src/libFLAC/stream_decoder.c

   1 /* libFLAC - Free Lossless Audio Coder library
   2  * Copyright (C) 2000  Josh Coalson
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Library General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA  02111-1307, USA.
  18  */
  19
  20 #include <assert.h>
  21 #include <stdio.h>
  22 #include <stdlib.h> /* for malloc() */
  23 #include "FLAC/stream_decoder.h"
  24 #include "private/bitbuffer.h"
  25 #include "private/crc.h"
  26 #include "private/fixed.h"
  27 #include "private/lpc.h"
  28
  29 typedef struct FLAC__StreamDecoderPrivate {
  30         FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data);
  31         FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__FrameHeader *header, const int32 *buffer[], void *client_data);
  32         void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
  33         void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
  34         void *client_data;
  35         FLAC__BitBuffer input;
  36         int32 *output[FLAC__MAX_CHANNELS];
  37         int32 *residual;
  38         unsigned output_capacity;
  39         uint32 last_frame_number;
  40         uint64 samples_decoded;
  41         bool has_stream_header;
  42         FLAC__StreamMetaData stream_header;
  43         FLAC__FrameHeader frame_header;
  44 } FLAC__StreamDecoderPrivate;
  45
  46 static byte ID3V2_TAG_[3] = { 'I', 'D', '3' };
  47
  48 static bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size);
  49 static bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder);
  50 static bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder);
  51 static bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder);
  52 static bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder);
  53 static bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame);
  54 static bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder);
  55 static bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel);
  56 static bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel);
  57 static bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order);
  58 static bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order);
  59 static bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel);
  60 static bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order);
  61 static bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder);
  62 static bool read_callback_(byte buffer[], unsigned *bytes, void *client_data);
  63
  64 const char *FLAC__StreamDecoderStateString[] = {
  65         "FLAC__STREAM_DECODER_SEARCH_FOR_METADATA",
  66         "FLAC__STREAM_DECODER_READ_METADATA",
  67         "FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC",
  68         "FLAC__STREAM_DECODER_READ_FRAME",
  69         "FLAC__STREAM_DECODER_RESYNC_IN_HEADER",
  70         "FLAC__STREAM_DECODER_END_OF_STREAM",
  71         "FLAC__STREAM_DECODER_ABORTED",
  72         "FLAC__STREAM_DECODER_UNPARSEABLE_STREAM",
  73         "FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
  74         "FLAC__STREAM_DECODER_UNINITIALIZED"
  75 };
  76
  77 const char *FLAC__StreamDecoderReadStatusString[] = {
  78         "FLAC__STREAM_DECODER_READ_CONTINUE",
  79         "FLAC__STREAM_DECODER_READ_END_OF_STREAM",
  80         "FLAC__STREAM_DECODER_READ_ABORT"
  81 };
  82
  83 const char *FLAC__StreamDecoderWriteStatusString[] = {
  84         "FLAC__STREAM_DECODER_WRITE_CONTINUE",
  85         "FLAC__STREAM_DECODER_WRITE_ABORT"
  86 };
  87
  88 const char *FLAC__StreamDecoderErrorStatusString[] = {
  89         "FLAC__STREAM_DECODER_ERROR_LOST_SYNC"
  90 };
  91
  92 FLAC__StreamDecoder *FLAC__stream_decoder_get_new_instance()
  93 {
  94         FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder*)malloc(sizeof(FLAC__StreamDecoder));
  95         if(decoder != 0) {
  96                 decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
  97                 decoder->guts = 0;
  98         }
  99         return decoder;
 100 }
 101
 102 void FLAC__stream_decoder_free_instance(FLAC__StreamDecoder *decoder)
 103 {
 104         free(decoder);
 105 }
 106
 107 FLAC__StreamDecoderState FLAC__stream_decoder_init(
 108         FLAC__StreamDecoder *decoder,
 109         FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data),
 110         FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__FrameHeader *header, const int32 *buffer[], void *client_data),
 111         void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data),
 112         void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data),
 113         void *client_data
 114 )
 115 {
 116         unsigned i;
 117
 118         assert(sizeof(int) >= 4); /* we want to die right away if this is not true */
 119         assert(decoder != 0);
 120         assert(read_callback != 0);
 121         assert(write_callback != 0);
 122         assert(metadata_callback != 0);
 123         assert(error_callback != 0);
 124         assert(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED);
 125         assert(decoder->guts == 0);
 126
 127         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;
 128
 129         decoder->guts = (FLAC__StreamDecoderPrivate*)malloc(sizeof(FLAC__StreamDecoderPrivate));
 130         if(decoder->guts == 0)
 131                 return decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 132
 133         decoder->guts->read_callback = read_callback;
 134         decoder->guts->write_callback = write_callback;
 135         decoder->guts->metadata_callback = metadata_callback;
 136         decoder->guts->error_callback = error_callback;
 137         decoder->guts->client_data = client_data;
 138
 139         FLAC__bitbuffer_init(&decoder->guts->input);
 140
 141         for(i = 0; i < FLAC__MAX_CHANNELS; i++)
 142                 decoder->guts->output[i] = 0;
 143         decoder->guts->residual = 0;
 144
 145         decoder->guts->output_capacity = 0;
 146         decoder->guts->last_frame_number = 0;
 147         decoder->guts->samples_decoded = 0;
 148         decoder->guts->has_stream_header = false;
 149
 150         return decoder->state;
 151 }
 152
 153 void FLAC__stream_decoder_finish(FLAC__StreamDecoder *decoder)
 154 {
 155         unsigned i;
 156         assert(decoder != 0);
 157         if(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED)
 158                 return;
 159         if(decoder->guts != 0) {
 160                 FLAC__bitbuffer_free(&decoder->guts->input);
 161                 for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
 162                         if(decoder->guts->output[i] != 0) {
 163                                 free(decoder->guts->output[i]);
 164                                 decoder->guts->output[i] = 0;
 165                         }
 166                 }
 167                 if(decoder->guts->residual != 0) {
 168                         free(decoder->guts->residual);
