The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/dev/sound/pcm/feeder_rate.c

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

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