apps/codecs/libffmpegFLAC/decoder.c

   1 /*
   2  * FLAC (Free Lossless Audio Codec) decoder
   3  * Copyright (c) 2003 Alex Beregszaszi
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19
  20 /**
  21  * @file flac.c
  22  * FLAC (Free Lossless Audio Codec) decoder
  23  * @author Alex Beregszaszi
  24  *
  25  * For more information on the FLAC format, visit:
  26  *  http://flac.sourceforge.net/
  27  *
  28  * This decoder can be used in 1 of 2 ways: Either raw FLAC data can be fed
  29  * through, starting from the initial 'fLaC' signature; or by passing the
  30  * 34-byte streaminfo structure through avctx->extradata[_size] followed
  31  * by data starting with the 0xFFF8 marker.
  32  */
  33
  34 #include <inttypes.h>
  35 #include <stdbool.h>
  36 #ifndef BUILD_STANDALONE
  37 #include "codeclib.h"
  38 #endif
  39
  40 #include "bitstream.h"
  41 #include "golomb.h"
  42
  43 #include "decoder.h"
  44
  45 #if defined(CPU_COLDFIRE)
  46 #include "coldfire.h"
  47 #elif defined(CPU_ARM)
  48 #include "arm.h"
  49 #endif
  50
  51 #define FFMAX(a,b) ((a) > (b) ? (a) : (b))
  52 #define FFMIN(a,b) ((a) > (b) ? (b) : (a))
  53
  54 static const int sample_rate_table[] ICONST_ATTR =
  55 { 0, 0, 0, 0,
  56   8000, 16000, 22050, 24000, 32000, 44100, 48000, 96000,
  57   0, 0, 0, 0 };
  58
  59 static const int sample_size_table[] ICONST_ATTR =
  60 { 0, 8, 12, 0, 16, 20, 24, 0 };
  61
  62 static const int blocksize_table[] ICONST_ATTR = {
  63      0,    192, 576<<0, 576<<1, 576<<2, 576<<3,      0,      0,
  64 256<<0, 256<<1, 256<<2, 256<<3, 256<<4, 256<<5, 256<<6, 256<<7
  65 };
  66
  67 static const uint8_t table_crc8[256] ICONST_ATTR = {
  68     0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15,
  69     0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d,
  70     0x70, 0x77, 0x7e, 0x79, 0x6c, 0x6b, 0x62, 0x65,
  71     0x48, 0x4f, 0x46, 0x41, 0x54, 0x53, 0x5a, 0x5d,
  72     0xe0, 0xe7, 0xee, 0xe9, 0xfc, 0xfb, 0xf2, 0xf5,
  73     0xd8, 0xdf, 0xd6, 0xd1, 0xc4, 0xc3, 0xca, 0xcd,
  74     0x90, 0x97, 0x9e, 0x99, 0x8c, 0x8b, 0x82, 0x85,
  75     0xa8, 0xaf, 0xa6, 0xa1, 0xb4, 0xb3, 0xba, 0xbd,
  76     0xc7, 0xc0, 0xc9, 0xce, 0xdb, 0xdc, 0xd5, 0xd2,
  77     0xff, 0xf8, 0xf1, 0xf6, 0xe3, 0xe4, 0xed, 0xea,
  78     0xb7, 0xb0, 0xb9, 0xbe, 0xab, 0xac, 0xa5, 0xa2,
  79     0x8f, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9d, 0x9a,
  80     0x27, 0x20, 0x29, 0x2e, 0x3b, 0x3c, 0x35, 0x32,
  81     0x1f, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0d, 0x0a,
  82     0x57, 0x50, 0x59, 0x5e, 0x4b, 0x4c, 0x45, 0x42,
  83     0x6f, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7d, 0x7a,
  84     0x89, 0x8e, 0x87, 0x80, 0x95, 0x92, 0x9b, 0x9c,
  85     0xb1, 0xb6, 0xbf, 0xb8, 0xad, 0xaa, 0xa3, 0xa4,
  86     0xf9, 0xfe, 0xf7, 0xf0, 0xe5, 0xe2, 0xeb, 0xec,
  87     0xc1, 0xc6, 0xcf, 0xc8, 0xdd, 0xda, 0xd3, 0xd4,
  88     0x69, 0x6e, 0x67, 0x60, 0x75, 0x72, 0x7b, 0x7c,
  89     0x51, 0x56, 0x5f, 0x58, 0x4d, 0x4a, 0x43, 0x44,
  90     0x19, 0x1e, 0x17, 0x10, 0x05, 0x02, 0x0b, 0x0c,
  91     0x21, 0x26, 0x2f, 0x28, 0x3d, 0x3a, 0x33, 0x34,
  92     0x4e, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5c, 0x5b,
  93     0x76, 0x71, 0x78, 0x7f, 0x6a, 0x6d, 0x64, 0x63,
  94     0x3e, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2c, 0x2b,
  95     0x06, 0x01, 0x08, 0x0f, 0x1a, 0x1d, 0x14, 0x13,
  96     0xae, 0xa9, 0xa0, 0xa7, 0xb2, 0xb5, 0xbc, 0xbb,
  97     0x96, 0x91, 0x98, 0x9f, 0x8a, 0x8d, 0x84, 0x83,
  98     0xde, 0xd9, 0xd0, 0xd7, 0xc2, 0xc5, 0xcc, 0xcb,
  99     0xe6, 0xe1, 0xe8, 0xef, 0xfa, 0xfd, 0xf4, 0xf3
 100 };
 101
 102 static int64_t get_utf8(GetBitContext *gb) ICODE_ATTR_FLAC;
 103 static int64_t get_utf8(GetBitContext *gb)
 104 {
 105     uint64_t val;
 106     int ones=0, bytes;
