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                 decoder->guts->stream_header.type = type;
 441                 decoder->guts->stream_header.is_last = last_block;
 442                 decoder->guts->stream_header.length = length;
 443                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MIN_BLOCK_SIZE_LEN, read_callback_, decoder))
 444                         return false; /* the read_callback_ sets the state for us */
 445                 decoder->guts->stream_header.data.encoding.min_blocksize = x;
 446                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MAX_BLOCK_SIZE_LEN, read_callback_, decoder))
 447                         return false; /* the read_callback_ sets the state for us */
 448                 decoder->guts->stream_header.data.encoding.max_blocksize = x;
 449                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MIN_FRAME_SIZE_LEN, read_callback_, decoder))
 450                         return false; /* the read_callback_ sets the state for us */
 451                 decoder->guts->stream_header.data.encoding.min_framesize = x;
 452                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_MAX_FRAME_SIZE_LEN, read_callback_, decoder))
 453                         return false; /* the read_callback_ sets the state for us */
 454                 decoder->guts->stream_header.data.encoding.max_framesize = x;
 455                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_SAMPLE_RATE_LEN, read_callback_, decoder))
 456                         return false; /* the read_callback_ sets the state for us */
 457                 decoder->guts->stream_header.data.encoding.sample_rate = x;
 458                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_CHANNELS_LEN, read_callback_, decoder))
 459                         return false; /* the read_callback_ sets the state for us */
 460                 decoder->guts->stream_header.data.encoding.channels = x+1;
 461                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_ENCODING_BITS_PER_SAMPLE_LEN, read_callback_, decoder))
 462                         return false; /* the read_callback_ sets the state for us */
 463                 decoder->guts->stream_header.data.encoding.bits_per_sample = x+1;
 464                 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))
 465                         return false; /* the read_callback_ sets the state for us */
 466                 decoder->guts->has_stream_header = true;
 467                 decoder->guts->metadata_callback(decoder, &decoder->guts->stream_header, decoder->guts->client_data);
 468         }
 469         else {
 470                 /* skip other metadata blocks */
 471                 for(i = 0; i < length; i++) {
 472                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 473                                 return false; /* the read_callback_ sets the state for us */
 474                 }
 475         }
 476
 477         if(last_block)
 478                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 479
 480         return true;
 481 }
 482
 483 bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder)
 484 {
 485         uint32 x;
 486         unsigned i, skip;
 487
 488         /* skip the version and flags bytes */
 489         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 24, read_callback_, decoder))
 490                 return false; /* the read_callback_ sets the state for us */
 491         /* get the size (in bytes) to skip */
 492         skip = 0;
 493         for(i = 0; i < 4; i++) {
 494                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 495                         return false; /* the read_callback_ sets the state for us */
 496                 skip <<= 7;
 497                 skip |= (x & 0x7f);
 498         }
 499         /* skip the rest of the tag */
 500         for(i = 0; i < skip; i++) {
 501                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 502                         return false; /* the read_callback_ sets the state for us */
 503         }
 504         return true;
 505 }
 506
 507 bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder)
 508 {
 509         uint32 x;
 510         bool first = 1;
 511
 512         /* If we know the total number of samples in the stream, stop if we've read that many. */
 513         /* This will stop us, for example, from wasting time trying to sync on an ID3V1 tag. */
 514         if(decoder->guts->has_stream_header && decoder->guts->stream_header.data.encoding.total_samples) {
 515                 if(decoder->guts->samples_decoded >= decoder->guts->stream_header.data.encoding.total_samples) {
 516                         decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
 517                         return true;
 518                 }
 519         }
 520
 521         /* make sure we're byte aligned */
 522         if(decoder->guts->input.consumed_bits != 0) {
 523                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
 524                         return false; /* the read_callback_ sets the state for us */
 525         }
 526
 527         while(1) {
 528                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 529                         return false; /* the read_callback_ sets the state for us */
 530                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 531                         unsigned y;
 532                         if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 533                                 return false; /* the read_callback_ sets the state for us */
 534                         if(!y) { /* MAGIC NUMBER for the last sync bit */
 535                                 decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 536                                 return true;
 537                         }
 538                 }
 539                 if(first) {
