamic range (only for downsampling).
524 */
525#define _Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, adv)			\
526	c += z >> Z_SHIFT;						\
527	z &= Z_MASK;							\
528	coeff = Z_COEFF_INTERPOLATE(z, z_coeff[c], z_dcoeff[c]);	\
529	x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);			\
530	v += Z_NORM_##BIT((intpcm64_t)x * coeff);			\
531	z += info->z_dy;						\
532	p adv##= info->channels * PCM_##BIT##_BPS
533
534/*
535 * XXX GCC4 optimization is such a !@#$%, need manual unrolling.
536 */
537#if defined(__GNUC__) && __GNUC__ >= 4
538#define Z_SINC_ACCUMULATE(...)	do {					\
539	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
540	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
541} while (0)
542#define Z_SINC_ACCUMULATE_DECR		2
543#else
544#define Z_SINC_ACCUMULATE(...)	do {					\
545	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
546} while (0)
547#define Z_SINC_ACCUMULATE_DECR		1
548#endif
549
550#define Z_DECLARE_SINC(SIGN, BIT, ENDIAN)					\
551static void									\
552z_feed_sinc_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)		\
553{										\
554	intpcm64_t v;								\
555	intpcm_t x;								\
556	uint8_t *p;								\
557	int32_t coeff, z, *z_coeff, *z_dcoeff;					\
558	uint32_t c, center, ch, i;						\
559										\
560	z_coeff = info->z_coeff;						\
561	z_dcoeff = info->z_dcoeff;						\
562	center = z_prev(info, info->z_start, info->z_size);			\
563	ch = info->channels * PCM_##BIT##_BPS;					\
564	dst += ch;								\
565										\
566	do {									\
567		dst -= PCM_##BIT##_BPS;						\
568		ch -= PCM_##BIT##_BPS;						\
569		v = 0;								\
570		z = info->z_alpha * info->z_dx;					\
571		c = 0;								\
572		p = info->z_delay + (z_next(info, center, 1) *			\
573		    info->channels * PCM_##BIT##_BPS) + ch;			\
574		for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR) 	\
575			Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, +);		\
576		z = info->z_dy - (info->z_alpha * info->z_dx);			\
577		c = 0;								\
578		p = info->z_delay + (center * info->channels *			\
579		    PCM_##BIT##_BPS) + ch;					\
580		for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR) 	\
581			Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, -);		\
582		if (info->z_scale != Z_ONE)					\
583			v = Z_SCALE_##BIT(v, info->z_scale);			\
584		else								\
585			v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;		\
586		Z_CLIP_CHECK(v, BIT);						\
587		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));	\
588	} while (ch != 0);							\
589}
590
591#define Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)				\
592static void									\
593z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)	\
594{										\
595	intpcm64_t v;								\
596	intpcm_t x;								\
597	uint8_t *p;								\
598	int32_t ch, i, start, *z_pcoeff;					\
599										\
600	ch = info->channels * PCM_##BIT##_BPS;					\
601	dst += ch;								\
602	start = z_prev(info, info->z_start, (info->z_size << 1) - 1) * ch;	\
603										\
604	do {									\
605		dst -= PCM_##BIT##_BPS;						\
606		ch -= PCM_##BIT##_BPS;						\
607		v = 0;								\
608		p = info->z_delay + start + ch;					\
609		z_pcoeff = info->z_pcoeff +					\
610		    ((info->z_alpha * info->z_size) << 1);			\
611		for (i = info->z_size; i != 0; i--) {				\
612			x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);		\
613			v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);		\
614			z_pcoeff++;						\
615			p += info->channels * PCM_##BIT##_BPS;			\
616			x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);		\
617			v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);		\
618			z_pcoeff++;						\
619			p += info->channels * PCM_##BIT##_BPS;			\
620		}								\
621		if (info->z_scale != Z_ONE)					\
622			v = Z_SCALE_##BIT(v, info->z_scale);			\
623		else								\
624			v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;		\
625		Z_CLIP_CHECK(v, BIT);						\
626		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));	\
627	} while (ch != 0);							\
628}
629
630#define Z_DECLARE(SIGN, BIT, ENDIAN)					\
631	Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)				\
632	Z_DECLARE_SINC(SIGN, BIT, ENDIAN)				\
633	Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)
634
635#if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
636Z_DECLARE(S, 16, LE)
637Z_DECLARE(S, 32, LE)
638#endif
639#if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
640Z_DECLARE(S, 16, BE)
641Z_DECLARE(S, 32, BE)
642#endif
643#ifdef SND_FEEDER_MULTIFORMAT
644Z_DECLARE(S,  8, NE)
645Z_DECLARE(S, 24, LE)
646Z_DECLARE(S, 24, BE)
647Z_DECLARE(U,  8, NE)
648Z_DECLARE(U, 16, LE)
649Z_DECLARE(U, 24, LE)
650Z_DECLARE(U, 32, LE)
651Z_DECLARE(U, 16, BE)
652Z_DECLARE(U, 24, BE)
653Z_DECLARE(U, 32, BE)
654#endif
655
656enum {
657	Z_RESAMPLER_ZOH,