 107
 108     while(get_bits1(gb))
 109         ones++;
 110
 111     if     (ones==0) bytes=0;
 112     else if(ones==1) return -1;
 113     else             bytes= ones - 1;
 114
 115     val= get_bits(gb, 7-ones);
 116     while(bytes--){
 117         const int tmp = get_bits(gb, 8);
 118
 119         if((tmp>>6) != 2)
 120             return -2;
 121         val<<=6;
 122         val|= tmp&0x3F;
 123     }
 124     return val;
 125 }
 126
 127 static int get_crc8(const uint8_t *buf, int count) ICODE_ATTR_FLAC;
 128 static int get_crc8(const uint8_t *buf, int count)
 129 {
 130     int crc=0;
 131     int i;
 132
 133     for(i=0; i<count; i++){
 134         crc = table_crc8[crc ^ buf[i]];
 135     }
 136
 137     return crc;
 138 }
 139
 140 static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 141 static int decode_residuals(FLACContext *s, int32_t* decoded, int pred_order)
 142 {
 143     int i, tmp, partition, method_type, rice_order;
 144     int sample = 0, samples;
 145
 146     method_type = get_bits(&s->gb, 2);
 147     if (method_type > 1){
 148         //fprintf(stderr,"illegal residual coding method %d\n", method_type);
 149         return -3;
 150     }
 151
 152     rice_order = get_bits(&s->gb, 4);
 153
 154     samples= s->blocksize >> rice_order;
 155
 156     sample=
 157     i= pred_order;
 158     for (partition = 0; partition < (1 << rice_order); partition++)
 159     {
 160         tmp = get_bits(&s->gb, method_type == 0 ? 4 : 5);
 161         if (tmp == (method_type == 0 ? 15 : 31))
 162         {
 163             //fprintf(stderr,"fixed len partition\n");
 164             tmp = get_bits(&s->gb, 5);
 165             for (; i < samples; i++, sample++)
 166                 decoded[sample] = get_sbits(&s->gb, tmp);
 167         }
 168         else
 169         {
 170             for (; i < samples; i++, sample++){
 171                 decoded[sample] = get_sr_golomb_flac(&s->gb, tmp, INT_MAX, 0);
 172             }
 173         }
 174         i= 0;
 175     }
 176
 177     return 0;
 178 }
 179
 180 static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 181 static int decode_subframe_fixed(FLACContext *s, int32_t* decoded, int pred_order)
 182 {
 183     const int blocksize = s->blocksize;
 184     int a, b, c, d, i;
 185
 186     /* warm up samples */
 187     for (i = 0; i < pred_order; i++)
 188     {
 189         decoded[i] = get_sbits(&s->gb, s->curr_bps);
 190     }
 191
 192     if (decode_residuals(s, decoded, pred_order) < 0)
 193         return -4;
 194
 195     a = decoded[pred_order-1];
 196     b = a - decoded[pred_order-2];
 197     c = b - decoded[pred_order-2] + decoded[pred_order-3];
 198     d = c - decoded[pred_order-2] + 2*decoded[pred_order-3] - decoded[pred_order-4];
 199
 200     switch(pred_order)
 201     {
 202         case 0:
 203             break;
 204         case 1:
 205             for (i = pred_order; i < blocksize; i++)
 206                 decoded[i] = a += decoded[i];
 207             break;
 208         case 2:
 209             for (i = pred_order; i < blocksize; i++)
 210                 decoded[i] = a += b += decoded[i];
 211             break;
 212         case 3:
 213             for (i = pred_order; i < blocksize; i++)
 214                 decoded[i] = a += b += c += decoded[i];
 215             break;
 216         case 4:
 217             for (i = pred_order; i < blocksize; i++)
 218                 decoded[i] = a += b += c += d += decoded[i];
 219             break;
 220         default:
 221             return -5;
 222     }
 223
 224     return 0;
 225 }
 226
 227 static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order) ICODE_ATTR_FLAC;
 228 static int decode_subframe_lpc(FLACContext *s, int32_t* decoded, int pred_order)
 229 {