 540                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 541                         first = 0;
 542                 }
 543         }
 544
 545         return true;
 546 }
 547
 548 bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame)
 549 {
 550         unsigned channel;
 551         unsigned i;
 552         int32 mid, side, left, right;
 553
 554         *got_a_frame = false;
 555
 556         if(!stream_decoder_read_frame_header_(decoder))
 557                 return false;
 558         if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
 559                 if(decoder->state == FLAC__STREAM_DECODER_RESYNC_IN_HEADER)
 560                         decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 561                 else
 562                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 563                 return true;
 564         }
 565         if(!stream_decoder_allocate_output_(decoder, decoder->guts->frame_header.blocksize))
 566                 return false;
 567         for(channel = 0; channel < decoder->guts->frame_header.channels; channel++) {
 568                 if(!stream_decoder_read_subframe_(decoder, channel))
 569                         return false;
 570                 if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
 571                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 572                         return true;
 573                 }
 574         }
 575         if(!stream_decoder_read_zero_padding_(decoder))
 576                 return false;
 577
 578         /* Undo any special channel coding */
 579         switch(decoder->guts->frame_header.channel_assignment) {
 580                 case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
 581                         /* do nothing */
 582                         break;
 583                 case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
 584                         assert(decoder->guts->frame_header.channels == 2);
 585                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 586                                 decoder->guts->output[1][i] = decoder->guts->output[0][i] - decoder->guts->output[1][i];
 587                         break;
 588                 case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
 589                         assert(decoder->guts->frame_header.channels == 2);
 590                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 591                                 decoder->guts->output[0][i] += decoder->guts->output[1][i];
 592                         break;
 593                 case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
 594                         assert(decoder->guts->frame_header.channels == 2);
 595                         for(i = 0; i < decoder->guts->frame_header.blocksize; i++) {
 596                                 mid = decoder->guts->output[0][i];
 597                                 side = decoder->guts->output[1][i];
 598                                 mid <<= 1;
 599                                 if(side & 1) /* i.e. if 'side' is odd... */
 600                                         mid++;
 601                                 left = mid + side;
 602                                 right = mid - side;
 603                                 decoder->guts->output[0][i] = left >> 1;
 604                                 decoder->guts->output[1][i] = right >> 1;
 605                         }
 606                         break;
 607                 default:
 608                         assert(0);
 609                         break;
 610         }
 611
 612         *got_a_frame = true;
 613
 614         /* put the latest values into the public section of the decoder instance */
 615         decoder->channels = decoder->guts->frame_header.channels;
 616         decoder->channel_assignment = decoder->guts->frame_header.channel_assignment;
 617         decoder->bits_per_sample = decoder->guts->frame_header.bits_per_sample;
 618         decoder->sample_rate = decoder->guts->frame_header.sample_rate;
 619         decoder->blocksize = decoder->guts->frame_header.blocksize;
 620
 621         decoder->guts->samples_decoded += decoder->guts->frame_header.blocksize;
 622
 623         /* write it */
 624         if(decoder->guts->write_callback(decoder, &decoder->guts->frame_header, decoder->guts->output, decoder->guts->client_data) != FLAC__STREAM_DECODER_WRITE_CONTINUE)
 625                 return false;
 626
 627         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 628         return true;
 629 }
 630
 631 bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder)
 632 {
 633         uint32 x;
 634         uint64 xx;
 635         unsigned i, blocksize_hint = 0, sample_rate_hint = 0;
 636         byte crc, raw_header[15]; /* MAGIC NUMBER based on the maximum frame header size, including CRC */
 637         unsigned raw_header_len;
 638         bool is_unparseable = false;
 639
 640         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 641
 642         /* init the raw header with the first 8 bits of the sync code */
 643         raw_header[0] = 0xff; /* MAGIC NUMBER for the first 8 frame sync bits */
 644         raw_header_len = 1;
 645
 646         /*
 647          * read in the raw header as bytes so we can CRC it, and parse it on the way
 648          */
 649         for(i = 0; i < 2; i++) {
 650                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 651                         return false; /* the read_callback_ sets the state for us */
 652                 else if(x == 0xff) { /* MAGIC NUMBER for the first part of the sync code */
 653                         /* if we get here it means our original sync was erroneous since the sync code cannot appear in the header */
 654                         uint32 y;
 655                         if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 656                                 return false; /* the read_callback_ sets the state for us */
