xref: /freebsd/sys/dev/sound/pcm/feeder_rate.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005-2009 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 /*
30  * feeder_rate: (Codename: Z Resampler), which means any effort to create
31  *              future replacement for this resampler are simply absurd unless
32  *              the world decide to add new alphabet after Z.
33  *
34  * FreeBSD bandlimited sinc interpolator, technically based on
35  * "Digital Audio Resampling" by Julius O. Smith III
36  *  - http://ccrma.stanford.edu/~jos/resample/
37  *
38  * The Good:
39  * + all out fixed point integer operations, no soft-float or anything like
40  *   that.
41  * + classic polyphase converters with high quality coefficient's polynomial
42  *   interpolators.
43  * + fast, faster, or the fastest of its kind.
44  * + compile time configurable.
45  * + etc etc..
46  *
47  * The Bad:
48  * - The z, z_, and Z_ . Due to mental block (or maybe just 0x7a69), I
49  *   couldn't think of anything simpler than that (feeder_rate_xxx is just
50  *   too long). Expect possible clashes with other zitizens (any?).
51  */
52 
53 #ifdef _KERNEL
54 #ifdef HAVE_KERNEL_OPTION_HEADERS
55 #include "opt_snd.h"
56 #endif
57 #include <dev/sound/pcm/sound.h>
58 #include <dev/sound/pcm/pcm.h>
59 #include "feeder_if.h"
60 
61 #define SND_USE_FXDIV
62 #include "snd_fxdiv_gen.h"
63 
64 SND_DECLARE_FILE("$FreeBSD$");
65 #endif
66 
67 #include "feeder_rate_gen.h"
68 
69 #if !defined(_KERNEL) && defined(SND_DIAGNOSTIC)
70 #undef Z_DIAGNOSTIC
71 #define Z_DIAGNOSTIC		1
72 #elif defined(_KERNEL)
73 #undef Z_DIAGNOSTIC
74 #endif
75 
76 #ifndef Z_QUALITY_DEFAULT
77 #define Z_QUALITY_DEFAULT	Z_QUALITY_LINEAR
78 #endif
79 
80 #define Z_RESERVOIR		2048
81 #define Z_RESERVOIR_MAX		131072
82 
83 #define Z_SINC_MAX		0x3fffff
84 #define Z_SINC_DOWNMAX		48		/* 384000 / 8000 */
85 
86 #ifdef _KERNEL
87 #define Z_POLYPHASE_MAX		183040		/* 286 taps, 640 phases */
88 #else
89 #define Z_POLYPHASE_MAX		1464320		/* 286 taps, 5120 phases */
90 #endif
91 
92 #define Z_RATE_DEFAULT		48000
93 
94 #define Z_RATE_MIN		FEEDRATE_RATEMIN
95 #define Z_RATE_MAX		FEEDRATE_RATEMAX
96 #define Z_ROUNDHZ		FEEDRATE_ROUNDHZ
97 #define Z_ROUNDHZ_MIN		FEEDRATE_ROUNDHZ_MIN
98 #define Z_ROUNDHZ_MAX		FEEDRATE_ROUNDHZ_MAX
99 
100 #define Z_RATE_SRC		FEEDRATE_SRC
101 #define Z_RATE_DST		FEEDRATE_DST
102 #define Z_RATE_QUALITY		FEEDRATE_QUALITY
103 #define Z_RATE_CHANNELS		FEEDRATE_CHANNELS
104 
105 #define Z_PARANOID		1
106 
107 #define Z_MULTIFORMAT		1
108 
109 #ifdef _KERNEL
110 #undef Z_USE_ALPHADRIFT
111 #define Z_USE_ALPHADRIFT	1
112 #endif
113 
114 #define Z_FACTOR_MIN		1
115 #define Z_FACTOR_MAX		Z_MASK
116 #define Z_FACTOR_SAFE(v)	(!((v) < Z_FACTOR_MIN || (v) > Z_FACTOR_MAX))
117 
118 struct z_info;
119 
120 typedef void (*z_resampler_t)(struct z_info *, uint8_t *);
121 
122 struct z_info {
123 	int32_t rsrc, rdst;	/* original source / destination rates */
124 	int32_t src, dst;	/* rounded source / destination rates */
125 	int32_t channels;	/* total channels */
126 	int32_t bps;		/* bytes-per-sample */
127 	int32_t quality;	/* resampling quality */
128 
129 	int32_t z_gx, z_gy;	/* interpolation / decimation ratio */
130 	int32_t z_alpha;	/* output sample time phase / drift */
131 	uint8_t *z_delay;	/* FIR delay line / linear buffer */
132 	int32_t *z_coeff;	/* FIR coefficients */
133 	int32_t *z_dcoeff;	/* FIR coefficients differences */
134 	int32_t *z_pcoeff;	/* FIR polyphase coefficients */
135 	int32_t z_scale;	/* output scaling */
136 	int32_t z_dx;		/* input sample drift increment */
137 	int32_t z_dy;		/* output sample drift increment */
138 #ifdef Z_USE_ALPHADRIFT
139 	int32_t z_alphadrift;	/* alpha drift rate */
140 	int32_t z_startdrift;	/* buffer start position drift rate */
141 #endif
142 	int32_t z_mask;		/* delay line full length mask */
143 	int32_t z_size;		/* half width of FIR taps */
144 	int32_t z_full;		/* full size of delay line */
145 	int32_t z_alloc;	/* largest allocated full size of delay line */
146 	int32_t z_start;	/* buffer processing start position */
147 	int32_t z_pos;		/* current position for the next feed */
148 #ifdef Z_DIAGNOSTIC
149 	uint32_t z_cycle;	/* output cycle, purely for statistical */
150 #endif
151 	int32_t z_maxfeed;	/* maximum feed to avoid 32bit overflow */
152 
153 	z_resampler_t z_resample;
154 };
155 
156 int feeder_rate_min = Z_RATE_MIN;
157 int feeder_rate_max = Z_RATE_MAX;
158 int feeder_rate_round = Z_ROUNDHZ;
159 int feeder_rate_quality = Z_QUALITY_DEFAULT;
160 
161 static int feeder_rate_polyphase_max = Z_POLYPHASE_MAX;
162 
163 #ifdef _KERNEL
164 static char feeder_rate_presets[] = FEEDER_RATE_PRESETS;
165 SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_rate_presets, CTLFLAG_RD,
166     &feeder_rate_presets, 0, "compile-time rate presets");
167 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_rate_polyphase_max, CTLFLAG_RWTUN,
168     &feeder_rate_polyphase_max, 0, "maximum allowable polyphase entries");
169 
170 static int
171 sysctl_hw_snd_feeder_rate_min(SYSCTL_HANDLER_ARGS)
172 {
173 	int err, val;
174 
175 	val = feeder_rate_min;
176 	err = sysctl_handle_int(oidp, &val, 0, req);
177 
178 	if (err != 0 || req->newptr == NULL || val == feeder_rate_min)
179 		return (err);
180 
181 	if (!(Z_FACTOR_SAFE(val) && val < feeder_rate_max))
182 		return (EINVAL);
183 
184 	feeder_rate_min = val;
185 
186 	return (0);
187 }
188 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_min, CTLTYPE_INT | CTLFLAG_RWTUN,
189     0, sizeof(int), sysctl_hw_snd_feeder_rate_min, "I",
190     "minimum allowable rate");
191 
192 static int
193 sysctl_hw_snd_feeder_rate_max(SYSCTL_HANDLER_ARGS)
194 {
195 	int err, val;
196 
197 	val = feeder_rate_max;
198 	err = sysctl_handle_int(oidp, &val, 0, req);
199 
200 	if (err != 0 || req->newptr == NULL || val == feeder_rate_max)
201 		return (err);
202 
203 	if (!(Z_FACTOR_SAFE(val) && val > feeder_rate_min))
204 		return (EINVAL);
205 
206 	feeder_rate_max = val;
207 
208 	return (0);
209 }
210 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_max, CTLTYPE_INT | CTLFLAG_RWTUN,
211     0, sizeof(int), sysctl_hw_snd_feeder_rate_max, "I",
212     "maximum allowable rate");
213 
214 static int
215 sysctl_hw_snd_feeder_rate_round(SYSCTL_HANDLER_ARGS)
216 {
217 	int err, val;
218 
219 	val = feeder_rate_round;
220 	err = sysctl_handle_int(oidp, &val, 0, req);
221 
222 	if (err != 0 || req->newptr == NULL || val == feeder_rate_round)
223 		return (err);
224 
225 	if (val < Z_ROUNDHZ_MIN || val > Z_ROUNDHZ_MAX)
226 		return (EINVAL);
227 
228 	feeder_rate_round = val - (val % Z_ROUNDHZ);
229 
230 	return (0);
231 }
232 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_round, CTLTYPE_INT | CTLFLAG_RWTUN,
233     0, sizeof(int), sysctl_hw_snd_feeder_rate_round, "I",
234     "sample rate converter rounding threshold");
235 
236 static int
237 sysctl_hw_snd_feeder_rate_quality(SYSCTL_HANDLER_ARGS)
238 {
239 	struct snddev_info *d;
240 	struct pcm_channel *c;
241 	struct pcm_feeder *f;
242 	int i, err, val;
243 
244 	val = feeder_rate_quality;
245 	err = sysctl_handle_int(oidp, &val, 0, req);
246 
247 	if (err != 0 || req->newptr == NULL || val == feeder_rate_quality)
248 		return (err);
249 
250 	if (val < Z_QUALITY_MIN || val > Z_QUALITY_MAX)
251 		return (EINVAL);
252 
253 	feeder_rate_quality = val;
254 
255 	/*
256 	 * Traverse all available channels on each device and try to
257 	 * set resampler quality if and only if it is exist as
258 	 * part of feeder chains and the channel is idle.