658	Z_RESAMPLER_LINEAR,
659	Z_RESAMPLER_SINC,
660	Z_RESAMPLER_SINC_POLYPHASE,
661	Z_RESAMPLER_LAST
662};
663
664#define Z_RESAMPLER_IDX(i)						\
665	(Z_IS_SINC(i) ? Z_RESAMPLER_SINC : (i)->quality)
666
667#define Z_RESAMPLER_ENTRY(SIGN, BIT, ENDIAN)					\
668	{									\
669	    AFMT_##SIGN##BIT##_##ENDIAN,					\
670	    {									\
671		[Z_RESAMPLER_ZOH]    = z_feed_zoh,				\
672		[Z_RESAMPLER_LINEAR] = z_feed_linear_##SIGN##BIT##ENDIAN,	\
673		[Z_RESAMPLER_SINC]   = z_feed_sinc_##SIGN##BIT##ENDIAN,		\
674		[Z_RESAMPLER_SINC_POLYPHASE]   =				\
675		    z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN			\
676	    }									\
677	}
678
679static const struct {
680	uint32_t format;
681	z_resampler_t resampler[Z_RESAMPLER_LAST];
682} z_resampler_tab[] = {
683#if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
684	Z_RESAMPLER_ENTRY(S, 16, LE),
685	Z_RESAMPLER_ENTRY(S, 32, LE),
686#endif
687#if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
688	Z_RESAMPLER_ENTRY(S, 16, BE),
689	Z_RESAMPLER_ENTRY(S, 32, BE),
690#endif
691#ifdef SND_FEEDER_MULTIFORMAT
692	Z_RESAMPLER_ENTRY(S,  8, NE),
693	Z_RESAMPLER_ENTRY(S, 24, LE),
694	Z_RESAMPLER_ENTRY(S, 24, BE),
695	Z_RESAMPLER_ENTRY(U,  8, NE),
696	Z_RESAMPLER_ENTRY(U, 16, LE),
697	Z_RESAMPLER_ENTRY(U, 24, LE),
698	Z_RESAMPLER_ENTRY(U, 32, LE),
699	Z_RESAMPLER_ENTRY(U, 16, BE),
700	Z_RESAMPLER_ENTRY(U, 24, BE),
701	Z_RESAMPLER_ENTRY(U, 32, BE),
702#endif
703};
704
705#define Z_RESAMPLER_TAB_SIZE						\
706	((int32_t)(sizeof(z_resampler_tab) / sizeof(z_resampler_tab[0])))
707
708static void
709z_resampler_reset(struct z_info *info)
710{
711
712	info->src = info->rsrc - (info->rsrc % ((feeder_rate_round > 0 &&
713	    info->rsrc > feeder_rate_round) ? feeder_rate_round : 1));
714	info->dst = info->rdst - (info->rdst % ((feeder_rate_round > 0 &&
715	    info->rdst > feeder_rate_round) ? feeder_rate_round : 1));
716	info->z_gx = 1;
717	info->z_gy = 1;
718	info->z_alpha = 0;
719	info->z_resample = NULL;
720	info->z_size = 1;
721	info->z_coeff = NULL;
722	info->z_dcoeff = NULL;
723	if (info->z_pcoeff != NULL) {
724		free(info->z_pcoeff, M_DEVBUF);
725		info->z_pcoeff = NULL;
726	}
727	info->z_scale = Z_ONE;
728	info->z_dx = Z_FULL_ONE;
729	info->z_dy = Z_FULL_ONE;
730#ifdef Z_DIAGNOSTIC
731	info->z_cycle = 0;
732#endif
733	if (info->quality < Z_QUALITY_MIN)
734		info->quality = Z_QUALITY_MIN;
735	else if (info->quality > Z_QUALITY_MAX)
736		info->quality = Z_QUALITY_MAX;
737}
738
739#ifdef Z_PARANOID
740static int32_t
741z_resampler_sinc_len(struct z_info *info)
742{
743	int32_t c, z, len, lmax;
744
745	if (!Z_IS_SINC(info))
746		return (1);
747
748	/*
749	 * A rather careful (or useless) way to calculate filter length.
750	 * Z_SINC_LEN() itself is accurate enough to do its job. Extra
751	 * sanity checking is not going to hurt though..
752	 */
753	c = 0;
754	z = info->z_dy;
755	len = 0;
756	lmax = z_coeff_tab[Z_SINC_COEFF_IDX(info)].len;
757
758	do {
759		c += z >> Z_SHIFT;
760		z &= Z_MASK;
761		z += info->z_dy;
762	} while (c < lmax && ++len > 0);
763
764	if (len != Z_SINC_LEN(info)) {
765#ifdef _KERNEL
766		printf("%s(): sinc l=%d != Z_SINC_LEN=%d\n",
767		    __func__, len, Z_SINC_LEN(info));
768#else
769		fprintf(stderr, "%s(): sinc l=%d != Z_SINC_LEN=%d\n",
770		    __func__, len, Z_SINC_LEN(info));
771		return (-1);
772#endif
773	}
774
775	return (len);
776}
777#else
778#define z_resampler_sinc_len(i)		(Z_IS_SINC(i) ? Z_SINC_LEN(i) : 1)
779#endif
780
781#define Z_POLYPHASE_COEFF_SHIFT		0
782
783/*
784 * Pick suitable polynomial interpolators based on filter oversampled ratio
785 * (2 ^ Z_DRIFT_SHIFT).
786 */
787#if !(defined(Z_COEFF_INTERP_ZOH) || defined(Z_COEFF_INTERP_LINEAR) ||		\
788    defined(Z_COEFF_INTERP_QUADRATIC) || defined(Z_COEFF_INTERP_HERMITE) ||	\
789    defined(Z_COEFF_INTER_BSPLINE) || defined(Z_COEFF_INTERP_OPT32X) ||		\
790    defined(Z_COEFF_INTERP_OPT16X) || defined(Z_COEFF_INTERP_OPT8X) ||		\
791    defined(Z_COEFF_INTERP_OPT4X) || defined(Z_COEFF_INTERP_OPT2X))
792#if Z_DRIFT_SHIFT >= 6
793#define Z_COEFF_INTERP_BSPLINE		1
794#elif Z_DRIFT_SHIFT >= 5
795#define Z_COEFF_INTERP_OPT32X		1
796#elif Z_DRIFT_SHIFT == 4
797#define Z_COEFF_INTERP_OPT16X		1
798#elif Z_DRIFT_SHIFT == 3
799#define Z_COEFF_INTERP_OPT8X		1
800#elif Z_DRIFT_SHIFT == 2
801#define Z_COEFF_INTERP_OPT4X		1
802#elif Z_DRIFT_SHIFT == 1
803#define Z_COEFF_INTERP_OPT2X		1
804#else
805#error "Z_DRIFT_SHIFT screwed!"
806#endif
807#endif
808
809/*
810 * In classic polyphase mode, the actual coefficients for each phases need to
811 * be calculated based on default prototype filters. For highly oversampled
812 * filter, linear or quadradatic interpolator should be enough. Anything less
813 * than that require 'special' interpolators to reduce interpolation errors.
