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  * 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: releng/11.2/sys/dev/sound/pcm/feeder_rate.c 331722 2018-03-29 02:50:57Z eadler $");
   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 SYSCTL_INT(_hw_snd, OID_AUTO, feeder_rate_polyphase_max, CTLFLAG_RWTUN,
  166     &feeder_rate_polyphase_max, 0, "maximum allowable polyphase entries");
  167 
  168 static int
  169 sysctl_hw_snd_feeder_rate_min(SYSCTL_HANDLER_ARGS)
  170 {
  171         int err, val;
  172 
  173         val = feeder_rate_min;
  174         err = sysctl_handle_int(oidp, &val, 0, req);
  175 
  176         if (err != 0 || req->newptr == NULL || val == feeder_rate_min)
  177                 return (err);
  178 
  179         if (!(Z_FACTOR_SAFE(val) && val < feeder_rate_max))
  180                 return (EINVAL);
  181 
  182         feeder_rate_min = val;
  183 
  184         return (0);
  185 }
  186 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_min, CTLTYPE_INT | CTLFLAG_RWTUN,
  187     0, sizeof(int), sysctl_hw_snd_feeder_rate_min, "I",
  188     "minimum allowable rate");
  189 
  190 static int
  191 sysctl_hw_snd_feeder_rate_max(SYSCTL_HANDLER_ARGS)
  192 {
  193         int err, val;
  194 
  195         val = feeder_rate_max;
  196         err = sysctl_handle_int(oidp, &val, 0, req);
  197 
  198         if (err != 0 || req->newptr == NULL || val == feeder_rate_max)
  199                 return (err);
  200 
  201         if (!(Z_FACTOR_SAFE(val) && val > feeder_rate_min))
  202                 return (EINVAL);
  203 
  204         feeder_rate_max = val;
  205 
  206         return (0);
  207 }
  208 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_max, CTLTYPE_INT | CTLFLAG_RWTUN,
  209     0, sizeof(int), sysctl_hw_snd_feeder_rate_max, "I",
  210     "maximum allowable rate");
  211 
  212 static int
  213 sysctl_hw_snd_feeder_rate_round(SYSCTL_HANDLER_ARGS)
  214 {
  215         int err, val;
  216 
  217         val = feeder_rate_round;
  218         err = sysctl_handle_int(oidp, &val, 0, req);
  219 
  220         if (err != 0 || req->newptr == NULL || val == feeder_rate_round)
  221                 return (err);
  222 
  223         if (val < Z_ROUNDHZ_MIN || val > Z_ROUNDHZ_MAX)
  224                 return (EINVAL);
  225 
  226         feeder_rate_round = val - (val % Z_ROUNDHZ);
  227 
  228         return (0);
  229 }
  230 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_round, CTLTYPE_INT | CTLFLAG_RWTUN,
  231     0, sizeof(int), sysctl_hw_snd_feeder_rate_round, "I",
  232     "sample rate converter rounding threshold");
  233 
  234 static int
  235 sysctl_hw_snd_feeder_rate_quality(SYSCTL_HANDLER_ARGS)
  236 {
  237         struct snddev_info *d;
  238         struct pcm_channel *c;
  239         struct pcm_feeder *f;
  240         int i, err, val;
  241 
  242         val = feeder_rate_quality;
  243         err = sysctl_handle_int(oidp, &val, 0, req);
  244 
  245         if (err != 0 || req->newptr == NULL || val == feeder_rate_quality)
  246                 return (err);
  247 
  248         if (val < Z_QUALITY_MIN || val > Z_QUALITY_MAX)
  249                 return (EINVAL);
  250 
  251         feeder_rate_quality = val;
  252 
  253         /*
  254          * Traverse all available channels on each device and try to
  255          * set resampler quality if and only if it is exist as
  256          * part of feeder chains and the channel is idle.
  257          */
  258         for (i = 0; pcm_devclass != NULL &&
  259             i < devclass_get_maxunit(pcm_devclass); i++) {
  260                 d = devclass_get_softc(pcm_devclass, i);
  261                 if (!PCM_REGISTERED(d))
  262                         continue;
  263                 PCM_LOCK(d);
  264                 PCM_WAIT(d);
  265                 PCM_ACQUIRE(d);
  266                 CHN_FOREACH(c, d, channels.pcm) {
  267                         CHN_LOCK(c);
  268                         f = chn_findfeeder(c, FEEDER_RATE);
  269                         if (f == NULL || f->data == NULL || CHN_STARTED(c)) {
  270                                 CHN_UNLOCK(c);
  271                                 continue;
  272                         }
  273                         (void)FEEDER_SET(f, FEEDRATE_QUALITY, val);
  274                         CHN_UNLOCK(c);
  275                 }
  276                 PCM_RELEASE(d);
  277                 PCM_UNLOCK(d);
  278         }
  279 
  280         return (0);
  281 }
  282 SYSCTL_PROC(_hw_snd, OID_AUTO, feeder_rate_quality, CTLTYPE_INT | CTLFLAG_RWTUN,
  283     0, sizeof(int), sysctl_hw_snd_feeder_rate_quality, "I",
  284     "sample rate converter quality ("__XSTRING(Z_QUALITY_MIN)"=low .. "
  285     __XSTRING(Z_QUALITY_MAX)"=high)");
  286 #endif  /* _KERNEL */
  287 
  288 
  289 /*
  290  * Resampler type.
  291  */
  292 #define Z_IS_ZOH(i)             ((i)->quality == Z_QUALITY_ZOH)
  293 #define Z_IS_LINEAR(i)          ((i)->quality == Z_QUALITY_LINEAR)
  294 #define Z_IS_SINC(i)            ((i)->quality > Z_QUALITY_LINEAR)
  295 
  296 /*
  297  * Macroses for accurate sample time drift calculations.
  298  *
  299  * gy2gx : given the amount of output, return the _exact_ required amount of
  300  *         input.
  301  * gx2gy : given the amount of input, return the _maximum_ amount of output
  302  *         that will be generated.
  303  * drift : given the amount of input and output, return the elapsed
  304  *         sample-time.
  305  */
  306 #define _Z_GCAST(x)             ((uint64_t)(x))
  307 
  308 #if defined(__GNUCLIKE_ASM) && defined(__i386__)
  309 /*
  310  * This is where i386 being beaten to a pulp. Fortunately this function is
  311  * rarely being called and if it is, it will decide the best (hopefully)
  312  * fastest way to do the division. If we can ensure that everything is dword
  313  * aligned, letting the compiler to call udivdi3 to do the division can be
  314  * faster compared to this.
  315  *
  316  * amd64 is the clear winner here, no question about it.
  317  */
  318 static __inline uint32_t
  319 Z_DIV(uint64_t v, uint32_t d)
  320 {
  321         uint32_t hi, lo, quo, rem;
  322 
  323         hi = v >> 32;
  324         lo = v & 0xffffffff;
  325 
  326         /*
  327          * As much as we can, try to avoid long division like a plague.
  328          */
  329         if (hi == 0)
  330                 quo = lo / d;
  331         else
  332                 __asm("divl %2"
  333                     : "=a" (quo), "=d" (rem)
  334                     : "r" (d), "" (lo), "1" (hi));
  335 
  336         return (quo);
  337 }
  338 #else
  339 #define Z_DIV(x, y)             ((x) / (y))
  340 #endif
  341 
  342 #define _Z_GY2GX(i, a, v)                                               \
  343         Z_DIV(((_Z_GCAST((i)->z_gx) * (v)) + ((i)->z_gy - (a) - 1)),    \
  344         (i)->z_gy)
  345 
  346 #define _Z_GX2GY(i, a, v)                                               \
  347         Z_DIV(((_Z_GCAST((i)->z_gy) * (v)) + (a)), (i)->z_gx)
  348 
  349 #define _Z_DRIFT(i, x, y)                                               \
  350         ((_Z_GCAST((i)->z_gy) * (x)) - (_Z_GCAST((i)->z_gx) * (y)))
  351 
  352 #define z_gy2gx(i, v)           _Z_GY2GX(i, (i)->z_alpha, v)
  353 #define z_gx2gy(i, v)           _Z_GX2GY(i, (i)->z_alpha, v)
  354 #define z_drift(i, x, y)        _Z_DRIFT(i, x, y)
  355 
  356 /*
  357  * Macroses for SINC coefficients table manipulations.. whatever.
  358  */
  359 #define Z_SINC_COEFF_IDX(i)     ((i)->quality - Z_QUALITY_LINEAR - 1)
  360 
  361 #define Z_SINC_LEN(i)                                                   \
  362         ((int32_t)(((uint64_t)z_coeff_tab[Z_SINC_COEFF_IDX(i)].len <<   \
  363             Z_SHIFT) / (i)->z_dy))
  364 
  365 #define Z_SINC_BASE_LEN(i)                                              \
  366         ((z_coeff_tab[Z_SINC_COEFF_IDX(i)].len - 1) >> (Z_DRIFT_SHIFT - 1))
  367 
  368 /*
  369  * Macroses for linear delay buffer operations. Alignment is not
  370  * really necessary since we're not using true circular buffer, but it
  371  * will help us guard against possible trespasser. To be honest,
  372  * the linear block operations does not need guarding at all due to
  373  * accurate drifting!