259 	 */
260 	for (i = 0; pcm_devclass != NULL &&
261 	    i < devclass_get_maxunit(pcm_devclass); i++) {
262 		d = devclass_get_softc(pcm_devclass, i);
263 		if (!PCM_REGISTERED(d))
264 			continue;
265 		PCM_LOCK(d);
266 		PCM_WAIT(d);
267 		PCM_ACQUIRE(d);
268 		CHN_FOREACH(c, d, channels.pcm) {
269 			CHN_LOCK(c);
270 			f = chn_findfeeder(c, FEEDER_RATE);
271 			if (f == NULL || f->data == NULL || CHN_STARTED(c)) {
272 				CHN_UNLOCK(c);
273 				continue;
274 			}
275 			(void)FEEDER_SET(f, FEEDRATE_QUALITY, val);
276 			CHN_UNLOCK(c);
277 		}
278 		PCM_RELEASE(d);
279 		PCM_UNLOCK(d);
280 	}
281 
282 	return (0);
283 }
284 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_quality, CTLTYPE_INT | CTLFLAG_RWTUN,
285     0, sizeof(int), sysctl_hw_snd_feeder_rate_quality, "I",
286     "sample rate converter quality ("__XSTRING(Z_QUALITY_MIN)"=low .. "
287     __XSTRING(Z_QUALITY_MAX)"=high)");
288 #endif	/* _KERNEL */
289 
290 
291 /*
292  * Resampler type.
293  */
294 #define Z_IS_ZOH(i)		((i)->quality == Z_QUALITY_ZOH)
295 #define Z_IS_LINEAR(i)		((i)->quality == Z_QUALITY_LINEAR)
296 #define Z_IS_SINC(i)		((i)->quality > Z_QUALITY_LINEAR)
297 
298 /*
299  * Macroses for accurate sample time drift calculations.
300  *
301  * gy2gx : given the amount of output, return the _exact_ required amount of
302  *         input.
303  * gx2gy : given the amount of input, return the _maximum_ amount of output
304  *         that will be generated.
305  * drift : given the amount of input and output, return the elapsed
306  *         sample-time.
307  */
308 #define _Z_GCAST(x)		((uint64_t)(x))
309 
310 #if defined(__GNUCLIKE_ASM) && defined(__i386__)
311 /*
312  * This is where i386 being beaten to a pulp. Fortunately this function is
313  * rarely being called and if it is, it will decide the best (hopefully)
314  * fastest way to do the division. If we can ensure that everything is dword
315  * aligned, letting the compiler to call udivdi3 to do the division can be
316  * faster compared to this.
317  *
318  * amd64 is the clear winner here, no question about it.
319  */
320 static __inline uint32_t
321 Z_DIV(uint64_t v, uint32_t d)
322 {
323 	uint32_t hi, lo, quo, rem;
324 
325 	hi = v >> 32;
326 	lo = v & 0xffffffff;
327 
328 	/*
329 	 * As much as we can, try to avoid long division like a plague.
330 	 */
331 	if (hi == 0)
332 		quo = lo / d;
333 	else
334 		__asm("divl %2"
335 		    : "=a" (quo), "=d" (rem)
336 		    : "r" (d), "0" (lo), "1" (hi));
337 
338 	return (quo);
339 }
340 #else
341 #define Z_DIV(x, y)		((x) / (y))
342 #endif
343 
344 #define _Z_GY2GX(i, a, v)						\
345 	Z_DIV(((_Z_GCAST((i)->z_gx) * (v)) + ((i)->z_gy - (a) - 1)),	\
346 	(i)->z_gy)
347 
348 #define _Z_GX2GY(i, a, v)						\
349 	Z_DIV(((_Z_GCAST((i)->z_gy) * (v)) + (a)), (i)->z_gx)
350 
351 #define _Z_DRIFT(i, x, y)						\
352 	((_Z_GCAST((i)->z_gy) * (x)) - (_Z_GCAST((i)->z_gx) * (y)))
353 
354 #define z_gy2gx(i, v)		_Z_GY2GX(i, (i)->z_alpha, v)
355 #define z_gx2gy(i, v)		_Z_GX2GY(i, (i)->z_alpha, v)
356 #define z_drift(i, x, y)	_Z_DRIFT(i, x, y)
357 
358 /*
359  * Macroses for SINC coefficients table manipulations.. whatever.
360  */
361 #define Z_SINC_COEFF_IDX(i)	((i)->quality - Z_QUALITY_LINEAR - 1)
362 
363 #define Z_SINC_LEN(i)							\
364 	((int32_t)(((uint64_t)z_coeff_tab[Z_SINC_COEFF_IDX(i)].len <<	\
365 	    Z_SHIFT) / (i)->z_dy))
366 
367 #define Z_SINC_BASE_LEN(i)						\
368 	((z_coeff_tab[Z_SINC_COEFF_IDX(i)].len - 1) >> (Z_DRIFT_SHIFT - 1))
369 
370 /*
371  * Macroses for linear delay buffer operations. Alignment is not
372  * really necessary since we're not using true circular buffer, but it
373  * will help us guard against possible trespasser. To be honest,
374  * the linear block operations does not need guarding at all due to
375  * accurate drifting!
376  */
377 #define z_align(i, v)		((v) & (i)->z_mask)
378 #define z_next(i, o, v)		z_align(i, (o) + (v))
379 #define z_prev(i, o, v)		z_align(i, (o) - (v))
380 #define z_fetched(i)		(z_align(i, (i)->z_pos - (i)->z_start) - 1)
381 #define z_free(i)		((i)->z_full - (i)->z_pos)
382 
383 /*
384  * Macroses for Bla Bla .. :)
385  */
386 #define z_copy(src, dst, sz)	(void)memcpy(dst, src, sz)
387 #define z_feed(...)		FEEDER_FEED(__VA_ARGS__)
388 
389 static __inline uint32_t
390 z_min(uint32_t x, uint32_t y)
391 {
392 
393 	return ((x < y) ? x : y);
394 }
395 
396 static int32_t
397 z_gcd(int32_t x, int32_t y)
398 {
399 	int32_t w;
400 
401 	while (y != 0) {
402 		w = x % y;
403 		x = y;
404 		y = w;
405 	}
406 
407 	return (x);
408 }
409 
410 static int32_t
411 z_roundpow2(int32_t v)
412 {
413 	int32_t i;
414 
415 	i = 1;
416 
417 	/*
418 	 * Let it overflow at will..
419 	 */
420 	while (i > 0 && i < v)
421 		i <<= 1;
422 
423 	return (i);
424 }
425 
426 /*
427  * Zero Order Hold, the worst of the worst, an insult against quality,
428  * but super fast.
429  */
430 static void
431 z_feed_zoh(struct z_info *info, uint8_t *dst)
432 {
433 #if 0
434 	z_copy(info->z_delay +
435 	    (info->z_start * info->channels * info->bps), dst,
436 	    info->channels * info->bps);
437 #else
438 	uint32_t cnt;
439 	uint8_t *src;
440 
441 	cnt = info->channels * info->bps;
442 	src = info->z_delay + (info->z_start * cnt);
443 
444 	/*
445 	 * This is a bit faster than doing bcopy() since we're dealing
446 	 * with possible unaligned samples.
447 	 */
448 	do {
449 		*dst++ = *src++;
450 	} while (--cnt != 0);
451 #endif
452 }
453 
454 /*
455  * Linear Interpolation. This at least sounds better (perceptually) and fast,
456  * but without any proper filtering which means aliasing still exist and
457  * could become worst with a right sample. Interpolation centered within
458  * Z_LINEAR_ONE between the present and previous sample and everything is
459  * done with simple 32bit scaling arithmetic.
460  */
461 #define Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)					\
462 static void									\
463 z_feed_linear_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)		\
464 {										\
465 	int32_t z;								\
466 	intpcm_t x, y;								\
467 	uint32_t ch;								\
468 	uint8_t *sx, *sy;							\
469 										\
470 	z = ((uint32_t)info->z_alpha * info->z_dx) >> Z_LINEAR_UNSHIFT;		\
471 										\
472 	sx = info->z_delay + (info->z_start * info->channels *			\
473 	    PCM_##BIT##_BPS);							\
474 	sy = sx - (info->channels * PCM_##BIT##_BPS);				\
475 										\
476 	ch = info->channels;							\
477 										\
478 	do {									\
479 		x = _PCM_READ_##SIGN##BIT##_##ENDIAN(sx);			\
480 		y = _PCM_READ_##SIGN##BIT##_##ENDIAN(sy);			\
481 		x = Z_LINEAR_INTERPOLATE_##BIT(z, x, y);			\
482 		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, x);			\
483 		sx += PCM_##BIT##_BPS;						\
484 		sy += PCM_##BIT##_BPS;						\
485 		dst += PCM_##BIT##_BPS;						\
486 	} while (--ch != 0);							\
487 }
488 
489 /*
490  * Userland clipping diagnostic check, not enabled in kernel compilation.