814 *
815 * "Polynomial Interpolators for High-Quality Resampling of Oversampled Audio"
816 *    by Olli Niemitalo
817 *    - http://www.student.oulu.fi/~oniemita/dsp/deip.pdf
818 *
819 */
820static int32_t
821z_coeff_interpolate(int32_t z, int32_t *z_coeff)
822{
823	int32_t coeff;
824#if defined(Z_COEFF_INTERP_ZOH)
825
826	/* 1-point, 0th-order (Zero Order Hold) */
827	z = z;
828	coeff = z_coeff[0];
829#elif defined(Z_COEFF_INTERP_LINEAR)
830	int32_t zl0, zl1;
831
832	/* 2-point, 1st-order Linear */
833	zl0 = z_coeff[0];
834	zl1 = z_coeff[1] - z_coeff[0];
835
836	coeff = Z_RSHIFT((int64_t)zl1 * z, Z_SHIFT) + zl0;
837#elif defined(Z_COEFF_INTERP_QUADRATIC)
838	int32_t zq0, zq1, zq2;
839
840	/* 3-point, 2nd-order Quadratic */
841	zq0 = z_coeff[0];
842	zq1 = z_coeff[1] - z_coeff[-1];
843	zq2 = z_coeff[1] + z_coeff[-1] - (z_coeff[0] << 1);
844
845	coeff = Z_RSHIFT((Z_RSHIFT((int64_t)zq2 * z, Z_SHIFT) +
846	    zq1) * z, Z_SHIFT + 1) + zq0;
847#elif defined(Z_COEFF_INTERP_HERMITE)
848	int32_t zh0, zh1, zh2, zh3;
849
850	/* 4-point, 3rd-order Hermite */
851	zh0 = z_coeff[0];
852	zh1 = z_coeff[1] - z_coeff[-1];
853	zh2 = (z_coeff[-1] << 1) - (z_coeff[0] * 5) + (z_coeff[1] << 2) -
854	    z_coeff[2];
855	zh3 = z_coeff[2] - z_coeff[-1] + ((z_coeff[0] - z_coeff[1]) * 3);
856
857	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zh3 * z, Z_SHIFT) +
858	    zh2) * z, Z_SHIFT) + zh1) * z, Z_SHIFT + 1) + zh0;
859#elif defined(Z_COEFF_INTERP_BSPLINE)
860	int32_t zb0, zb1, zb2, zb3;
861
862	/* 4-point, 3rd-order B-Spline */
863	zb0 = Z_RSHIFT(0x15555555LL * (((int64_t)z_coeff[0] << 2) +
864	    z_coeff[-1] + z_coeff[1]), 30);
865	zb1 = z_coeff[1] - z_coeff[-1];
866	zb2 = z_coeff[-1] + z_coeff[1] - (z_coeff[0] << 1);
867	zb3 = Z_RSHIFT(0x15555555LL * (((z_coeff[0] - z_coeff[1]) * 3) +
868	    z_coeff[2] - z_coeff[-1]), 30);
869
870	coeff = (Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zb3 * z, Z_SHIFT) +
871	    zb2) * z, Z_SHIFT) + zb1) * z, Z_SHIFT) + zb0 + 1) >> 1;
872#elif defined(Z_COEFF_INTERP_OPT32X)
873	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
874	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
875
876	/* 6-point, 5th-order Optimal 32x */
877	zoz = z - (Z_ONE >> 1);
878	zoe1 = z_coeff[1] + z_coeff[0];
879	zoe2 = z_coeff[2] + z_coeff[-1];
880	zoe3 = z_coeff[3] + z_coeff[-2];
881	zoo1 = z_coeff[1] - z_coeff[0];
882	zoo2 = z_coeff[2] - z_coeff[-1];
883	zoo3 = z_coeff[3] - z_coeff[-2];
884
885	zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
886	    (0x00170c29LL * zoe3), 30);
887	zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
888	    (0x008cd4dcLL * zoo3), 30);
889	zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
890	    (0x0160b5d0LL * zoe3), 30);
891	zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
892	    (0x01cfe914LL * zoo3), 30);
893	zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
894	    (0x015508ddLL * zoe3), 30);
895	zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
896	    (0x0082d81aLL * zoo3), 30);
897
898	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
899	    (int64_t)zoc5 * zoz, Z_SHIFT) +
900	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
901	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
902#elif defined(Z_COEFF_INTERP_OPT16X)
903	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
904	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
905
906	/* 6-point, 5th-order Optimal 16x */
907	zoz = z - (Z_ONE >> 1);
908	zoe1 = z_coeff[1] + z_coeff[0];
909	zoe2 = z_coeff[2] + z_coeff[-1];
910	zoe3 = z_coeff[3] + z_coeff[-2];
911	zoo1 = z_coeff[1] - z_coeff[0];
912	zoo2 = z_coeff[2] - z_coeff[-1];
913	zoo3 = z_coeff[3] - z_coeff[-2];
914
915	zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
916	    (0x00170c29LL * zoe3), 30);
917	zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
918	    (0x008cd4dcLL * zoo3), 30);
919	zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
920	    (0x0160b5d0LL * zoe3), 30);
921	zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
922	    (0x01cfe914LL * zoo3), 30);
923	zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
924	    (0x015508ddLL * zoe3), 30);
925	zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
926	    (0x0082d81aLL * zoo3), 30);
927
928	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
929	    (int64_t)zoc5 * zoz, Z_SHIFT) +
930	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
931	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
932#elif defined(Z_COEFF_INTERP_OPT8X)
933	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
934	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
935
936	/* 6-point, 5th-order Optimal 8x */
937	zoz = z - (Z_ONE >> 1);
938	zoe1 = z_coeff[1] + z_coeff[0];
939	zoe2 = z_coeff[2] + z_coeff[-1];
940	zoe3 = z_coeff[3] + z_coeff[-2];
941	zoo1 = z_coeff[1] - z_coeff[0];
942	zoo2 = z_coeff[2] - z_coeff[-1];
943	zoo3 = z_coeff[3] - z_coeff[-2];
944
945	zoc0 = Z_RSHIFT((0x1aa9b47dLL * zoe1) + (0x053d9944LL * zoe2) +
946	    (0x0018b23fLL * zoe3), 30);
947	zoc1 = Z_RSHIFT((0x14a104d1LL * zoo1) + (0x0d7d2504LL * zoo2) +
948	    (0x0094b599LL * zoo3), 30);
949	zoc2 = Z_RSHIFT((-0x0d22530bLL * zoe1) + (0x0bb37a2cLL * zoe2) +
950	    (0x016ed8e0LL * zoe3), 30);
951	zoc3 = Z_RSHIFT((-0x0d744b1cLL * zoo1) + (0x01649591LL * zoo2) +
952	    (0x01dae93aLL * zoo3), 30);
953	zoc4 = Z_RSHIFT((0x02a7ee1bLL * zoe1) + (-0x03fbdb24LL * zoe2) +
954	    (0x0153ed07LL * zoe3), 30);
955	zoc5 = Z_RSHIFT((0x04cf9b6cLL * zoo1) + (-0x0266b378LL * zoo2) +
956	    (0x007a7c26LL * zoo3), 30);
