juce/source/src/audio/audio_file_formats/flac/libFLAC/fixed.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  Josh Coalson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * - Neither the name of the Xiph.org Foundation nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include "juce_FlacHeader.h"
  33 #if JUCE_USE_FLAC
  34
  35
  36 #if HAVE_CONFIG_H
  37 #  include <config.h>
  38 #endif
  39
  40 #include <math.h>
  41 #include <string.h>
  42 #include "include/private/bitmath.h"
  43 #include "include/private/fixed.h"
  44 #include "../assert.h"
  45
  46 #ifndef M_LN2
  47 /* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */
  48 #define M_LN2 0.69314718055994530942
  49 #endif
  50
  51 #ifdef min
  52 #undef min
  53 #endif
  54 #define min(x,y) ((x) < (y)? (x) : (y))
  55
  56 #ifdef local_abs
  57 #undef local_abs
  58 #endif
  59 #define local_abs(x) ((unsigned)((x)<0? -(x) : (x)))
  60
  61 #ifdef FLAC__INTEGER_ONLY_LIBRARY
  62 /* rbps stands for residual bits per sample
  63  *
  64  *             (ln(2) * err)
  65  * rbps = log  (-----------)
  66  *           2 (     n     )
  67  */
  68 static FLAC__fixedpoint local__compute_rbps_integerized(FLAC__uint32 err, FLAC__uint32 n)
  69 {
  70         FLAC__uint32 rbps;
  71         unsigned bits; /* the number of bits required to represent a number */
  72         int fracbits; /* the number of bits of rbps that comprise the fractional part */
  73
  74         FLAC__ASSERT(sizeof(rbps) == sizeof(FLAC__fixedpoint));
  75         FLAC__ASSERT(err > 0);
  76         FLAC__ASSERT(n > 0);
  77
  78         FLAC__ASSERT(n <= FLAC__MAX_BLOCK_SIZE);
  79         if(err <= n)
  80                 return 0;
  81         /*
  82          * The above two things tell us 1) n fits in 16 bits; 2) err/n > 1.
  83          * These allow us later to know we won't lose too much precision in the
  84          * fixed-point division (err<<fracbits)/n.
  85          */
  86
  87         fracbits = (8*sizeof(err)) - (FLAC__bitmath_ilog2(err)+1);
  88
  89         err <<= fracbits;
  90         err /= n;
  91         /* err now holds err/n with fracbits fractional bits */
  92
  93         /*
  94          * Whittle err down to 16 bits max.  16 significant bits is enough for
  95          * our purposes.
  96          */
  97         FLAC__ASSERT(err > 0);
  98         bits = FLAC__bitmath_ilog2(err)+1;
  99         if(bits > 16) {
 100                 err >>= (bits-16);
 101                 fracbits -= (bits-16);
 102         }
 103         rbps = (FLAC__uint32)err;
 104
 105         /* Multiply by fixed-point version of ln(2), with 16 fractional bits */
 106         rbps *= FLAC__FP_LN2;
 107         fracbits += 16;
 108         FLAC__ASSERT(fracbits >= 0);
 109
 110         /* FLAC__fixedpoint_log2 requires fracbits%4 to be 0 */
 111         {
 112                 const int f = fracbits & 3;
 113                 if(f) {
 114                         rbps >>= f;
 115                         fracbits -= f;
 116                 }
 117         }
 118
 119         rbps = FLAC__fixedpoint_log2(rbps, fracbits, (unsigned)(-1));
 120
 121         if(rbps == 0)
 122                 return 0;
 123
 124         /*
 125          * The return value must have 16 fractional bits.  Since the whole part
 126          * of the base-2 log of a 32 bit number must fit in 5 bits, and fracbits
 127          * must be >= -3, these assertion allows us to be able to shift rbps
 128          * left if necessary to get 16 fracbits without losing any bits of the
 129          * whole part of rbps.
 130          *
 131          * There is a slight chance due to accumulated error that the whole part
 132          * will require 6 bits, so we use 6 in the assertion.  Really though as
 133          * long as it fits in 13 bits (32 - (16 - (-3))) we are fine.