 169                         decoder->guts->residual = 0;
 170                 }
 171                 free(decoder->guts);
 172                 decoder->guts = 0;
 173         }
 174         decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
 175 }
 176
 177 bool FLAC__stream_decoder_flush(FLAC__StreamDecoder *decoder)
 178 {
 179         assert(decoder != 0);
 180
 181         if(!FLAC__bitbuffer_clear(&decoder->guts->input)) {
 182                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 183                 return false;
 184         }
 185
 186         return true;
 187 }
 188
 189 bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder)
 190 {
 191         assert(decoder != 0);
 192
 193         if(!FLAC__stream_decoder_flush(decoder)) {
 194                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 195                 return false;
 196         }
 197         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;
 198
 199         return true;
 200 }
 201
 202 bool FLAC__stream_decoder_process_whole_stream(FLAC__StreamDecoder *decoder)
 203 {
 204         bool dummy;
 205         assert(decoder != 0);
 206
 207         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 208                 return true;
 209
 210         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);
 211
 212         if(!FLAC__stream_decoder_reset(decoder)) {
 213                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 214                 return false;
 215         }
 216
 217         while(1) {
 218                 switch(decoder->state) {
 219                         case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
 220                                 if(!stream_decoder_find_metadata_(decoder))
 221                                         return false; /* above function sets the status for us */
 222                                 break;
 223                         case FLAC__STREAM_DECODER_READ_METADATA:
 224                                 if(!stream_decoder_read_metadata_(decoder))
 225                                         return false; /* above function sets the status for us */
 226                                 break;
 227                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 228                                 if(!stream_decoder_frame_sync_(decoder))
 229                                         return true; /* above function sets the status for us */
 230                                 break;
 231                         case FLAC__STREAM_DECODER_READ_FRAME:
 232                                 if(!stream_decoder_read_frame_(decoder, &dummy))
 233                                         return false; /* above function sets the status for us */
 234                                 break;
 235                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 236                                 return true;
 237                         default:
 238                                 assert(0);
 239                 }
 240         }
 241 }
 242
 243 bool FLAC__stream_decoder_process_metadata(FLAC__StreamDecoder *decoder)
 244 {
 245         assert(decoder != 0);
 246
 247         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 248                 return true;
 249
 250         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);
 251
 252         if(!FLAC__stream_decoder_reset(decoder)) {
 253                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 254                 return false;
 255         }
 256
 257         while(1) {
 258                 switch(decoder->state) {
 259                         case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
 260                                 if(!stream_decoder_find_metadata_(decoder))
 261                                         return false; /* above function sets the status for us */
 262                                 break;
 263                         case FLAC__STREAM_DECODER_READ_METADATA:
 264                                 if(!stream_decoder_read_metadata_(decoder))
 265                                         return false; /* above function sets the status for us */
 266                                 break;
 267                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 268                                 return true;
 269                                 break;
 270                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 271                                 return true;
 272                         default:
 273                                 assert(0);
 274                 }
 275         }
 276 }
 277
 278 bool FLAC__stream_decoder_process_one_frame(FLAC__StreamDecoder *decoder)
 279 {
 280         bool got_a_frame;
 281         assert(decoder != 0);
 282
 283         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 284                 return true;
 285
 286         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);
 287
 288         while(1) {
 289                 switch(decoder->state) {
 290                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 291                                 if(!stream_decoder_frame_sync_(decoder))
 292                                         return true; /* above function sets the status for us */
 293                                 break;
 294                         case FLAC__STREAM_DECODER_READ_FRAME:
 295                                 if(!stream_decoder_read_frame_(decoder, &got_a_frame))
 296                                         return false; /* above function sets the status for us */
 297                                 if(got_a_frame)
 298                                         return true; /* above function sets the status for us */
 299                                 break;
 300                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 301                                 return true;
 302                         default:
 303                                 assert(0);
 304                 }
 305         }
 306 }
 307
 308 bool FLAC__stream_decoder_process_remaining_frames(FLAC__StreamDecoder *decoder)
 309 {
 310         bool dummy;
 311         assert(decoder != 0);
 312
 313         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 314                 return true;
 315
 316         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);
 317
 318         while(1) {
 319                 switch(decoder->state) {
 320                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 321                                 if(!stream_decoder_frame_sync_(decoder))
 322                                         return true; /* above function sets the status for us */
 323                                 break;
 324                         case FLAC__STREAM_DECODER_READ_FRAME:
 325                                 if(!stream_decoder_read_frame_(decoder, &dummy))
 326                                         return false; /* above function sets the status for us */