957
958	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
959	    (int64_t)zoc5 * zoz, Z_SHIFT) +
960	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
961	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
962#elif defined(Z_COEFF_INTERP_OPT4X)
963	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
964	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
965
966	/* 6-point, 5th-order Optimal 4x */
967	zoz = z - (Z_ONE >> 1);
968	zoe1 = z_coeff[1] + z_coeff[0];
969	zoe2 = z_coeff[2] + z_coeff[-1];
970	zoe3 = z_coeff[3] + z_coeff[-2];
971	zoo1 = z_coeff[1] - z_coeff[0];
972	zoo2 = z_coeff[2] - z_coeff[-1];
973	zoo3 = z_coeff[3] - z_coeff[-2];
974
975	zoc0 = Z_RSHIFT((0x1a8eda43LL * zoe1) + (0x0556ee38LL * zoe2) +
976	    (0x001a3784LL * zoe3), 30);
977	zoc1 = Z_RSHIFT((0x143d863eLL * zoo1) + (0x0d910e36LL * zoo2) +
978	    (0x009ca889LL * zoo3), 30);
979	zoc2 = Z_RSHIFT((-0x0d026821LL * zoe1) + (0x0b837773LL * zoe2) +
980	    (0x017ef0c6LL * zoe3), 30);
981	zoc3 = Z_RSHIFT((-0x0cef1502LL * zoo1) + (0x01207a8eLL * zoo2) +
982	    (0x01e936dbLL * zoo3), 30);
983	zoc4 = Z_RSHIFT((0x029fe643LL * zoe1) + (-0x03ef3fc8LL * zoe2) +
984	    (0x014f5923LL * zoe3), 30);
985	zoc5 = Z_RSHIFT((0x043a9d08LL * zoo1) + (-0x02154febLL * zoo2) +
986	    (0x00670dbdLL * zoo3), 30);
987
988	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
989	    (int64_t)zoc5 * zoz, Z_SHIFT) +
990	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
991	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
992#elif defined(Z_COEFF_INTERP_OPT2X)
993	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
994	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
995
996	/* 6-point, 5th-order Optimal 2x */
997	zoz = z - (Z_ONE >> 1);
998	zoe1 = z_coeff[1] + z_coeff[0];
999	zoe2 = z_coeff[2] + z_coeff[-1];
1000	zoe3 = z_coeff[3] + z_coeff[-2];
1001	zoo1 = z_coeff[1] - z_coeff[0];
1002	zoo2 = z_coeff[2] - z_coeff[-1];
1003	zoo3 = z_coeff[3] - z_coeff[-2];
1004
1005	zoc0 = Z_RSHIFT((0x19edb6fdLL * zoe1) + (0x05ebd062LL * zoe2) +
1006	    (0x00267881LL * zoe3), 30);
1007	zoc1 = Z_RSHIFT((0x1223af76LL * zoo1) + (0x0de3dd6bLL * zoo2) +
1008	    (0x00d683cdLL * zoo3), 30);
1009	zoc2 = Z_RSHIFT((-0x0c3ee068LL * zoe1) + (0x0a5c3769LL * zoe2) +
1010	    (0x01e2aceaLL * zoe3), 30);
1011	zoc3 = Z_RSHIFT((-0x0a8ab614LL * zoo1) + (-0x0019522eLL * zoo2) +
1012	    (0x022cefc7LL * zoo3), 30);
1013	zoc4 = Z_RSHIFT((0x0276187dLL * zoe1) + (-0x03a801e8LL * zoe2) +
1014	    (0x0131d935LL * zoe3), 30);
1015	zoc5 = Z_RSHIFT((0x02c373f5LL * zoo1) + (-0x01275f83LL * zoo2) +
1016	    (0x0018ee79LL * zoo3), 30);
1017
1018	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
1019	    (int64_t)zoc5 * zoz, Z_SHIFT) +
1020	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
1021	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
1022#else
1023#error "Interpolation type screwed!"
1024#endif
1025
1026#if Z_POLYPHASE_COEFF_SHIFT > 0
1027	coeff = Z_RSHIFT(coeff, Z_POLYPHASE_COEFF_SHIFT);
1028#endif
1029	return (coeff);
1030}
1031
1032static int
1033z_resampler_build_polyphase(struct z_info *info)
1034{
1035	int32_t alpha, c, i, z, idx;
1036
1037	/* Let this be here first. */
1038	if (info->z_pcoeff != NULL) {
1039		free(info->z_pcoeff, M_DEVBUF);
1040		info->z_pcoeff = NULL;
1041	}
1042
1043	if (feeder_rate_polyphase_max < 1)
1044		return (ENOTSUP);
1045
1046	if (((int64_t)info->z_size * info->z_gy * 2) >
1047	    feeder_rate_polyphase_max) {
1048#ifndef _KERNEL
1049		fprintf(stderr, "Polyphase entries exceed: [%d/%d] %jd > %d\n",
1050		    info->z_gx, info->z_gy,
1051		    (intmax_t)info->z_size * info->z_gy * 2,
1052		    feeder_rate_polyphase_max);
1053#endif
1054		return (E2BIG);
1055	}
1056
1057	info->z_pcoeff = malloc(sizeof(int32_t) *
1058	    info->z_size * info->z_gy * 2, M_DEVBUF, M_NOWAIT | M_ZERO);
1059	if (info->z_pcoeff == NULL)
1060		return (ENOMEM);
1061
1062	for (alpha = 0; alpha < info->z_gy; alpha++) {
1063		z = alpha * info->z_dx;
1064		c = 0;
1065		for (i = info->z_size; i != 0; i--) {
1066			c += z >> Z_SHIFT;
1067			z &= Z_MASK;
1068			idx = (alpha * info->z_size * 2) +
1069			    (info->z_size * 2) - i;
1070			info->z_pcoeff[idx] =
1071			    z_coeff_interpolate(z, info->z_coeff + c);
1072			z += info->z_dy;
1073		}
1074		z = info->z_dy - (alpha * info->z_dx);
1075		c = 0;
1076		for (i = info->z_size; i != 0; i--) {
1077			c += z >> Z_SHIFT;
1078			z &= Z_MASK;
1079			idx = (alpha * info->z_size * 2) + i - 1;
1080			info->z_pcoeff[idx] =
1081			    z_coeff_interpolate(z, info->z_coeff + c);
1082			z += info->z_dy;
1083		}
1084	}
1085
1086#ifndef _KERNEL
1087	fprintf(stderr, "Polyphase: [%d/%d] %d entries\n",
1088	    info->z_gx, info->z_gy, info->z_size * info->z_gy * 2);
1089#endif
1090
1091	return (0);
1092}
1093
1094static int
1095z_resampler_setup(struct pcm_feeder *f)
1096{
1097	struct z_info *info;
1098	int64_t gy2gx_max, gx2gy_max;
1099	uint32_t format;
1100	int32_t align, i, z_scale;
1101	int adaptive;
1102
1103	info = f->data;
1104	z_resampler_reset(info);
1105
1106	if (info->src == info->dst)
1107		return (0);
1108
1109	/* Shrink by greatest common divisor. */
1110	i = z_gcd(info->src, info->dst);
1111	info->z_gx = info->src / i;
1112	info->z_gy = info->dst / i;
1113
1114	/* Too big, or too small. Bail out. */
1115	if (!(Z_FACTOR_SAFE(info->z_gx) && Z_FACTOR_SAFE(info->z_gy)))
1116		return (EINVAL);
1117
1118	format = f->desc->in;
1119	adaptive = 0;
1120	z_scale = 0;
1121
1122	/*
1123	 * Setup everything: filter length, conversion factor, etc.