  374  */
  375 #define z_align(i, v)           ((v) & (i)->z_mask)
  376 #define z_next(i, o, v)         z_align(i, (o) + (v))
  377 #define z_prev(i, o, v)         z_align(i, (o) - (v))
  378 #define z_fetched(i)            (z_align(i, (i)->z_pos - (i)->z_start) - 1)
  379 #define z_free(i)               ((i)->z_full - (i)->z_pos)
  380 
  381 /*
  382  * Macroses for Bla Bla .. :)
  383  */
  384 #define z_copy(src, dst, sz)    (void)memcpy(dst, src, sz)
  385 #define z_feed(...)             FEEDER_FEED(__VA_ARGS__)
  386 
  387 static __inline uint32_t
  388 z_min(uint32_t x, uint32_t y)
  389 {
  390 
  391         return ((x < y) ? x : y);
  392 }
  393 
  394 static int32_t
  395 z_gcd(int32_t x, int32_t y)
  396 {
  397         int32_t w;
  398 
  399         while (y != 0) {
  400                 w = x % y;
  401                 x = y;
  402                 y = w;
  403         }
  404 
  405         return (x);
  406 }
  407 
  408 static int32_t
  409 z_roundpow2(int32_t v)
  410 {
  411         int32_t i;
  412 
  413         i = 1;
  414 
  415         /*
  416          * Let it overflow at will..
  417          */
  418         while (i > 0 && i < v)
  419                 i <<= 1;
  420 
  421         return (i);
  422 }
  423 
  424 /*
  425  * Zero Order Hold, the worst of the worst, an insult against quality,
  426  * but super fast.
  427  */
  428 static void
  429 z_feed_zoh(struct z_info *info, uint8_t *dst)
  430 {
  431 #if 0
  432         z_copy(info->z_delay +
  433             (info->z_start * info->channels * info->bps), dst,
  434             info->channels * info->bps);
  435 #else
  436         uint32_t cnt;
  437         uint8_t *src;
  438 
  439         cnt = info->channels * info->bps;
  440         src = info->z_delay + (info->z_start * cnt);
  441 
  442         /*
  443          * This is a bit faster than doing bcopy() since we're dealing
  444          * with possible unaligned samples.
  445          */
  446         do {
  447                 *dst++ = *src++;
  448         } while (--cnt != 0);
  449 #endif
  450 }
  451 
  452 /*
  453  * Linear Interpolation. This at least sounds better (perceptually) and fast,
  454  * but without any proper filtering which means aliasing still exist and
  455  * could become worst with a right sample. Interpolation centered within
  456  * Z_LINEAR_ONE between the present and previous sample and everything is
  457  * done with simple 32bit scaling arithmetic.
  458  */
  459 #define Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)                                     \
  460 static void                                                                     \
  461 z_feed_linear_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)            \
  462 {                                                                               \
  463         int32_t z;                                                              \
  464         intpcm_t x, y;                                                          \
  465         uint32_t ch;                                                            \
  466         uint8_t *sx, *sy;                                                       \
  467                                                                                 \
  468         z = ((uint32_t)info->z_alpha * info->z_dx) >> Z_LINEAR_UNSHIFT;         \
  469                                                                                 \
  470         sx = info->z_delay + (info->z_start * info->channels *                  \
  471             PCM_##BIT##_BPS);                                                   \
  472         sy = sx - (info->channels * PCM_##BIT##_BPS);                           \
  473                                                                                 \
  474         ch = info->channels;                                                    \
  475                                                                                 \
  476         do {                                                                    \
  477                 x = _PCM_READ_##SIGN##BIT##_##ENDIAN(sx);                       \
  478                 y = _PCM_READ_##SIGN##BIT##_##ENDIAN(sy);                       \
  479                 x = Z_LINEAR_INTERPOLATE_##BIT(z, x, y);                        \
  480                 _PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, x);                      \
  481                 sx += PCM_##BIT##_BPS;                                          \
  482                 sy += PCM_##BIT##_BPS;                                          \
  483                 dst += PCM_##BIT##_BPS;                                         \
  484         } while (--ch != 0);                                                    \
  485 }
  486 
  487 /*
  488  * Userland clipping diagnostic check, not enabled in kernel compilation.
  489  * While doing sinc interpolation, unrealistic samples like full scale sine
  490  * wav will clip, but for other things this will not make any noise at all.
  491  * Everybody should learn how to normalized perceived loudness of their own
  492  * music/sounds/samples (hint: ReplayGain).
  493  */
  494 #ifdef Z_DIAGNOSTIC
  495 #define Z_CLIP_CHECK(v, BIT)    do {                                    \
  496         if ((v) > PCM_S##BIT##_MAX) {                                   \
  497                 fprintf(stderr, "Overflow: v=%jd, max=%jd\n",           \
  498                     (intmax_t)(v), (intmax_t)PCM_S##BIT##_MAX);         \
  499         } else if ((v) < PCM_S##BIT##_MIN) {                            \
  500                 fprintf(stderr, "Underflow: v=%jd, min=%jd\n",          \
  501                     (intmax_t)(v), (intmax_t)PCM_S##BIT##_MIN);         \
  502         }                                                               \
  503 } while (0)
  504 #else
  505 #define Z_CLIP_CHECK(...)
  506 #endif
  507 
  508 #define Z_CLAMP(v, BIT)                                                 \
  509         (((v) > PCM_S##BIT##_MAX) ? PCM_S##BIT##_MAX :                  \
  510         (((v) < PCM_S##BIT##_MIN) ? PCM_S##BIT##_MIN : (v)))
  511 
  512 /*
  513  * Sine Cardinal (SINC) Interpolation. Scaling is done in 64 bit, so
  514  * there's no point to hold the plate any longer. All samples will be
  515  * shifted to a full 32 bit, scaled and restored during write for
  516  * maximum dynamic range (only for downsampling).
  517  */
  518 #define _Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, adv)                      \
  519         c += z >> Z_SHIFT;                                              \
  520         z &= Z_MASK;                                                    \
  521         coeff = Z_COEFF_INTERPOLATE(z, z_coeff[c], z_dcoeff[c]);        \
  522         x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);                        \
  523         v += Z_NORM_##BIT((intpcm64_t)x * coeff);                       \
  524         z += info->z_dy;                                                \
  525         p adv##= info->channels * PCM_##BIT##_BPS
  526 
  527 /* 
  528  * XXX GCC4 optimization is such a !@#$%, need manual unrolling.