 327                                 break;
 328                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 329                                 return true;
 330                         default:
 331                                 assert(0);
 332                 }
 333         }
 334 }
 335
 336 unsigned FLAC__stream_decoder_input_bytes_unconsumed(FLAC__StreamDecoder *decoder)
 337 {
 338         assert(decoder != 0);
 339         return decoder->guts->input.bytes - decoder->guts->input.consumed_bytes;
 340 }
 341
 342 bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size)
 343 {
 344         unsigned i;
 345         int32 *tmp;
 346
 347         if(size <= decoder->guts->output_capacity)
 348                 return true;
 349
 350         for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
 351                 if(decoder->guts->output[i] != 0) {
 352                         free(decoder->guts->output[i]);
 353                         decoder->guts->output[i] = 0;
 354                 }
 355         }
 356         if(decoder->guts->residual != 0) {
 357                 free(decoder->guts->residual);
 358                 decoder->guts->residual = 0;
 359         }
 360
 361         for(i = 0; i < decoder->guts->frame_header.channels; i++) {
 362                 tmp = (int32*)malloc(sizeof(int32)*size);
 363                 if(tmp == 0) {
 364                         decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 365                         return false;
 366                 }
 367                 decoder->guts->output[i] = tmp;
 368         }
 369         tmp = (int32*)malloc(sizeof(int32)*size);
 370         if(tmp == 0) {
 371                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 372                 return false;
 373         }
 374         decoder->guts->residual = tmp;
 375
 376         decoder->guts->output_capacity = size;
 377
 378         return true;
 379 }
 380
 381 bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder)
 382 {
 383         uint32 x;
 384         unsigned i, id;
 385         bool first = 1;
 386
 387         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 388
 389         for(i = id = 0; i < 4; ) {
 390                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 391                         return false; /* the read_callback_ sets the state for us */
 392                 if(x == FLAC__STREAM_SYNC_STRING[i]) {
 393                         first = 1;
 394                         i++;
 395                         id = 0;
 396                         continue;
 397                 }
 398                 if(x == ID3V2_TAG_[id]) {
 399                         id++;
 400                         i = 0;
 401                         if(id == 3) {
 402                                 if(!stream_decoder_skip_id3v2_tag_(decoder))
 403                                         return false; /* the read_callback_ sets the state for us */
 404                         }
 405                         continue;
 406                 }
 407                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 408                         unsigned y;
 409                         if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 410                                 return false; /* the read_callback_ sets the state for us */
 411                         if(!y) { /* MAGIC NUMBER for the last sync bit */
 412                                 decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 413                                 return true;
 414                         }
 415                 }
 416                 i = 0;
 417                 if(first) {
 418                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 419                         first = 0;
 420                 }
 421         }
 422
 423         decoder->state = FLAC__STREAM_DECODER_READ_METADATA;
 424         return true;
 425 }
 426
 427 bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder)
 428 {
 429         uint32 i, x, last_block, type, length;
 430
 431         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 432
 433         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &last_block, FLAC__STREAM_METADATA_IS_LAST_LEN, read_callback_, decoder))
 434                 return false; /* the read_callback_ sets the state for us */
 435         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &type, FLAC__STREAM_METADATA_TYPE_LEN, read_callback_, decoder))
 436                 return false; /* the read_callback_ sets the state for us */
 437         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &length, FLAC__STREAM_METADATA_LENGTH_LEN, read_callback_, decoder))
 438                 return false; /* the read_callback_ sets the state for us */
 439         if(type == FLAC__METADATA_TYPE_ENCODING) {
 440                 unsigned used_bits = 0;
 441                 decoder->guts->stream_header.type = type;
 442                 decoder->guts->stream_header.is_last = last_block;
 443                 decoder->guts->stream_header.length = length;
 444
 445                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MIN_BLOCK_SIZE_LEN, read_callback_, decoder))
 446                         return false; /* the read_callback_ sets the state for us */
 447                 decoder->guts->stream_header.data.encoding.min_blocksize = x;
 448                 used_bits += FLAC__STREAM_METADATA_ENCODING_MIN_BLOCK_SIZE_LEN;
 449
 450                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MAX_BLOCK_SIZE_LEN, read_callback_, decoder))
 451                         return false; /* the read_callback_ sets the state for us */
 452                 decoder->guts->stream_header.data.encoding.max_blocksize = x;
 453                 used_bits += FLAC__STREAM_METADATA_ENCODING_MAX_BLOCK_SIZE_LEN;
 454
 455                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MIN_FRAME_SIZE_LEN, read_callback_, decoder))
 456                         return false; /* the read_callback_ sets the state for us */
 457                 decoder->guts->stream_header.data.encoding.min_framesize = x;
 458                 used_bits += FLAC__STREAM_METADATA_ENCODING_MIN_FRAME_SIZE_LEN;
 459
 460                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MAX_FRAME_SIZE_LEN, read_callback_, decoder))
 461                         return false; /* the read_callback_ sets the state for us */
 462                 decoder->guts->stream_header.data.encoding.max_framesize = x;
 463                 used_bits += FLAC__STREAM_METADATA_ENCODING_MAX_FRAME_SIZE_LEN;
 464
 465                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_SAMPLE_RATE_LEN, read_callback_, decoder))
 466                         return false; /* the read_callback_ sets the state for us */
 467                 decoder->guts->stream_header.data.encoding.sample_rate = x;
 468                 used_bits += FLAC__STREAM_METADATA_ENCODING_SAMPLE_RATE_LEN;
 469