 230     int sum, i, j;
 231     int64_t wsum;
 232     int coeff_prec, qlevel;
 233     int coeffs[pred_order];
 234
 235     /* warm up samples */
 236     for (i = 0; i < pred_order; i++)
 237     {
 238         decoded[i] = get_sbits(&s->gb, s->curr_bps);
 239     }
 240
 241     coeff_prec = get_bits(&s->gb, 4) + 1;
 242     if (coeff_prec == 16)
 243     {
 244         //fprintf(stderr,"invalid coeff precision\n");
 245         return -6;
 246     }
 247     qlevel = get_sbits(&s->gb, 5);
 248     if (qlevel < 0)
 249     {
 250         //fprintf(stderr,"qlevel %d not supported, maybe buggy stream\n", qlevel);
 251         return -7;
 252     }
 253
 254     for (i = 0; i < pred_order; i++)
 255     {
 256         coeffs[i] = get_sbits(&s->gb, coeff_prec);
 257     }
 258
 259     if (decode_residuals(s, decoded, pred_order) < 0)
 260         return -8;
 261
 262     if ((s->bps + coeff_prec + av_log2(pred_order)) <= 32) {
 263         #if defined(CPU_COLDFIRE)
 264         (void)sum;
 265         lpc_decode_emac(s->blocksize - pred_order, qlevel, pred_order,
 266                         decoded + pred_order, coeffs);
 267         #elif defined(CPU_ARM)
 268         (void)sum;
 269         lpc_decode_arm(s->blocksize - pred_order, qlevel, pred_order,
 270                        decoded + pred_order, coeffs);
 271         #else
 272         for (i = pred_order; i < s->blocksize; i++)
 273         {
 274             sum = 0;
 275             for (j = 0; j < pred_order; j++)
 276                 sum += coeffs[j] * decoded[i-j-1];
 277             decoded[i] += sum >> qlevel;
 278         }
 279         #endif
 280     } else {
 281         #if defined(CPU_COLDFIRE)
 282         (void)wsum;
 283         (void)j;
 284         lpc_decode_emac_wide(s->blocksize - pred_order, qlevel, pred_order,
 285                              decoded + pred_order, coeffs);
 286         #else
 287         for (i = pred_order; i < s->blocksize; i++)
 288         {
 289             wsum = 0;
 290             for (j = 0; j < pred_order; j++)
 291                 wsum += (int64_t)coeffs[j] * (int64_t)decoded[i-j-1];
 292             decoded[i] += wsum >> qlevel;
 293         }
 294         #endif
 295     }
 296
 297     return 0;
 298 }
 299
 300 static inline int decode_subframe(FLACContext *s, int channel, int32_t* decoded)
 301 {
 302     int type, wasted = 0;
 303     int i, tmp;
 304
 305     s->curr_bps = s->bps;
 306     if(channel == 0){
 307         if(s->decorrelation == RIGHT_SIDE)
 308             s->curr_bps++;
 309     }else{
 310         if(s->decorrelation == LEFT_SIDE || s->decorrelation == MID_SIDE)
 311             s->curr_bps++;
 312     }
 313
 314     if (get_bits1(&s->gb))
 315     {
 316         //fprintf(stderr,"invalid subframe padding\n");
 317         return -9;
 318     }
 319     type = get_bits(&s->gb, 6);
 320 //    wasted = get_bits1(&s->gb);
 321
 322 //    if (wasted)
 323 //    {
 324 //        while (!get_bits1(&s->gb))
 325 //            wasted++;
 326 //        if (wasted)
 327 //            wasted++;
 328 //        s->curr_bps -= wasted;
 329 //    }
 330 #if 0
 331     wasted= 16 - av_log2(show_bits(&s->gb, 17));
 332     skip_bits(&s->gb, wasted+1);
 333     s->curr_bps -= wasted;
 334 #else
 335     if (get_bits1(&s->gb))
 336     {
 337         wasted = 1;
 338         while (!get_bits1(&s->gb))
 339             wasted++;
 340         s->curr_bps -= wasted;
 341         //fprintf(stderr,"%d wasted bits\n", wasted);
 342     }
 343 #endif
 344 //FIXME use av_log2 for types
 345     if (type == 0)
 346     {
 347         //fprintf(stderr,"coding type: constant\n");
 348         tmp = get_sbits(&s->gb, s->curr_bps);
 349         for (i = 0; i < s->blocksize; i++)
 350             decoded[i] = tmp;
 351     }