 657                         if(!y) { /* MAGIC NUMBER for the last sync bit */
 658                                 decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 659                                 return true;
 660                         }
 661                         else {
 662                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 663                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 664                                 return true;
 665                         }
 666                 }
 667                 raw_header[raw_header_len++] = (byte)x;
 668         }
 669         assert(!(raw_header[1] & 0x80)); /* last sync bit should be confirmed zero before we get here */
 670
 671         switch(x = raw_header[1] >> 4) {
 672                 case 0:
 673                         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 */
 674                                 decoder->guts->frame_header.blocksize = decoder->guts->stream_header.data.encoding.min_blocksize;
 675                         else
 676                                 is_unparseable = true;
 677                         break;
 678                 case 1:
 679                         decoder->guts->frame_header.blocksize = 192;
 680                         break;
 681                 case 2:
 682                 case 3:
 683                 case 4:
 684                 case 5:
 685                         decoder->guts->frame_header.blocksize = 576 << (x-2);
 686                         break;
 687                 case 6:
 688                 case 7:
 689                         blocksize_hint = x;
 690                         break;
 691                 default:
 692                         assert(0);
 693                         break;
 694         }
 695
 696         switch(x = raw_header[1] & 0x0f) {
 697                 case 0:
 698                         if(decoder->guts->has_stream_header)
 699                                 decoder->guts->frame_header.sample_rate = decoder->guts->stream_header.data.encoding.sample_rate;
 700                         else
 701                                 is_unparseable = true;
 702                         break;
 703                 case 1:
 704                 case 2:
 705                 case 3:
 706                         is_unparseable = true;
 707                         break;
 708                 case 4:
 709                         decoder->guts->frame_header.sample_rate = 8000;
 710                         break;
 711                 case 5:
 712                         decoder->guts->frame_header.sample_rate = 16000;
 713                         break;
 714                 case 6:
 715                         decoder->guts->frame_header.sample_rate = 22050;
 716                         break;
 717                 case 7:
 718                         decoder->guts->frame_header.sample_rate = 24000;
 719                         break;
 720                 case 8:
 721                         decoder->guts->frame_header.sample_rate = 32000;
 722                         break;
 723                 case 9:
 724                         decoder->guts->frame_header.sample_rate = 44100;
 725                         break;
 726                 case 10:
 727                         decoder->guts->frame_header.sample_rate = 48000;
 728                         break;
 729                 case 11:
 730                         decoder->guts->frame_header.sample_rate = 96000;
 731                         break;
 732                 case 12:
 733                 case 13:
 734                 case 14:
 735                         sample_rate_hint = x;
 736                         break;
 737                 case 15:
 738                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 739                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 740                         return true;
 741                 default:
 742                         assert(0);
 743         }
 744
 745         x = (unsigned)(raw_header[2] >> 4);
 746         if(x & 8) {
 747                 decoder->guts->frame_header.channels = 2;
 748                 switch(x & 7) {
 749                         case 0:
 750                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
 751                                 break;
 752                         case 1:
 753                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
 754                                 break;
 755                         case 2:
 756                                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_MID_SIDE;
 757                                 break;
 758                         default:
 759                                 is_unparseable = true;
 760                                 break;
 761                 }
 762         }
 763         else {
 764                 decoder->guts->frame_header.channels = (unsigned)x + 1;
 765                 decoder->guts->frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT;
 766         }
 767
 768         switch(x = (unsigned)(raw_header[2] & 0x0e) >> 1) {
 769                 case 0:
 770                         if(decoder->guts->has_stream_header)
 771                                 decoder->guts->frame_header.bits_per_sample = decoder->guts->stream_header.data.encoding.bits_per_sample;
 772                         else
 773                                 is_unparseable = true;
 774                         break;
 775                 case 1:
 776                         decoder->guts->frame_header.bits_per_sample = 8;
 777                         break;
 778                 case 2:
 779                         decoder->guts->frame_header.bits_per_sample = 12;
 780                         break;
 781                 case 4:
 782                         decoder->guts->frame_header.bits_per_sample = 16;