491  * While doing sinc interpolation, unrealistic samples like full scale sine
492  * wav will clip, but for other things this will not make any noise at all.
493  * Everybody should learn how to normalized perceived loudness of their own
494  * music/sounds/samples (hint: ReplayGain).
495  */
496 #ifdef Z_DIAGNOSTIC
497 #define Z_CLIP_CHECK(v, BIT)	do {					\
498 	if ((v) > PCM_S##BIT##_MAX) {					\
499 		fprintf(stderr, "Overflow: v=%jd, max=%jd\n",		\
500 		    (intmax_t)(v), (intmax_t)PCM_S##BIT##_MAX);		\
501 	} else if ((v) < PCM_S##BIT##_MIN) {				\
502 		fprintf(stderr, "Underflow: v=%jd, min=%jd\n",		\
503 		    (intmax_t)(v), (intmax_t)PCM_S##BIT##_MIN);		\
504 	}								\
505 } while (0)
506 #else
507 #define Z_CLIP_CHECK(...)
508 #endif
509 
510 #define Z_CLAMP(v, BIT)							\
511 	(((v) > PCM_S##BIT##_MAX) ? PCM_S##BIT##_MAX :			\
512 	(((v) < PCM_S##BIT##_MIN) ? PCM_S##BIT##_MIN : (v)))
513 
514 /*
515  * Sine Cardinal (SINC) Interpolation. Scaling is done in 64 bit, so
516  * there's no point to hold the plate any longer. All samples will be
517  * shifted to a full 32 bit, scaled and restored during write for
518  * maximum dynamic range (only for downsampling).
519  */
520 #define _Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, adv)			\
521 	c += z >> Z_SHIFT;						\
522 	z &= Z_MASK;							\
523 	coeff = Z_COEFF_INTERPOLATE(z, z_coeff[c], z_dcoeff[c]);	\
524 	x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);			\
525 	v += Z_NORM_##BIT((intpcm64_t)x * coeff);			\
526 	z += info->z_dy;						\
527 	p adv##= info->channels * PCM_##BIT##_BPS
528 
529 /*
530  * XXX GCC4 optimization is such a !@#$%, need manual unrolling.
531  */
532 #if defined(__GNUC__) && __GNUC__ >= 4
533 #define Z_SINC_ACCUMULATE(...)	do {					\
534 	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
535 	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
536 } while (0)
537 #define Z_SINC_ACCUMULATE_DECR		2
538 #else
539 #define Z_SINC_ACCUMULATE(...)	do {					\
540 	_Z_SINC_ACCUMULATE(__VA_ARGS__);				\
541 } while (0)
542 #define Z_SINC_ACCUMULATE_DECR		1
543 #endif
544 
545 #define Z_DECLARE_SINC(SIGN, BIT, ENDIAN)					\
546 static void									\
547 z_feed_sinc_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)		\
548 {										\
549 	intpcm64_t v;								\
550 	intpcm_t x;								\
551 	uint8_t *p;								\
552 	int32_t coeff, z, *z_coeff, *z_dcoeff;					\
553 	uint32_t c, center, ch, i;						\
554 										\
555 	z_coeff = info->z_coeff;						\
556 	z_dcoeff = info->z_dcoeff;						\
557 	center = z_prev(info, info->z_start, info->z_size);			\
558 	ch = info->channels * PCM_##BIT##_BPS;					\
559 	dst += ch;								\
560 										\
561 	do {									\
562 		dst -= PCM_##BIT##_BPS;						\
563 		ch -= PCM_##BIT##_BPS;						\
564 		v = 0;								\
565 		z = info->z_alpha * info->z_dx;					\
566 		c = 0;								\
567 		p = info->z_delay + (z_next(info, center, 1) *			\
568 		    info->channels * PCM_##BIT##_BPS) + ch;			\
569 		for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR) 	\
570 			Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, +);		\
571 		z = info->z_dy - (info->z_alpha * info->z_dx);			\
572 		c = 0;								\
573 		p = info->z_delay + (center * info->channels *			\
574 		    PCM_##BIT##_BPS) + ch;					\
575 		for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR) 	\
576 			Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, -);		\
577 		if (info->z_scale != Z_ONE)					\
578 			v = Z_SCALE_##BIT(v, info->z_scale);			\
579 		else								\
580 			v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;		\
581 		Z_CLIP_CHECK(v, BIT);						\
582 		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));	\
583 	} while (ch != 0);							\
584 }
585 
586 #define Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)				\
587 static void									\
588 z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)	\
589 {										\
590 	intpcm64_t v;								\
591 	intpcm_t x;								\
592 	uint8_t *p;								\
593 	int32_t ch, i, start, *z_pcoeff;					\
594 										\
595 	ch = info->channels * PCM_##BIT##_BPS;					\
596 	dst += ch;								\
597 	start = z_prev(info, info->z_start, (info->z_size << 1) - 1) * ch;	\
598 										\
599 	do {									\
600 		dst -= PCM_##BIT##_BPS;						\
601 		ch -= PCM_##BIT##_BPS;						\
602 		v = 0;								\
603 		p = info->z_delay + start + ch;					\
604 		z_pcoeff = info->z_pcoeff +					\
605 		    ((info->z_alpha * info->z_size) << 1);			\
606 		for (i = info->z_size; i != 0; i--) {				\
607 			x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);		\
608 			v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);		\
609 			z_pcoeff++;						\
610 			p += info->channels * PCM_##BIT##_BPS;			\
611 			x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);		\
612 			v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);		\
613 			z_pcoeff++;						\
614 			p += info->channels * PCM_##BIT##_BPS;			\
615 		}								\
616 		if (info->z_scale != Z_ONE)					\
617 			v = Z_SCALE_##BIT(v, info->z_scale);			\
618 		else								\
619 			v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;		\
620 		Z_CLIP_CHECK(v, BIT);						\
621 		_PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));	\
622 	} while (ch != 0);							\
623 }
624 
625 #define Z_DECLARE(SIGN, BIT, ENDIAN)					\
626 	Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)				\
627 	Z_DECLARE_SINC(SIGN, BIT, ENDIAN)				\
628 	Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)
629 
630 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
631 Z_DECLARE(S, 16, LE)
632 Z_DECLARE(S, 32, LE)
633 #endif
634 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
635 Z_DECLARE(S, 16, BE)
636 Z_DECLARE(S, 32, BE)
637 #endif
638 #ifdef SND_FEEDER_MULTIFORMAT
639 Z_DECLARE(S,  8, NE)
640 Z_DECLARE(S, 24, LE)
641 Z_DECLARE(S, 24, BE)
642 Z_DECLARE(U,  8, NE)
643 Z_DECLARE(U, 16, LE)
644 Z_DECLARE(U, 24, LE)
645 Z_DECLARE(U, 32, LE)
646 Z_DECLARE(U, 16, BE)
647 Z_DECLARE(U, 24, BE)
648 Z_DECLARE(U, 32, BE)
649 #endif
650 
651 enum {
652 	Z_RESAMPLER_ZOH,
653 	Z_RESAMPLER_LINEAR,
654 	Z_RESAMPLER_SINC,
655 	Z_RESAMPLER_SINC_POLYPHASE,
656 	Z_RESAMPLER_LAST
657 };
658 
659 #define Z_RESAMPLER_IDX(i)						\
660 	(Z_IS_SINC(i) ? Z_RESAMPLER_SINC : (i)->quality)
661 
662 #define Z_RESAMPLER_ENTRY(SIGN, BIT, ENDIAN)					\
663 	{									\
664 	    AFMT_##SIGN##BIT##_##ENDIAN,					\
665 	    {									\
666 		[Z_RESAMPLER_ZOH]    = z_feed_zoh,				\
667 		[Z_RESAMPLER_LINEAR] = z_feed_linear_##SIGN##BIT##ENDIAN,	\
668 		[Z_RESAMPLER_SINC]   = z_feed_sinc_##SIGN##BIT##ENDIAN,		\
669 		[Z_RESAMPLER_SINC_POLYPHASE]   =				\
670 		    z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN			\
671 	    }									\
672 	}
673 
674 static const struct {
675 	uint32_t format;
676 	z_resampler_t resampler[Z_RESAMPLER_LAST];
677 } z_resampler_tab[] = {
678 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
679 	Z_RESAMPLER_ENTRY(S, 16, LE),
680 	Z_RESAMPLER_ENTRY(S, 32, LE),
681 #endif
682 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
683 	Z_RESAMPLER_ENTRY(S, 16, BE),
684 	Z_RESAMPLER_ENTRY(S, 32, BE),
685 #endif
686 #ifdef SND_FEEDER_MULTIFORMAT
687 	Z_RESAMPLER_ENTRY(S,  8, NE),
688 	Z_RESAMPLER_ENTRY(S, 24, LE),
689 	Z_RESAMPLER_ENTRY(S, 24, BE),
690 	Z_RESAMPLER_ENTRY(U,  8, NE),
691 	Z_RESAMPLER_ENTRY(U, 16, LE),
692 	Z_RESAMPLER_ENTRY(U, 24, LE),
693 	Z_RESAMPLER_ENTRY(U, 32, LE),
694 	Z_RESAMPLER_ENTRY(U, 16, BE),
695 	Z_RESAMPLER_ENTRY(U, 24, BE),
696 	Z_RESAMPLER_ENTRY(U, 32, BE),
697 #endif
698 };
699 
700 #define Z_RESAMPLER_TAB_SIZE						\
701 	((int32_t)(sizeof(z_resampler_tab) / sizeof(z_resampler_tab[0])))
702 
703 static void
704 z_resampler_reset(struct z_info *info)
705 {
706 
707 	info->src = info->rsrc - (info->rsrc % ((feeder_rate_round > 0 &&
708 	    info->rsrc > feeder_rate_round) ? feeder_rate_round : 1));
709 	info->dst = info->rdst - (info->rdst % ((feeder_rate_round > 0 &&
710 	    info->rdst > feeder_rate_round) ? feeder_rate_round : 1));
711 	info->z_gx = 1;
712 	info->z_gy = 1;
713 	info->z_alpha = 0;
714 	info->z_resample = NULL;
715 	info->z_size = 1;
716 	info->z_coeff = NULL;
717 	info->z_dcoeff = NULL;
718 	if (info->z_pcoeff != NULL) {
719 		free(info->z_pcoeff, M_DEVBUF);
720 		info->z_pcoeff = NULL;
721 	}
722 	info->z_scale = Z_ONE;
723 	info->z_dx = Z_FULL_ONE;
724 	info->z_dy = Z_FULL_ONE;
725 #ifdef Z_DIAGNOSTIC
726 	info->z_cycle = 0;
727 #endif
728 	if (info->quality < Z_QUALITY_MIN)
729 		info->quality = Z_QUALITY_MIN;
730 	else if (info->quality > Z_QUALITY_MAX)
731 		info->quality = Z_QUALITY_MAX;
732 }
733 
734 #ifdef Z_PARANOID
735 static int32_t
736 z_resampler_sinc_len(struct z_info *info)
737 {
738 	int32_t c, z, len, lmax;
739 
740 	if (!Z_IS_SINC(info))
741 		return (1);
742 
743 	/*
744 	 * A rather careful (or useless) way to calculate filter length.