 352     else if (type == 1)
 353     {
 354         //fprintf(stderr,"coding type: verbatim\n");
 355         for (i = 0; i < s->blocksize; i++)
 356             decoded[i] = get_sbits(&s->gb, s->curr_bps);
 357     }
 358     else if ((type >= 8) && (type <= 12))
 359     {
 360         //fprintf(stderr,"coding type: fixed\n");
 361         if (decode_subframe_fixed(s, decoded, type & ~0x8) < 0)
 362             return -10;
 363     }
 364     else if (type >= 32)
 365     {
 366         //fprintf(stderr,"coding type: lpc\n");
 367         if (decode_subframe_lpc(s, decoded, (type & ~0x20)+1) < 0)
 368             return -11;
 369     }
 370     else
 371     {
 372         //fprintf(stderr,"Unknown coding type: %d\n",type);
 373         return -12;
 374     }
 375
 376     if (wasted)
 377     {
 378         int i;
 379         for (i = 0; i < s->blocksize; i++)
 380             decoded[i] <<= wasted;
 381     }
 382
 383     return 0;
 384 }
 385
 386 static int decode_frame(FLACContext *s,
 387                         int32_t* decoded0,
 388                         int32_t* decoded1,
 389                         void (*yield)(void)) ICODE_ATTR_FLAC;
 390 static int decode_frame(FLACContext *s,
 391                         int32_t* decoded0,
 392                         int32_t* decoded1,
 393                         void (*yield)(void))
 394 {
 395     int blocksize_code, sample_rate_code, sample_size_code, assignment, crc8;
 396     int decorrelation, bps, blocksize, samplerate;
 397     int res;
 398
 399     blocksize_code = get_bits(&s->gb, 4);
 400
 401     sample_rate_code = get_bits(&s->gb, 4);
 402
 403     assignment = get_bits(&s->gb, 4); /* channel assignment */
 404     if (assignment < 8 && s->channels == assignment+1)
 405         decorrelation = INDEPENDENT;
 406     else if (assignment >=8 && assignment < 11 && s->channels == 2)
 407         decorrelation = LEFT_SIDE + assignment - 8;
 408     else
 409     {
 410         return -13;
 411     }
 412
 413     sample_size_code = get_bits(&s->gb, 3);
 414     if(sample_size_code == 0)
 415         bps= s->bps;
 416     else if((sample_size_code != 3) && (sample_size_code != 7))
 417         bps = sample_size_table[sample_size_code];
 418     else
 419     {
 420         return -14;
 421     }
 422
 423     if (get_bits1(&s->gb))
 424     {
 425         return -15;
 426     }
 427
 428     /* Get the samplenumber of the first sample in this block */
 429     s->samplenumber=get_utf8(&s->gb);
 430
 431     /* samplenumber actually contains the frame number for streams
 432        with a constant block size - so we multiply by blocksize to
 433        get the actual sample number */
 434     if (s->min_blocksize == s->max_blocksize) {
 435         s->samplenumber*=s->min_blocksize;
 436     }
 437
 438 #if 0
 439     if (/*((blocksize_code == 6) || (blocksize_code == 7)) &&*/
 440         (s->min_blocksize != s->max_blocksize)){
 441     }else{
 442     }
 443 #endif
 444
 445     if (blocksize_code == 0)
 446         blocksize = s->min_blocksize;
 447     else if (blocksize_code == 6)
 448         blocksize = get_bits(&s->gb, 8)+1;
 449     else if (blocksize_code == 7)
 450         blocksize = get_bits(&s->gb, 16)+1;
 451     else
 452         blocksize = blocksize_table[blocksize_code];
 453
 454     if(blocksize > s->max_blocksize){
 455         return -16;
 456     }
 457
 458     if (sample_rate_code == 0){
 459         samplerate= s->samplerate;
 460     }else if ((sample_rate_code > 3) && (sample_rate_code < 12))
 461         samplerate = sample_rate_table[sample_rate_code];
 462     else if (sample_rate_code == 12)
 463         samplerate = get_bits(&s->gb, 8) * 1000;
 464     else if (sample_rate_code == 13)
 465         samplerate = get_bits(&s->gb, 16);
