src/libFLAC/stream_decoder.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2000,2001  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 <string.h> /* for memset/memcpy() */
  24 #include "FLAC/stream_decoder.h"
  25 #include "private/bitbuffer.h"
  26 #include "private/cpu.h"
  27 #include "private/crc.h"
  28 #include "private/fixed.h"
  29 #include "private/lpc.h"
  30
  31 typedef struct FLAC__StreamDecoderPrivate {
  32         FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data);
  33         FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const int32 *buffer[], void *client_data);
  34         void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
  35         void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
  36         void (*local_lpc_restore_signal)(const int32 residual[], unsigned data_len, const int32 qlp_coeff[], unsigned order, int lp_quantization, int32 data[]);
  37         void *client_data;
  38         FLAC__BitBuffer input;
  39         int32 *output[FLAC__MAX_CHANNELS];
  40         int32 *residual[FLAC__MAX_CHANNELS];
  41         unsigned output_capacity, output_channels;
  42         uint32 last_frame_number;
  43         uint64 samples_decoded;
  44         bool has_stream_info, has_seek_table;
  45         FLAC__StreamMetaData stream_info;
  46         FLAC__StreamMetaData seek_table;
  47         FLAC__Frame frame;
  48         bool cached; /* true if there is a byte in lookahead */
  49         FLAC__CPUInfo cpuinfo;
  50         byte header_warmup[2]; /* contains the sync code and reserved bits */
  51         byte lookahead; /* temp storage when we need to look ahead one byte in the stream */
  52 } FLAC__StreamDecoderPrivate;
  53
  54 static byte ID3V2_TAG_[3] = { 'I', 'D', '3' };
  55
  56 static bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size, unsigned channels);
  57 static bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder);
  58 static bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder);
  59 static bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder);
  60 static bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder);
  61 static bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame);
  62 static bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder);
  63 static bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
  64 static bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
  65 static bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order);
  66 static bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order);
  67 static bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps);
  68 static bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order, int32 *residual);
  69 static bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder);
  70 static bool read_callback_(byte buffer[], unsigned *bytes, void *client_data);
  71
  72 const char *FLAC__StreamDecoderStateString[] = {
  73         "FLAC__STREAM_DECODER_SEARCH_FOR_METADATA",
  74         "FLAC__STREAM_DECODER_READ_METADATA",
  75         "FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC",
  76         "FLAC__STREAM_DECODER_READ_FRAME",
  77         "FLAC__STREAM_DECODER_END_OF_STREAM",
  78         "FLAC__STREAM_DECODER_ABORTED",
  79         "FLAC__STREAM_DECODER_UNPARSEABLE_STREAM",
  80         "FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
  81         "FLAC__STREAM_DECODER_UNINITIALIZED"
  82 };
  83
  84 const char *FLAC__StreamDecoderReadStatusString[] = {
  85         "FLAC__STREAM_DECODER_READ_CONTINUE",
  86         "FLAC__STREAM_DECODER_READ_END_OF_STREAM",
  87         "FLAC__STREAM_DECODER_READ_ABORT"
  88 };
  89
  90 const char *FLAC__StreamDecoderWriteStatusString[] = {
  91         "FLAC__STREAM_DECODER_WRITE_CONTINUE",
  92         "FLAC__STREAM_DECODER_WRITE_ABORT"
  93 };
  94
  95 const char *FLAC__StreamDecoderErrorStatusString[] = {
  96         "FLAC__STREAM_DECODER_ERROR_LOST_SYNC",
  97         "FLAC__STREAM_DECODER_ERROR_BAD_HEADER",
  98         "FLAC__STREAM_DECODER_ERROR_FRAME_CRC_MISMATCH"
  99 };
 100
 101 FLAC__StreamDecoder *FLAC__stream_decoder_get_new_instance()
 102 {
 103         FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder*)malloc(sizeof(FLAC__StreamDecoder));
 104         if(decoder != 0) {
 105                 decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
 106                 decoder->guts = 0;
 107         }
 108         return decoder;
 109 }
 110
 111 void FLAC__stream_decoder_free_instance(FLAC__StreamDecoder *decoder)
 112 {
 113         free(decoder);
 114 }
 115
 116 FLAC__StreamDecoderState FLAC__stream_decoder_init(
 117         FLAC__StreamDecoder *decoder,
 118         FLAC__StreamDecoderReadStatus (*read_callback)(const FLAC__StreamDecoder *decoder, byte buffer[], unsigned *bytes, void *client_data),
 119         FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const int32 *buffer[], void *client_data),
 120         void (*metadata_callback)(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data),
 121         void (*error_callback)(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data),
 122         void *client_data
 123 )
 124 {
 125         unsigned i;
 126
 127         assert(sizeof(int) >= 4); /* we want to die right away if this is not true */
 128         assert(decoder != 0);
 129         assert(read_callback != 0);
 130         assert(write_callback != 0);
 131         assert(metadata_callback != 0);
 132         assert(error_callback != 0);
 133         assert(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED);
 134         assert(decoder->guts == 0);
 135
 136         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;
 137
 138         decoder->guts = (FLAC__StreamDecoderPrivate*)malloc(sizeof(FLAC__StreamDecoderPrivate));
 139         if(decoder->guts == 0)
 140                 return decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 141
 142         decoder->guts->read_callback = read_callback;
 143         decoder->guts->write_callback = write_callback;
 144         decoder->guts->metadata_callback = metadata_callback;
 145         decoder->guts->error_callback = error_callback;
 146         decoder->guts->client_data = client_data;
 147
 148         FLAC__bitbuffer_init(&decoder->guts->input);
 149
 150         for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
 151                 decoder->guts->output[i] = 0;
 152                 decoder->guts->residual[i] = 0;
 153         }
 154
 155         decoder->guts->output_capacity = 0;
 156         decoder->guts->output_channels = 0;
 157         decoder->guts->last_frame_number = 0;
 158         decoder->guts->samples_decoded = 0;
 159         decoder->guts->has_stream_info = false;
 160         decoder->guts->has_seek_table = false;
 161         decoder->guts->cached = false;
 162
 163         /*
 164          * get the CPU info and set the function pointers
 165          */
 166         FLAC__cpu_info(&decoder->guts->cpuinfo);
 167         /* first default to the non-asm routines */
 168         decoder->guts->local_lpc_restore_signal = FLAC__lpc_restore_signal;
 169         /* now override with asm where appropriate */
 170 #ifndef FLAC__NO_ASM
 171         assert(decoder->guts->cpuinfo.use_asm);
 172 #ifdef FLAC__CPU_IA32
 173         assert(decoder->guts->cpuinfo.type == FLAC__CPUINFO_TYPE_IA32);
 174 #ifdef FLAC__HAS_NASM
 175 #if 0
 176         /* @@@ MMX version needs bps check */
 177         if(decoder->guts->cpuinfo.data.ia32.mmx && @@@bps check here@@@)
 178                 decoder->guts->local_lpc_restore_signal = FLAC__lpc_restore_signal_asm_i386_mmx;
 179         else
 180 #endif
 181 fprintf(stderr,"@@@ got _asm_i386 of lpc_restore_signal()\n");
 182                 decoder->guts->local_lpc_restore_signal = FLAC__lpc_restore_signal_asm_i386;
 183 #endif
 184 #endif
 185 #endif
 186
 187         return decoder->state;
 188 }
 189
 190 void FLAC__stream_decoder_finish(FLAC__StreamDecoder *decoder)
 191 {
 192         unsigned i;
 193         assert(decoder != 0);
 194         if(decoder->state == FLAC__STREAM_DECODER_UNINITIALIZED)