 134          */
 135         FLAC__ASSERT((int)FLAC__bitmath_ilog2(rbps)+1 <= fracbits + 6);
 136         FLAC__ASSERT(fracbits >= -3);
 137
 138         /* now shift the decimal point into place */
 139         if(fracbits < 16)
 140                 return rbps << (16-fracbits);
 141         else if(fracbits > 16)
 142                 return rbps >> (fracbits-16);
 143         else
 144                 return rbps;
 145 }
 146
 147 static FLAC__fixedpoint local__compute_rbps_wide_integerized(FLAC__uint64 err, FLAC__uint32 n)
 148 {
 149         FLAC__uint32 rbps;
 150         unsigned bits; /* the number of bits required to represent a number */
 151         int fracbits; /* the number of bits of rbps that comprise the fractional part */
 152
 153         FLAC__ASSERT(sizeof(rbps) == sizeof(FLAC__fixedpoint));
 154         FLAC__ASSERT(err > 0);
 155         FLAC__ASSERT(n > 0);
 156
 157         FLAC__ASSERT(n <= FLAC__MAX_BLOCK_SIZE);
 158         if(err <= n)
 159                 return 0;
 160         /*
 161          * The above two things tell us 1) n fits in 16 bits; 2) err/n > 1.
 162          * These allow us later to know we won't lose too much precision in the
 163          * fixed-point division (err<<fracbits)/n.
 164          */
 165
 166         fracbits = (8*sizeof(err)) - (FLAC__bitmath_ilog2_wide(err)+1);
 167
 168         err <<= fracbits;
 169         err /= n;
 170         /* err now holds err/n with fracbits fractional bits */
 171
 172         /*
 173          * Whittle err down to 16 bits max.  16 significant bits is enough for
 174          * our purposes.
 175          */
 176         FLAC__ASSERT(err > 0);
 177         bits = FLAC__bitmath_ilog2_wide(err)+1;
 178         if(bits > 16) {
 179                 err >>= (bits-16);
 180                 fracbits -= (bits-16);
 181         }
 182         rbps = (FLAC__uint32)err;
 183
 184         /* Multiply by fixed-point version of ln(2), with 16 fractional bits */
 185         rbps *= FLAC__FP_LN2;
 186         fracbits += 16;
 187         FLAC__ASSERT(fracbits >= 0);
 188
 189         /* FLAC__fixedpoint_log2 requires fracbits%4 to be 0 */
 190         {
 191                 const int f = fracbits & 3;
 192                 if(f) {
 193                         rbps >>= f;
 194                         fracbits -= f;
 195                 }
 196         }
 197
 198         rbps = FLAC__fixedpoint_log2(rbps, fracbits, (unsigned)(-1));
 199
 200         if(rbps == 0)
 201                 return 0;
 202
 203         /*
 204          * The return value must have 16 fractional bits.  Since the whole part
 205          * of the base-2 log of a 32 bit number must fit in 5 bits, and fracbits
 206          * must be >= -3, these assertion allows us to be able to shift rbps
 207          * left if necessary to get 16 fracbits without losing any bits of the
 208          * whole part of rbps.
 209          *
 210          * There is a slight chance due to accumulated error that the whole part
 211          * will require 6 bits, so we use 6 in the assertion.  Really though as
 212          * long as it fits in 13 bits (32 - (16 - (-3))) we are fine.
 213          */
 214         FLAC__ASSERT((int)FLAC__bitmath_ilog2(rbps)+1 <= fracbits + 6);
 215         FLAC__ASSERT(fracbits >= -3);
 216
 217         /* now shift the decimal point into place */
 218         if(fracbits < 16)
 219                 return rbps << (16-fracbits);
 220         else if(fracbits > 16)
 221                 return rbps >> (fracbits-16);
 222         else
 223                 return rbps;
 224 }
 225 #endif
 226
 227 #ifndef FLAC__INTEGER_ONLY_LIBRARY
 228 unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
 229 #else
 230 unsigned FLAC__fixed_compute_best_predictor(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
 231 #endif
 232 {
 233         FLAC__int32 last_error_0 = data[-1];
 234         FLAC__int32 last_error_1 = data[-1] - data[-2];
 235         FLAC__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]);
 236         FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]);
 237         FLAC__int32 error, save;
 238         FLAC__uint32 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0;
 239         unsigned i, order;
 240
 241         for(i = 0; i < data_len; i++) {
 242                 error  = data[i]     ; total_error_0 += local_abs(error);                      save = error;
 243                 error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error;
 244                 error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error;
 245                 error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error;
 246                 error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save;
 247         }
 248
 249         if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4))
 250                 order = 0;
 251         else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4))
 252                 order = 1;
 253         else if(total_error_2 < min(total_error_3, total_error_4))
 254                 order = 2;
 255         else if(total_error_3 < total_error_4)
 256                 order = 3;
 257         else
 258                 order = 4;
 259
 260         /* Estimate the expected number of bits per residual signal sample. */
 261         /* 'total_error*' is linearly related to the variance of the residual */
 262         /* signal, so we use it directly to compute E(|x|) */
 263         FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
 264         FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
 265         FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
 266         FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
 267         FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
 268 #ifndef FLAC__INTEGER_ONLY_LIBRARY
 269         residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
 270         residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
 271         residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
 272         residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
 273         residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
 274 #else
 275         residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_integerized(total_error_0, data_len) : 0;
 276         residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_integerized(total_error_1, data_len) : 0;
 277         residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_integerized(total_error_2, data_len) : 0;
 278         residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_integerized(total_error_3, data_len) : 0;
 279         residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_integerized(total_error_4, data_len) : 0;
 280 #endif
 281
 282         return order;
 283 }
 284
 285 #ifndef FLAC__INTEGER_ONLY_LIBRARY
 286 unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__float residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
 287 #else
 288 unsigned FLAC__fixed_compute_best_predictor_wide(const FLAC__int32 data[], unsigned data_len, FLAC__fixedpoint residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1])
 289 #endif
 290 {
 291         FLAC__int32 last_error_0 = data[-1];
 292         FLAC__int32 last_error_1 = data[-1] - data[-2];
 293         FLAC__int32 last_error_2 = last_error_1 - (data[-2] - data[-3]);
 294         FLAC__int32 last_error_3 = last_error_2 - (data[-2] - 2*data[-3] + data[-4]);
 295         FLAC__int32 error, save;
 296         /* total_error_* are 64-bits to avoid overflow when encoding
 297          * erratic signals when the bits-per-sample and blocksize are
 298          * large.