745 	 * Z_SINC_LEN() itself is accurate enough to do its job. Extra
746 	 * sanity checking is not going to hurt though..
747 	 */
748 	c = 0;
749 	z = info->z_dy;
750 	len = 0;
751 	lmax = z_coeff_tab[Z_SINC_COEFF_IDX(info)].len;
752 
753 	do {
754 		c += z >> Z_SHIFT;
755 		z &= Z_MASK;
756 		z += info->z_dy;
757 	} while (c < lmax && ++len > 0);
758 
759 	if (len != Z_SINC_LEN(info)) {
760 #ifdef _KERNEL
761 		printf("%s(): sinc l=%d != Z_SINC_LEN=%d\n",
762 		    __func__, len, Z_SINC_LEN(info));
763 #else
764 		fprintf(stderr, "%s(): sinc l=%d != Z_SINC_LEN=%d\n",
765 		    __func__, len, Z_SINC_LEN(info));
766 		return (-1);
767 #endif
768 	}
769 
770 	return (len);
771 }
772 #else
773 #define z_resampler_sinc_len(i)		(Z_IS_SINC(i) ? Z_SINC_LEN(i) : 1)
774 #endif
775 
776 #define Z_POLYPHASE_COEFF_SHIFT		0
777 
778 /*
779  * Pick suitable polynomial interpolators based on filter oversampled ratio
780  * (2 ^ Z_DRIFT_SHIFT).
781  */
782 #if !(defined(Z_COEFF_INTERP_ZOH) || defined(Z_COEFF_INTERP_LINEAR) ||		\
783     defined(Z_COEFF_INTERP_QUADRATIC) || defined(Z_COEFF_INTERP_HERMITE) ||	\
784     defined(Z_COEFF_INTER_BSPLINE) || defined(Z_COEFF_INTERP_OPT32X) ||		\
785     defined(Z_COEFF_INTERP_OPT16X) || defined(Z_COEFF_INTERP_OPT8X) ||		\
786     defined(Z_COEFF_INTERP_OPT4X) || defined(Z_COEFF_INTERP_OPT2X))
787 #if Z_DRIFT_SHIFT >= 6
788 #define Z_COEFF_INTERP_BSPLINE		1
789 #elif Z_DRIFT_SHIFT >= 5
790 #define Z_COEFF_INTERP_OPT32X		1
791 #elif Z_DRIFT_SHIFT == 4
792 #define Z_COEFF_INTERP_OPT16X		1
793 #elif Z_DRIFT_SHIFT == 3
794 #define Z_COEFF_INTERP_OPT8X		1
795 #elif Z_DRIFT_SHIFT == 2
796 #define Z_COEFF_INTERP_OPT4X		1
797 #elif Z_DRIFT_SHIFT == 1
798 #define Z_COEFF_INTERP_OPT2X		1
799 #else
800 #error "Z_DRIFT_SHIFT screwed!"
801 #endif
802 #endif
803 
804 /*
805  * In classic polyphase mode, the actual coefficients for each phases need to
806  * be calculated based on default prototype filters. For highly oversampled
807  * filter, linear or quadradatic interpolator should be enough. Anything less
808  * than that require 'special' interpolators to reduce interpolation errors.
809  *
810  * "Polynomial Interpolators for High-Quality Resampling of Oversampled Audio"
811  *    by Olli Niemitalo
812  *    - http://www.student.oulu.fi/~oniemita/dsp/deip.pdf
813  *
814  */
815 static int32_t
816 z_coeff_interpolate(int32_t z, int32_t *z_coeff)
817 {
818 	int32_t coeff;
819 #if defined(Z_COEFF_INTERP_ZOH)
820 
821 	/* 1-point, 0th-order (Zero Order Hold) */
822 	z = z;
823 	coeff = z_coeff[0];
824 #elif defined(Z_COEFF_INTERP_LINEAR)
825 	int32_t zl0, zl1;
826 
827 	/* 2-point, 1st-order Linear */
828 	zl0 = z_coeff[0];
829 	zl1 = z_coeff[1] - z_coeff[0];
830 
831 	coeff = Z_RSHIFT((int64_t)zl1 * z, Z_SHIFT) + zl0;
832 #elif defined(Z_COEFF_INTERP_QUADRATIC)
833 	int32_t zq0, zq1, zq2;
834 
835 	/* 3-point, 2nd-order Quadratic */
836 	zq0 = z_coeff[0];
837 	zq1 = z_coeff[1] - z_coeff[-1];
838 	zq2 = z_coeff[1] + z_coeff[-1] - (z_coeff[0] << 1);
839 
840 	coeff = Z_RSHIFT((Z_RSHIFT((int64_t)zq2 * z, Z_SHIFT) +
841 	    zq1) * z, Z_SHIFT + 1) + zq0;
842 #elif defined(Z_COEFF_INTERP_HERMITE)
843 	int32_t zh0, zh1, zh2, zh3;
844 
845 	/* 4-point, 3rd-order Hermite */
846 	zh0 = z_coeff[0];
847 	zh1 = z_coeff[1] - z_coeff[-1];
848 	zh2 = (z_coeff[-1] << 1) - (z_coeff[0] * 5) + (z_coeff[1] << 2) -
849 	    z_coeff[2];
850 	zh3 = z_coeff[2] - z_coeff[-1] + ((z_coeff[0] - z_coeff[1]) * 3);
851 
852 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zh3 * z, Z_SHIFT) +
853 	    zh2) * z, Z_SHIFT) + zh1) * z, Z_SHIFT + 1) + zh0;
854 #elif defined(Z_COEFF_INTERP_BSPLINE)
855 	int32_t zb0, zb1, zb2, zb3;
856 
857 	/* 4-point, 3rd-order B-Spline */
858 	zb0 = Z_RSHIFT(0x15555555LL * (((int64_t)z_coeff[0] << 2) +
859 	    z_coeff[-1] + z_coeff[1]), 30);
860 	zb1 = z_coeff[1] - z_coeff[-1];
861 	zb2 = z_coeff[-1] + z_coeff[1] - (z_coeff[0] << 1);
862 	zb3 = Z_RSHIFT(0x15555555LL * (((z_coeff[0] - z_coeff[1]) * 3) +
863 	    z_coeff[2] - z_coeff[-1]), 30);
864 
865 	coeff = (Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zb3 * z, Z_SHIFT) +
866 	    zb2) * z, Z_SHIFT) + zb1) * z, Z_SHIFT) + zb0 + 1) >> 1;
867 #elif defined(Z_COEFF_INTERP_OPT32X)
868 	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
869 	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
870 
871 	/* 6-point, 5th-order Optimal 32x */
872 	zoz = z - (Z_ONE >> 1);
873 	zoe1 = z_coeff[1] + z_coeff[0];
874 	zoe2 = z_coeff[2] + z_coeff[-1];
875 	zoe3 = z_coeff[3] + z_coeff[-2];
876 	zoo1 = z_coeff[1] - z_coeff[0];
877 	zoo2 = z_coeff[2] - z_coeff[-1];
878 	zoo3 = z_coeff[3] - z_coeff[-2];
879 
880 	zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
881 	    (0x00170c29LL * zoe3), 30);
882 	zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
883 	    (0x008cd4dcLL * zoo3), 30);
884 	zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
885 	    (0x0160b5d0LL * zoe3), 30);
886 	zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
887 	    (0x01cfe914LL * zoo3), 30);
888 	zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
889 	    (0x015508ddLL * zoe3), 30);
890 	zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
891 	    (0x0082d81aLL * zoo3), 30);
892 
893 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
894 	    (int64_t)zoc5 * zoz, Z_SHIFT) +
895 	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