  529  */
  530 #if defined(__GNUC__) && __GNUC__ >= 4
  531 #define Z_SINC_ACCUMULATE(...)  do {                                    \
  532         _Z_SINC_ACCUMULATE(__VA_ARGS__);                                \
  533         _Z_SINC_ACCUMULATE(__VA_ARGS__);                                \
  534 } while (0)
  535 #define Z_SINC_ACCUMULATE_DECR          2
  536 #else
  537 #define Z_SINC_ACCUMULATE(...)  do {                                    \
  538         _Z_SINC_ACCUMULATE(__VA_ARGS__);                                \
  539 } while (0)
  540 #define Z_SINC_ACCUMULATE_DECR          1
  541 #endif
  542 
  543 #define Z_DECLARE_SINC(SIGN, BIT, ENDIAN)                                       \
  544 static void                                                                     \
  545 z_feed_sinc_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)              \
  546 {                                                                               \
  547         intpcm64_t v;                                                           \
  548         intpcm_t x;                                                             \
  549         uint8_t *p;                                                             \
  550         int32_t coeff, z, *z_coeff, *z_dcoeff;                                  \
  551         uint32_t c, center, ch, i;                                              \
  552                                                                                 \
  553         z_coeff = info->z_coeff;                                                \
  554         z_dcoeff = info->z_dcoeff;                                              \
  555         center = z_prev(info, info->z_start, info->z_size);                     \
  556         ch = info->channels * PCM_##BIT##_BPS;                                  \
  557         dst += ch;                                                              \
  558                                                                                 \
  559         do {                                                                    \
  560                 dst -= PCM_##BIT##_BPS;                                         \
  561                 ch -= PCM_##BIT##_BPS;                                          \
  562                 v = 0;                                                          \
  563                 z = info->z_alpha * info->z_dx;                                 \
  564                 c = 0;                                                          \
  565                 p = info->z_delay + (z_next(info, center, 1) *                  \
  566                     info->channels * PCM_##BIT##_BPS) + ch;                     \
  567                 for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR)     \
  568                         Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, +);                \
  569                 z = info->z_dy - (info->z_alpha * info->z_dx);                  \
  570                 c = 0;                                                          \
  571                 p = info->z_delay + (center * info->channels *                  \
  572                     PCM_##BIT##_BPS) + ch;                                      \
  573                 for (i = info->z_size; i != 0; i -= Z_SINC_ACCUMULATE_DECR)     \
  574                         Z_SINC_ACCUMULATE(SIGN, BIT, ENDIAN, -);                \
  575                 if (info->z_scale != Z_ONE)                                     \
  576                         v = Z_SCALE_##BIT(v, info->z_scale);                    \
  577                 else                                                            \
  578                         v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;                \
  579                 Z_CLIP_CHECK(v, BIT);                                           \
  580                 _PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));        \
  581         } while (ch != 0);                                                      \
  582 }
  583 
  584 #define Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)                             \
  585 static void                                                                     \
  586 z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN(struct z_info *info, uint8_t *dst)    \
  587 {                                                                               \
  588         intpcm64_t v;                                                           \
  589         intpcm_t x;                                                             \
  590         uint8_t *p;                                                             \
  591         int32_t ch, i, start, *z_pcoeff;                                        \
  592                                                                                 \
  593         ch = info->channels * PCM_##BIT##_BPS;                                  \
  594         dst += ch;                                                              \
  595         start = z_prev(info, info->z_start, (info->z_size << 1) - 1) * ch;      \
  596                                                                                 \
  597         do {                                                                    \
  598                 dst -= PCM_##BIT##_BPS;                                         \
  599                 ch -= PCM_##BIT##_BPS;                                          \
  600                 v = 0;                                                          \
  601                 p = info->z_delay + start + ch;                                 \
  602                 z_pcoeff = info->z_pcoeff +                                     \
  603                     ((info->z_alpha * info->z_size) << 1);                      \
  604                 for (i = info->z_size; i != 0; i--) {                           \
  605                         x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);                \
  606                         v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);           \
  607                         z_pcoeff++;                                             \
  608                         p += info->channels * PCM_##BIT##_BPS;                  \
  609                         x = _PCM_READ_##SIGN##BIT##_##ENDIAN(p);                \
  610                         v += Z_NORM_##BIT((intpcm64_t)x * *z_pcoeff);           \
  611                         z_pcoeff++;                                             \
  612                         p += info->channels * PCM_##BIT##_BPS;                  \
  613                 }                                                               \
  614                 if (info->z_scale != Z_ONE)                                     \
  615                         v = Z_SCALE_##BIT(v, info->z_scale);                    \
  616                 else                                                            \
  617                         v >>= Z_COEFF_SHIFT - Z_GUARD_BIT_##BIT;                \
  618                 Z_CLIP_CHECK(v, BIT);                                           \
  619                 _PCM_WRITE_##SIGN##BIT##_##ENDIAN(dst, Z_CLAMP(v, BIT));        \
  620         } while (ch != 0);                                                      \
  621 }
  622 
  623 #define Z_DECLARE(SIGN, BIT, ENDIAN)                                    \
  624         Z_DECLARE_LINEAR(SIGN, BIT, ENDIAN)                             \
  625         Z_DECLARE_SINC(SIGN, BIT, ENDIAN)                               \
  626         Z_DECLARE_SINC_POLYPHASE(SIGN, BIT, ENDIAN)
  627 
  628 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
  629 Z_DECLARE(S, 16, LE)
  630 Z_DECLARE(S, 32, LE)
  631 #endif
  632 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
  633 Z_DECLARE(S, 16, BE)
  634 Z_DECLARE(S, 32, BE)
  635 #endif
  636 #ifdef SND_FEEDER_MULTIFORMAT
  637 Z_DECLARE(S,  8, NE)
  638 Z_DECLARE(S, 24, LE)
  639 Z_DECLARE(S, 24, BE)
  640 Z_DECLARE(U,  8, NE)
  641 Z_DECLARE(U, 16, LE)
  642 Z_DECLARE(U, 24, LE)
  643 Z_DECLARE(U, 32, LE)
  644 Z_DECLARE(U, 16, BE)
  645 Z_DECLARE(U, 24, BE)
  646 Z_DECLARE(U, 32, BE)
  647 #endif
  648 
  649 enum {
  650         Z_RESAMPLER_ZOH,
  651         Z_RESAMPLER_LINEAR,
  652         Z_RESAMPLER_SINC,
  653         Z_RESAMPLER_SINC_POLYPHASE,
  654         Z_RESAMPLER_LAST
  655 };
  656 
  657 #define Z_RESAMPLER_IDX(i)                                              \
  658         (Z_IS_SINC(i) ? Z_RESAMPLER_SINC : (i)->quality)
  659 
  660 #define Z_RESAMPLER_ENTRY(SIGN, BIT, ENDIAN)                                    \
  661         {                                                                       \
  662             AFMT_##SIGN##BIT##_##ENDIAN,                                        \
  663             {                                                                   \
  664                 [Z_RESAMPLER_ZOH]    = z_feed_zoh,                              \
  665                 [Z_RESAMPLER_LINEAR] = z_feed_linear_##SIGN##BIT##ENDIAN,       \
  666                 [Z_RESAMPLER_SINC]   = z_feed_sinc_##SIGN##BIT##ENDIAN,         \
  667                 [Z_RESAMPLER_SINC_POLYPHASE]   =                                \
  668                     z_feed_sinc_polyphase_##SIGN##BIT##ENDIAN                   \
  669             }                                                                   \
  670         }
  671 
  672 static const struct {
  673         uint32_t format;
  674         z_resampler_t resampler[Z_RESAMPLER_LAST];
  675 } z_resampler_tab[] = {
  676 #if BYTE_ORDER == LITTLE_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
  677         Z_RESAMPLER_ENTRY(S, 16, LE),
  678         Z_RESAMPLER_ENTRY(S, 32, LE),
  679 #endif
  680 #if BYTE_ORDER == BIG_ENDIAN || defined(SND_FEEDER_MULTIFORMAT)
  681         Z_RESAMPLER_ENTRY(S, 16, BE),
  682         Z_RESAMPLER_ENTRY(S, 32, BE),
  683 #endif
  684 #ifdef SND_FEEDER_MULTIFORMAT
  685         Z_RESAMPLER_ENTRY(S,  8, NE),
  686         Z_RESAMPLER_ENTRY(S, 24, LE),
  687         Z_RESAMPLER_ENTRY(S, 24, BE),
  688         Z_RESAMPLER_ENTRY(U,  8, NE),
  689         Z_RESAMPLER_ENTRY(U, 16, LE),
  690         Z_RESAMPLER_ENTRY(U, 24, LE),
  691         Z_RESAMPLER_ENTRY(U, 32, LE),
  692         Z_RESAMPLER_ENTRY(U, 16, BE),
  693         Z_RESAMPLER_ENTRY(U, 24, BE),
  694         Z_RESAMPLER_ENTRY(U, 32, BE),
  695 #endif
  696 };
  697 
  698 #define Z_RESAMPLER_TAB_SIZE                                            \
  699         ((int32_t)(sizeof(z_resampler_tab) / sizeof(z_resampler_tab[0])))
  700 
  701 static void
  702 z_resampler_reset(struct z_info *info)
  703 {
  704 
  705         info->src = info->rsrc - (info->rsrc % ((feeder_rate_round > 0 &&
  706             info->rsrc > feeder_rate_round) ? feeder_rate_round : 1));
  707         info->dst = info->rdst - (info->rdst % ((feeder_rate_round > 0 &&
  708             info->rdst > feeder_rate_round) ? feeder_rate_round : 1));
  709         info->z_gx = 1;
  710         info->z_gy = 1;
  711         info->z_alpha = 0;
  712         info->z_resample = NULL;
  713         info->z_size = 1;
  714         info->z_coeff = NULL;
  715         info->z_dcoeff = NULL;
  716         if (info->z_pcoeff != NULL) {
  717                 free(info->z_pcoeff, M_DEVBUF);
  718                 info->z_pcoeff = NULL;
  719         }
  720         info->z_scale = Z_ONE;
  721         info->z_dx = Z_FULL_ONE;
  722         info->z_dy = Z_FULL_ONE;
  723 #ifdef Z_DIAGNOSTIC
  724         info->z_cycle = 0;
  725 #endif
  726         if (info->quality < Z_QUALITY_MIN)
  727                 info->quality = Z_QUALITY_MIN;
  728         else if (info->quality > Z_QUALITY_MAX)
  729                 info->quality = Z_QUALITY_MAX;
  730 }
  731 
  732 #ifdef Z_PARANOID
  733 static int32_t
  734 z_resampler_sinc_len(struct z_info *info)
  735 {
  736         int32_t c, z, len, lmax;
  737 
  738         if (!Z_IS_SINC(info))
  739                 return (1);
  740 
  741         /*
  742          * A rather careful (or useless) way to calculate filter length.
  743          * Z_SINC_LEN() itself is accurate enough to do its job. Extra
  744          * sanity checking is not going to hurt though..