 470                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_CHANNELS_LEN, read_callback_, decoder))
 471                         return false; /* the read_callback_ sets the state for us */
 472                 decoder->guts->stream_header.data.encoding.channels = x+1;
 473                 used_bits += FLAC__STREAM_METADATA_ENCODING_CHANNELS_LEN;
 474
 475                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_BITS_PER_SAMPLE_LEN, read_callback_, decoder))
 476                         return false; /* the read_callback_ sets the state for us */
 477                 decoder->guts->stream_header.data.encoding.bits_per_sample = x+1;
 478                 used_bits += FLAC__STREAM_METADATA_ENCODING_BITS_PER_SAMPLE_LEN;
 479
 480                 if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &decoder->guts->stream_header.data.encoding.total_samples, FLAC__STREAM_METADATA_ENCODING_TOTAL_SAMPLES_LEN, read_callback_, decoder))
 481                         return false; /* the read_callback_ sets the state for us */
 482                 used_bits += FLAC__STREAM_METADATA_ENCODING_TOTAL_SAMPLES_LEN;
 483
 484                 /* skip the rest of the block */
 485                 assert(used_bits % 8 == 0);
 486                 length -= (used_bits / 8);
 487                 for(i = 0; i < length; i++) {
 488                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 489                                 return false; /* the read_callback_ sets the state for us */
 490                 }
 491
 492                 decoder->guts->has_stream_header = true;
 493                 decoder->guts->metadata_callback(decoder, &decoder->guts->stream_header, decoder->guts->client_data);
 494         }
 495         else {
 496                 /* skip other metadata blocks */
 497                 for(i = 0; i < length; i++) {
 498                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 499                                 return false; /* the read_callback_ sets the state for us */
 500                 }
 501         }
 502
 503         if(last_block)
 504                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 505
 506         return true;
 507 }
 508
 509 bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder)
 510 {
 511         uint32 x;
 512         unsigned i, skip;
 513
 514         /* skip the version and flags bytes */
 515         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 24, read_callback_, decoder))
 516                 return false; /* the read_callback_ sets the state for us */
 517         /* get the size (in bytes) to skip */
 518         skip = 0;
 519         for(i = 0; i < 4; i++) {
 520                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 521                         return false; /* the read_callback_ sets the state for us */
 522                 skip <<= 7;
 523                 skip |= (x & 0x7f);
 524         }
 525         /* skip the rest of the tag */
 526         for(i = 0; i < skip; i++) {
 527                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 528                         return false; /* the read_callback_ sets the state for us */
 529         }
 530         return true;
 531 }
 532
 533 bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder)
 534 {
 535         uint32 x;
 536         bool first = 1;
 537
 538         /* If we know the total number of samples in the stream, stop if we've read that many. */
 539         /* This will stop us, for example, from wasting time trying to sync on an ID3V1 tag. */
 540         if(decoder->guts->has_stream_header && decoder->guts->stream_header.data.encoding.total_samples) {
 541                 if(decoder->guts->samples_decoded >= decoder->guts->stream_header.data.encoding.total_samples) {
 542                         decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
 543                         return true;
 544                 }
 545         }
 546
 547         /* make sure we're byte aligned */
 548         if(decoder->guts->input.consumed_bits != 0) {
 549                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
 550                         return false; /* the read_callback_ sets the state for us */
 551         }
 552
 553         while(1) {
 554                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 555                         return false; /* the read_callback_ sets the state for us */
 556                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 557                         unsigned y;
 558                         if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 559                                 return false; /* the read_callback_ sets the state for us */
 560                         if(!y) { /* MAGIC NUMBER for the last sync bit */
 561                                 decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 562                                 return true;
 563                         }
 564                 }
 565                 if(first) {
 566                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 567                         first = 0;
 568                 }
 569         }
 570
 571         return true;
 572 }
 573
 574 bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame)
 575 {
 576         unsigned channel;
 577         unsigned i;
 578         int32 mid, side, left, right;
 579
 580         *got_a_frame = false;
 581
 582         if(!stream_decoder_read_frame_header_(decoder))
 583                 return false;
 584         if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
 585                 if(decoder->state == FLAC__STREAM_DECODER_RESYNC_IN_HEADER)
 586                         decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 587                 else
 588                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 589                 return true;
 590         }
 591         if(!stream_decoder_allocate_output_(decoder, decoder->guts->frame_header.blocksize))
 592                 return false;
 593         for(channel = 0; channel < decoder->guts->frame_header.channels; channel++) {
 594                 if(!stream_decoder_read_subframe_(decoder, channel))
 595                         return false;
 596                 if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
 597                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 598                         return true;
 599                 }
 600         }
 601         if(!stream_decoder_read_zero_padding_(decoder))
 602                 return false;
 603
 604         /* Undo any special channel coding */
 605         switch(decoder->guts->frame_header.channel_assignment) {
 606                 case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
 607                         /* do nothing */
 608                         break;
 609                 case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
 610                         assert(decoder->guts->frame_header.channels == 2);