896 	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
897 #elif defined(Z_COEFF_INTERP_OPT16X)
898 	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
899 	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
900 
901 	/* 6-point, 5th-order Optimal 16x */
902 	zoz = z - (Z_ONE >> 1);
903 	zoe1 = z_coeff[1] + z_coeff[0];
904 	zoe2 = z_coeff[2] + z_coeff[-1];
905 	zoe3 = z_coeff[3] + z_coeff[-2];
906 	zoo1 = z_coeff[1] - z_coeff[0];
907 	zoo2 = z_coeff[2] - z_coeff[-1];
908 	zoo3 = z_coeff[3] - z_coeff[-2];
909 
910 	zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
911 	    (0x00170c29LL * zoe3), 30);
912 	zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
913 	    (0x008cd4dcLL * zoo3), 30);
914 	zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
915 	    (0x0160b5d0LL * zoe3), 30);
916 	zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
917 	    (0x01cfe914LL * zoo3), 30);
918 	zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
919 	    (0x015508ddLL * zoe3), 30);
920 	zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
921 	    (0x0082d81aLL * zoo3), 30);
922 
923 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
924 	    (int64_t)zoc5 * zoz, Z_SHIFT) +
925 	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
926 	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
927 #elif defined(Z_COEFF_INTERP_OPT8X)
928 	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
929 	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
930 
931 	/* 6-point, 5th-order Optimal 8x */
932 	zoz = z - (Z_ONE >> 1);
933 	zoe1 = z_coeff[1] + z_coeff[0];
934 	zoe2 = z_coeff[2] + z_coeff[-1];
935 	zoe3 = z_coeff[3] + z_coeff[-2];
936 	zoo1 = z_coeff[1] - z_coeff[0];
937 	zoo2 = z_coeff[2] - z_coeff[-1];
938 	zoo3 = z_coeff[3] - z_coeff[-2];
939 
940 	zoc0 = Z_RSHIFT((0x1aa9b47dLL * zoe1) + (0x053d9944LL * zoe2) +
941 	    (0x0018b23fLL * zoe3), 30);
942 	zoc1 = Z_RSHIFT((0x14a104d1LL * zoo1) + (0x0d7d2504LL * zoo2) +
943 	    (0x0094b599LL * zoo3), 30);
944 	zoc2 = Z_RSHIFT((-0x0d22530bLL * zoe1) + (0x0bb37a2cLL * zoe2) +
945 	    (0x016ed8e0LL * zoe3), 30);
946 	zoc3 = Z_RSHIFT((-0x0d744b1cLL * zoo1) + (0x01649591LL * zoo2) +
947 	    (0x01dae93aLL * zoo3), 30);
948 	zoc4 = Z_RSHIFT((0x02a7ee1bLL * zoe1) + (-0x03fbdb24LL * zoe2) +
949 	    (0x0153ed07LL * zoe3), 30);
950 	zoc5 = Z_RSHIFT((0x04cf9b6cLL * zoo1) + (-0x0266b378LL * zoo2) +
951 	    (0x007a7c26LL * zoo3), 30);
952 
953 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
954 	    (int64_t)zoc5 * zoz, Z_SHIFT) +
955 	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
956 	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
957 #elif defined(Z_COEFF_INTERP_OPT4X)
958 	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
959 	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
960 
961 	/* 6-point, 5th-order Optimal 4x */
962 	zoz = z - (Z_ONE >> 1);
963 	zoe1 = z_coeff[1] + z_coeff[0];
964 	zoe2 = z_coeff[2] + z_coeff[-1];
965 	zoe3 = z_coeff[3] + z_coeff[-2];
966 	zoo1 = z_coeff[1] - z_coeff[0];
967 	zoo2 = z_coeff[2] - z_coeff[-1];
968 	zoo3 = z_coeff[3] - z_coeff[-2];
969 
970 	zoc0 = Z_RSHIFT((0x1a8eda43LL * zoe1) + (0x0556ee38LL * zoe2) +
971 	    (0x001a3784LL * zoe3), 30);
972 	zoc1 = Z_RSHIFT((0x143d863eLL * zoo1) + (0x0d910e36LL * zoo2) +
973 	    (0x009ca889LL * zoo3), 30);
974 	zoc2 = Z_RSHIFT((-0x0d026821LL * zoe1) + (0x0b837773LL * zoe2) +
975 	    (0x017ef0c6LL * zoe3), 30);
976 	zoc3 = Z_RSHIFT((-0x0cef1502LL * zoo1) + (0x01207a8eLL * zoo2) +
977 	    (0x01e936dbLL * zoo3), 30);
978 	zoc4 = Z_RSHIFT((0x029fe643LL * zoe1) + (-0x03ef3fc8LL * zoe2) +
979 	    (0x014f5923LL * zoe3), 30);
980 	zoc5 = Z_RSHIFT((0x043a9d08LL * zoo1) + (-0x02154febLL * zoo2) +
981 	    (0x00670dbdLL * zoo3), 30);
982 
983 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
984 	    (int64_t)zoc5 * zoz, Z_SHIFT) +
985 	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
986 	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
987 #elif defined(Z_COEFF_INTERP_OPT2X)
988 	int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
989 	int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
990 
991 	/* 6-point, 5th-order Optimal 2x */
992 	zoz = z - (Z_ONE >> 1);
993 	zoe1 = z_coeff[1] + z_coeff[0];
994 	zoe2 = z_coeff[2] + z_coeff[-1];
995 	zoe3 = z_coeff[3] + z_coeff[-2];
996 	zoo1 = z_coeff[1] - z_coeff[0];
997 	zoo2 = z_coeff[2] - z_coeff[-1];
998 	zoo3 = z_coeff[3] - z_coeff[-2];
999 
1000 	zoc0 = Z_RSHIFT((0x19edb6fdLL * zoe1) + (0x05ebd062LL * zoe2) +
1001 	    (0x00267881LL * zoe3), 30);
1002 	zoc1 = Z_RSHIFT((0x1223af76LL * zoo1) + (0x0de3dd6bLL * zoo2) +
1003 	    (0x00d683cdLL * zoo3), 30);
1004 	zoc2 = Z_RSHIFT((-0x0c3ee068LL * zoe1) + (0x0a5c3769LL * zoe2) +
1005 	    (0x01e2aceaLL * zoe3), 30);
1006 	zoc3 = Z_RSHIFT((-0x0a8ab614LL * zoo1) + (-0x0019522eLL * zoo2) +
1007 	    (0x022cefc7LL * zoo3), 30);
1008 	zoc4 = Z_RSHIFT((0x0276187dLL * zoe1) + (-0x03a801e8LL * zoe2) +
1009 	    (0x0131d935LL * zoe3), 30);
1010 	zoc5 = Z_RSHIFT((0x02c373f5LL * zoo1) + (-0x01275f83LL * zoo2) +
1011 	    (0x0018ee79LL * zoo3), 30);
1012 
1013 	coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
1014 	    (int64_t)zoc5 * zoz, Z_SHIFT) +
1015 	    zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
1016 	    zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
1017 #else
1018 #error "Interpolation type screwed!"