  745          */
  746         c = 0;
  747         z = info->z_dy;
  748         len = 0;
  749         lmax = z_coeff_tab[Z_SINC_COEFF_IDX(info)].len;
  750 
  751         do {
  752                 c += z >> Z_SHIFT;
  753                 z &= Z_MASK;
  754                 z += info->z_dy;
  755         } while (c < lmax && ++len > 0);
  756 
  757         if (len != Z_SINC_LEN(info)) {
  758 #ifdef _KERNEL
  759                 printf("%s(): sinc l=%d != Z_SINC_LEN=%d\n",
  760                     __func__, len, Z_SINC_LEN(info));
  761 #else
  762                 fprintf(stderr, "%s(): sinc l=%d != Z_SINC_LEN=%d\n",
  763                     __func__, len, Z_SINC_LEN(info));
  764                 return (-1);
  765 #endif
  766         }
  767 
  768         return (len);
  769 }
  770 #else
  771 #define z_resampler_sinc_len(i)         (Z_IS_SINC(i) ? Z_SINC_LEN(i) : 1)
  772 #endif
  773 
  774 #define Z_POLYPHASE_COEFF_SHIFT         0
  775 
  776 /*
  777  * Pick suitable polynomial interpolators based on filter oversampled ratio
  778  * (2 ^ Z_DRIFT_SHIFT).
  779  */
  780 #if !(defined(Z_COEFF_INTERP_ZOH) || defined(Z_COEFF_INTERP_LINEAR) ||          \
  781     defined(Z_COEFF_INTERP_QUADRATIC) || defined(Z_COEFF_INTERP_HERMITE) ||     \
  782     defined(Z_COEFF_INTER_BSPLINE) || defined(Z_COEFF_INTERP_OPT32X) ||         \
  783     defined(Z_COEFF_INTERP_OPT16X) || defined(Z_COEFF_INTERP_OPT8X) ||          \
  784     defined(Z_COEFF_INTERP_OPT4X) || defined(Z_COEFF_INTERP_OPT2X))
  785 #if Z_DRIFT_SHIFT >= 6
  786 #define Z_COEFF_INTERP_BSPLINE          1
  787 #elif Z_DRIFT_SHIFT >= 5
  788 #define Z_COEFF_INTERP_OPT32X           1
  789 #elif Z_DRIFT_SHIFT == 4
  790 #define Z_COEFF_INTERP_OPT16X           1
  791 #elif Z_DRIFT_SHIFT == 3
  792 #define Z_COEFF_INTERP_OPT8X            1
  793 #elif Z_DRIFT_SHIFT == 2
  794 #define Z_COEFF_INTERP_OPT4X            1
  795 #elif Z_DRIFT_SHIFT == 1
  796 #define Z_COEFF_INTERP_OPT2X            1
  797 #else
  798 #error "Z_DRIFT_SHIFT screwed!"
  799 #endif
  800 #endif
  801 
  802 /*
  803  * In classic polyphase mode, the actual coefficients for each phases need to
  804  * be calculated based on default prototype filters. For highly oversampled
  805  * filter, linear or quadradatic interpolator should be enough. Anything less
  806  * than that require 'special' interpolators to reduce interpolation errors.
  807  *
  808  * "Polynomial Interpolators for High-Quality Resampling of Oversampled Audio"
  809  *    by Olli Niemitalo
  810  *    - http://www.student.oulu.fi/~oniemita/dsp/deip.pdf
  811  *
  812  */
  813 static int32_t
  814 z_coeff_interpolate(int32_t z, int32_t *z_coeff)
  815 {
  816         int32_t coeff;
  817 #if defined(Z_COEFF_INTERP_ZOH)
  818 
  819         /* 1-point, 0th-order (Zero Order Hold) */
  820         z = z;
  821         coeff = z_coeff[0];
  822 #elif defined(Z_COEFF_INTERP_LINEAR)
  823         int32_t zl0, zl1;
  824 
  825         /* 2-point, 1st-order Linear */
  826         zl0 = z_coeff[0];
  827         zl1 = z_coeff[1] - z_coeff[0];
  828 
  829         coeff = Z_RSHIFT((int64_t)zl1 * z, Z_SHIFT) + zl0;
  830 #elif defined(Z_COEFF_INTERP_QUADRATIC)
  831         int32_t zq0, zq1, zq2;
  832 
  833         /* 3-point, 2nd-order Quadratic */
  834         zq0 = z_coeff[0];
  835         zq1 = z_coeff[1] - z_coeff[-1];
  836         zq2 = z_coeff[1] + z_coeff[-1] - (z_coeff[0] << 1);
  837 
  838         coeff = Z_RSHIFT((Z_RSHIFT((int64_t)zq2 * z, Z_SHIFT) +
  839             zq1) * z, Z_SHIFT + 1) + zq0;
  840 #elif defined(Z_COEFF_INTERP_HERMITE)
  841         int32_t zh0, zh1, zh2, zh3;
  842 
  843         /* 4-point, 3rd-order Hermite */
  844         zh0 = z_coeff[0];
  845         zh1 = z_coeff[1] - z_coeff[-1];
  846         zh2 = (z_coeff[-1] << 1) - (z_coeff[0] * 5) + (z_coeff[1] << 2) -
  847             z_coeff[2];
  848         zh3 = z_coeff[2] - z_coeff[-1] + ((z_coeff[0] - z_coeff[1]) * 3);
  849 
  850         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zh3 * z, Z_SHIFT) +
  851             zh2) * z, Z_SHIFT) + zh1) * z, Z_SHIFT + 1) + zh0;
  852 #elif defined(Z_COEFF_INTERP_BSPLINE)
  853         int32_t zb0, zb1, zb2, zb3;
  854 
  855         /* 4-point, 3rd-order B-Spline */
  856         zb0 = Z_RSHIFT(0x15555555LL * (((int64_t)z_coeff[0] << 2) +
  857             z_coeff[-1] + z_coeff[1]), 30);
  858         zb1 = z_coeff[1] - z_coeff[-1];
  859         zb2 = z_coeff[-1] + z_coeff[1] - (z_coeff[0] << 1);
  860         zb3 = Z_RSHIFT(0x15555555LL * (((z_coeff[0] - z_coeff[1]) * 3) +
  861             z_coeff[2] - z_coeff[-1]), 30);
  862 
  863         coeff = (Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((int64_t)zb3 * z, Z_SHIFT) +
  864             zb2) * z, Z_SHIFT) + zb1) * z, Z_SHIFT) + zb0 + 1) >> 1;
  865 #elif defined(Z_COEFF_INTERP_OPT32X)
  866         int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
  867         int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
  868 
  869         /* 6-point, 5th-order Optimal 32x */
  870         zoz = z - (Z_ONE >> 1);
  871         zoe1 = z_coeff[1] + z_coeff[0];
  872         zoe2 = z_coeff[2] + z_coeff[-1];
  873         zoe3 = z_coeff[3] + z_coeff[-2];
  874         zoo1 = z_coeff[1] - z_coeff[0];
  875         zoo2 = z_coeff[2] - z_coeff[-1];
  876         zoo3 = z_coeff[3] - z_coeff[-2];
  877 
  878         zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
  879             (0x00170c29LL * zoe3), 30);
  880         zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
  881             (0x008cd4dcLL * zoo3), 30);
  882         zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
  883             (0x0160b5d0LL * zoe3), 30);
  884         zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
  885             (0x01cfe914LL * zoo3), 30);
  886         zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
  887             (0x015508ddLL * zoe3), 30);
  888         zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
  889             (0x0082d81aLL * zoo3), 30);
  890 
  891         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
  892             (int64_t)zoc5 * zoz, Z_SHIFT) +
  893             zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
  894             zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
  895 #elif defined(Z_COEFF_INTERP_OPT16X)
  896         int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
  897         int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
  898 
  899         /* 6-point, 5th-order Optimal 16x */
  900         zoz = z - (Z_ONE >> 1);
  901         zoe1 = z_coeff[1] + z_coeff[0];
  902         zoe2 = z_coeff[2] + z_coeff[-1];
  903         zoe3 = z_coeff[3] + z_coeff[-2];
  904         zoo1 = z_coeff[1] - z_coeff[0];
  905         zoo2 = z_coeff[2] - z_coeff[-1];
  906         zoo3 = z_coeff[3] - z_coeff[-2];
  907 
  908         zoc0 = Z_RSHIFT((0x1ac2260dLL * zoe1) + (0x0526cdcaLL * zoe2) +
  909             (0x00170c29LL * zoe3), 30);
  910         zoc1 = Z_RSHIFT((0x14f8a49aLL * zoo1) + (0x0d6d1109LL * zoo2) +
  911             (0x008cd4dcLL * zoo3), 30);
  912         zoc2 = Z_RSHIFT((-0x0d3e94a4LL * zoe1) + (0x0bddded4LL * zoe2) +
  913             (0x0160b5d0LL * zoe3), 30);
  914         zoc3 = Z_RSHIFT((-0x0de10cc4LL * zoo1) + (0x019b2a7dLL * zoo2) +
  915             (0x01cfe914LL * zoo3), 30);
  916         zoc4 = Z_RSHIFT((0x02aa12d7LL * zoe1) + (-0x03ff1bb3LL * zoe2) +
  917             (0x015508ddLL * zoe3), 30);
  918         zoc5 = Z_RSHIFT((0x051d29e5LL * zoo1) + (-0x028e7647LL * zoo2) +
  919             (0x0082d81aLL * zoo3), 30);
  920 
  921         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
  922             (int64_t)zoc5 * zoz, Z_SHIFT) +
  923             zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
  924             zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
  925 #elif defined(Z_COEFF_INTERP_OPT8X)
  926         int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
  927         int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
  928 
  929         /* 6-point, 5th-order Optimal 8x */