 783                         break;
 784                 case 5:
 785                         decoder->guts->frame_header.bits_per_sample = 20;
 786                         break;
 787                 case 6:
 788                         decoder->guts->frame_header.bits_per_sample = 24;
 789                         break;
 790                 case 3:
 791                 case 7:
 792                         is_unparseable = true;
 793                         break;
 794                 default:
 795                         assert(0);
 796                         break;
 797         }
 798
 799         if(raw_header[2] & 0x01) { /* this should be a zero padding bit */
 800                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 801                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 802                 return true;
 803         }
 804
 805         if(blocksize_hint) {
 806                 if(!FLAC__bitbuffer_read_utf8_uint64(&decoder->guts->input, &xx, read_callback_, decoder, raw_header, &raw_header_len))
 807                         return false; /* the read_callback_ sets the state for us */
 808                 if(xx == 0xffffffffffffffff) {
 809                         if(raw_header[raw_header_len-1] == 0xff) { /* MAGIC NUMBER for sync code */
 810                                 uint32 y;
 811                                 if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 812                                         return false; /* the read_callback_ sets the state for us */
 813                                 if(!y) { /* MAGIC NUMBER for the last sync bit */
 814                                         decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 815                                         return true;
 816                                 }
 817                                 else {
 818                                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 819                                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 820                                         return true;
 821                                 }
 822                         }
 823                         else {
 824                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 825                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 826                                 return true;
 827                         }
 828                 }
 829                 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 */
 830                         decoder->guts->frame_header.number.sample_number = (uint64)decoder->guts->last_frame_number * (int64)decoder->guts->stream_header.data.encoding.min_blocksize + xx;
 831                 else
 832                         decoder->guts->frame_header.number.sample_number = xx;
 833         }
 834         else {
 835                 if(!FLAC__bitbuffer_read_utf8_uint32(&decoder->guts->input, &x, read_callback_, decoder, raw_header, &raw_header_len))
 836                         return false; /* the read_callback_ sets the state for us */
 837                 if(x == 0xffffffff) {
 838                         if(raw_header[raw_header_len-1] == 0xff) { /* MAGIC NUMBER for sync code */
 839                                 uint32 y;
 840                                 if(!FLAC__bitbuffer_peek_bit(&decoder->guts->input, &y, read_callback_, decoder))
 841                                         return false; /* the read_callback_ sets the state for us */
 842                                 if(!y) { /* MAGIC NUMBER for the last sync bit */
 843                                         decoder->state = FLAC__STREAM_DECODER_RESYNC_IN_HEADER;
 844                                         return true;
 845                                 }
 846                                 else {
 847                                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 848                                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 849                                         return true;
 850                                 }
 851                         }
 852                         else {
 853                                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 854                                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 855                                 return true;
 856                         }
 857                 }
 858                 decoder->guts->last_frame_number = x;
 859                 if(decoder->guts->has_stream_header) {
 860                         decoder->guts->frame_header.number.sample_number = (int64)decoder->guts->stream_header.data.encoding.min_blocksize * (int64)x;
 861                 }
 862                 else {
 863                         is_unparseable = true;
 864                 }
 865         }
 866
 867         if(blocksize_hint) {
 868                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 869                         return false; /* the read_callback_ sets the state for us */
 870                 raw_header[raw_header_len++] = (byte)x;
 871                 if(blocksize_hint == 7) {
 872                         uint32 _x;
 873                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
 874                                 return false; /* the read_callback_ sets the state for us */
 875                         raw_header[raw_header_len++] = (byte)_x;
 876                         x = (x << 8) | _x;
 877                 }
 878                 decoder->guts->frame_header.blocksize = x+1;
 879         }
 880
 881         if(sample_rate_hint) {
 882                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 883                         return false; /* the read_callback_ sets the state for us */
 884                 raw_header[raw_header_len++] = (byte)x;
 885                 if(sample_rate_hint != 12) {
 886                         uint32 _x;