 195                 return;
 196         if(decoder->guts != 0) {
 197                 if(decoder->guts->has_seek_table) {
 198                         free(decoder->guts->seek_table.data.seek_table.points);
 199                         decoder->guts->seek_table.data.seek_table.points = 0;
 200                 }
 201                 FLAC__bitbuffer_free(&decoder->guts->input);
 202                 for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
 203                         if(decoder->guts->output[i] != 0) {
 204                                 free(decoder->guts->output[i]);
 205                                 decoder->guts->output[i] = 0;
 206                         }
 207                         if(decoder->guts->residual[i] != 0) {
 208                                 free(decoder->guts->residual[i]);
 209                                 decoder->guts->residual[i] = 0;
 210                         }
 211                 }
 212                 free(decoder->guts);
 213                 decoder->guts = 0;
 214         }
 215         decoder->state = FLAC__STREAM_DECODER_UNINITIALIZED;
 216 }
 217
 218 bool FLAC__stream_decoder_flush(FLAC__StreamDecoder *decoder)
 219 {
 220         assert(decoder != 0);
 221
 222         if(!FLAC__bitbuffer_clear(&decoder->guts->input)) {
 223                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 224                 return false;
 225         }
 226
 227         return true;
 228 }
 229
 230 bool FLAC__stream_decoder_reset(FLAC__StreamDecoder *decoder)
 231 {
 232         assert(decoder != 0);
 233
 234         if(!FLAC__stream_decoder_flush(decoder)) {
 235                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 236                 return false;
 237         }
 238         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_METADATA;
 239
 240         decoder->guts->samples_decoded = 0;
 241
 242         return true;
 243 }
 244
 245 bool FLAC__stream_decoder_process_whole_stream(FLAC__StreamDecoder *decoder)
 246 {
 247         bool dummy;
 248         assert(decoder != 0);
 249
 250         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 251                 return true;
 252
 253         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);
 254
 255         if(!FLAC__stream_decoder_reset(decoder)) {
 256                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 257                 return false;
 258         }
 259
 260         while(1) {
 261                 switch(decoder->state) {
 262                         case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
 263                                 if(!stream_decoder_find_metadata_(decoder))
 264                                         return false; /* above function sets the status for us */
 265                                 break;
 266                         case FLAC__STREAM_DECODER_READ_METADATA:
 267                                 if(!stream_decoder_read_metadata_(decoder))
 268                                         return false; /* above function sets the status for us */
 269                                 break;
 270                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 271                                 if(!stream_decoder_frame_sync_(decoder))
 272                                         return true; /* above function sets the status for us */
 273                                 break;
 274                         case FLAC__STREAM_DECODER_READ_FRAME:
 275                                 if(!stream_decoder_read_frame_(decoder, &dummy))
 276                                         return false; /* above function sets the status for us */
 277                                 break;
 278                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 279                                 return true;
 280                         default:
 281                                 assert(0);
 282                 }
 283         }
 284 }
 285
 286 bool FLAC__stream_decoder_process_metadata(FLAC__StreamDecoder *decoder)
 287 {
 288         assert(decoder != 0);
 289
 290         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 291                 return true;
 292
 293         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_METADATA);
 294
 295         if(!FLAC__stream_decoder_reset(decoder)) {
 296                 decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 297                 return false;
 298         }
 299
 300         while(1) {
 301                 switch(decoder->state) {
 302                         case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:
 303                                 if(!stream_decoder_find_metadata_(decoder))
 304                                         return false; /* above function sets the status for us */
 305                                 break;
 306                         case FLAC__STREAM_DECODER_READ_METADATA:
 307                                 if(!stream_decoder_read_metadata_(decoder))
 308                                         return false; /* above function sets the status for us */
 309                                 break;
 310                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 311                                 return true;
 312                                 break;
 313                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 314                                 return true;
 315                         default:
 316                                 assert(0);
 317                 }
 318         }
 319 }
 320
 321 bool FLAC__stream_decoder_process_one_frame(FLAC__StreamDecoder *decoder)
 322 {
 323         bool got_a_frame;
 324         assert(decoder != 0);
 325
 326         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 327                 return true;
 328
 329         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);
 330
 331         while(1) {
 332                 switch(decoder->state) {
 333                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 334                                 if(!stream_decoder_frame_sync_(decoder))
 335                                         return true; /* above function sets the status for us */
 336                                 break;
 337                         case FLAC__STREAM_DECODER_READ_FRAME:
 338                                 if(!stream_decoder_read_frame_(decoder, &got_a_frame))
 339                                         return false; /* above function sets the status for us */
 340                                 if(got_a_frame)
 341                                         return true; /* above function sets the status for us */
 342                                 break;
 343                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 344                                 return true;
 345                         default:
 346                                 assert(0);
 347                 }
 348         }
 349 }
 350
 351 bool FLAC__stream_decoder_process_remaining_frames(FLAC__StreamDecoder *decoder)
 352 {
 353         bool dummy;
 354         assert(decoder != 0);
 355
 356         if(decoder->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 357                 return true;
 358
 359         assert(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC);
 360
 361         while(1) {
 362                 switch(decoder->state) {
 363                         case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:
 364                                 if(!stream_decoder_frame_sync_(decoder))
 365                                         return true; /* above function sets the status for us */
 366                                 break;
 367                         case FLAC__STREAM_DECODER_READ_FRAME:
 368                                 if(!stream_decoder_read_frame_(decoder, &dummy))
 369                                         return false; /* above function sets the status for us */
 370                                 break;
 371                         case FLAC__STREAM_DECODER_END_OF_STREAM:
 372                                 return true;
 373                         default:
 374                                 assert(0);
 375                 }
 376         }
 377 }
 378
 379 unsigned FLAC__stream_decoder_input_bytes_unconsumed(FLAC__StreamDecoder *decoder)
 380 {
 381         assert(decoder != 0);
 382         return decoder->guts->input.bytes - decoder->guts->input.consumed_bytes;
 383 }
 384
 385 bool stream_decoder_allocate_output_(FLAC__StreamDecoder *decoder, unsigned size, unsigned channels)
 386 {
 387         unsigned i;
 388         int32 *tmp;
 389
 390         if(size <= decoder->guts->output_capacity && channels <= decoder->guts->output_channels)
 391                 return true;
 392
 393         /* @@@ should change to use realloc() */
 394
 395         for(i = 0; i < FLAC__MAX_CHANNELS; i++) {
 396                 if(decoder->guts->output[i] != 0) {
 397                         free(decoder->guts->output[i]);
 398                         decoder->guts->output[i] = 0;
 399                 }
 400                 if(decoder->guts->residual[i] != 0) {
 401                         free(decoder->guts->residual[i]);
 402                         decoder->guts->residual[i] = 0;
 403                 }
 404         }
 405
 406         for(i = 0; i < channels; i++) {
 407                 tmp = (int32*)malloc(sizeof(int32)*size);
 408                 if(tmp == 0) {
 409                         decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 410                         return false;
 411                 }
 412                 decoder->guts->output[i] = tmp;
 413
 414                 tmp = (int32*)malloc(sizeof(int32)*size);
 415                 if(tmp == 0) {
 416                         decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 417                         return false;
 418                 }
 419                 decoder->guts->residual[i] = tmp;
 420         }
 421
 422         decoder->guts->output_capacity = size;
 423         decoder->guts->output_channels = channels;
 424
 425         return true;
 426 }
 427
 428 bool stream_decoder_find_metadata_(FLAC__StreamDecoder *decoder)
 429 {
 430         uint32 x;
 431         unsigned i, id;
 432         bool first = true;
 433
 434         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 435
 436         for(i = id = 0; i < 4; ) {
 437                 if(decoder->guts->cached) {
 438                         x = (uint32)decoder->guts->lookahead;
 439                         decoder->guts->cached = false;
 440                 }
 441                 else {
 442                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 443                                 return false; /* the read_callback_ sets the state for us */
 444                 }
 445                 if(x == FLAC__STREAM_SYNC_STRING[i]) {
 446                         first = true;
 447                         i++;
 448                         id = 0;
 449                         continue;
 450                 }
 451                 if(x == ID3V2_TAG_[id]) {
 452                         id++;
 453                         i = 0;
 454                         if(id == 3) {
 455                                 if(!stream_decoder_skip_id3v2_tag_(decoder))
 456                                         return false; /* the read_callback_ sets the state for us */
 457                         }
 458                         continue;
 459                 }
 460                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 461                         decoder->guts->header_warmup[0] = (byte)x;
 462                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 463                                 return false; /* the read_callback_ sets the state for us */
 464
 465                         /* we have to check if we just read two 0xff's in a row; the second may actually be the beginning of the sync code */
 466                         /* else we have to check if the second byte is the end of a sync code */
 467                         if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 468                                 decoder->guts->lookahead = (byte)x;
 469                                 decoder->guts->cached = true;
 470                         }
 471                         else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */
 472                                 decoder->guts->header_warmup[1] = (byte)x;
 473                                 decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 474                                 return true;
 475                         }
 476                 }
 477                 i = 0;
 478                 if(first) {
 479                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 480                         first = false;
 481                 }
 482         }
 483
 484         decoder->state = FLAC__STREAM_DECODER_READ_METADATA;
 485         return true;
 486 }
 487
 488 bool stream_decoder_read_metadata_(FLAC__StreamDecoder *decoder)
 489 {
 490         uint32 i, x, last_block, type, length;
 491         uint64 xx;
 492
 493         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 494
 495         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &last_block, FLAC__STREAM_METADATA_IS_LAST_LEN, read_callback_, decoder))
 496                 return false; /* the read_callback_ sets the state for us */
 497         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &type, FLAC__STREAM_METADATA_TYPE_LEN, read_callback_, decoder))
 498                 return false; /* the read_callback_ sets the state for us */
 499         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &length, FLAC__STREAM_METADATA_LENGTH_LEN, read_callback_, decoder))
 500                 return false; /* the read_callback_ sets the state for us */
 501         if(type == FLAC__METADATA_TYPE_STREAMINFO) {
 502                 unsigned used_bits = 0;
 503                 decoder->guts->stream_info.type = type;
 504                 decoder->guts->stream_info.is_last = last_block;
 505                 decoder->guts->stream_info.length = length;
 506
 507                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN, read_callback_, decoder))
 508                         return false; /* the read_callback_ sets the state for us */
 509                 decoder->guts->stream_info.data.stream_info.min_blocksize = x;
 510                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_MIN_BLOCK_SIZE_LEN;
 511
 512                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN, read_callback_, decoder))
 513                         return false; /* the read_callback_ sets the state for us */
 514                 decoder->guts->stream_info.data.stream_info.max_blocksize = x;
 515                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_MAX_BLOCK_SIZE_LEN;
 516
 517                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN, read_callback_, decoder))
 518                         return false; /* the read_callback_ sets the state for us */
 519                 decoder->guts->stream_info.data.stream_info.min_framesize = x;
 520                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN;
 521
 522                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN, read_callback_, decoder))
 523                         return false; /* the read_callback_ sets the state for us */
 524                 decoder->guts->stream_info.data.stream_info.max_framesize = x;
 525                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_MAX_FRAME_SIZE_LEN;
 526
 527                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN, read_callback_, decoder))
 528                         return false; /* the read_callback_ sets the state for us */
 529                 decoder->guts->stream_info.data.stream_info.sample_rate = x;
 530                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_SAMPLE_RATE_LEN;
 531
 532                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN, read_callback_, decoder))