  930         zoz = z - (Z_ONE >> 1);
  931         zoe1 = z_coeff[1] + z_coeff[0];
  932         zoe2 = z_coeff[2] + z_coeff[-1];
  933         zoe3 = z_coeff[3] + z_coeff[-2];
  934         zoo1 = z_coeff[1] - z_coeff[0];
  935         zoo2 = z_coeff[2] - z_coeff[-1];
  936         zoo3 = z_coeff[3] - z_coeff[-2];
  937 
  938         zoc0 = Z_RSHIFT((0x1aa9b47dLL * zoe1) + (0x053d9944LL * zoe2) +
  939             (0x0018b23fLL * zoe3), 30);
  940         zoc1 = Z_RSHIFT((0x14a104d1LL * zoo1) + (0x0d7d2504LL * zoo2) +
  941             (0x0094b599LL * zoo3), 30);
  942         zoc2 = Z_RSHIFT((-0x0d22530bLL * zoe1) + (0x0bb37a2cLL * zoe2) +
  943             (0x016ed8e0LL * zoe3), 30);
  944         zoc3 = Z_RSHIFT((-0x0d744b1cLL * zoo1) + (0x01649591LL * zoo2) +
  945             (0x01dae93aLL * zoo3), 30);
  946         zoc4 = Z_RSHIFT((0x02a7ee1bLL * zoe1) + (-0x03fbdb24LL * zoe2) +
  947             (0x0153ed07LL * zoe3), 30);
  948         zoc5 = Z_RSHIFT((0x04cf9b6cLL * zoo1) + (-0x0266b378LL * zoo2) +
  949             (0x007a7c26LL * zoo3), 30);
  950 
  951         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
  952             (int64_t)zoc5 * zoz, Z_SHIFT) +
  953             zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
  954             zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
  955 #elif defined(Z_COEFF_INTERP_OPT4X)
  956         int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
  957         int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
  958 
  959         /* 6-point, 5th-order Optimal 4x */
  960         zoz = z - (Z_ONE >> 1);
  961         zoe1 = z_coeff[1] + z_coeff[0];
  962         zoe2 = z_coeff[2] + z_coeff[-1];
  963         zoe3 = z_coeff[3] + z_coeff[-2];
  964         zoo1 = z_coeff[1] - z_coeff[0];
  965         zoo2 = z_coeff[2] - z_coeff[-1];
  966         zoo3 = z_coeff[3] - z_coeff[-2];
  967 
  968         zoc0 = Z_RSHIFT((0x1a8eda43LL * zoe1) + (0x0556ee38LL * zoe2) +
  969             (0x001a3784LL * zoe3), 30);
  970         zoc1 = Z_RSHIFT((0x143d863eLL * zoo1) + (0x0d910e36LL * zoo2) +
  971             (0x009ca889LL * zoo3), 30);
  972         zoc2 = Z_RSHIFT((-0x0d026821LL * zoe1) + (0x0b837773LL * zoe2) +
  973             (0x017ef0c6LL * zoe3), 30);
  974         zoc3 = Z_RSHIFT((-0x0cef1502LL * zoo1) + (0x01207a8eLL * zoo2) +
  975             (0x01e936dbLL * zoo3), 30);
  976         zoc4 = Z_RSHIFT((0x029fe643LL * zoe1) + (-0x03ef3fc8LL * zoe2) +
  977             (0x014f5923LL * zoe3), 30);
  978         zoc5 = Z_RSHIFT((0x043a9d08LL * zoo1) + (-0x02154febLL * zoo2) +
  979             (0x00670dbdLL * zoo3), 30);
  980 
  981         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
  982             (int64_t)zoc5 * zoz, Z_SHIFT) +
  983             zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
  984             zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
  985 #elif defined(Z_COEFF_INTERP_OPT2X)
  986         int32_t zoz, zoe1, zoe2, zoe3, zoo1, zoo2, zoo3;
  987         int32_t zoc0, zoc1, zoc2, zoc3, zoc4, zoc5;
  988 
  989         /* 6-point, 5th-order Optimal 2x */
  990         zoz = z - (Z_ONE >> 1);
  991         zoe1 = z_coeff[1] + z_coeff[0];
  992         zoe2 = z_coeff[2] + z_coeff[-1];
  993         zoe3 = z_coeff[3] + z_coeff[-2];
  994         zoo1 = z_coeff[1] - z_coeff[0];
  995         zoo2 = z_coeff[2] - z_coeff[-1];
  996         zoo3 = z_coeff[3] - z_coeff[-2];
  997 
  998         zoc0 = Z_RSHIFT((0x19edb6fdLL * zoe1) + (0x05ebd062LL * zoe2) +
  999             (0x00267881LL * zoe3), 30);
 1000         zoc1 = Z_RSHIFT((0x1223af76LL * zoo1) + (0x0de3dd6bLL * zoo2) +
 1001             (0x00d683cdLL * zoo3), 30);
 1002         zoc2 = Z_RSHIFT((-0x0c3ee068LL * zoe1) + (0x0a5c3769LL * zoe2) +
 1003             (0x01e2aceaLL * zoe3), 30);
 1004         zoc3 = Z_RSHIFT((-0x0a8ab614LL * zoo1) + (-0x0019522eLL * zoo2) +
 1005             (0x022cefc7LL * zoo3), 30);
 1006         zoc4 = Z_RSHIFT((0x0276187dLL * zoe1) + (-0x03a801e8LL * zoe2) +
 1007             (0x0131d935LL * zoe3), 30);
 1008         zoc5 = Z_RSHIFT((0x02c373f5LL * zoo1) + (-0x01275f83LL * zoo2) +
 1009             (0x0018ee79LL * zoo3), 30);
 1010 
 1011         coeff = Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT((Z_RSHIFT(
 1012             (int64_t)zoc5 * zoz, Z_SHIFT) +
 1013             zoc4) * zoz, Z_SHIFT) + zoc3) * zoz, Z_SHIFT) +
 1014             zoc2) * zoz, Z_SHIFT) + zoc1) * zoz, Z_SHIFT) + zoc0;
 1015 #else
 1016 #error "Interpolation type screwed!"
 1017 #endif
 1018 
 1019 #if Z_POLYPHASE_COEFF_SHIFT > 0
 1020         coeff = Z_RSHIFT(coeff, Z_POLYPHASE_COEFF_SHIFT);
 1021 #endif
 1022         return (coeff);
 1023 }
 1024 
 1025 static int
 1026 z_resampler_build_polyphase(struct z_info *info)
 1027 {
 1028         int32_t alpha, c, i, z, idx;
 1029 
 1030         /* Let this be here first. */
 1031         if (info->z_pcoeff != NULL) {
 1032                 free(info->z_pcoeff, M_DEVBUF);
 1033                 info->z_pcoeff = NULL;
 1034         }
 1035 
 1036         if (feeder_rate_polyphase_max < 1)
 1037                 return (ENOTSUP);
 1038 
 1039         if (((int64_t)info->z_size * info->z_gy * 2) >
 1040             feeder_rate_polyphase_max) {
 1041 #ifndef _KERNEL
 1042                 fprintf(stderr, "Polyphase entries exceed: [%d/%d] %jd > %d\n",
 1043                     info->z_gx, info->z_gy,
 1044                     (intmax_t)info->z_size * info->z_gy * 2,
 1045                     feeder_rate_polyphase_max);
 1046 #endif
 1047                 return (E2BIG);
 1048         }
 1049 
 1050         info->z_pcoeff = malloc(sizeof(int32_t) *
 1051             info->z_size * info->z_gy * 2, M_DEVBUF, M_NOWAIT | M_ZERO);
 1052         if (info->z_pcoeff == NULL)
 1053                 return (ENOMEM);
 1054 
 1055         for (alpha = 0; alpha < info->z_gy; alpha++) {
 1056                 z = alpha * info->z_dx;
 1057                 c = 0;
 1058                 for (i = info->z_size; i != 0; i--) {
 1059                         c += z >> Z_SHIFT;
 1060                         z &= Z_MASK;
 1061                         idx = (alpha * info->z_size * 2) +
 1062                             (info->z_size * 2) - i;
 1063                         info->z_pcoeff[idx] =
 1064                             z_coeff_interpolate(z, info->z_coeff + c);
 1065                         z += info->z_dy;
 1066                 }
 1067                 z = info->z_dy - (alpha * info->z_dx);
 1068                 c = 0;
 1069                 for (i = info->z_size; i != 0; i--) {
 1070                         c += z >> Z_SHIFT;
 1071                         z &= Z_MASK;
 1072                         idx = (alpha * info->z_size * 2) + i - 1;
 1073                         info->z_pcoeff[idx] =
 1074                             z_coeff_interpolate(z, info->z_coeff + c);
 1075                         z += info->z_dy;
 1076                 }
 1077         }
 1078         
 1079 #ifndef _KERNEL
 1080         fprintf(stderr, "Polyphase: [%d/%d] %d entries\n",
 1081             info->z_gx, info->z_gy, info->z_size * info->z_gy * 2);
 1082 #endif
 1083 
 1084         return (0);
 1085 }
 1086 
 1087 static int
 1088 z_resampler_setup(struct pcm_feeder *f)
 1089 {
 1090         struct z_info *info;
 1091         int64_t gy2gx_max, gx2gy_max;
 1092         uint32_t format;
 1093         int32_t align, i, z_scale;
 1094         int adaptive;
 1095 
 1096         info = f->data;
 1097         z_resampler_reset(info);
 1098 
 1099         if (info->src == info->dst)
 1100                 return (0);
 1101 
 1102         /* Shrink by greatest common divisor. */
 1103         i = z_gcd(info->src, info->dst);
 1104         info->z_gx = info->src / i;
 1105         info->z_gy = info->dst / i;
 1106 
 1107         /* Too big, or too small. Bail out. */
 1108         if (!(Z_FACTOR_SAFE(info->z_gx) && Z_FACTOR_SAFE(info->z_gy)))
 1109                 return (EINVAL);
 1110 
 1111         format = f->desc->in;
 1112         adaptive = 0;
 1113         z_scale = 0;
 1114 
 1115         /*
 1116          * Setup everything: filter length, conversion factor, etc.