1019 #endif
1020 
1021 #if Z_POLYPHASE_COEFF_SHIFT > 0
1022 	coeff = Z_RSHIFT(coeff, Z_POLYPHASE_COEFF_SHIFT);
1023 #endif
1024 	return (coeff);
1025 }
1026 
1027 static int
1028 z_resampler_build_polyphase(struct z_info *info)
1029 {
1030 	int32_t alpha, c, i, z, idx;
1031 
1032 	/* Let this be here first. */
1033 	if (info->z_pcoeff != NULL) {
1034 		free(info->z_pcoeff, M_DEVBUF);
1035 		info->z_pcoeff = NULL;
1036 	}
1037 
1038 	if (feeder_rate_polyphase_max < 1)
1039 		return (ENOTSUP);
1040 
1041 	if (((int64_t)info->z_size * info->z_gy * 2) >
1042 	    feeder_rate_polyphase_max) {
1043 #ifndef _KERNEL
1044 		fprintf(stderr, "Polyphase entries exceed: [%d/%d] %jd > %d\n",
1045 		    info->z_gx, info->z_gy,
1046 		    (intmax_t)info->z_size * info->z_gy * 2,
1047 		    feeder_rate_polyphase_max);
1048 #endif
1049 		return (E2BIG);
1050 	}
1051 
1052 	info->z_pcoeff = malloc(sizeof(int32_t) *
1053 	    info->z_size * info->z_gy * 2, M_DEVBUF, M_NOWAIT | M_ZERO);
1054 	if (info->z_pcoeff == NULL)
1055 		return (ENOMEM);
1056 
1057 	for (alpha = 0; alpha < info->z_gy; alpha++) {
1058 		z = alpha * info->z_dx;
1059 		c = 0;
1060 		for (i = info->z_size; i != 0; i--) {
1061 			c += z >> Z_SHIFT;
1062 			z &= Z_MASK;
1063 			idx = (alpha * info->z_size * 2) +
1064 			    (info->z_size * 2) - i;
1065 			info->z_pcoeff[idx] =
1066 			    z_coeff_interpolate(z, info->z_coeff + c);
1067 			z += info->z_dy;
1068 		}
1069 		z = info->z_dy - (alpha * info->z_dx);
1070 		c = 0;
1071 		for (i = info->z_size; i != 0; i--) {
1072 			c += z >> Z_SHIFT;
1073 			z &= Z_MASK;
1074 			idx = (alpha * info->z_size * 2) + i - 1;
1075 			info->z_pcoeff[idx] =
1076 			    z_coeff_interpolate(z, info->z_coeff + c);
1077 			z += info->z_dy;
1078 		}
1079 	}
1080 
1081 #ifndef _KERNEL
1082 	fprintf(stderr, "Polyphase: [%d/%d] %d entries\n",
1083 	    info->z_gx, info->z_gy, info->z_size * info->z_gy * 2);
1084 #endif
1085 
1086 	return (0);
1087 }
1088 
1089 static int
1090 z_resampler_setup(struct pcm_feeder *f)
1091 {
1092 	struct z_info *info;
1093 	int64_t gy2gx_max, gx2gy_max;
1094 	uint32_t format;
1095 	int32_t align, i, z_scale;
1096 	int adaptive;
1097 
1098 	info = f->data;
1099 	z_resampler_reset(info);
1100 
1101 	if (info->src == info->dst)
1102 		return (0);
1103 
1104 	/* Shrink by greatest common divisor. */
1105 	i = z_gcd(info->src, info->dst);
1106 	info->z_gx = info->src / i;
1107 	info->z_gy = info->dst / i;
1108 
1109 	/* Too big, or too small. Bail out. */
1110 	if (!(Z_FACTOR_SAFE(info->z_gx) && Z_FACTOR_SAFE(info->z_gy)))
1111 		return (EINVAL);
1112 
1113 	format = f->desc->in;
1114 	adaptive = 0;
1115 	z_scale = 0;
1116 
1117 	/*
1118 	 * Setup everything: filter length, conversion factor, etc.
1119 	 */
1120 	if (Z_IS_SINC(info)) {
1121 		/*
1122 		 * Downsampling, or upsampling scaling factor. As long as the
1123 		 * factor can be represented by a fraction of 1 << Z_SHIFT,
1124 		 * we're pretty much in business. Scaling is not needed for
1125 		 * upsampling, so we just slap Z_ONE there.
1126 		 */
1127 		if (info->z_gx > info->z_gy)
1128 			/*
1129 			 * If the downsampling ratio is beyond sanity,
1130 			 * enable semi-adaptive mode. Although handling
1131 			 * extreme ratio is possible, the result of the
1132 			 * conversion is just pointless, unworthy,
1133 			 * nonsensical noises, etc.
1134 			 */
1135 			if ((info->z_gx / info->z_gy) > Z_SINC_DOWNMAX)
1136 				z_scale = Z_ONE / Z_SINC_DOWNMAX;
1137 			else
1138 				z_scale = ((uint64_t)info->z_gy << Z_SHIFT) /
1139 				    info->z_gx;
1140 		else
1141 			z_scale = Z_ONE;
1142 
1143 		/*
1144 		 * This is actually impossible, unless anything above
1145 		 * overflow.
1146 		 */
1147 		if (z_scale < 1)
1148 			return (E2BIG);
1149 
1150 		/*
1151 		 * Calculate sample time/coefficients index drift. It is
1152 		 * a constant for upsampling, but downsampling require
1153 		 * heavy duty filtering with possible too long filters.
1154 		 * If anything goes wrong, revisit again and enable
1155 		 * adaptive mode.
1156 		 */
1157 z_setup_adaptive_sinc:
1158 		if (info->z_pcoeff != NULL) {
1159 			free(info->z_pcoeff, M_DEVBUF);
1160 			info->z_pcoeff = NULL;
1161 		}
1162 
1163 		if (adaptive == 0) {
1164 			info->z_dy = z_scale << Z_DRIFT_SHIFT;
1165 			if (info->z_dy < 1)
1166 				return (E2BIG);
1167 			info->z_scale = z_scale;
1168 		} else {
1169 			info->z_dy = Z_FULL_ONE;
1170 			info->z_scale = Z_ONE;
1171 		}
1172 
1173 #if 0
1174 #define Z_SCALE_DIV	10000
1175 #define Z_SCALE_LIMIT(s, v)						\
1176 	((((uint64_t)(s) * (v)) + (Z_SCALE_DIV >> 1)) / Z_SCALE_DIV)
1177 
1178 		info->z_scale = Z_SCALE_LIMIT(info->z_scale, 9780);
1179 #endif
1180 
1181 		/* Smallest drift increment. */
1182 		info->z_dx = info->z_dy / info->z_gy;
1183 
1184 		/*
1185 		 * Overflow or underflow. Try adaptive, let it continue and
1186 		 * retry.
1187 		 */
1188 		if (info->z_dx < 1) {
1189 			if (adaptive == 0) {
1190 				adaptive = 1;
1191 				goto z_setup_adaptive_sinc;
1192 			}
1193 			return (E2BIG);
1194 		}
1195 
1196 		/*
1197 		 * Round back output drift.
1198 		 */
1199 		info->z_dy = info->z_dx * info->z_gy;
1200 
1201 		for (i = 0; i < Z_COEFF_TAB_SIZE; i++) {
1202 			if (Z_SINC_COEFF_IDX(info) != i)
1203 				continue;
1204 			/*
1205 			 * Calculate required filter length and guard
1206 			 * against possible abusive result. Note that
1207 			 * this represents only 1/2 of the entire filter
1208 			 * length.
1209 			 */
1210 			info->z_size = z_resampler_sinc_len(info);
1211 
1212 			/*
1213 			 * Multiple of 2 rounding, for better accumulator
1214 			 * performance.
1215 			 */
1216 			info->z_size &= ~1;
1217 
1218 			if (info->z_size < 2 || info->z_size > Z_SINC_MAX) {
1219 				if (adaptive == 0) {
1220 					adaptive = 1;
1221 					goto z_setup_adaptive_sinc;
1222 				}
1223 				return (E2BIG);
1224 			}
1225 			info->z_coeff = z_coeff_tab[i].coeff + Z_COEFF_OFFSET;
1226 			info->z_dcoeff = z_coeff_tab[i].dcoeff;
1227 			break;
1228 		}
1229 
1230 		if (info->z_coeff == NULL || info->z_dcoeff == NULL)
1231 			return (EINVAL);
1232 	} else if (Z_IS_LINEAR(info)) {
1233 		/*
1234 		 * Don't put much effort if we're doing linear interpolation.
1235 		 * Just center the interpolation distance within Z_LINEAR_ONE,
1236 		 * and be happy about it.
1237 		 */
1238 		info->z_dx = Z_LINEAR_FULL_ONE / info->z_gy;
1239 	}
1240 
1241 	/*
1242 	 * We're safe for now, lets continue.. Look for our resampler
1243 	 * depending on configured format and quality.
1244 	 */
1245 	for (i = 0; i < Z_RESAMPLER_TAB_SIZE; i++) {
1246 		int ridx;
1247 
1248 		if (AFMT_ENCODING(format) != z_resampler_tab[i].format)
1249 			continue;
1250 		if (Z_IS_SINC(info) && adaptive == 0 &&
1251 		    z_resampler_build_polyphase(info) == 0)
1252 			ridx = Z_RESAMPLER_SINC_POLYPHASE;
1253 		else
1254 			ridx = Z_RESAMPLER_IDX(info);
1255 		info->z_resample = z_resampler_tab[i].resampler[ridx];
1256 		break;
1257 	}
1258 
1259 	if (info->z_resample == NULL)
1260 		return (EINVAL);
1261 
1262 	info->bps = AFMT_BPS(format);
1263 	align = info->channels * info->bps;
1264 
1265 	/*
1266 	 * Calculate largest value that can be fed into z_gy2gx() and
1267 	 * z_gx2gy() without causing (signed) 32bit overflow. z_gy2gx() will
1268 	 * be called early during feeding process to determine how much input
1269 	 * samples that is required to generate requested output, while
1270 	 * z_gx2gy() will be called just before samples filtering /
1271 	 * accumulation process based on available samples that has been
1272 	 * calculated using z_gx2gy().
1273 	 *
1274 	 * Now that is damn confusing, I guess ;-) .