 533                         return false; /* the read_callback_ sets the state for us */
 534                 decoder->guts->stream_info.data.stream_info.channels = x+1;
 535                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_CHANNELS_LEN;
 536
 537                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN, read_callback_, decoder))
 538                         return false; /* the read_callback_ sets the state for us */
 539                 decoder->guts->stream_info.data.stream_info.bits_per_sample = x+1;
 540                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_BITS_PER_SAMPLE_LEN;
 541
 542                 if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &decoder->guts->stream_info.data.stream_info.total_samples, FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN, read_callback_, decoder))
 543                         return false; /* the read_callback_ sets the state for us */
 544                 used_bits += FLAC__STREAM_METADATA_STREAMINFO_TOTAL_SAMPLES_LEN;
 545
 546                 for(i = 0; i < 16; i++) {
 547                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 548                                 return false; /* the read_callback_ sets the state for us */
 549                         decoder->guts->stream_info.data.stream_info.md5sum[i] = (byte)x;
 550                 }
 551                 used_bits += i*8;
 552
 553                 /* skip the rest of the block */
 554                 assert(used_bits % 8 == 0);
 555                 length -= (used_bits / 8);
 556                 for(i = 0; i < length; i++) {
 557                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 558                                 return false; /* the read_callback_ sets the state for us */
 559                 }
 560
 561                 decoder->guts->has_stream_info = true;
 562                 decoder->guts->metadata_callback(decoder, &decoder->guts->stream_info, decoder->guts->client_data);
 563         }
 564         else if(type == FLAC__METADATA_TYPE_SEEKTABLE) {
 565                 unsigned real_points;
 566
 567                 decoder->guts->seek_table.type = type;
 568                 decoder->guts->seek_table.is_last = last_block;
 569                 decoder->guts->seek_table.length = length;
 570
 571                 decoder->guts->seek_table.data.seek_table.num_points = length / FLAC__STREAM_METADATA_SEEKPOINT_LEN;
 572
 573                 if(0 == (decoder->guts->seek_table.data.seek_table.points = (FLAC__StreamMetaData_SeekPoint*)malloc(decoder->guts->seek_table.data.seek_table.num_points * sizeof(FLAC__StreamMetaData_SeekPoint)))) {
 574                         decoder->state = FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 575                         return false;
 576                 }
 577                 for(i = real_points = 0; i < decoder->guts->seek_table.data.seek_table.num_points; i++) {
 578                         if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &xx, FLAC__STREAM_METADATA_SEEKPOINT_SAMPLE_NUMBER_LEN, read_callback_, decoder))
 579                                 return false; /* the read_callback_ sets the state for us */
 580                         decoder->guts->seek_table.data.seek_table.points[real_points].sample_number = xx;
 581
 582                         if(!FLAC__bitbuffer_read_raw_uint64(&decoder->guts->input, &xx, FLAC__STREAM_METADATA_SEEKPOINT_STREAM_OFFSET_LEN, read_callback_, decoder))
 583                                 return false; /* the read_callback_ sets the state for us */
 584                         decoder->guts->seek_table.data.seek_table.points[real_points].stream_offset = xx;
 585
 586                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__STREAM_METADATA_SEEKPOINT_FRAME_SAMPLES_LEN, read_callback_, decoder))
 587                                 return false; /* the read_callback_ sets the state for us */
 588                         decoder->guts->seek_table.data.seek_table.points[real_points].frame_samples = x;
 589
 590                         if(decoder->guts->seek_table.data.seek_table.points[real_points].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER)
 591                                 real_points++;
 592                 }
 593                 decoder->guts->seek_table.data.seek_table.num_points = real_points;
 594
 595                 decoder->guts->has_seek_table = true;
 596                 decoder->guts->metadata_callback(decoder, &decoder->guts->seek_table, decoder->guts->client_data);
 597         }
 598         else {
 599                 /* skip other metadata blocks */
 600                 for(i = 0; i < length; i++) {
 601                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 602                                 return false; /* the read_callback_ sets the state for us */
 603                 }
 604         }
 605
 606         if(last_block)
 607                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 608
 609         return true;
 610 }
 611
 612 bool stream_decoder_skip_id3v2_tag_(FLAC__StreamDecoder *decoder)
 613 {
 614         uint32 x;
 615         unsigned i, skip;
 616
 617         /* skip the version and flags bytes */
 618         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 24, read_callback_, decoder))
 619                 return false; /* the read_callback_ sets the state for us */
 620         /* get the size (in bytes) to skip */
 621         skip = 0;
 622         for(i = 0; i < 4; i++) {
 623                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 624                         return false; /* the read_callback_ sets the state for us */
 625                 skip <<= 7;
 626                 skip |= (x & 0x7f);
 627         }
 628         /* skip the rest of the tag */
 629         for(i = 0; i < skip; i++) {
 630                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 631                         return false; /* the read_callback_ sets the state for us */
 632         }
 633         return true;
 634 }
 635
 636 bool stream_decoder_frame_sync_(FLAC__StreamDecoder *decoder)
 637 {
 638         uint32 x;
 639         bool first = true;
 640
 641         /* If we know the total number of samples in the stream, stop if we've read that many. */
 642         /* This will stop us, for example, from wasting time trying to sync on an ID3V1 tag. */
 643         if(decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.total_samples) {
 644                 if(decoder->guts->samples_decoded >= decoder->guts->stream_info.data.stream_info.total_samples) {
 645                         decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
 646                         return true;
 647                 }
 648         }
 649
 650         /* make sure we're byte aligned */
 651         if(decoder->guts->input.consumed_bits != 0) {
 652                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
 653                         return false; /* the read_callback_ sets the state for us */
 654         }
 655
 656         while(1) {
 657                 if(decoder->guts->cached) {
 658                         x = (uint32)decoder->guts->lookahead;
 659                         decoder->guts->cached = false;
 660                 }
 661                 else {
 662                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 663                                 return false; /* the read_callback_ sets the state for us */
 664                 }
 665                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 666                         decoder->guts->header_warmup[0] = (byte)x;
 667                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 668                                 return false; /* the read_callback_ sets the state for us */
 669
 670                         /* we have to check if we just read two 0xff's in a row; the second may actually be the beginning of the sync code */
 671                         /* else we have to check if the second byte is the end of a sync code */