 1117          */
 1118         if (Z_IS_SINC(info)) {
 1119                 /*
 1120                  * Downsampling, or upsampling scaling factor. As long as the
 1121                  * factor can be represented by a fraction of 1 << Z_SHIFT,
 1122                  * we're pretty much in business. Scaling is not needed for
 1123                  * upsampling, so we just slap Z_ONE there.
 1124                  */
 1125                 if (info->z_gx > info->z_gy)
 1126                         /*
 1127                          * If the downsampling ratio is beyond sanity,
 1128                          * enable semi-adaptive mode. Although handling
 1129                          * extreme ratio is possible, the result of the
 1130                          * conversion is just pointless, unworthy,
 1131                          * nonsensical noises, etc.
 1132                          */
 1133                         if ((info->z_gx / info->z_gy) > Z_SINC_DOWNMAX)
 1134                                 z_scale = Z_ONE / Z_SINC_DOWNMAX;
 1135                         else
 1136                                 z_scale = ((uint64_t)info->z_gy << Z_SHIFT) /
 1137                                     info->z_gx;
 1138                 else
 1139                         z_scale = Z_ONE;
 1140 
 1141                 /*
 1142                  * This is actually impossible, unless anything above
 1143                  * overflow.
 1144                  */
 1145                 if (z_scale < 1)
 1146                         return (E2BIG);
 1147 
 1148                 /*
 1149                  * Calculate sample time/coefficients index drift. It is
 1150                  * a constant for upsampling, but downsampling require
 1151                  * heavy duty filtering with possible too long filters.
 1152                  * If anything goes wrong, revisit again and enable
 1153                  * adaptive mode.
 1154                  */
 1155 z_setup_adaptive_sinc:
 1156                 if (info->z_pcoeff != NULL) {
 1157                         free(info->z_pcoeff, M_DEVBUF);
 1158                         info->z_pcoeff = NULL;
 1159                 }
 1160 
 1161                 if (adaptive == 0) {
 1162                         info->z_dy = z_scale << Z_DRIFT_SHIFT;
 1163                         if (info->z_dy < 1)
 1164                                 return (E2BIG);
 1165                         info->z_scale = z_scale;
 1166                 } else {
 1167                         info->z_dy = Z_FULL_ONE;
 1168                         info->z_scale = Z_ONE;
 1169                 }
 1170 
 1171 #if 0
 1172 #define Z_SCALE_DIV     10000
 1173 #define Z_SCALE_LIMIT(s, v)                                             \
 1174         ((((uint64_t)(s) * (v)) + (Z_SCALE_DIV >> 1)) / Z_SCALE_DIV)
 1175 
 1176                 info->z_scale = Z_SCALE_LIMIT(info->z_scale, 9780);
 1177 #endif
 1178 
 1179                 /* Smallest drift increment. */
 1180                 info->z_dx = info->z_dy / info->z_gy;
 1181 
 1182                 /*
 1183                  * Overflow or underflow. Try adaptive, let it continue and
 1184                  * retry.
 1185                  */
 1186                 if (info->z_dx < 1) {
 1187                         if (adaptive == 0) {
 1188                                 adaptive = 1;
 1189                                 goto z_setup_adaptive_sinc;
 1190                         }
 1191                         return (E2BIG);
 1192                 }
 1193 
 1194                 /*
 1195                  * Round back output drift.
 1196                  */
 1197                 info->z_dy = info->z_dx * info->z_gy;
 1198 
 1199                 for (i = 0; i < Z_COEFF_TAB_SIZE; i++) {
 1200                         if (Z_SINC_COEFF_IDX(info) != i)
 1201                                 continue;
 1202                         /*
 1203                          * Calculate required filter length and guard
 1204                          * against possible abusive result. Note that
 1205                          * this represents only 1/2 of the entire filter
 1206                          * length.
 1207                          */
 1208                         info->z_size = z_resampler_sinc_len(info);
 1209 
 1210                         /*
 1211                          * Multiple of 2 rounding, for better accumulator
 1212                          * performance.
 1213                          */
 1214                         info->z_size &= ~1;
 1215 
 1216                         if (info->z_size < 2 || info->z_size > Z_SINC_MAX) {
 1217                                 if (adaptive == 0) {
 1218                                         adaptive = 1;
 1219                                         goto z_setup_adaptive_sinc;
 1220                                 }
 1221                                 return (E2BIG);
 1222                         }
 1223                         info->z_coeff = z_coeff_tab[i].coeff + Z_COEFF_OFFSET;
 1224                         info->z_dcoeff = z_coeff_tab[i].dcoeff;
 1225                         break;
 1226                 }
 1227 
 1228                 if (info->z_coeff == NULL || info->z_dcoeff == NULL)
 1229                         return (EINVAL);
 1230         } else if (Z_IS_LINEAR(info)) {
 1231                 /*
 1232                  * Don't put much effort if we're doing linear interpolation.
 1233                  * Just center the interpolation distance within Z_LINEAR_ONE,
 1234                  * and be happy about it.
 1235                  */
 1236                 info->z_dx = Z_LINEAR_FULL_ONE / info->z_gy;
 1237         }
 1238 
 1239         /*
 1240          * We're safe for now, lets continue.. Look for our resampler
 1241          * depending on configured format and quality.
 1242          */
 1243         for (i = 0; i < Z_RESAMPLER_TAB_SIZE; i++) {
 1244                 int ridx;
 1245 
 1246                 if (AFMT_ENCODING(format) != z_resampler_tab[i].format)
 1247                         continue;
 1248                 if (Z_IS_SINC(info) && adaptive == 0 &&
 1249                     z_resampler_build_polyphase(info) == 0)
 1250                         ridx = Z_RESAMPLER_SINC_POLYPHASE;
 1251                 else
 1252                         ridx = Z_RESAMPLER_IDX(info);
 1253                 info->z_resample = z_resampler_tab[i].resampler[ridx];
 1254                 break;
 1255         }
 1256 
 1257         if (info->z_resample == NULL)
 1258                 return (EINVAL);
 1259 
 1260         info->bps = AFMT_BPS(format);
 1261         align = info->channels * info->bps;
 1262 
 1263         /*
 1264          * Calculate largest value that can be fed into z_gy2gx() and
 1265          * z_gx2gy() without causing (signed) 32bit overflow. z_gy2gx() will
 1266          * be called early during feeding process to determine how much input
 1267          * samples that is required to generate requested output, while
 1268          * z_gx2gy() will be called just before samples filtering /
 1269          * accumulation process based on available samples that has been
 1270          * calculated using z_gx2gy().
 1271          *
 1272          * Now that is damn confusing, I guess ;-) .
 1273          */
 1274         gy2gx_max = (((uint64_t)info->z_gy * INT32_MAX) - info->z_gy + 1) /
 1275             info->z_gx;
 1276 
 1277         if ((gy2gx_max * align) > SND_FXDIV_MAX)
 1278                 gy2gx_max = SND_FXDIV_MAX / align;
 1279 
 1280         if (gy2gx_max < 1)
 1281                 return (E2BIG);
 1282 
 1283         gx2gy_max = (((uint64_t)info->z_gx * INT32_MAX) - info->z_gy) /
 1284             info->z_gy;
 1285 
 1286         if (gx2gy_max > INT32_MAX)
 1287                 gx2gy_max = INT32_MAX;
 1288 
 1289         if (gx2gy_max < 1)
 1290                 return (E2BIG);
 1291 
 1292         /*
 1293          * Ensure that z_gy2gx() at its largest possible calculated value
 1294          * (alpha = 0) will not cause overflow further late during z_gx2gy()
 1295          * stage.