1275 	 */
1276 	gy2gx_max = (((uint64_t)info->z_gy * INT32_MAX) - info->z_gy + 1) /
1277 	    info->z_gx;
1278 
1279 	if ((gy2gx_max * align) > SND_FXDIV_MAX)
1280 		gy2gx_max = SND_FXDIV_MAX / align;
1281 
1282 	if (gy2gx_max < 1)
1283 		return (E2BIG);
1284 
1285 	gx2gy_max = (((uint64_t)info->z_gx * INT32_MAX) - info->z_gy) /
1286 	    info->z_gy;
1287 
1288 	if (gx2gy_max > INT32_MAX)
1289 		gx2gy_max = INT32_MAX;
1290 
1291 	if (gx2gy_max < 1)
1292 		return (E2BIG);
1293 
1294 	/*
1295 	 * Ensure that z_gy2gx() at its largest possible calculated value
1296 	 * (alpha = 0) will not cause overflow further late during z_gx2gy()
1297 	 * stage.
1298 	 */
1299 	if (z_gy2gx(info, gy2gx_max) > _Z_GCAST(gx2gy_max))
1300 		return (E2BIG);
1301 
1302 	info->z_maxfeed = gy2gx_max * align;
1303 
1304 #ifdef Z_USE_ALPHADRIFT
1305 	info->z_startdrift = z_gy2gx(info, 1);
1306 	info->z_alphadrift = z_drift(info, info->z_startdrift, 1);
1307 #endif
1308 
1309 	i = z_gy2gx(info, 1);
1310 	info->z_full = z_roundpow2((info->z_size << 1) + i);
1311 
1312 	/*
1313 	 * Too big to be true, and overflowing left and right like mad ..
1314 	 */
1315 	if ((info->z_full * align) < 1) {
1316 		if (adaptive == 0 && Z_IS_SINC(info)) {
1317 			adaptive = 1;
1318 			goto z_setup_adaptive_sinc;
1319 		}
1320 		return (E2BIG);
1321 	}
1322 
1323 	/*
1324 	 * Increase full buffer size if its too small to reduce cyclic
1325 	 * buffer shifting in main conversion/feeder loop.
1326 	 */
1327 	while (info->z_full < Z_RESERVOIR_MAX &&
1328 	    (info->z_full - (info->z_size << 1)) < Z_RESERVOIR)
1329 		info->z_full <<= 1;
1330 
1331 	/* Initialize buffer position. */
1332 	info->z_mask = info->z_full - 1;
1333 	info->z_start = z_prev(info, info->z_size << 1, 1);
1334 	info->z_pos = z_next(info, info->z_start, 1);
1335 
1336 	/*
1337 	 * Allocate or reuse delay line buffer, whichever makes sense.
1338 	 */
1339 	i = info->z_full * align;
1340 	if (i < 1)
1341 		return (E2BIG);
1342 
1343 	if (info->z_delay == NULL || info->z_alloc < i ||
1344 	    i <= (info->z_alloc >> 1)) {
1345 		if (info->z_delay != NULL)
1346 			free(info->z_delay, M_DEVBUF);
1347 		info->z_delay = malloc(i, M_DEVBUF, M_NOWAIT | M_ZERO);
1348 		if (info->z_delay == NULL)
1349 			return (ENOMEM);
1350 		info->z_alloc = i;
1351 	}
1352 
1353 	/*
1354 	 * Zero out head of buffer to avoid pops and clicks.
1355 	 */
1356 	memset(info->z_delay, sndbuf_zerodata(f->desc->out),
1357 	    info->z_pos * align);
1358 
1359 #ifdef Z_DIAGNOSTIC
1360 	/*
1361 	 * XXX Debuging mess !@#$%^
1362 	 */
1363 #define dumpz(x)	fprintf(stderr, "\t%12s = %10u : %-11d\n",	\
1364 			    "z_"__STRING(x), (uint32_t)info->z_##x,	\
1365 			    (int32_t)info->z_##x)
1366 	fprintf(stderr, "\n%s():\n", __func__);
1367 	fprintf(stderr, "\tchannels=%d, bps=%d, format=0x%08x, quality=%d\n",
1368 	    info->channels, info->bps, format, info->quality);
1369 	fprintf(stderr, "\t%d (%d) -> %d (%d), ",
1370 	    info->src, info->rsrc, info->dst, info->rdst);
1371 	fprintf(stderr, "[%d/%d]\n", info->z_gx, info->z_gy);
1372 	fprintf(stderr, "\tminreq=%d, ", z_gy2gx(info, 1));
1373 	if (adaptive != 0)
1374 		z_scale = Z_ONE;
1375 	fprintf(stderr, "factor=0x%08x/0x%08x (%f)\n",
1376 	    z_scale, Z_ONE, (double)z_scale / Z_ONE);
1377 	fprintf(stderr, "\tbase_length=%d, ", Z_SINC_BASE_LEN(info));
1378 	fprintf(stderr, "adaptive=%s\n", (adaptive != 0) ? "YES" : "NO");
1379 	dumpz(size);
1380 	dumpz(alloc);
1381 	if (info->z_alloc < 1024)
1382 		fprintf(stderr, "\t%15s%10d Bytes\n",
1383 		    "", info->z_alloc);
1384 	else if (info->z_alloc < (1024 << 10))
1385 		fprintf(stderr, "\t%15s%10d KBytes\n",
1386 		    "", info->z_alloc >> 10);
1387 	else if (info->z_alloc < (1024 << 20))
1388 		fprintf(stderr, "\t%15s%10d MBytes\n",
1389 		    "", info->z_alloc >> 20);
1390 	else
1391 		fprintf(stderr, "\t%15s%10d GBytes\n",
1392 		    "", info->z_alloc >> 30);
1393 	fprintf(stderr, "\t%12s   %10d (min output samples)\n",
1394 	    "",
1395 	    (int32_t)z_gx2gy(info, info->z_full - (info->z_size << 1)));
1396 	fprintf(stderr, "\t%12s   %10d (min allocated output samples)\n",
1397 	    "",
1398 	    (int32_t)z_gx2gy(info, (info->z_alloc / align) -
1399 	    (info->z_size << 1)));
1400 	fprintf(stderr, "\t%12s = %10d\n",
1401 	    "z_gy2gx()", (int32_t)z_gy2gx(info, 1));
1402 	fprintf(stderr, "\t%12s = %10d -> z_gy2gx() -> %d\n",
1403 	    "Max", (int32_t)gy2gx_max, (int32_t)z_gy2gx(info, gy2gx_max));
1404 	fprintf(stderr, "\t%12s = %10d\n",
1405 	    "z_gx2gy()", (int32_t)z_gx2gy(info, 1));
1406 	fprintf(stderr, "\t%12s = %10d -> z_gx2gy() -> %d\n",
1407 	    "Max", (int32_t)gx2gy_max, (int32_t)z_gx2gy(info, gx2gy_max));
1408 	dumpz(maxfeed);
1409 	dumpz(full);
1410 	dumpz(start);
1411 	dumpz(pos);
1412 	dumpz(scale);
1413 	fprintf(stderr, "\t%12s   %10f\n", "",
1414 	    (double)info->z_scale / Z_ONE);
1415 	dumpz(dx);
1416 	fprintf(stderr, "\t%12s   %10f\n", "",
1417 	    (double)info->z_dx / info->z_dy);
1418 	dumpz(dy);
1419 	fprintf(stderr, "\t%12s   %10d (drift step)\n", "",
1420 	    info->z_dy >> Z_SHIFT);
1421 	fprintf(stderr, "\t%12s   %10d (scaling differences)\n", "",
1422 	    (z_scale << Z_DRIFT_SHIFT) - info->z_dy);
1423 	fprintf(stderr, "\t%12s = %u bytes\n",
1424 	    "intpcm32_t", sizeof(intpcm32_t));
1425 	fprintf(stderr, "\t%12s = 0x%08x, smallest=%.16lf\n",
1426 	    "Z_ONE", Z_ONE, (double)1.0 / (double)Z_ONE);
1427 #endif
1428 
1429 	return (0);
1430 }
1431 
1432 static int
1433 z_resampler_set(struct pcm_feeder *f, int what, int32_t value)
1434 {
1435 	struct z_info *info;
1436 	int32_t oquality;
1437 
1438 	info = f->data;
1439 
1440 	switch (what) {
1441 	case Z_RATE_SRC:
1442 		if (value < feeder_rate_min || value > feeder_rate_max)
1443 			return (E2BIG);
1444 		if (value == info->rsrc)
1445 			return (0);
1446 		info->rsrc = value;
1447 		break;
1448 	case Z_RATE_DST:
1449 		if (value < feeder_rate_min || value > feeder_rate_max)
1450 			return (E2BIG);
1451 		if (value == info->rdst)
1452 			return (0);
1453 		info->rdst = value;
1454 		break;
1455 	case Z_RATE_QUALITY:
1456 		if (value < Z_QUALITY_MIN || value > Z_QUALITY_MAX)
1457 			return (EINVAL);
1458 		if (value == info->quality)
1459 			return (0);
1460 		/*
1461 		 * If we failed to set the requested quality, restore
1462 		 * the old one. We cannot afford leaving it broken since
1463 		 * passive feeder chains like vchans never reinitialize
1464 		 * itself.