1124	 */
1125	if (Z_IS_SINC(info)) {
1126		/*
1127		 * Downsampling, or upsampling scaling factor. As long as the
1128		 * factor can be represented by a fraction of 1 << Z_SHIFT,
1129		 * we're pretty much in business. Scaling is not needed for
1130		 * upsampling, so we just slap Z_ONE there.
1131		 */
1132		if (info->z_gx > info->z_gy)
1133			/*
1134			 * If the downsampling ratio is beyond sanity,
1135			 * enable semi-adaptive mode. Although handling
1136			 * extreme ratio is possible, the result of the
1137			 * conversion is just pointless, unworthy,
1138			 * nonsensical noises, etc.
1139			 */
1140			if ((info->z_gx / info->z_gy) > Z_SINC_DOWNMAX)
1141				z_scale = Z_ONE / Z_SINC_DOWNMAX;
1142			else
1143				z_scale = ((uint64_t)info->z_gy << Z_SHIFT) /
1144				    info->z_gx;
1145		else
1146			z_scale = Z_ONE;
1147
1148		/*
1149		 * This is actually impossible, unless anything above
1150		 * overflow.
1151		 */
1152		if (z_scale < 1)
1153			return (E2BIG);
1154
1155		/*
1156		 * Calculate sample time/coefficients index drift. It is
1157		 * a constant for upsampling, but downsampling require
1158		 * heavy duty filtering with possible too long filters.
1159		 * If anything goes wrong, revisit again and enable
1160		 * adaptive mode.
1161		 */
1162z_setup_adaptive_sinc:
1163		if (info->z_pcoeff != NULL) {
1164			free(info->z_pcoeff, M_DEVBUF);
1165			info->z_pcoeff = NULL;
1166		}
1167
1168		if (adaptive == 0) {
1169			info->z_dy = z_scale << Z_DRIFT_SHIFT;
1170			if (info->z_dy < 1)
1171				return (E2BIG);
1172			info->z_scale = z_scale;
1173		} else {
1174			info->z_dy = Z_FULL_ONE;
1175			info->z_scale = Z_ONE;
1176		}
1177
1178#if 0
1179#define Z_SCALE_DIV	10000
1180#define Z_SCALE_LIMIT(s, v)						\
1181	((((uint64_t)(s) * (v)) + (Z_SCALE_DIV >> 1)) / Z_SCALE_DIV)
1182
1183		info->z_scale = Z_SCALE_LIMIT(info->z_scale, 9780);
1184#endif
1185
1186		/* Smallest drift increment. */
1187		info->z_dx = info->z_dy / info->z_gy;
1188
1189		/*
1190		 * Overflow or underflow. Try adaptive, let it continue and
1191		 * retry.
1192		 */
1193		if (info->z_dx < 1) {
1194			if (adaptive == 0) {
1195				adaptive = 1;
1196				goto z_setup_adaptive_sinc;
1197			}
1198			return (E2BIG);
1199		}
1200
1201		/*
1202		 * Round back output drift.
1203		 */
1204		info->z_dy = info->z_dx * info->z_gy;
1205
1206		for (i = 0; i < Z_COEFF_TAB_SIZE; i++) {
1207			if (Z_SINC_COEFF_IDX(info) != i)
1208				continue;
1209			/*
1210			 * Calculate required filter length and guard
1211			 * against possible abusive result. Note that
1212			 * this represents only 1/2 of the entire filter
1213			 * length.
1214			 */
1215			info->z_size = z_resampler_sinc_len(info);
1216
1217			/*
1218			 * Multiple of 2 rounding, for better accumulator
1219			 * performance.
1220			 */
1221			info->z_size &= ~1;
1222
1223			if (info->z_size < 2 || info->z_size > Z_SINC_MAX) {
1224				if (adaptive == 0) {
1225					adaptive = 1;
1226					goto z_setup_adaptive_sinc;
1227				}
1228				return (E2BIG);
1229			}
1230			info->z_coeff = z_coeff_tab[i].coeff + Z_COEFF_OFFSET;
1231			info->z_dcoeff = z_coeff_tab[i].dcoeff;
1232			break;
1233		}
1234
1235		if (info->z_coeff == NULL || info->z_dcoeff == NULL)
1236			return (EINVAL);
1237	} else if (Z_IS_LINEAR(info)) {
1238		/*
1239		 * Don't put much effort if we're doing linear interpolation.
1240		 * Just center the interpolation distance within Z_LINEAR_ONE,
1241		 * and be happy about it.
1242		 */
1243		info->z_dx = Z_LINEAR_FULL_ONE / info->z_gy;
1244	}
1245
1246	/*
1247	 * We're safe for now, lets continue.. Look for our resampler
1248	 * depending on configured format and quality.