 466     else if (sample_rate_code == 14)
 467         samplerate = get_bits(&s->gb, 16) * 10;
 468     else{
 469         return -17;
 470     }
 471
 472     skip_bits(&s->gb, 8);
 473     crc8= get_crc8(s->gb.buffer, get_bits_count(&s->gb)/8);
 474     if(crc8){
 475         return -18;
 476     }
 477
 478     s->blocksize    = blocksize;
 479     s->samplerate   = samplerate;
 480     s->bps          = bps;
 481     s->decorrelation= decorrelation;
 482
 483     yield();
 484     /* subframes */
 485     if ((res=decode_subframe(s, 0, decoded0)) < 0)
 486         return res-100;
 487
 488     yield();
 489
 490     if (s->channels==2) {
 491       if ((res=decode_subframe(s, 1, decoded1)) < 0)
 492           return res-200;
 493     }
 494
 495     yield();
 496     align_get_bits(&s->gb);
 497
 498     /* frame footer */
 499     skip_bits(&s->gb, 16); /* data crc */
 500
 501     return 0;
 502 }
 503
 504 int flac_decode_frame(FLACContext *s,
 505                              int32_t* decoded0,
 506                              int32_t* decoded1,
 507                              uint8_t *buf, int buf_size,
 508                              void (*yield)(void))
 509 {
 510     int tmp;
 511     int i;
 512     int framesize;
 513     int scale;
 514
 515     init_get_bits(&s->gb, buf, buf_size*8);
 516
 517     tmp = get_bits(&s->gb, 16);
 518     if ((tmp & 0xFFFE) != 0xFFF8){
 519         return -41;
 520     }
 521
 522     if ((framesize=decode_frame(s,decoded0,decoded1,yield)) < 0){
 523        s->bitstream_size=0;
 524        s->bitstream_index=0;
 525        return framesize;
 526     }
 527
 528     yield();
 529
 530     scale=FLAC_OUTPUT_DEPTH-s->bps;
 531     switch(s->decorrelation)
 532     {
 533         case INDEPENDENT:
 534             if (s->channels==1) {;
 535                 for (i = 0; i < s->blocksize; i++)
 536                 {
 537                     decoded0[i] = decoded0[i] << scale;
 538                 }
 539             } else {
 540                 for (i = 0; i < s->blocksize; i++)
 541                 {
 542                     decoded0[i] = decoded0[i] << scale;
 543                     decoded1[i] = decoded1[i] << scale;
 544                 }
 545             }
 546             break;
 547         case LEFT_SIDE:
 548             //assert(s->channels == 2);
 549             for (i = 0; i < s->blocksize; i++)
 550             {
 551                 decoded1[i] = (decoded0[i] - decoded1[i]) << scale;
 552                 decoded0[i] = decoded0[i] << scale;
 553             }
 554             break;
 555         case RIGHT_SIDE:
 556             //assert(s->channels == 2);
 557             for (i = 0; i < s->blocksize; i++)
 558             {
 559                 decoded0[i] = (decoded0[i] + decoded1[i]) << scale;
 560                 decoded1[i] = decoded1[i] << scale;
 561             }
 562             break;
 563         case MID_SIDE:
 564             //assert(s->channels == 2);
 565             for (i = 0; i < s->blocksize; i++)
 566             {
 567                 int mid, side;
 568                 mid = decoded0[i];
 569                 side = decoded1[i];
 570
 571 #if 1 //needs to be checked but IMHO it should be binary identical
 572                 mid -= side>>1;
 573                 decoded0[i] = (mid + side) << scale;
 574                 decoded1[i] = mid << scale;
 575 #else
 576
 577                 mid <<= 1;
 578                 if (side & 1)
 579                     mid++;
 580                 decoded0[i] = ((mid + side) >> 1) << scale;
 581                 decoded1[i] = ((mid - side) >> 1) << scale;
 582 #endif
 583             }
 584             break;
 585     }
 586
 587     s->framesize = (get_bits_count(&s->gb)+7)>>3;
 588
 589     return 0;
 590 }