 299          */
 300         FLAC__uint64 total_error_0 = 0, total_error_1 = 0, total_error_2 = 0, total_error_3 = 0, total_error_4 = 0;
 301         unsigned i, order;
 302
 303         for(i = 0; i < data_len; i++) {
 304                 error  = data[i]     ; total_error_0 += local_abs(error);                      save = error;
 305                 error -= last_error_0; total_error_1 += local_abs(error); last_error_0 = save; save = error;
 306                 error -= last_error_1; total_error_2 += local_abs(error); last_error_1 = save; save = error;
 307                 error -= last_error_2; total_error_3 += local_abs(error); last_error_2 = save; save = error;
 308                 error -= last_error_3; total_error_4 += local_abs(error); last_error_3 = save;
 309         }
 310
 311         if(total_error_0 < min(min(min(total_error_1, total_error_2), total_error_3), total_error_4))
 312                 order = 0;
 313         else if(total_error_1 < min(min(total_error_2, total_error_3), total_error_4))
 314                 order = 1;
 315         else if(total_error_2 < min(total_error_3, total_error_4))
 316                 order = 2;
 317         else if(total_error_3 < total_error_4)
 318                 order = 3;
 319         else
 320                 order = 4;
 321
 322         /* Estimate the expected number of bits per residual signal sample. */
 323         /* 'total_error*' is linearly related to the variance of the residual */
 324         /* signal, so we use it directly to compute E(|x|) */
 325         FLAC__ASSERT(data_len > 0 || total_error_0 == 0);
 326         FLAC__ASSERT(data_len > 0 || total_error_1 == 0);
 327         FLAC__ASSERT(data_len > 0 || total_error_2 == 0);
 328         FLAC__ASSERT(data_len > 0 || total_error_3 == 0);
 329         FLAC__ASSERT(data_len > 0 || total_error_4 == 0);
 330 #ifndef FLAC__INTEGER_ONLY_LIBRARY
 331 #if defined _MSC_VER || defined __MINGW32__
 332         /* with MSVC you have to spoon feed it the casting */
 333         residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
 334         residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
 335         residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
 336         residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
 337         residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)(FLAC__int64)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
 338 #else
 339         residual_bits_per_sample[0] = (FLAC__float)((total_error_0 > 0) ? log(M_LN2 * (FLAC__double)total_error_0 / (FLAC__double)data_len) / M_LN2 : 0.0);
 340         residual_bits_per_sample[1] = (FLAC__float)((total_error_1 > 0) ? log(M_LN2 * (FLAC__double)total_error_1 / (FLAC__double)data_len) / M_LN2 : 0.0);
 341         residual_bits_per_sample[2] = (FLAC__float)((total_error_2 > 0) ? log(M_LN2 * (FLAC__double)total_error_2 / (FLAC__double)data_len) / M_LN2 : 0.0);
 342         residual_bits_per_sample[3] = (FLAC__float)((total_error_3 > 0) ? log(M_LN2 * (FLAC__double)total_error_3 / (FLAC__double)data_len) / M_LN2 : 0.0);
 343         residual_bits_per_sample[4] = (FLAC__float)((total_error_4 > 0) ? log(M_LN2 * (FLAC__double)total_error_4 / (FLAC__double)data_len) / M_LN2 : 0.0);
 344 #endif
 345 #else
 346         residual_bits_per_sample[0] = (total_error_0 > 0) ? local__compute_rbps_wide_integerized(total_error_0, data_len) : 0;
 347         residual_bits_per_sample[1] = (total_error_1 > 0) ? local__compute_rbps_wide_integerized(total_error_1, data_len) : 0;
 348         residual_bits_per_sample[2] = (total_error_2 > 0) ? local__compute_rbps_wide_integerized(total_error_2, data_len) : 0;
 349         residual_bits_per_sample[3] = (total_error_3 > 0) ? local__compute_rbps_wide_integerized(total_error_3, data_len) : 0;
 350         residual_bits_per_sample[4] = (total_error_4 > 0) ? local__compute_rbps_wide_integerized(total_error_4, data_len) : 0;
 351 #endif
 352
 353         return order;
 354 }
 355
 356 void FLAC__fixed_compute_residual(const FLAC__int32 data[], unsigned data_len, unsigned order, FLAC__int32 residual[])