1249	 */
1250	for (i = 0; i < Z_RESAMPLER_TAB_SIZE; i++) {
1251		int ridx;
1252
1253		if (AFMT_ENCODING(format) != z_resampler_tab[i].format)
1254			continue;
1255		if (Z_IS_SINC(info) && adaptive == 0 &&
1256		    z_resampler_build_polyphase(info) == 0)
1257			ridx = Z_RESAMPLER_SINC_POLYPHASE;
1258		else
1259			ridx = Z_RESAMPLER_IDX(info);
1260		info->z_resample = z_resampler_tab[i].resampler[ridx];
1261		break;
1262	}
1263
1264	if (info->z_resample == NULL)
1265		return (EINVAL);
1266
1267	info->bps = AFMT_BPS(format);
1268	align = info->channels * info->bps;
1269
1270	/*
1271	 * Calculate largest value that can be fed into z_gy2gx() and
1272	 * z_gx2gy() without causing (signed) 32bit overflow. z_gy2gx() will
1273	 * be called early during feeding process to determine how much input
1274	 * samples that is required to generate requested output, while
1275	 * z_gx2gy() will be called just before samples filtering /
1276	 * accumulation process based on available samples that has been
1277	 * calculated using z_gx2gy().
1278	 *
1279	 * Now that is damn confusing, I guess ;-) .
1280	 */
1281	gy2gx_max = (((uint64_t)info->z_gy * INT32_MAX) - info->z_gy + 1) /
1282	    info->z_gx;
1283
1284	if ((gy2gx_max * align) > SND_FXDIV_MAX)
1285		gy2gx_max = SND_FXDIV_MAX / align;
1286
1287	if (gy2gx_max < 1)
1288		return (E2BIG);
1289
1290	gx2gy_max = (((uint64_t)info->z_gx * INT32_MAX) - info->z_gy) /
1291	    info->z_gy;
1292
1293	if (gx2gy_max > INT32_MAX)
1294		gx2gy_max = INT32_MAX;
1295
1296	if (gx2gy_max < 1)
1297		return (E2BIG);
1298
1299	/*
1300	 * Ensure that z_gy2gx() at its largest possible calculated value
1301	 * (alpha = 0) will not cause overflow further late during z_gx2gy()
1302	 * stage.
1303	 */
1304	if (z_gy2gx(info, gy2gx_max) > _Z_GCAST(gx2gy_max))
1305		return (E2BIG);
1306
1307	info->z_maxfeed = gy2gx_max * align;
1308
1309#ifdef Z_USE_ALPHADRIFT
1310	info->z_startdrift = z_gy2gx(info, 1);
1311	info->z_alphadrift = z_drift(info, info->z_startdrift, 1);
1312#endif
1313
1314	i = z_gy2gx(info, 1);
1315	info->z_full = z_roundpow2((info->z_size << 1) + i);
1316
1317	/*
1318	 * Too big to be true, and overflowing left and right like mad ..
1319	 */
1320	if ((info->z_full * align) < 1) {
1321		if (adaptive == 0 && Z_IS_SINC(info)) {
1322			adaptive = 1;
1323			goto z_setup_adaptive_sinc;
1324		}
1325		return (E2BIG);
1326	}
1327
1328	/*
1329	 * Increase full buffer size if its too small to reduce cyclic
1330	 * buffer shifting in main conversion/feeder loop.
1331	 */
1332	while (info->z_full < Z_RESERVOIR_MAX &&
1333	    (info->z_full - (info->z_size << 1)) < Z_RESERVOIR)
1334		info->z_full <<= 1;
1335
1336	/* Initialize buffer position. */
1337	info->z_mask = info->z_full - 1;
1338	info->z_start = z_prev(info, info->z_size << 1, 1);
1339	info->z_pos = z_next(info, info->z_start, 1);
1340
1341	/*
1342	 * Allocate or reuse delay line buffer, whichever makes sense.
1343	 */
1344	i = info->z_full * align;
1345	if (i < 1)
1346		return (E2BIG);
1347
1348	if (info->z_delay == NULL || info->z_alloc < i ||
1349	    i <= (info->z_alloc >> 1)) {
1350		if (info->z_delay != NULL)
1351			free(info->z_delay, M_DEVBUF);
1352		info->z_delay = malloc(i, M_DEVBUF, M_NOWAIT | M_ZERO);
1353		if (info->z_delay == NULL)
1354			return (ENOMEM);
1355		info->z_alloc = i;
1356	}
1357
1358	/*
1359	 * Zero out head of buffer to avoid pops and clicks.