 672                         if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 673                                 decoder->guts->lookahead = (byte)x;
 674                                 decoder->guts->cached = true;
 675                         }
 676                         else if(x >> 2 == 0x3e) { /* MAGIC NUMBER for the last 6 sync bits */
 677                                 decoder->guts->header_warmup[1] = (byte)x;
 678                                 decoder->state = FLAC__STREAM_DECODER_READ_FRAME;
 679                                 return true;
 680                         }
 681                 }
 682                 if(first) {
 683                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
 684                         first = 0;
 685                 }
 686         }
 687
 688         return true;
 689 }
 690
 691 bool stream_decoder_read_frame_(FLAC__StreamDecoder *decoder, bool *got_a_frame)
 692 {
 693         unsigned channel;
 694         unsigned i;
 695         int32 mid, side, left, right;
 696         uint16 frame_crc; /* the one we calculate from the input stream */
 697         uint32 x;
 698
 699         *got_a_frame = false;
 700
 701         /* init the CRC */
 702         frame_crc = 0;
 703         FLAC__CRC16_UPDATE(decoder->guts->header_warmup[0], frame_crc);
 704         FLAC__CRC16_UPDATE(decoder->guts->header_warmup[1], frame_crc);
 705         FLAC__bitbuffer_init_read_crc16(&decoder->guts->input, frame_crc);
 706
 707         if(!stream_decoder_read_frame_header_(decoder))
 708                 return false;
 709         if(decoder->state == FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC)
 710                 return true;
 711         if(!stream_decoder_allocate_output_(decoder, decoder->guts->frame.header.blocksize, decoder->guts->frame.header.channels))
 712                 return false;
 713         for(channel = 0; channel < decoder->guts->frame.header.channels; channel++) {
 714                 /*
 715                  * first figure the correct bits-per-sample of the subframe
 716                  */
 717                 unsigned bps = decoder->guts->frame.header.bits_per_sample;
 718                 switch(decoder->guts->frame.header.channel_assignment) {
 719                         case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
 720                                 /* no adjustment needed */
 721                                 break;
 722                         case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
 723                                 assert(decoder->guts->frame.header.channels == 2);
 724                                 if(channel == 1)
 725                                         bps++;
 726                                 break;
 727                         case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
 728                                 assert(decoder->guts->frame.header.channels == 2);
 729                                 if(channel == 0)
 730                                         bps++;
 731                                 break;
 732                         case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
 733                                 assert(decoder->guts->frame.header.channels == 2);
 734                                 if(channel == 1)
 735                                         bps++;
 736                                 break;
 737                         default:
 738                                 assert(0);
 739                 }
 740                 /*
 741                  * now read it
 742                  */
 743                 if(!stream_decoder_read_subframe_(decoder, channel, bps))
 744                         return false;
 745                 if(decoder->state != FLAC__STREAM_DECODER_READ_FRAME) {
 746                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 747                         return true;
 748                 }
 749         }
 750         if(!stream_decoder_read_zero_padding_(decoder))
 751                 return false;
 752
 753         /*
 754          * Read the frame CRC-16 from the footer and check
 755          */
 756         frame_crc = decoder->guts->input.read_crc16;
 757         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, FLAC__FRAME_FOOTER_CRC_LEN, read_callback_, decoder))
 758                 return false; /* the read_callback_ sets the state for us */
 759         if(frame_crc == (uint16)x) {
 760                 /* Undo any special channel coding */
 761                 switch(decoder->guts->frame.header.channel_assignment) {
 762                         case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
 763                                 /* do nothing */
 764                                 break;
 765                         case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
 766                                 assert(decoder->guts->frame.header.channels == 2);
 767                                 for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
 768                                         decoder->guts->output[1][i] = decoder->guts->output[0][i] - decoder->guts->output[1][i];
 769                                 break;
 770                         case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
 771                                 assert(decoder->guts->frame.header.channels == 2);
 772                                 for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
 773                                         decoder->guts->output[0][i] += decoder->guts->output[1][i];
 774                                 break;
 775                         case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
 776                                 assert(decoder->guts->frame.header.channels == 2);
 777                                 for(i = 0; i < decoder->guts->frame.header.blocksize; i++) {
 778                                         mid = decoder->guts->output[0][i];
 779                                         side = decoder->guts->output[1][i];
 780                                         mid <<= 1;
 781                                         if(side & 1) /* i.e. if 'side' is odd... */
 782                                                 mid++;
 783                                         left = mid + side;
 784                                         right = mid - side;
 785                                         decoder->guts->output[0][i] = left >> 1;
 786                                         decoder->guts->output[1][i] = right >> 1;
 787                                 }
 788                                 break;
 789                         default:
 790                                 assert(0);
 791                                 break;
 792                 }
 793         }
 794         else {
 795                 /* Bad frame, emit error and zero the output signal */
 796                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_FRAME_CRC_MISMATCH, decoder->guts->client_data);
 797                 for(channel = 0; channel < decoder->guts->frame.header.channels; channel++) {
 798                         memset(decoder->guts->output[channel], 0, sizeof(int32) * decoder->guts->frame.header.blocksize);
 799                 }
 800         }
 801
 802         *got_a_frame = true;
 803
 804         /* put the latest values into the public section of the decoder instance */
 805         decoder->channels = decoder->guts->frame.header.channels;
 806         decoder->channel_assignment = decoder->guts->frame.header.channel_assignment;
 807         decoder->bits_per_sample = decoder->guts->frame.header.bits_per_sample;
 808         decoder->sample_rate = decoder->guts->frame.header.sample_rate;
 809         decoder->blocksize = decoder->guts->frame.header.blocksize;
 810
 811         decoder->guts->samples_decoded = decoder->guts->frame.header.number.sample_number + decoder->guts->frame.header.blocksize;
 812
 813         /* write it */
 814         /* NOTE: some versions of GCC can't figure out const-ness right and will give you an 'incompatible pointer type' warning on arg 3 here: */