 1296          */
 1297         if (z_gy2gx(info, gy2gx_max) > _Z_GCAST(gx2gy_max))
 1298                 return (E2BIG);
 1299 
 1300         info->z_maxfeed = gy2gx_max * align;
 1301 
 1302 #ifdef Z_USE_ALPHADRIFT
 1303         info->z_startdrift = z_gy2gx(info, 1);
 1304         info->z_alphadrift = z_drift(info, info->z_startdrift, 1);
 1305 #endif
 1306 
 1307         i = z_gy2gx(info, 1);
 1308         info->z_full = z_roundpow2((info->z_size << 1) + i);
 1309 
 1310         /*
 1311          * Too big to be true, and overflowing left and right like mad ..
 1312          */
 1313         if ((info->z_full * align) < 1) {
 1314                 if (adaptive == 0 && Z_IS_SINC(info)) {
 1315                         adaptive = 1;
 1316                         goto z_setup_adaptive_sinc;
 1317                 }
 1318                 return (E2BIG);
 1319         }
 1320 
 1321         /*
 1322          * Increase full buffer size if its too small to reduce cyclic
 1323          * buffer shifting in main conversion/feeder loop.
 1324          */
 1325         while (info->z_full < Z_RESERVOIR_MAX &&
 1326             (info->z_full - (info->z_size << 1)) < Z_RESERVOIR)
 1327                 info->z_full <<= 1;
 1328 
 1329         /* Initialize buffer position. */
 1330         info->z_mask = info->z_full - 1;
 1331         info->z_start = z_prev(info, info->z_size << 1, 1);
 1332         info->z_pos = z_next(info, info->z_start, 1);
 1333 
 1334         /*
 1335          * Allocate or reuse delay line buffer, whichever makes sense.
 1336          */
 1337         i = info->z_full * align;
 1338         if (i < 1)
 1339                 return (E2BIG);
 1340 
 1341         if (info->z_delay == NULL || info->z_alloc < i ||
 1342             i <= (info->z_alloc >> 1)) {
 1343                 if (info->z_delay != NULL)
 1344                         free(info->z_delay, M_DEVBUF);
 1345                 info->z_delay = malloc(i, M_DEVBUF, M_NOWAIT | M_ZERO);
 1346                 if (info->z_delay == NULL)
 1347                         return (ENOMEM);
 1348                 info->z_alloc = i;
 1349         }
 1350 
 1351         /*
 1352          * Zero out head of buffer to avoid pops and clicks.
 1353          */
 1354         memset(info->z_delay, sndbuf_zerodata(f->desc->out),
 1355             info->z_pos * align);
 1356 
 1357 #ifdef Z_DIAGNOSTIC
 1358         /*
 1359          * XXX Debuging mess !@#$%^
 1360          */
 1361 #define dumpz(x)        fprintf(stderr, "\t%12s = %10u : %-11d\n",      \
 1362                             "z_"__STRING(x), (uint32_t)info->z_##x,     \
 1363                             (int32_t)info->z_##x)
 1364         fprintf(stderr, "\n%s():\n", __func__);
 1365         fprintf(stderr, "\tchannels=%d, bps=%d, format=0x%08x, quality=%d\n",
 1366             info->channels, info->bps, format, info->quality);
 1367         fprintf(stderr, "\t%d (%d) -> %d (%d), ",
 1368             info->src, info->rsrc, info->dst, info->rdst);
 1369         fprintf(stderr, "[%d/%d]\n", info->z_gx, info->z_gy);
 1370         fprintf(stderr, "\tminreq=%d, ", z_gy2gx(info, 1));
 1371         if (adaptive != 0)
 1372                 z_scale = Z_ONE;
 1373         fprintf(stderr, "factor=0x%08x/0x%08x (%f)\n",
 1374             z_scale, Z_ONE, (double)z_scale / Z_ONE);
 1375         fprintf(stderr, "\tbase_length=%d, ", Z_SINC_BASE_LEN(info));
 1376         fprintf(stderr, "adaptive=%s\n", (adaptive != 0) ? "YES" : "NO");
 1377         dumpz(size);
 1378         dumpz(alloc);
 1379         if (info->z_alloc < 1024)
 1380                 fprintf(stderr, "\t%15s%10d Bytes\n",
 1381                     "", info->z_alloc);
 1382         else if (info->z_alloc < (1024 << 10))
 1383                 fprintf(stderr, "\t%15s%10d KBytes\n",
 1384                     "", info->z_alloc >> 10);
 1385         else if (info->z_alloc < (1024 << 20))
 1386                 fprintf(stderr, "\t%15s%10d MBytes\n",
 1387                     "", info->z_alloc >> 20);
 1388         else
 1389                 fprintf(stderr, "\t%15s%10d GBytes\n",
 1390                     "", info->z_alloc >> 30);
 1391         fprintf(stderr, "\t%12s   %10d (min output samples)\n",
 1392             "",
 1393             (int32_t)z_gx2gy(info, info->z_full - (info->z_size << 1)));
 1394         fprintf(stderr, "\t%12s   %10d (min allocated output samples)\n",
 1395             "",
 1396             (int32_t)z_gx2gy(info, (info->z_alloc / align) -
 1397             (info->z_size << 1)));
 1398         fprintf(stderr, "\t%12s = %10d\n",
 1399             "z_gy2gx()", (int32_t)z_gy2gx(info, 1));
 1400         fprintf(stderr, "\t%12s = %10d -> z_gy2gx() -> %d\n",
 1401             "Max", (int32_t)gy2gx_max, (int32_t)z_gy2gx(info, gy2gx_max));
 1402         fprintf(stderr, "\t%12s = %10d\n",
 1403             "z_gx2gy()", (int32_t)z_gx2gy(info, 1));
 1404         fprintf(stderr, "\t%12s = %10d -> z_gx2gy() -> %d\n",
 1405             "Max", (int32_t)gx2gy_max, (int32_t)z_gx2gy(info, gx2gy_max));
 1406         dumpz(maxfeed);
 1407         dumpz(full);
 1408         dumpz(start);
 1409         dumpz(pos);
 1410         dumpz(scale);
 1411         fprintf(stderr, "\t%12s   %10f\n", "",
 1412             (double)info->z_scale / Z_ONE);
 1413         dumpz(dx);
 1414         fprintf(stderr, "\t%12s   %10f\n", "",
 1415             (double)info->z_dx / info->z_dy);
 1416         dumpz(dy);
 1417         fprintf(stderr, "\t%12s   %10d (drift step)\n", "",
 1418             info->z_dy >> Z_SHIFT);
 1419         fprintf(stderr, "\t%12s   %10d (scaling differences)\n", "",
 1420             (z_scale << Z_DRIFT_SHIFT) - info->z_dy);
 1421         fprintf(stderr, "\t%12s = %u bytes\n",
 1422             "intpcm32_t", sizeof(intpcm32_t));
 1423         fprintf(stderr, "\t%12s = 0x%08x, smallest=%.16lf\n",
 1424             "Z_ONE", Z_ONE, (double)1.0 / (double)Z_ONE);
 1425 #endif
 1426 
 1427         return (0);
 1428 }
 1429 
 1430 static int
 1431 z_resampler_set(struct pcm_feeder *f, int what, int32_t value)
 1432 {
 1433         struct z_info *info;
 1434         int32_t oquality;
 1435 
 1436         info = f->data;
 1437 
 1438         switch (what) {
 1439         case Z_RATE_SRC:
 1440                 if (value < feeder_rate_min || value > feeder_rate_max)
 1441                         return (E2BIG);
 1442                 if (value == info->rsrc)
 1443                         return (0);
 1444                 info->rsrc = value;
 1445                 break;
 1446         case Z_RATE_DST:
 1447                 if (value < feeder_rate_min || value > feeder_rate_max)
 1448                         return (E2BIG);
 1449                 if (value == info->rdst)
 1450                         return (0);
 1451                 info->rdst = value;
 1452                 break;
 1453         case Z_RATE_QUALITY:
 1454                 if (value < Z_QUALITY_MIN || value > Z_QUALITY_MAX)
 1455                         return (EINVAL);
 1456                 if (value == info->quality)
 1457                         return (0);
 1458                 /*
 1459                  * If we failed to set the requested quality, restore
 1460                  * the old one. We cannot afford leaving it broken since
 1461                  * passive feeder chains like vchans never reinitialize
 1462                  * itself.