1465 		 */
1466 		oquality = info->quality;
1467 		info->quality = value;
1468 		if (z_resampler_setup(f) == 0)
1469 			return (0);
1470 		info->quality = oquality;
1471 		break;
1472 	case Z_RATE_CHANNELS:
1473 		if (value < SND_CHN_MIN || value > SND_CHN_MAX)
1474 			return (EINVAL);
1475 		if (value == info->channels)
1476 			return (0);
1477 		info->channels = value;
1478 		break;
1479 	default:
1480 		return (EINVAL);
1481 		break;
1482 	}
1483 
1484 	return (z_resampler_setup(f));
1485 }
1486 
1487 static int
1488 z_resampler_get(struct pcm_feeder *f, int what)
1489 {
1490 	struct z_info *info;
1491 
1492 	info = f->data;
1493 
1494 	switch (what) {
1495 	case Z_RATE_SRC:
1496 		return (info->rsrc);
1497 		break;
1498 	case Z_RATE_DST:
1499 		return (info->rdst);
1500 		break;
1501 	case Z_RATE_QUALITY:
1502 		return (info->quality);
1503 		break;
1504 	case Z_RATE_CHANNELS:
1505 		return (info->channels);
1506 		break;
1507 	default:
1508 		break;
1509 	}
1510 
1511 	return (-1);
1512 }
1513 
1514 static int
1515 z_resampler_init(struct pcm_feeder *f)
1516 {
1517 	struct z_info *info;
1518 	int ret;
1519 
1520 	if (f->desc->in != f->desc->out)
1521 		return (EINVAL);
1522 
1523 	info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO);
1524 	if (info == NULL)
1525 		return (ENOMEM);
1526 
1527 	info->rsrc = Z_RATE_DEFAULT;
1528 	info->rdst = Z_RATE_DEFAULT;
1529 	info->quality = feeder_rate_quality;
1530 	info->channels = AFMT_CHANNEL(f->desc->in);
1531 
1532 	f->data = info;
1533 
1534 	ret = z_resampler_setup(f);
1535 	if (ret != 0) {
1536 		if (info->z_pcoeff != NULL)
1537 			free(info->z_pcoeff, M_DEVBUF);
1538 		if (info->z_delay != NULL)
1539 			free(info->z_delay, M_DEVBUF);
1540 		free(info, M_DEVBUF);
1541 		f->data = NULL;
1542 	}
1543 
1544 	return (ret);
1545 }
1546 
1547 static int
1548 z_resampler_free(struct pcm_feeder *f)
1549 {
1550 	struct z_info *info;
1551 
1552 	info = f->data;
1553 	if (info != NULL) {
1554 		if (info->z_pcoeff != NULL)
1555 			free(info->z_pcoeff, M_DEVBUF);
1556 		if (info->z_delay != NULL)
1557 			free(info->z_delay, M_DEVBUF);
1558 		free(info, M_DEVBUF);
1559 	}
1560 
1561 	f->data = NULL;
1562 
1563 	return (0);
1564 }
1565 
1566 static uint32_t
1567 z_resampler_feed_internal(struct pcm_feeder *f, struct pcm_channel *c,
1568     uint8_t *b, uint32_t count, void *source)
1569 {
1570 	struct z_info *info;
1571 	int32_t alphadrift, startdrift, reqout, ocount, reqin, align;
1572 	int32_t fetch, fetched, start, cp;
1573 	uint8_t *dst;
1574 
1575 	info = f->data;
1576 	if (info->z_resample == NULL)
1577 		return (z_feed(f->source, c, b, count, source));
1578 
1579 	/*
1580 	 * Calculate sample size alignment and amount of sample output.
1581 	 * We will do everything in sample domain, but at the end we
1582 	 * will jump back to byte domain.
1583 	 */
1584 	align = info->channels * info->bps;
1585 	ocount = SND_FXDIV(count, align);
1586 	if (ocount == 0)
1587 		return (0);
1588 
1589 	/*
1590 	 * Calculate amount of input samples that is needed to generate
1591 	 * exact amount of output.
1592 	 */
1593 	reqin = z_gy2gx(info, ocount) - z_fetched(info);
1594 
1595 #ifdef Z_USE_ALPHADRIFT
1596 	startdrift = info->z_startdrift;
1597 	alphadrift = info->z_alphadrift;
1598 #else
1599 	startdrift = _Z_GY2GX(info, 0, 1);
1600 	alphadrift = z_drift(info, startdrift, 1);
1601 #endif
1602 
1603 	dst = b;
1604 
1605 	do {
1606 		if (reqin != 0) {
1607 			fetch = z_min(z_free(info), reqin);
1608 			if (fetch == 0) {
1609 				/*
1610 				 * No more free spaces, so wind enough
1611 				 * samples back to the head of delay line
1612 				 * in byte domain.
1613 				 */
1614 				fetched = z_fetched(info);
1615 				start = z_prev(info, info->z_start,
1616 				    (info->z_size << 1) - 1);
1617 				cp = (info->z_size << 1) + fetched;
1618 				z_copy(info->z_delay + (start * align),
1619 				    info->z_delay, cp * align);
1620 				info->z_start =
1621 				    z_prev(info, info->z_size << 1, 1);
1622 				info->z_pos =
1623 				    z_next(info, info->z_start, fetched + 1);
1624 				fetch = z_min(z_free(info), reqin);
1625 #ifdef Z_DIAGNOSTIC
1626 				if (1) {
1627 					static uint32_t kk = 0;
1628 					fprintf(stderr,
1629 					    "Buffer Move: "
1630 					    "start=%d fetched=%d cp=%d "
1631 					    "cycle=%u [%u]\r",
1632 					    start, fetched, cp, info->z_cycle,
1633 					    ++kk);
1634 				}
1635 				info->z_cycle = 0;
1636 #endif
1637 			}
1638 			if (fetch != 0) {
1639 				/*
1640 				 * Fetch in byte domain and jump back
1641 				 * to sample domain.
1642 				 */
1643 				fetched = SND_FXDIV(z_feed(f->source, c,
1644 				    info->z_delay + (info->z_pos * align),
1645 				    fetch * align, source), align);
1646 				/*
1647 				 * Prepare to convert fetched buffer,
1648 				 * or mark us done if we cannot fulfill
1649 				 * the request.
1650 				 */
1651 				reqin -= fetched;
1652 				info->z_pos += fetched;
1653 				if (fetched != fetch)
1654 					reqin = 0;
1655 			}
1656 		}
1657 
1658 		reqout = z_min(z_gx2gy(info, z_fetched(info)), ocount);
1659 		if (reqout != 0) {
1660 			ocount -= reqout;
1661 
1662 			/*
1663 			 * Drift.. drift.. drift..
1664 			 *
1665 			 * Notice that there are 2 methods of doing the drift
1666 			 * operations: The former is much cleaner (in a sense
1667 			 * of mathematical readings of my eyes), but slower
1668 			 * due to integer division in z_gy2gx(). Nevertheless,
1669 			 * both should give the same exact accurate drifting
1670 			 * results, so the later is favourable.
1671 			 */
1672 			do {
1673 				info->z_resample(info, dst);
1674 #if 0
1675 				startdrift = z_gy2gx(info, 1);
1676 				alphadrift = z_drift(info, startdrift, 1);
1677 				info->z_start += startdrift;
1678 				info->z_alpha += alphadrift;
1679 #else
1680 				info->z_alpha += alphadrift;
1681 				if (info->z_alpha < info->z_gy)
1682 					info->z_start += startdrift;
1683 				else {
1684 					info->z_start += startdrift - 1;
1685 					info->z_alpha -= info->z_gy;
1686 				}
1687 #endif
1688 				dst += align;
1689 #ifdef Z_DIAGNOSTIC
1690 				info->z_cycle++;
1691 #endif
1692 			} while (--reqout != 0);
1693 		}
1694 	} while (reqin != 0 && ocount != 0);
1695 
1696 	/*
1697 	 * Back to byte domain..
1698 	 */
1699 	return (dst - b);
1700 }
1701 
1702 static int
1703 z_resampler_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
1704     uint32_t count, void *source)
1705 {
1706 	uint32_t feed, maxfeed, left;
1707 
1708 	/*
1709 	 * Split count to smaller chunks to avoid possible 32bit overflow.
1710 	 */
1711 	maxfeed = ((struct z_info *)(f->data))->z_maxfeed;
1712 	left = count;
1713 
1714 	do {
1715 		feed = z_resampler_feed_internal(f, c, b,
1716 		    z_min(maxfeed, left), source);
1717 		b += feed;
1718 		left -= feed;
1719 	} while (left != 0 && feed != 0);
1720 
1721 	return (count - left);
1722 }
1723 
1724 static struct pcm_feederdesc feeder_rate_desc[] = {
1725 	{ FEEDER_RATE, 0, 0, 0, 0 },
1726 	{ 0, 0, 0, 0, 0 },
1727 };
1728 
1729 static kobj_method_t feeder_rate_methods[] = {
1730 	KOBJMETHOD(feeder_init,		z_resampler_init),
1731 	KOBJMETHOD(feeder_free,		z_resampler_free),
1732 	KOBJMETHOD(feeder_set,		z_resampler_set),
1733 	KOBJMETHOD(feeder_get,		z_resampler_get),
1734 	KOBJMETHOD(feeder_feed,		z_resampler_feed),
1735 	KOBJMETHOD_END
1736 };
1737 
1738 FEEDER_DECLARE(feeder_rate, NULL);
1739