 815         if(decoder->guts->write_callback(decoder, &decoder->guts->frame, decoder->guts->output, decoder->guts->client_data) != FLAC__STREAM_DECODER_WRITE_CONTINUE)
 816                 return false;
 817
 818         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 819         return true;
 820 }
 821
 822 bool stream_decoder_read_frame_header_(FLAC__StreamDecoder *decoder)
 823 {
 824         uint32 x;
 825         uint64 xx;
 826         unsigned i, blocksize_hint = 0, sample_rate_hint = 0;
 827         byte crc8, raw_header[16]; /* MAGIC NUMBER based on the maximum frame header size, including CRC */
 828         unsigned raw_header_len;
 829         bool is_unparseable = false;
 830         const bool is_known_variable_blocksize_stream = (decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.min_blocksize != decoder->guts->stream_info.data.stream_info.max_blocksize);
 831         const bool is_known_fixed_blocksize_stream = (decoder->guts->has_stream_info && decoder->guts->stream_info.data.stream_info.min_blocksize == decoder->guts->stream_info.data.stream_info.max_blocksize);
 832
 833         assert(decoder->guts->input.consumed_bits == 0); /* make sure we're byte aligned */
 834
 835         /* init the raw header with the saved bits from synchronization */
 836         raw_header[0] = decoder->guts->header_warmup[0];
 837         raw_header[1] = decoder->guts->header_warmup[1];
 838         raw_header_len = 2;
 839
 840         /*
 841          * check to make sure that the reserved bits are 0
 842          */
 843         if(raw_header[1] & 0x03) { /* MAGIC NUMBER */
 844                 is_unparseable = true;
 845         }
 846
 847         /*
 848          * Note that along the way as we read the header, we look for a sync
 849          * code inside.  If we find one it would indicate that our original
 850          * sync was bad since there cannot be a sync code in a valid header.
 851          */
 852
 853         /*
 854          * read in the raw header as bytes so we can CRC it, and parse it on the way
 855          */
 856         for(i = 0; i < 2; i++) {
 857                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
 858                         return false; /* the read_callback_ sets the state for us */
 859                 if(x == 0xff) { /* MAGIC NUMBER for the first 8 frame sync bits */
 860                         /* if we get here it means our original sync was erroneous since the sync code cannot appear in the header */
 861                         decoder->guts->lookahead = (byte)x;
 862                         decoder->guts->cached = true;
 863                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
 864                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 865                         return true;
 866                 }
 867                 raw_header[raw_header_len++] = (byte)x;
 868         }
 869
 870         switch(x = raw_header[2] >> 4) {
 871                 case 0:
 872                         if(is_known_fixed_blocksize_stream)
 873                                 decoder->guts->frame.header.blocksize = decoder->guts->stream_info.data.stream_info.min_blocksize;
 874                         else
 875                                 is_unparseable = true;
 876                         break;
 877                 case 1:
 878                         decoder->guts->frame.header.blocksize = 192;
 879                         break;
 880                 case 2:
 881                 case 3:
 882                 case 4:
 883                 case 5:
 884                         decoder->guts->frame.header.blocksize = 576 << (x-2);
 885                         break;
 886                 case 6:
 887                 case 7:
 888                         blocksize_hint = x;
 889                         break;
 890                 case 8:
 891                 case 9:
 892                 case 10:
 893                 case 11:
 894                 case 12:
 895                 case 13:
 896                 case 14:
 897                 case 15:
 898                         decoder->guts->frame.header.blocksize = 256 << (x-8);
 899                         break;
 900                 default:
 901                         assert(0);
 902                         break;
 903         }
 904
 905         switch(x = raw_header[2] & 0x0f) {
 906                 case 0:
 907                         if(decoder->guts->has_stream_info)
 908                                 decoder->guts->frame.header.sample_rate = decoder->guts->stream_info.data.stream_info.sample_rate;
 909                         else
 910                                 is_unparseable = true;
 911                         break;
 912                 case 1:
 913                 case 2:
 914                 case 3:
 915                         is_unparseable = true;
 916                         break;
 917                 case 4:
 918                         decoder->guts->frame.header.sample_rate = 8000;
 919                         break;
 920                 case 5:
 921                         decoder->guts->frame.header.sample_rate = 16000;
 922                         break;
 923                 case 6:
 924                         decoder->guts->frame.header.sample_rate = 22050;
 925                         break;
 926                 case 7:
 927                         decoder->guts->frame.header.sample_rate = 24000;
 928                         break;
 929                 case 8:
 930                         decoder->guts->frame.header.sample_rate = 32000;
 931                         break;
 932                 case 9:
 933                         decoder->guts->frame.header.sample_rate = 44100;
 934                         break;
 935                 case 10:
 936                         decoder->guts->frame.header.sample_rate = 48000;
 937                         break;
 938                 case 11:
 939                         decoder->guts->frame.header.sample_rate = 96000;
 940                         break;
 941                 case 12:
 942                 case 13:
 943                 case 14:
 944                         sample_rate_hint = x;
 945                         break;
 946                 case 15:
 947                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
 948                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
 949                         return true;
 950                 default:
 951                         assert(0);
 952         }
 953
 954         x = (unsigned)(raw_header[3] >> 4);
 955         if(x & 8) {
 956                 decoder->guts->frame.header.channels = 2;
 957                 switch(x & 7) {
 958                         case 0:
 959                                 decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE;
 960                                 break;
 961                         case 1:
 962                                 decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE;
 963                                 break;
 964                         case 2:
 965                                 decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_MID_SIDE;
 966                                 break;
 967                         default:
 968                                 is_unparseable = true;
 969                                 break;
 970                 }
 971         }
 972         else {
 973                 decoder->guts->frame.header.channels = (unsigned)x + 1;
 974                 decoder->guts->frame.header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT;
 975         }
 976
 977         switch(x = (unsigned)(raw_header[3] & 0x0e) >> 1) {
 978                 case 0:
 979                         if(decoder->guts->has_stream_info)
 980                                 decoder->guts->frame.header.bits_per_sample = decoder->guts->stream_info.data.stream_info.bits_per_sample;
 981                         else
 982                                 is_unparseable = true;
 983                         break;
 984                 case 1:
 985                         decoder->guts->frame.header.bits_per_sample = 8;
 986                         break;
 987                 case 2:
 988                         decoder->guts->frame.header.bits_per_sample = 12;
 989                         break;
 990                 case 4:
 991                         decoder->guts->frame.header.bits_per_sample = 16;
 992                         break;
 993                 case 5:
 994                         decoder->guts->frame.header.bits_per_sample = 20;
 995                         break;
 996                 case 6:
 997                         decoder->guts->frame.header.bits_per_sample = 24;
 998                         break;
 999                 case 3:
1000                 case 7:
1001                         is_unparseable = true;
1002                         break;
1003                 default:
1004                         assert(0);
1005                         break;
1006         }
1007
1008         if(raw_header[3] & 0x01) { /* this should be a zero padding bit */
1009                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
1010                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1011                 return true;
1012         }
1013
1014         if(blocksize_hint && is_known_variable_blocksize_stream) {
1015                 if(!FLAC__bitbuffer_read_utf8_uint64(&decoder->guts->input, &xx, read_callback_, decoder, raw_header, &raw_header_len))
1016                         return false; /* the read_callback_ sets the state for us */
1017                 if(xx == 0xffffffffffffffff) { /* i.e. non-UTF8 code... */
1018                         decoder->guts->lookahead = raw_header[raw_header_len-1]; /* back up as much as we can */
1019                         decoder->guts->cached = true;
1020                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
1021                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1022                         return true;
1023                 }
1024                 decoder->guts->frame.header.number.sample_number = xx;
1025         }
1026         else {
1027                 if(!FLAC__bitbuffer_read_utf8_uint32(&decoder->guts->input, &x, read_callback_, decoder, raw_header, &raw_header_len))
1028                         return false; /* the read_callback_ sets the state for us */
1029                 if(x == 0xffffffff) { /* i.e. non-UTF8 code... */
1030                         decoder->guts->lookahead = raw_header[raw_header_len-1]; /* back up as much as we can */
1031                         decoder->guts->cached = true;
1032                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
1033                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1034                         return true;
1035                 }
1036                 decoder->guts->last_frame_number = x;
1037                 if(decoder->guts->has_stream_info) {
1038                         decoder->guts->frame.header.number.sample_number = (int64)decoder->guts->stream_info.data.stream_info.min_blocksize * (int64)x;
1039                 }
1040                 else {
1041                         is_unparseable = true;
1042                 }
1043         }
1044
1045         if(blocksize_hint) {
1046                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
1047                         return false; /* the read_callback_ sets the state for us */
1048                 raw_header[raw_header_len++] = (byte)x;
1049                 if(blocksize_hint == 7) {
1050                         uint32 _x;
1051                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
1052                                 return false; /* the read_callback_ sets the state for us */
1053                         raw_header[raw_header_len++] = (byte)_x;
1054                         x = (x << 8) | _x;
1055                 }
1056                 decoder->guts->frame.header.blocksize = x+1;
1057         }
1058
1059         if(sample_rate_hint) {
1060                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
1061                         return false; /* the read_callback_ sets the state for us */
1062                 raw_header[raw_header_len++] = (byte)x;
1063                 if(sample_rate_hint != 12) {
1064                         uint32 _x;
1065                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &_x, 8, read_callback_, decoder))
1066                                 return false; /* the read_callback_ sets the state for us */
1067                         raw_header[raw_header_len++] = (byte)_x;
1068                         x = (x << 8) | _x;
1069                 }
1070                 if(sample_rate_hint == 12)
1071                         decoder->guts->frame.header.sample_rate = x*1000;
1072                 else if(sample_rate_hint == 13)
1073                         decoder->guts->frame.header.sample_rate = x;
1074                 else
1075                         decoder->guts->frame.header.sample_rate = x*10;
1076         }
1077
1078         /* read the CRC-8 byte */
1079         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder))
1080                 return false; /* the read_callback_ sets the state for us */
1081         crc8 = (byte)x;
1082
1083         if(FLAC__crc8(raw_header, raw_header_len) != crc8) {
1084                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_BAD_HEADER, decoder->guts->client_data);
1085                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1086                 return true;
1087         }
1088
1089         if(is_unparseable) {
1090                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1091                 return false;
1092         }
1093
1094         return true;
1095 }
1096
1097 bool stream_decoder_read_subframe_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
1098 {
1099         uint32 x;
1100         bool wasted_bits;
1101
1102         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &x, 8, read_callback_, decoder)) /* MAGIC NUMBER */
1103                 return false; /* the read_callback_ sets the state for us */
1104
1105         wasted_bits = (x & 1);
1106         x &= 0xfe;
1107
1108         if(wasted_bits) {
1109                 unsigned u;
1110                 if(!FLAC__bitbuffer_read_unary_unsigned(&decoder->guts->input, &u, read_callback_, decoder))
1111                         return false; /* the read_callback_ sets the state for us */
1112                 decoder->guts->frame.subframes[channel].wasted_bits = u+1;
1113                 bps -= decoder->guts->frame.subframes[channel].wasted_bits;
1114         }
1115         else
1116                 decoder->guts->frame.subframes[channel].wasted_bits = 0;
1117
1118         /*
1119          * Lots of magic numbers here
1120          */
1121         if(x & 0x80) {
1122                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1123                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1124                 return true;
1125         }
1126         else if(x == 0) {
1127                 if(!stream_decoder_read_subframe_constant_(decoder, channel, bps))
1128                         return false;
1129         }
1130         else if(x == 2) {
1131                 if(!stream_decoder_read_subframe_verbatim_(decoder, channel, bps))
1132                         return false;
1133         }
1134         else if(x < 16) {
1135                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1136                 return false;
1137         }
1138         else if(x <= 24) {
1139                 if(!stream_decoder_read_subframe_fixed_(decoder, channel, bps, (x>>1)&7))
1140                         return false;
1141         }
1142         else if(x < 64) {
1143                 decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1144                 return false;
1145         }
1146         else {
1147                 if(!stream_decoder_read_subframe_lpc_(decoder, channel, bps, ((x>>1)&31)+1))
1148                         return false;
1149         }
1150
1151         if(wasted_bits) {
1152                 unsigned i;