 887                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
 888                                 return false; /* the read_callback_ sets the state for us */
 889                         raw_header[raw_header_len++] = (byte)_x;
 890                         x = (x << 8) | _x;
 891                 }
 892                 if(sample_rate_hint == 12)
 893                         decoder->guts->frame_header.sample_rate = x*1000;
 894                 else if(sample_rate_hint == 13)
 895                         decoder->guts->frame_header.sample_rate = x;
 896                 else
 897                         decoder->guts->frame_header.sample_rate = x*10;
 898         }
 899
 900         /* read the crc byte */
 901         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 902                 return false; /* the read_callback_ sets the state for us */
 903         crc = (byte)x;
 904
 905         if(FLAC__crc8(raw_header, raw_header_len) != crc) {
 906                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 907                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 908                 return true;
 909         }
 910
 911         if(is_unparseable) {
 912                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 913                 return false;
 914         }
 915
 916         return true;
 917 }
 918
 919 bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel)
 920 {
 921         uint32 x;
 922
 923         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__SUBFRAME_HEADER_TYPE_LEN, read_callback_, decoder))
 924                 return false; /* the read_callback_ sets the state for us */
 925         if(x & 0x01 || x & 0x80) {
 926                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 927                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 928                 return true;
 929         }
 930         else if(x == 0) {
 931                 return stream_decoder_read_subframe_constant_(decoder, channel);
 932         }
 933         else if(x == 2) {
 934                 return stream_decoder_read_subframe_verbatim_(decoder, channel);
 935         }
 936         else if(x < 16) {
 937                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 938                 return false;
 939         }
 940         else if(x <= 24) {
 941                 return stream_decoder_read_subframe_fixed_(decoder, channel, (x>>1)&7);
 942         }
 943         else if(x < 64) {
 944                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 945                 return false;
 946         }
 947         else {
 948                 return stream_decoder_read_subframe_lpc_(decoder, channel, ((x>>1)&31)+1);
 949         }
 950 }
 951
 952 bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel)
 953 {
 954         int32 x;
 955         unsigned i;
 956
 957         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
 958                 return false; /* the read_callback_ sets the state for us */
 959
 960         for(i = 0; i < decoder->guts->frame_header.blocksize; i++)
 961                 decoder->guts->output[channel][i] = x;
 962
 963         return true;
 964 }
 965
 966 bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order)
 967 {
 968         FLAC__SubframeHeader_Fixed subframe_header;
 969         int32 i32;
 970         uint32 u32;
 971         unsigned u;
 972
 973         subframe_header.order = order;
 974
 975         /* read warm-up samples */
 976         for(u = 0; u < order; u++) {
 977                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
 978                         return false; /* the read_callback_ sets the state for us */
 979                 decoder->guts->output[channel][u] = i32;
 980         }
 981
 982         /* read entropy coding method info */
 983         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
 984                 return false; /* the read_callback_ sets the state for us */
 985         subframe_header.entropy_coding_method.type = u32;
 986         switch(subframe_header.entropy_coding_method.type) {
 987                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
 988                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
 989                                 return false; /* the read_callback_ sets the state for us */
 990                         subframe_header.entropy_coding_method.data.partitioned_rice.order = u32;
 991                         break;
 992                 default:
 993                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
 994                         return false;
 995         }
 996
 997         /* read residual */
 998         switch(subframe_header.entropy_coding_method.type) {
 999                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1000                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe_header.entropy_coding_method.data.partitioned_rice.order))
1001                                 return false;
1002                         break;
1003                 default:
1004                         assert(0);
1005         }
1006
1007         /* decode the subframe */
1008         FLAC__fixed_restore_signal(decoder->guts->residual, decoder->guts->frame_header.blocksize-order, order, decoder->guts->output[channel]+order);
1009
1010         return true;
1011 }
1012
1013 bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, const unsigned order)
1014 {
1015         FLAC__SubframeHeader_LPC subframe_header;
1016         int32 i32;
1017         uint32 u32;
1018         unsigned u;
1019
1020         subframe_header.order = order;
1021
1022         /* read warm-up samples */
1023         for(u = 0; u < order; u++) {
1024                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
1025                         return false; /* the read_callback_ sets the state for us */
1026                 decoder->guts->output[channel][u] = i32;