 1463                  */
 1464                 oquality = info->quality;
 1465                 info->quality = value;
 1466                 if (z_resampler_setup(f) == 0)
 1467                         return (0);
 1468                 info->quality = oquality;
 1469                 break;
 1470         case Z_RATE_CHANNELS:
 1471                 if (value < SND_CHN_MIN || value > SND_CHN_MAX)
 1472                         return (EINVAL);
 1473                 if (value == info->channels)
 1474                         return (0);
 1475                 info->channels = value;
 1476                 break;
 1477         default:
 1478                 return (EINVAL);
 1479                 break;
 1480         }
 1481 
 1482         return (z_resampler_setup(f));
 1483 }
 1484 
 1485 static int
 1486 z_resampler_get(struct pcm_feeder *f, int what)
 1487 {
 1488         struct z_info *info;
 1489 
 1490         info = f->data;
 1491 
 1492         switch (what) {
 1493         case Z_RATE_SRC:
 1494                 return (info->rsrc);
 1495                 break;
 1496         case Z_RATE_DST:
 1497                 return (info->rdst);
 1498                 break;
 1499         case Z_RATE_QUALITY:
 1500                 return (info->quality);
 1501                 break;
 1502         case Z_RATE_CHANNELS:
 1503                 return (info->channels);
 1504                 break;
 1505         default:
 1506                 break;
 1507         }
 1508 
 1509         return (-1);
 1510 }
 1511 
 1512 static int
 1513 z_resampler_init(struct pcm_feeder *f)
 1514 {
 1515         struct z_info *info;
 1516         int ret;
 1517 
 1518         if (f->desc->in != f->desc->out)
 1519                 return (EINVAL);
 1520 
 1521         info = malloc(sizeof(*info), M_DEVBUF, M_NOWAIT | M_ZERO);
 1522         if (info == NULL)
 1523                 return (ENOMEM);
 1524 
 1525         info->rsrc = Z_RATE_DEFAULT;
 1526         info->rdst = Z_RATE_DEFAULT;
 1527         info->quality = feeder_rate_quality;
 1528         info->channels = AFMT_CHANNEL(f->desc->in);
 1529 
 1530         f->data = info;
 1531 
 1532         ret = z_resampler_setup(f);
 1533         if (ret != 0) {
 1534                 if (info->z_pcoeff != NULL)
 1535                         free(info->z_pcoeff, M_DEVBUF);
 1536                 if (info->z_delay != NULL)
 1537                         free(info->z_delay, M_DEVBUF);
 1538                 free(info, M_DEVBUF);
 1539                 f->data = NULL;
 1540         }
 1541 
 1542         return (ret);
 1543 }
 1544 
 1545 static int
 1546 z_resampler_free(struct pcm_feeder *f)
 1547 {
 1548         struct z_info *info;
 1549 
 1550         info = f->data;
 1551         if (info != NULL) {
 1552                 if (info->z_pcoeff != NULL)
 1553                         free(info->z_pcoeff, M_DEVBUF);
 1554                 if (info->z_delay != NULL)
 1555                         free(info->z_delay, M_DEVBUF);
 1556                 free(info, M_DEVBUF);
 1557         }
 1558 
 1559         f->data = NULL;
 1560 
 1561         return (0);
 1562 }
 1563 
 1564 static uint32_t
 1565 z_resampler_feed_internal(struct pcm_feeder *f, struct pcm_channel *c,
 1566     uint8_t *b, uint32_t count, void *source)
 1567 {
 1568         struct z_info *info;
 1569         int32_t alphadrift, startdrift, reqout, ocount, reqin, align;
 1570         int32_t fetch, fetched, start, cp;
 1571         uint8_t *dst;
 1572 
 1573         info = f->data;
 1574         if (info->z_resample == NULL)
 1575                 return (z_feed(f->source, c, b, count, source));
 1576 
 1577         /*
 1578          * Calculate sample size alignment and amount of sample output.
 1579          * We will do everything in sample domain, but at the end we
 1580          * will jump back to byte domain.
 1581          */
 1582         align = info->channels * info->bps;
 1583         ocount = SND_FXDIV(count, align);
 1584         if (ocount == 0)
 1585                 return (0);
 1586 
 1587         /*
 1588          * Calculate amount of input samples that is needed to generate
 1589          * exact amount of output.
 1590          */
 1591         reqin = z_gy2gx(info, ocount) - z_fetched(info);
 1592 
 1593 #ifdef Z_USE_ALPHADRIFT
 1594         startdrift = info->z_startdrift;
 1595         alphadrift = info->z_alphadrift;
 1596 #else
 1597         startdrift = _Z_GY2GX(info, 0, 1);
 1598         alphadrift = z_drift(info, startdrift, 1);
 1599 #endif
 1600 
 1601         dst = b;
 1602 
 1603         do {
 1604                 if (reqin != 0) {
 1605                         fetch = z_min(z_free(info), reqin);
 1606                         if (fetch == 0) {
 1607                                 /*
 1608                                  * No more free spaces, so wind enough
 1609                                  * samples back to the head of delay line
 1610                                  * in byte domain.
 1611                                  */
 1612                                 fetched = z_fetched(info);
 1613                                 start = z_prev(info, info->z_start,
 1614                                     (info->z_size << 1) - 1);
 1615                                 cp = (info->z_size << 1) + fetched;
 1616                                 z_copy(info->z_delay + (start * align),
 1617                                     info->z_delay, cp * align);
 1618                                 info->z_start =
 1619                                     z_prev(info, info->z_size << 1, 1);
 1620                                 info->z_pos =
 1621                                     z_next(info, info->z_start, fetched + 1);
 1622                                 fetch = z_min(z_free(info), reqin);
 1623 #ifdef Z_DIAGNOSTIC
 1624                                 if (1) {
 1625                                         static uint32_t kk = 0;
 1626                                         fprintf(stderr,
 1627                                             "Buffer Move: "
 1628                                             "start=%d fetched=%d cp=%d "
 1629                                             "cycle=%u [%u]\r",
 1630                                             start, fetched, cp, info->z_cycle,
 1631                                             ++kk);
 1632                                 }
 1633                                 info->z_cycle = 0;
 1634 #endif
 1635                         }
 1636                         if (fetch != 0) {
 1637                                 /*
 1638                                  * Fetch in byte domain and jump back
 1639                                  * to sample domain.
 1640                                  */
 1641                                 fetched = SND_FXDIV(z_feed(f->source, c,
 1642                                     info->z_delay + (info->z_pos * align),
 1643                                     fetch * align, source), align);
 1644                                 /*
 1645                                  * Prepare to convert fetched buffer,
 1646                                  * or mark us done if we cannot fulfill
 1647                                  * the request.
 1648                                  */
 1649                                 reqin -= fetched;
 1650                                 info->z_pos += fetched;
 1651                                 if (fetched != fetch)
 1652                                         reqin = 0;
 1653                         }
 1654                 }
 1655 
 1656                 reqout = z_min(z_gx2gy(info, z_fetched(info)), ocount);
 1657                 if (reqout != 0) {
 1658                         ocount -= reqout;
 1659 
 1660                         /*
 1661                          * Drift.. drift.. drift..
 1662                          *
 1663                          * Notice that there are 2 methods of doing the drift
 1664                          * operations: The former is much cleaner (in a sense
 1665                          * of mathematical readings of my eyes), but slower
 1666                          * due to integer division in z_gy2gx(). Nevertheless,
 1667                          * both should give the same exact accurate drifting
 1668                          * results, so the later is favourable.
 1669                          */
 1670                         do {
 1671                                 info->z_resample(info, dst);
 1672 #if 0
 1673                                 startdrift = z_gy2gx(info, 1);
 1674                                 alphadrift = z_drift(info, startdrift, 1);
 1675                                 info->z_start += startdrift;
 1676                                 info->z_alpha += alphadrift;
 1677 #else
 1678                                 info->z_alpha += alphadrift;
 1679                                 if (info->z_alpha < info->z_gy)
 1680                                         info->z_start += startdrift;
 1681                                 else {
 1682                                         info->z_start += startdrift - 1;
 1683                                         info->z_alpha -= info->z_gy;
 1684                                 }
 1685 #endif
 1686                                 dst += align;
 1687 #ifdef Z_DIAGNOSTIC
 1688                                 info->z_cycle++;
 1689 #endif
 1690                         } while (--reqout != 0);
 1691                 }
 1692         } while (reqin != 0 && ocount != 0);
 1693 
 1694         /*
 1695          * Back to byte domain..
 1696          */
 1697         return (dst - b);
 1698 }
 1699 
 1700 static int
 1701 z_resampler_feed(struct pcm_feeder *f, struct pcm_channel *c, uint8_t *b,
 1702     uint32_t count, void *source)
 1703 {
 1704         uint32_t feed, maxfeed, left;
 1705 
 1706         /*
 1707          * Split count to smaller chunks to avoid possible 32bit overflow.
 1708          */
 1709         maxfeed = ((struct z_info *)(f->data))->z_maxfeed;
 1710         left = count;
 1711 
 1712         do {
 1713                 feed = z_resampler_feed_internal(f, c, b,
 1714                     z_min(maxfeed, left), source);
 1715                 b += feed;
 1716                 left -= feed;
 1717         } while (left != 0 && feed != 0);
 1718 
 1719         return (count - left);
 1720 }
 1721 
 1722 static struct pcm_feederdesc feeder_rate_desc[] = {
 1723         { FEEDER_RATE, 0, 0, 0, 0 },
 1724         { 0, 0, 0, 0, 0 },
 1725 };
 1726 
 1727 static kobj_method_t feeder_rate_methods[] = {
 1728         KOBJMETHOD(feeder_init,         z_resampler_init),
 1729         KOBJMETHOD(feeder_free,         z_resampler_free),
 1730         KOBJMETHOD(feeder_set,          z_resampler_set),
 1731         KOBJMETHOD(feeder_get,          z_resampler_get),
 1732         KOBJMETHOD(feeder_feed,         z_resampler_feed),
 1733         KOBJMETHOD_END
 1734 };
 1735 
 1736 FEEDER_DECLARE(feeder_rate, NULL);

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