1360	 */
1361	memset(info->z_delay, sndbuf_zerodata(f->desc->out),
1362	    info->z_pos * align);
1363
1364#ifdef Z_DIAGNOSTIC
1365	/*
1366	 * XXX Debuging mess !@#$%^
1367	 */
1368#define dumpz(x)	fprintf(stderr, "\t%12s = %10u : %-11d\n",	\
1369			    "z_"__STRING(x), (uint32_t)info->z_##x,	\
1370			    (int32_t)info->z_##x)
1371	fprintf(stderr, "\n%s():\n", __func__);
1372	fprintf(stderr, "\tchannels=%d, bps=%d, format=0x%08x, quality=%d\n",
1373	    info->channels, info->bps, format, info->quality);
1374	fprintf(stderr, "\t%d (%d) -> %d (%d), ",
1375	    info->src, info->rsrc, info->dst, info->rdst);
1376	fprintf(stderr, "[%d/%d]\n", info->z_gx, info->z_gy);
1377	fprintf(stderr, "\tminreq=%d, ", z_gy2gx(info, 1));
1378	if (adaptive != 0)
1379		z_scale = Z_ONE;
1380	fprintf(stderr, "factor=0x%08x/0x%08x (%f)\n",
1381	    z_scale, Z_ONE, (double)z_scale / Z_ONE);
1382	fprintf(stderr, "\tbase_length=%d, ", Z_SINC_BASE_LEN(info));
1383	fprintf(stderr, "adaptive=%s\n", (adaptive != 0) ? "YES" : "NO");
1384	dumpz(size);
1385	dumpz(alloc);
1386	if (info->z_alloc < 1024)
1387		fprintf(stderr, "\t%15s%10d Bytes\n",
1388		    "", info->z_alloc);
1389	else if (info->z_alloc < (1024 << 10))
1390		fprintf(stderr, "\t%15s%10d KBytes\n",
1391		    "", info->z_alloc >> 10);
1392	else if (info->z_alloc < (1024 << 20))
1393		fprintf(stderr, "\t%15s%10d MBytes\n",
1394		    "", info->z_alloc >> 20);
1395	else
1396		fprintf(stderr, "\t%15s%10d GBytes\n",
1397		    "", info->z_alloc >> 30);
1398	fprintf(stderr, "\t%12s   %10d (min output samples)\n",
1399	    "",
1400	    (int32_t)z_gx2gy(info, info->z_full - (info->z_size << 1)));
1401	fprintf(stderr, "\t%12s   %10d (min allocated output samples)\n",
1402	    "",
1403	    (int32_t)z_gx2gy(info, (info->z_alloc / align) -
1404	    (info->z_size << 1)));
1405	fprintf(stderr, "\t%12s = %10d\n",
1406	    "z_gy2gx()", (int32_t)z_gy2gx(info, 1));
1407	fprintf(stderr, "\t%12s = %10d -> z_gy2gx() -> %d\n",
1408	    "Max", (int32_t)gy2gx_max, (int32_t)z_gy2gx(info, gy2gx_max));
1409	fprintf(stderr, "\t%12s = %10d\n",
1410	    "z_gx2gy()", (int32_t)z_gx2gy(info, 1));
1411	fprintf(stderr, "\t%12s = %10d -> z_gx2gy() -> %d\n",
1412	    "Max", (int32_t)gx2gy_max, (int32_t)z_gx2gy(info, gx2gy_max));
1413	dumpz(maxfeed);
1414	dumpz(full);
1415	dumpz(start);
1416	dumpz(pos);
1417	dumpz(scale);
1418	fprintf(stderr, "\t%12s   %10f\n", "",
1419	    (double)info->z_scale / Z_ONE);
1420	dumpz(dx);
1421	fprintf(stderr, "\t%12s   %10f\n", "",
1422	    (double)info->z_dx / info->z_dy);
1423	dumpz(dy);
1424	fprintf(stderr, "\t%12s   %10d (drift step)\n", "",
1425	    info->z_dy >> Z_SHIFT);
1426	fprintf(stderr, "\t%12s   %10d (scaling differences)\n", "",
1427	    (z_scale << Z_DRIFT_SHIFT) - info->z_dy);
1428	fprintf(stderr, "\t%12s = %u bytes\n",
1429	    "intpcm32_t", sizeof(intpcm32_t));
1430	fprintf(stderr, "\t%12s = 0x%08x, smallest=%.16lf\n",
1431	    "Z_ONE", Z_ONE, (double)1.0 / (double)Z_ONE);
1432#endif
1433
1434	return (0);
1435}
1436
1437static int
1438z_resampler_set(struct pcm_feeder *f, int what, int32_t value)
1439{
1440	struct z_info *info;
1441	int32_t oquality;
1442
1443	info = f->data;
1444
1445	switch (what) {
1446	case Z_RATE_SRC:
1447		if (value < feeder_rate_min || value > feeder_rate_max)
1448			return (E2BIG);
1449		if (value == info->rsrc)
1450			return (0);
1451		info->rsrc = value;
1452		break;
1453	case Z_RATE_DST:
1454		if (value < feeder_rate_min || value > feeder_rate_max)
1455			return (E2BIG);
1456		if (value == info->rdst)
1457			return (0);
1458		info->rdst = value;
1459		break;
1460	case Z_RATE_QUALITY:
1461		if (value < Z_QUALITY_MIN || value > Z_QUALITY_MAX)
1462			return (EINVAL);
1463		if (value == info->quality)
1464			return (0);
1465		/*
1466		 * If we failed to set the requested quality, restore
1467		 * the old one. We cannot afford leaving it broken since
1468		 * passive feeder chains like vchans never reinitialize
1469		 * itself.
1470		 */
1471		oquality = info->quality;
1472		info->quality = value;
1473		if (z_resampler_setup(f) == 0)
1474			return (0);
1475		info->quality = oquality;
1476		break;
1477	case Z_RATE_CHANNELS:
1478		if (value < SND_CHN_MIN || value > SND_CHN_MAX)
1479			return (EINVAL);
1480		if (value == info->channels)
1481			return (0);
1482		info->channels = value;
1483		break;
1484	default:
1485		return (EINVAL);
1486		break;
1487	}
1488
1489	return (z_resampler_setup(f));
1490}
1491
1492static int
1493z_resampler_get(struct pcm_feeder *f, int what)
1494{
1495	struct z_info *info;
1496
1497	info = f->data;
1498
1499	switch (what) {
1500	case Z_RATE_SRC:
1501		return (info->rsrc);
1502		break;
1503	case Z_RATE_DST:
1504		return (info->rdst);
1505		break;
1506	case Z_RATE_QUALITY:
1507		return (info->quality);
1508		break;
1509	case Z_RATE_CHANNELS:
1510		return (info->channels);
1511		break;
1512	default:
1513		break;
1514	}
1515
1516	return (-1);
1517}
1518
1519static int
1520z_resampler_init(struct pcm_feeder *f)
1521{
1522	struct z_info *info;
1523	int ret;
1524
1525	if (f->desc->in != f->desc->out)
1526		return (EINVAL);
1527
1528	info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO);
1529	if (info == NULL)
1530		return (ENOMEM);
1531
1532	info->rsrc = Z_RATE_DEFAULT;
1533	info->rdst = Z_RATE_DEFAULT;
1534	info->quality = feeder_rate_quality;
1535	info->channels = AFMT_CHANNEL(f->desc->in);
1536
1537	f->data = info;
1538
1539	ret = z_resampler_setup(f);
1540	if (ret != 0) {
1541		if (info->z_pcoeff != NULL)
1542			free(info->z_pcoeff, M_DEVBUF);
1543		if (info->z_delay != NULL)
1544			free(info->z_delay, M_DEVBUF);
1545		free(info, M_DEVBUF);
1546		f->data = NULL;
1547	}
1548
1549	return (ret);
1550}
1551
1552static int
1553z_resampler_free(struct pcm_feeder *f)
1554{
1555	struct z_info *info;
1556
1557	info = f->data;
1558	if (info != NULL) {
1559		if (info->z_pcoeff != NULL)
1560			free(info->z_pcoeff, M_DEVBUF);
1561		if (info->z_delay != NULL)
1562			free(info->z_delay, M_DEVBUF);
1563		free(info, M_DEVBUF);
1564	}
1565
1566	f->data = NULL;
1567
1568	return (0);
1569}
1570
1571static uint32_t
1572z_resampler_feed_internal(struct pcm_feeder *f, struct pcm_channel *c,
1573    uint8_t *b, uint32_t count, void *source)
1574{
1575	struct z_info *info;
1576	int32_t alphadrift, startdrift, reqout, ocount, reqin, align;
1577	int32_t fetch, fetched, start, cp;
1578	uint8_t *dst;
1579
1580	info = f->data;
1581	if (info->z_resample == NULL)
1582		return (z_feed(f->source, c, b, count, source));
1583
1584	/*
1585	 * Calculate sample size alignment and amount of sample output.
