xref: /dragonfly/sys/dev/sound/pcm/feeder_rate.c (revision 9348a738)
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 
62 SND_DECLARE_FILE("$FreeBSD: head/sys/dev/sound/pcm/feeder_rate.c 267992 2014-06-28 03:56:17Z hselasky $");
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 
116 struct z_info;
117 
118 typedef void (*z_resampler_t)(struct z_info *, uint8_t *);
119 
120 struct 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 
154 int feeder_rate_min = Z_RATE_MIN;
155 int feeder_rate_max = Z_RATE_MAX;
156 int feeder_rate_round = Z_ROUNDHZ;
157 int feeder_rate_quality = Z_QUALITY_DEFAULT;
158 
159 static int feeder_rate_polyphase_max = Z_POLYPHASE_MAX;
160 
161 #ifdef _KERNEL
162 static char feeder_rate_presets[] = FEEDER_RATE_PRESETS;
163 SYSCTL_STRING(_hw_snd, OID_AUTO, feeder_rate_presets, CTLFLAG_RD,
164     &feeder_rate_presets, 0, "compile-time rate presets");
165 
166 TUNABLE_INT("hw.snd.feeder_rate_min", &feeder_rate_min);
167 TUNABLE_INT("hw.snd.feeder_rate_max", &feeder_rate_max);
168 TUNABLE_INT("hw.snd.feeder_rate_round", &feeder_rate_round);
169 TUNABLE_INT("hw.snd.feeder_rate_quality", &feeder_rate_quality);
170 
171 TUNABLE_INT("hw.snd.feeder_rate_polyphase_max", &feeder_rate_polyphase_max);
172 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_rate_polyphase_max, CTLFLAG_RW,
173     &feeder_rate_polyphase_max, 0, "maximum allowable polyphase entries");
174 
175 static int
176 sysctl_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 }
193 SYSCTL_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 
197 static int
198 sysctl_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 }
215 SYSCTL_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 
219 static int
220 sysctl_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 }
237 SYSCTL_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 
241 static int
242 sysctl_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 }
289 SYSCTL_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  */
325 static __inline uint32_t
326 Z_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 
394 static __inline uint32_t
395 z_min(uint32_t x, uint32_t y)
396 {
397 
398 	return ((x < y) ? x : y);
399 }
400 
401 static int32_t
402 z_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 
415 static int32_t
416 z_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  */
435 static void
436 z_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)					\
467 static void									\
468 z_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)					\
551 static void									\
552 z_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)				\
592 static void									\
593 z_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)
636 Z_DECLARE(S, 16, LE)
637 Z_DECLARE(S, 32, LE)
638 #endif
639 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
640 Z_DECLARE(S, 16, BE)
641 Z_DECLARE(S, 32, BE)
642 #endif
643 #ifdef SND_FEEDER_MULTIFORMAT
644 Z_DECLARE(S,  8, NE)
645 Z_DECLARE(S, 24, LE)
646 Z_DECLARE(S, 24, BE)
647 Z_DECLARE(U,  8, NE)
648 Z_DECLARE(U, 16, LE)
649 Z_DECLARE(U, 24, LE)
650 Z_DECLARE(U, 32, LE)
651 Z_DECLARE(U, 16, BE)
652 Z_DECLARE(U, 24, BE)
653 Z_DECLARE(U, 32, BE)
654 #endif
655 
656 enum {
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 
679 static 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 
708 static void
709 z_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 		kfree(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
740 static int32_t
741 z_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 		kprintf("%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  */
820 static int32_t
821 z_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 
1032 static int
1033 z_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 		kfree(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 = kmalloc(sizeof(int32_t) *
1058 	    info->z_size * info->z_gy * 2, M_DEVBUF, M_WAITOK | 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 
1094 static int
1095 z_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 		 */
1162 z_setup_adaptive_sinc:
1163 		if (info->z_pcoeff != NULL) {
1164 			kfree(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 			kfree(info->z_delay, M_DEVBUF);
1352 		info->z_delay = kmalloc(i, M_DEVBUF, M_WAITOK | 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 
1437 static int
1438 z_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 
1492 static int
1493 z_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 
1519 static int
1520 z_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 = kmalloc(sizeof(*info), M_DEVBUF, M_WAITOK | 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 			kfree(info->z_pcoeff, M_DEVBUF);
1543 		if (info->z_delay != NULL)
1544 			kfree(info->z_delay, M_DEVBUF);
1545 		kfree(info, M_DEVBUF);
1546 		f->data = NULL;
1547 	}
1548 
1549 	return (ret);
1550 }
1551 
1552 static int
1553 z_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 			kfree(info->z_pcoeff, M_DEVBUF);
1561 		if (info->z_delay != NULL)
1562 			kfree(info->z_delay, M_DEVBUF);
1563 		kfree(info, M_DEVBUF);
1564 	}
1565 
1566 	f->data = NULL;
1567 
1568 	return (0);
1569 }
1570 
1571 static uint32_t
1572 z_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 
1707 static int
1708 z_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 
1729 static struct pcm_feederdesc feeder_rate_desc[] = {
1730 	{ FEEDER_RATE, 0, 0, 0, 0 },
1731 	{ 0, 0, 0, 0, 0 },
1732 };
1733 
1734 static 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 
1743 FEEDER_DECLARE(feeder_rate, NULL);
1744