 611                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 612                                 decoder->guts->output[1][i] = decoder->guts->output[0][i] - decoder->guts->output[1][i];
 613                         break;
 614                 case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
 615                         assert(decoder->guts->frame_header.channels == 2);
 616                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 617                                 decoder->guts->output[0][i] += decoder->guts->output[1][i];
 618                         break;
 619                 case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
 620                         assert(decoder->guts->frame_header.channels == 2);
 621                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++) {
 622                                 mid = decoder->guts->output[0][i];
 623                                 side = decoder->guts->output[1][i];
 624                                 mid <<= 1;
 625                                 if(side & 1) /* i.e. if 'side' is odd... */
 626                                         mid++;
 627                                 left = mid + side;
 628                                 right = mid - side;
 629                                 decoder->guts->output[0][i] = left >> 1;
 630                                 decoder->guts->output[1][i] = right >> 1;
 631                         }
 632                         break;
 633                 default:
 634                         assert(0);
 635                         break;
 636         }
 637
 638         *got_a_frame = true;
 639
 640         /* put the latest values into the public section of the decoder instance */
 641         decoder->channels = decoder->guts->frame_header.channels;
 642         decoder->channel_assignment = decoder->guts->frame_header.channel_assignment;
 643         decoder->bits_per_sample = decoder->guts->frame_header.bits_per_sample;
 644         decoder->sample_rate = decoder->guts->frame_header.sample_rate;
 645         decoder->blocksize = decoder->guts->frame_header.blocksize;
 646
 647         decoder->guts->samples_decoded += decoder->guts->frame_header.blocksize;
 648
 649         /* write it */
 650         if(decoder->guts->write_callback(decoder, &decoder->guts->frame_header, decoder->guts->output, decoder->guts->client_data) != FLAC__STREAM_DECODER_WRITE_CONTINUE)
 651                 return false;
 652
 653         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 654         return true;
 655 }
 656
 657 bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder)
 658 {
 659         uint32 x;
 660         uint64 xx;
 661         unsigned i, blocksize_hint = 0, sample_rate_hint = 0;
 662         byte crc, raw_header[15]; /* MAGIC NUMBER based on the maximum frame header size, including CRC */
 663         unsigned raw_header_len;
 664         bool is_unparseable = false;
 665
 666         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 667
 668         /* init the raw header with the first 8 bits of the sync code */
 669         raw_header[0] = 0xff; /* MAGIC NUMBER for the first 8 frame sync bits */
 670         raw_header_len = 1;
 671
 672         /*
 673          * read in the raw header as bytes so we can CRC it, and parse it on the way
 674          */
 675         for(i = 0; i < 2; i++) {
 676                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 677                         return false; /* the read_callback_ sets the state for us */
 678                 else if(x == 0xff) { /* MAGIC NUMBER for the first part of the sync code */
 679                         /* if we get here it means our original sync was erroneous since the sync code cannot appear in the header */
 680                         uint32 y;
 681                         if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 682                                 return false; /* the read_callback_ sets the state for us */
 683                         if(!y) { /* MAGIC NUMBER for the last sync bit */
 684                                 decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 685                                 return true;
 686                         }
 687                         else {
 688                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 689                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 690                                 return true;
 691                         }
 692                 }
 693                 raw_header[raw_header_len++] = (byte)x;
 694         }
 695         assert(!(raw_header[1] & 0x80)); /* last sync bit should be confirmed zero before we get here */
 696
 697         switch(x = raw_header[1] >> 4) {
 698                 case 0:
 699                         if(decoder->guts->has_stream_header && decoder->guts->stream_header.data.encoding.min_blocksize == decoder->guts->stream_header.data.encoding.max_blocksize) /* i.e. it's a fixed-blocksize stream */
 700                                 decoder->guts->frame_header.blocksize = decoder->guts->stream_header.data.encoding.min_blocksize;
 701                         else
 702                                 is_unparseable = true;
 703                         break;
 704                 case 1:
 705                         decoder->guts->frame_header.blocksize = 192;
 706                         break;
 707                 case 2:
 708                 case 3:
 709                 case 4:
 710                 case 5:
 711                         decoder->guts->frame_header.blocksize = 576 << (x-2);
 712                         break;
 713                 case 6:
 714                 case 7:
 715                         blocksize_hint = x;
 716                         break;
 717                 default:
 718                         assert(0);
 719                         break;
 720         }
 721
 722         switch(x = raw_header[1] & 0x0f) {
 723                 case 0:
 724                         if(decoder->guts->has_stream_header)
 725                                 decoder->guts->frame_header.sample_rate = decoder->guts->stream_header.data.encoding.sample_rate;
 726                         else
 727                                 is_unparseable = true;
 728                         break;
 729                 case 1:
 730                 case 2:
 731                 case 3:
 732                         is_unparseable = true;
 733                         break;
 734                 case 4:
 735                         decoder->guts->frame_header.sample_rate = 8000;
 736                         break;
 737                 case 5:
 738                         decoder->guts->frame_header.sample_rate = 16000;
 739                         break;
 740                 case 6:
 741                         decoder->guts->frame_header.sample_rate = 22050;
 742                         break;
 743                 case 7:
 744                         decoder->guts->frame_header.sample_rate = 24000;
 745                         break;
 746                 case 8:
 747                         decoder->guts->frame_header.sample_rate = 32000;
 748                         break;
 749                 case 9:
 750                         decoder->guts->frame_header.sample_rate = 44100;
 751                         break;
 752                 case 10:
 753                         decoder->guts->frame_header.sample_rate = 48000;
 754                         break;
 755                 case 11:
 756                         decoder->guts->frame_header.sample_rate = 96000;
 757                         break;
 758                 case 12:
 759                 case 13:
 760                 case 14:
 761                         sample_rate_hint = x;
 762                         break;
 763                 case 15:
 764                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 765                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 766                         return true;
 767                 default:
 768                         assert(0);
 769         }
 770
 771         x = (unsigned)(raw_header[2] >> 4);
 772         if(x & 8) {
 773                 decoder->guts->frame_header.channels = 2;
 774                 switch(x & 7) {
 775                         case 0:
 776                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
 777                                 break;
 778                         case 1:
 779                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
 780                                 break;
 781                         case 2:
 782                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_MID_SIDE;
 783                                 break;
 784                         default:
 785                                 is_unparseable = true;
 786                                 break;
 787                 }
 788         }
 789         else {
 790                 decoder->guts->frame_header.channels = (unsigned)x + 1;
 791                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT;
 792         }
 793
 794         switch(x = (unsigned)(raw_header[2] & 0x0e) >> 1) {
 795                 case 0:
 796                         if(decoder->guts->has_stream_header)
 797                                 decoder->guts->frame_header.bits_per_sample = decoder->guts->stream_header.data.encoding.bits_per_sample;
 798                         else
 799                                 is_unparseable = true;
 800                         break;
 801                 case 1:
 802                         decoder->guts->frame_header.bits_per_sample = 8;
 803                         break;
 804                 case 2:
 805                         decoder->guts->frame_header.bits_per_sample = 12;
 806                         break;
 807                 case 4:
 808                         decoder->guts->frame_header.bits_per_sample = 16;
 809                         break;
 810                 case 5:
 811                         decoder->guts->frame_header.bits_per_sample = 20;
 812                         break;
 813                 case 6:
 814                         decoder->guts->frame_header.bits_per_sample = 24;
 815                         break;
 816                 case 3:
 817                 case 7:
 818                         is_unparseable = true;
 819                         break;
 820                 default:
 821                         assert(0);
 822                         break;
 823         }
 824
 825         if(raw_header[2] & 0x01) { /* this should be a zero padding bit */
 826                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 827                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 828                 return true;
 829         }
 830
 831         if(blocksize_hint) {
 832                 if(!FLAC__bitbuffer_read_utf8_uint64(&decoder->guts->input, &xx, read_callback_, decoder, raw_header, &raw_header_len))
 833                         return false; /* the read_callback_ sets the state for us */
 834                 if(xx == 0xffffffffffffffff) {
 835                         if(raw_header[raw_header_len-1] == 0xff) { /* MAGIC NUMBER for sync code */
 836                                 uint32 y;
 837                                 if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 838                                         return false; /* the read_callback_ sets the state for us */
 839                                 if(!y) { /* MAGIC NUMBER for the last sync bit */
 840                                         decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 841                                         return true;
 842                                 }
 843                                 else {
 844                                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 845                                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 846                                         return true;
 847                                 }
 848                         }
 849                         else {
 850                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 851                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 852                                 return true;
 853                         }
 854                 }
 855                 if(decoder->guts->has_stream_header && decoder->guts->stream_header.data.encoding.min_blocksize == decoder->guts->stream_header.data.encoding.max_blocksize) /* i.e. it's a fixed-blocksize stream */
 856                         decoder->guts->frame_header.number.sample_number = (uint64)decoder->guts->last_frame_number * (int64)decoder->guts->stream_header.data.encoding.min_blocksize + xx;
 857                 else
 858                         decoder->guts->frame_header.number.sample_number = xx;
 859         }
 860         else {
 861                 if(!FLAC__bitbuffer_read_utf8_uint32(&decoder->guts->input, &x, read_callback_, decoder, raw_header, &raw_header_len))
 862                         return false; /* the read_callback_ sets the state for us */
 863                 if(x == 0xffffffff) {
 864                         if(raw_header[raw_header_len-1] == 0xff) { /* MAGIC NUMBER for sync code */
 865                                 uint32 y;
 866                                 if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 867                                         return false; /* the read_callback_ sets the state for us */
 868                                 if(!y) { /* MAGIC NUMBER for the last sync bit */
 869                                         decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 870                                         return true;
 871                                 }
 872                                 else {