1027         }
1028
1029         /* read qlp coeff precision */
1030         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__SUBFRAME_HEADER_LPC_QLP_COEFF_PRECISION_LEN, read_callback_, decoder))
1031                 return false; /* the read_callback_ sets the state for us */
1032         if(u32 == 15) {
1033                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1034                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1035                 return true;
1036         }
1037         subframe_header.qlp_coeff_precision = u32+1;
1038
1039         /* read qlp shift */
1040         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, FLAC__SUBFRAME_HEADER_LPC_QLP_SHIFT_LEN, read_callback_, decoder))
1041                 return false; /* the read_callback_ sets the state for us */
1042         subframe_header.quantization_level = i32;
1043
1044         /* read quantized lp coefficiencts */
1045         for(u = 0; u < order; u++) {
1046                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, subframe_header.qlp_coeff_precision, read_callback_, decoder))
1047                         return false; /* the read_callback_ sets the state for us */
1048                 subframe_header.qlp_coeff[u] = i32;
1049         }
1050
1051         /* read entropy coding method info */
1052         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
1053                 return false; /* the read_callback_ sets the state for us */
1054         subframe_header.entropy_coding_method.type = u32;
1055         switch(subframe_header.entropy_coding_method.type) {
1056                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1057                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
1058                                 return false; /* the read_callback_ sets the state for us */
1059                         subframe_header.entropy_coding_method.data.partitioned_rice.order = u32;
1060                         break;
1061                 default:
1062                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1063                         return false;
1064         }
1065
1066         /* read residual */
1067         switch(subframe_header.entropy_coding_method.type) {
1068                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1069                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe_header.entropy_coding_method.data.partitioned_rice.order))
1070                                 return false;
1071                         break;
1072                 default:
1073                         assert(0);
1074         }
1075
1076         /* decode the subframe */
1077         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);
1078
1079         return true;
1080 }
1081
1082 bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel)
1083 {
1084         int32 x;
1085         unsigned i;
1086
1087         for(i = 0; i < decoder->guts->frame_header.blocksize; i++) {
1088                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, decoder->guts->frame_header.bits_per_sample, read_callback_, decoder))
1089                         return false; /* the read_callback_ sets the state for us */
1090                 decoder->guts->output[channel][i] = x;
1091         }
1092
1093         return true;
1094 }
1095
1096 bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order)
1097 {
1098         uint32 rice_parameter;
1099         int i;
1100         unsigned partition, sample, u;
1101         const unsigned partitions = 1u << partition_order;
1102         const unsigned partition_samples = partition_order > 0? decoder->guts->frame_header.blocksize >> partition_order : decoder->guts->frame_header.blocksize - predictor_order;
1103
1104         sample = 0;
1105         for(partition = 0; partition < partitions; partition++) {
1106                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &rice_parameter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN, read_callback_, decoder))
1107                         return false; /* the read_callback_ sets the state for us */
1108                 for(u = (partition_order == 0 || partition > 0)? 0 : predictor_order; u < partition_samples; u++, sample++) {
1109                         if(!FLAC__bitbuffer_read_rice_signed(&decoder->guts->input, &i, rice_parameter, read_callback_, decoder))
1110                                 return false; /* the read_callback_ sets the state for us */
1111                         decoder->guts->residual[sample] = i;
1112                 }
1113         }
1114
1115         return true;
1116 }
1117
1118 bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder)
1119 {
1120         if(decoder->guts->input.consumed_bits != 0) {
1121                 uint32 zero;
1122                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &zero, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
1123                         return false; /* the read_callback_ sets the state for us */
1124                 if(zero != 0) {
1125                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1126                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1127                 }
1128         }
1129         return true;
1130 }
1131
1132 bool read_callback_(byte buffer[], unsigned *bytes, void *client_data)
1133 {
1134         FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder *)client_data;
1135         FLAC__StreamDecoderReadStatus status;
1136         status = decoder->guts->read_callback(decoder, buffer, bytes, decoder->guts->client_data);
1137         if(status == FLAC__STREAM_DECODER_READ_END_OF_STREAM)
1138                 decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
1139         else if(status == FLAC__STREAM_DECODER_READ_ABORT)
1140                 decoder->state = FLAC__STREAM_DECODER_ABORTED;
1141         return status == FLAC__STREAM_DECODER_READ_CONTINUE;
1142 }