 357 {
 358         const int idata_len = (int)data_len;
 359         int i;
 360
 361         switch(order) {
 362                 case 0:
 363                         FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
 364                         memcpy(residual, data, sizeof(residual[0])*data_len);
 365                         break;
 366                 case 1:
 367                         for(i = 0; i < idata_len; i++)
 368                                 residual[i] = data[i] - data[i-1];
 369                         break;
 370                 case 2:
 371                         for(i = 0; i < idata_len; i++)
 372 #if 1 /* OPT: may be faster with some compilers on some systems */
 373                                 residual[i] = data[i] - (data[i-1] << 1) + data[i-2];
 374 #else
 375                                 residual[i] = data[i] - 2*data[i-1] + data[i-2];
 376 #endif
 377                         break;
 378                 case 3:
 379                         for(i = 0; i < idata_len; i++)
 380 #if 1 /* OPT: may be faster with some compilers on some systems */
 381                                 residual[i] = data[i] - (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) - data[i-3];
 382 #else
 383                                 residual[i] = data[i] - 3*data[i-1] + 3*data[i-2] - data[i-3];
 384 #endif
 385                         break;
 386                 case 4:
 387                         for(i = 0; i < idata_len; i++)
 388 #if 1 /* OPT: may be faster with some compilers on some systems */
 389                                 residual[i] = data[i] - ((data[i-1]+data[i-3])<<2) + ((data[i-2]<<2) + (data[i-2]<<1)) + data[i-4];
 390 #else
 391                                 residual[i] = data[i] - 4*data[i-1] + 6*data[i-2] - 4*data[i-3] + data[i-4];
 392 #endif
 393                         break;
 394                 default:
 395                         FLAC__ASSERT(0);
 396         }
 397 }
 398
 399 void FLAC__fixed_restore_signal(const FLAC__int32 residual[], unsigned data_len, unsigned order, FLAC__int32 data[])
 400 {
 401         int i, idata_len = (int)data_len;
 402
 403         switch(order) {
 404                 case 0:
 405                         FLAC__ASSERT(sizeof(residual[0]) == sizeof(data[0]));
 406                         memcpy(data, residual, sizeof(residual[0])*data_len);
 407                         break;
 408                 case 1:
 409                         for(i = 0; i < idata_len; i++)
 410                                 data[i] = residual[i] + data[i-1];
 411                         break;
 412                 case 2:
 413                         for(i = 0; i < idata_len; i++)
 414 #if 1 /* OPT: may be faster with some compilers on some systems */
 415                                 data[i] = residual[i] + (data[i-1]<<1) - data[i-2];
 416 #else
 417                                 data[i] = residual[i] + 2*data[i-1] - data[i-2];
 418 #endif
 419                         break;
 420                 case 3:
 421                         for(i = 0; i < idata_len; i++)
 422 #if 1 /* OPT: may be faster with some compilers on some systems */
 423                                 data[i] = residual[i] + (((data[i-1]-data[i-2])<<1) + (data[i-1]-data[i-2])) + data[i-3];
 424 #else
 425                                 data[i] = residual[i] + 3*data[i-1] - 3*data[i-2] + data[i-3];
 426 #endif
 427                         break;
 428                 case 4:
 429                         for(i = 0; i < idata_len; i++)
 430 #if 1 /* OPT: may be faster with some compilers on some systems */
 431                                 data[i] = residual[i] + ((data[i-1]+data[i-3])<<2) - ((data[i-2]<<2) + (data[i-2]<<1)) - data[i-4];
 432 #else
 433                                 data[i] = residual[i] + 4*data[i-1] - 6*data[i-2] + 4*data[i-3] - data[i-4];
 434 #endif
 435                         break;
 436                 default:
 437                         FLAC__ASSERT(0);
 438         }
 439 }
 440
 441 #endif