 873                                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 874                                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 875                                         return true;
 876                                 }
 877                         }
 878                         else {
 879                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 880                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 881                                 return true;
 882                         }
 883                 }
 884                 decoder->guts->last_frame_number = x;
 885                 if(decoder->guts->has_stream_header) {
 886                         decoder->guts->frame_header.number.sample_number = (int64)decoder->guts->stream_header.data.encoding.min_blocksize * (int64)x;
 887                 }
 888                 else {
 889                         is_unparseable = true;
 890                 }
 891         }
 892
 893         if(blocksize_hint) {
 894                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 895                         return false; /* the read_callback_ sets the state for us */
 896                 raw_header[raw_header_len++] = (byte)x;
 897                 if(blocksize_hint == 7) {
 898                         uint32 _x;
 899                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
 900                                 return false; /* the read_callback_ sets the state for us */
 901                         raw_header[raw_header_len++] = (byte)_x;
 902                         x = (x << 8) | _x;
 903                 }
 904                 decoder->guts->frame_header.blocksize = x+1;
 905         }
 906
 907         if(sample_rate_hint) {
 908                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 909                         return false; /* the read_callback_ sets the state for us */
 910                 raw_header[raw_header_len++] = (byte)x;
 911                 if(sample_rate_hint != 12) {
 912                         uint32 _x;
 913                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
 914                                 return false; /* the read_callback_ sets the state for us */
 915                         raw_header[raw_header_len++] = (byte)_x;
 916                         x = (x << 8) | _x;
 917                 }
 918                 if(sample_rate_hint == 12)
 919                         decoder->guts->frame_header.sample_rate = x*1000;
 920                 else if(sample_rate_hint == 13)
 921                         decoder->guts->frame_header.sample_rate = x;
 922                 else
 923                         decoder->guts->frame_header.sample_rate = x*10;
 924         }
 925
 926         /* read the crc byte */
 927         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 928                 return false; /* the read_callback_ sets the state for us */
 929         crc = (byte)x;
 930
 931         if(FLAC__crc8(raw_header, raw_header_len) != crc) {
 932                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 933                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 934                 return true;
 935         }
 936
 937         if(is_unparseable) {
 938                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 939                 return false;
 940         }
 941
 942         return true;
 943 }
 944
 945 bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel)
 946 {
 947         uint32 x;
 948
 949         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__SUBFRAME_HEADER_TYPE_LEN, read_callback_, decoder))
 950                 return false; /* the read_callback_ sets the state for us */
 951         if(x & 0x01 || x & 0x80) {
 952                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 953                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 954                 return true;
 955         }
 956         else if(x == 0) {
 957                 return stream_decoder_read_subframe_constant_(decoder, channel);
 958         }
 959         else if(x == 2) {
 960                 return stream_decoder_read_subframe_verbatim_(decoder, channel);
 961         }
 962         else if(x < 16) {
 963                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 964                 return false;
 965         }
 966         else if(x <= 24) {
 967                 return stream_decoder_read_subframe_fixed_(decoder, channel, (x>>1)&7);
 968         }
 969         else if(x < 64) {
 970                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 971                 return false;
 972         }
 973         else {
 974                 return stream_decoder_read_subframe_lpc_(decoder, channel, ((x>>1)&31)+1);
 975         }
 976 }
 977
 978 bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel)
 979 {
 980         int32 x;
 981         unsigned i;
 982
 983         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
 984                 return false; /* the read_callback_ sets the state for us */
 985
 986         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 987                 decoder->guts->output[channel][i] = x;
 988
 989         return true;
 990 }
 991
 992 bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order)
 993 {
 994         FLAC__SubframeHeader_Fixed subframe_header;
 995         int32 i32;
 996         uint32 u32;
 997         unsigned u;
 998
 999         subframe_header.order = order;
1000
1001         /* read warm-up samples */
1002         for(u = 0; u < order; u++) {
1003                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
1004                         return false; /* the read_callback_ sets the state for us */
1005                 decoder->guts->output[channel][u] = i32;
1006         }
1007
1008         /* read entropy coding method info */
1009         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
1010                 return false; /* the read_callback_ sets the state for us */
1011         subframe_header.entropy_coding_method.type = u32;
1012         switch(subframe_header.entropy_coding_method.type) {
1013                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1014                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
1015                                 return false; /* the read_callback_ sets the state for us */
1016                         subframe_header.entropy_coding_method.data.partitioned_rice.order = u32;
1017                         break;
1018                 default:
1019                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1020                         return false;
1021         }
1022
1023         /* read residual */
1024         switch(subframe_header.entropy_coding_method.type) {
1025                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1026                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe_header.entropy_coding_method.data.partitioned_rice.order))