1586	 * We will do everything in sample domain, but at the end we
1587	 * will jump back to byte domain.
1588	 */
1589	align = info->channels * info->bps;
1590	ocount = SND_FXDIV(count, align);
1591	if (ocount == 0)
1592		return (0);
1593
1594	/*
1595	 * Calculate amount of input samples that is needed to generate
1596	 * exact amount of output.
1597	 */
1598	reqin = z_gy2gx(info, ocount) - z_fetched(info);
1599
1600#ifdef Z_USE_ALPHADRIFT
1601	startdrift = info->z_startdrift;
1602	alphadrift = info->z_alphadrift;
1603#else
1604	startdrift = _Z_GY2GX(info, 0, 1);
1605	alphadrift = z_drift(info, startdrift, 1);
1606#endif
1607
1608	dst = b;
1609
1610	do {
1611		if (reqin != 0) {
1612			fetch = z_min(z_free(info), reqin);
1613			if (fetch == 0) {
1614				/*
1615				 * No more free spaces, so wind enough
1616				 * samples back to the head of delay line
1617				 * in byte domain.
1618				 */
1619				fetched = z_fetched(info);
1620				start = z_prev(info, info->z_start,
1621				    (info->z_size << 1) - 1);
1622				cp = (info->z_size << 1) + fetched;
1623				z_copy(info->z_delay + (start * align),
1624				    info->z_delay, cp * align);
1625				info->z_start =
1626				    z_prev(info, info->z_size << 1, 1);
1627				info->z_pos =
1628				    z_next(info, info->z_start, fetched + 1);
1629				fetch = z_min(z_free(info), reqin);
1630#ifdef Z_DIAGNOSTIC
1631				if (1) {
1632					static uint32_t kk = 0;
1633					fprintf(stderr,
1634					    "Buffer Move: "
1635					    "start=%d fetched=%d cp=%d "
1636					    "cycle=%u [%u]\r",
1637					    start, fetched, cp, info->z_cycle,
1638					    ++kk);
1639				}
1640				info->z_cycle = 0;
1641#endif
1642			}
1643			if (fetch != 0) {
1644				/*
1645				 * Fetch in byte domain and jump back
1646				 * to sample domain.
1647				 */
1648				fetched = SND_FXDIV(z_feed(f->source, c,
1649				    info->z_delay + (info->z_pos * align),
1650				    fetch * align, source), align);
1651				/*
1652				 * Prepare to convert fetched buffer,
1653				 * or mark us done if we cannot fulfill
1654				 * the request.
1655				 */
1656				reqin -= fetched;
1657				info->z_pos += fetched;
1658				if (fetched != fetch)
1659					reqin = 0;
1660			}
1661		}
1662
1663		reqout = z_min(z_gx2gy(info, z_fetched(info)), ocount);
1664		if (reqout != 0) {
1665			ocount -= reqout;
1666
1667			/*
1668			 * Drift.. drift.. drift..
1669			 *
1670			 * Notice that there are 2 methods of doing the drift
1671			 * operations: The former is much cleaner (in a sense
1672			 * of mathematical readings of my eyes), but slower
1673			 * due to integer division in z_gy2gx(). Nevertheless,
1674			 * both should give the same exact accurate drifting
1675			 * results, so the later is favourable.
1676			 */
1677			do {
1678				info->z_resample(info, dst);
1679#if 0
1680				startdrift = z_gy2gx(info, 1);
1681				alphadrift = z_drift(info, startdrift, 1);
1682				info->z_start += startdrift;
1683				info->z_alpha += alphadrift;
1684#else
1685				info->z_alpha += alphadrift;
1686				if (info->z_alpha < info->z_gy)
1687					info->z_start += startdrift;
1688				else {
1689					info->z_start += startdrift - 1;
1690					info->z_alpha -= info->z_gy;
1691				}
1692#endif
1693				dst += align;
1694#ifdef Z_DIAGNOSTIC
1695				info->z_cycle++;
1696#endif
1697			} while (--reqout != 0);
1698		}
1699	} while (reqin != 0 && ocount != 0);
1700
1701	/*
1702	 * Back to byte domain..
1703	 */
1704	return (dst - b);
1705}
1706
1707static int
1708z_resampler_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
1709    uint32_t count, void *source)
1710{
1711	uint32_t feed, maxfeed, left;
1712
1713	/*
1714	 * Split count to smaller chunks to avoid possible 32bit overflow.
1715	 */
1716	maxfeed = ((struct z_info *)(f->data))->z_maxfeed;
1717	left = count;
1718
1719	do {
1720		feed = z_resampler_feed_internal(f, c, b,
1721		    z_min(maxfeed, left), source);
1722		b += feed;
1723		left -= feed;
1724	} while (left != 0 && feed != 0);
1725
1726	return (count - left);
1727}
1728
1729static struct pcm_feederdesc feeder_rate_desc[] = {
1730	{ FEEDER_RATE, 0, 0, 0, 0 },
1731	{ 0, 0, 0, 0, 0 },
1732};
1733
1734static kobj_method_t feeder_rate_methods[] = {
1735	KOBJMETHOD(feeder_init,		z_resampler_init),
1736	KOBJMETHOD(feeder_free,		z_resampler_free),
1737	KOBJMETHOD(feeder_set,		z_resampler_set),
1738	KOBJMETHOD(feeder_get,		z_resampler_get),
1739	KOBJMETHOD(feeder_feed,		z_resampler_feed),
1740	KOBJMETHOD_END
1741};
1742
1743FEEDER_DECLARE(feeder_rate, NULL);
1744