1027                                 return false;
1028                         break;
1029                 default:
1030                         assert(0);
1031         }
1032
1033         /* decode the subframe */
1034         FLAC__fixed_restore_signal(decoder->guts->residual, decoder->guts->frame_header.blocksize-order, order, decoder->guts->output[channel]+order);
1035
1036         return true;
1037 }
1038
1039 bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order)
1040 {
1041         FLAC__SubframeHeader_LPC subframe_header;
1042         int32 i32;
1043         uint32 u32;
1044         unsigned u;
1045
1046         subframe_header.order = order;
1047
1048         /* read warm-up samples */
1049         for(u = 0; u < order; u++) {
1050                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
1051                         return false; /* the read_callback_ sets the state for us */
1052                 decoder->guts->output[channel][u] = i32;
1053         }
1054
1055         /* read qlp coeff precision */
1056         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__SUBFRAME_HEADER_LPC_QLP_COEFF_PRECISION_LEN, read_callback_, decoder))
1057                 return false; /* the read_callback_ sets the state for us */
1058         if(u32 == 15) {
1059                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1060                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1061                 return true;
1062         }
1063         subframe_header.qlp_coeff_precision = u32+1;
1064
1065         /* read qlp shift */
1066         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, FLAC__SUBFRAME_HEADER_LPC_QLP_SHIFT_LEN, read_callback_, decoder))
1067                 return false; /* the read_callback_ sets the state for us */
1068         subframe_header.quantization_level = i32;
1069
1070         /* read quantized lp coefficiencts */
1071         for(u = 0; u < order; u++) {
1072                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, subframe_header.qlp_coeff_precision, read_callback_, decoder))
1073                         return false; /* the read_callback_ sets the state for us */
1074                 subframe_header.qlp_coeff[u] = i32;
1075         }
1076
1077         /* read entropy coding method info */
1078         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
1079                 return false; /* the read_callback_ sets the state for us */
1080         subframe_header.entropy_coding_method.type = u32;
1081         switch(subframe_header.entropy_coding_method.type) {
1082                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1083                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
1084                                 return false; /* the read_callback_ sets the state for us */
1085                         subframe_header.entropy_coding_method.data.partitioned_rice.order = u32;
1086                         break;
1087                 default:
1088                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1089                         return false;
1090         }
1091
1092         /* read residual */
1093         switch(subframe_header.entropy_coding_method.type) {
1094                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1095                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe_header.entropy_coding_method.data.partitioned_rice.order))
1096                                 return false;
1097                         break;
1098                 default:
1099                         assert(0);
1100         }
1101
1102         /* decode the subframe */
1103         FLAC__lpc_restore_signal(decoder->guts->residual, decoder->guts->frame_header.blocksize-order, subframe_header.qlp_coeff, order, subframe_header.quantization_level, decoder->guts->output[channel]+order);
1104
1105         return true;
1106 }
1107
1108 bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel)
1109 {
1110         int32 x;
1111         unsigned i;
1112
1113         for(i = 0; i < decoder->guts->frame_header.blocksize; i++) {
1114                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
1115                         return false; /* the read_callback_ sets the state for us */
1116                 decoder->guts->output[channel][i] = x;
1117         }
1118
1119         return true;
1120 }
1121
1122 bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order)
1123 {
1124         uint32 rice_parameter;
1125         int i;
1126         unsigned partition, sample, u;
1127         const unsigned partitions = 1u << partition_order;
1128         const unsigned partition_samples = partition_order > 0? decoder->guts->frame_header.blocksize >> partition_order : decoder->guts->frame_header.blocksize - predictor_order;
1129
1130         sample = 0;
1131         for(partition = 0; partition < partitions; partition++) {
1132                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &rice_parameter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN, read_callback_, decoder))
1133                         return false; /* the read_callback_ sets the state for us */
1134                 for(u = (partition_order == 0 || partition > 0)? 0 : predictor_order; u < partition_samples; u++, sample++) {
1135                         if(!FLAC__bitbuffer_read_rice_signed(&decoder->guts->input, &i, rice_parameter, read_callback_, decoder))
1136                                 return false; /* the read_callback_ sets the state for us */
1137                         decoder->guts->residual[sample] = i;
1138                 }
1139         }
1140
1141         return true;
1142 }
1143
1144 bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder)
1145 {
1146         if(decoder->guts->input.consumed_bits != 0) {
1147                 uint32 zero;
1148                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &zero, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
1149                         return false; /* the read_callback_ sets the state for us */
1150                 if(zero != 0) {
1151                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1152                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1153                 }
1154         }
1155         return true;
1156 }
1157
1158 bool read_callback_(byte buffer[], unsigned *bytes, void *client_data)
1159 {
1160         FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder *)client_data;
1161         FLAC__StreamDecoderReadStatus status;
1162         status = decoder->guts->read_callback(decoder, buffer, bytes, decoder->guts->client_data);
1163         if(status == FLAC__STREAM_DECODER_READ_END_OF_STREAM)
1164                 decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
1165         else if(status == FLAC__STREAM_DECODER_READ_ABORT)
1166                 decoder->state = FLAC__STREAM_DECODER_ABORTED;
1167         return status == FLAC__STREAM_DECODER_READ_CONTINUE;
1168 }