1153                 x = decoder->guts->frame.subframes[channel].wasted_bits;
1154                 for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
1155                         decoder->guts->output[channel][i] <<= x;
1156         }
1157
1158         return true;
1159 }
1160
1161 bool stream_decoder_read_subframe_constant_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
1162 {
1163         FLAC__Subframe_Constant *subframe = &decoder->guts->frame.subframes[channel].data.constant;
1164         int32 x;
1165         unsigned i;
1166         int32 *output = decoder->guts->output[channel];
1167
1168         decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_CONSTANT;
1169
1170         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, bps, read_callback_, decoder))
1171                 return false; /* the read_callback_ sets the state for us */
1172
1173         subframe->value = x;
1174
1175         /* decode the subframe */
1176         for(i = 0; i < decoder->guts->frame.header.blocksize; i++)
1177                 output[i] = x;
1178
1179         return true;
1180 }
1181
1182 bool stream_decoder_read_subframe_fixed_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order)
1183 {
1184         FLAC__Subframe_Fixed *subframe = &decoder->guts->frame.subframes[channel].data.fixed;
1185         int32 i32;
1186         uint32 u32;
1187         unsigned u;
1188
1189         decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_FIXED;
1190
1191         subframe->residual = decoder->guts->residual[channel];
1192         subframe->order = order;
1193
1194         /* read warm-up samples */
1195         for(u = 0; u < order; u++) {
1196                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, bps, read_callback_, decoder))
1197                         return false; /* the read_callback_ sets the state for us */
1198                 subframe->warmup[u] = i32;
1199         }
1200
1201         /* read entropy coding method info */
1202         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
1203                 return false; /* the read_callback_ sets the state for us */
1204         subframe->entropy_coding_method.type = u32;
1205         switch(subframe->entropy_coding_method.type) {
1206                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1207                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
1208                                 return false; /* the read_callback_ sets the state for us */
1209                         subframe->entropy_coding_method.data.partitioned_rice.order = u32;
1210                         break;
1211                 default:
1212                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1213                         return false;
1214         }
1215
1216         /* read residual */
1217         switch(subframe->entropy_coding_method.type) {
1218                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1219                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe->entropy_coding_method.data.partitioned_rice.order, decoder->guts->residual[channel]))
1220                                 return false;
1221                         break;
1222                 default:
1223                         assert(0);
1224         }
1225
1226         /* decode the subframe */
1227         memcpy(decoder->guts->output[channel], subframe->warmup, sizeof(int32) * order);
1228         FLAC__fixed_restore_signal(decoder->guts->residual[channel], decoder->guts->frame.header.blocksize-order, order, decoder->guts->output[channel]+order);
1229
1230         return true;
1231 }
1232
1233 bool stream_decoder_read_subframe_lpc_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps, const unsigned order)
1234 {
1235         FLAC__Subframe_LPC *subframe = &decoder->guts->frame.subframes[channel].data.lpc;
1236         int32 i32;
1237         uint32 u32;
1238         unsigned u;
1239
1240         decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_LPC;
1241
1242         subframe->residual = decoder->guts->residual[channel];
1243         subframe->order = order;
1244
1245         /* read warm-up samples */
1246         for(u = 0; u < order; u++) {
1247                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, bps, read_callback_, decoder))
1248                         return false; /* the read_callback_ sets the state for us */
1249                 subframe->warmup[u] = i32;
1250         }
1251
1252         /* read qlp coeff precision */
1253         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN, read_callback_, decoder))
1254                 return false; /* the read_callback_ sets the state for us */
1255         if(u32 == (1u << FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN) - 1) {
1256                 decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1257                 decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1258                 return true;
1259         }
1260         subframe->qlp_coeff_precision = u32+1;
1261
1262         /* read qlp shift */
1263         if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN, read_callback_, decoder))
1264                 return false; /* the read_callback_ sets the state for us */
1265         subframe->quantization_level = i32;
1266
1267         /* read quantized lp coefficiencts */
1268         for(u = 0; u < order; u++) {
1269                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i32, subframe->qlp_coeff_precision, read_callback_, decoder))
1270                         return false; /* the read_callback_ sets the state for us */
1271                 subframe->qlp_coeff[u] = i32;
1272         }
1273
1274         /* read entropy coding method info */
1275         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_TYPE_LEN, read_callback_, decoder))
1276                 return false; /* the read_callback_ sets the state for us */
1277         subframe->entropy_coding_method.type = u32;
1278         switch(subframe->entropy_coding_method.type) {
1279                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1280                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &u32, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN, read_callback_, decoder))
1281                                 return false; /* the read_callback_ sets the state for us */
1282                         subframe->entropy_coding_method.data.partitioned_rice.order = u32;
1283                         break;
1284                 default:
1285                         decoder->state = FLAC__STREAM_DECODER_UNPARSEABLE_STREAM;
1286                         return false;
1287         }
1288
1289         /* read residual */
1290         switch(subframe->entropy_coding_method.type) {
1291                 case FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE:
1292                         if(!stream_decoder_read_residual_partitioned_rice_(decoder, order, subframe->entropy_coding_method.data.partitioned_rice.order, decoder->guts->residual[channel]))
1293                                 return false;
1294                         break;
1295                 default:
1296                         assert(0);
1297         }
1298
1299         /* decode the subframe */
1300         memcpy(decoder->guts->output[channel], subframe->warmup, sizeof(int32) * order);
1301         decoder->guts->local_lpc_restore_signal(decoder->guts->residual[channel], decoder->guts->frame.header.blocksize-order, subframe->qlp_coeff, order, subframe->quantization_level, decoder->guts->output[channel]+order);
1302
1303         return true;
1304 }
1305
1306 bool stream_decoder_read_subframe_verbatim_(FLAC__StreamDecoder *decoder, unsigned channel, unsigned bps)
1307 {
1308         FLAC__Subframe_Verbatim *subframe = &decoder->guts->frame.subframes[channel].data.verbatim;
1309         int32 x, *residual = decoder->guts->residual[channel];
1310         unsigned i;
1311
1312         decoder->guts->frame.subframes[channel].type = FLAC__SUBFRAME_TYPE_VERBATIM;
1313
1314         subframe->data = residual;
1315
1316         for(i = 0; i < decoder->guts->frame.header.blocksize; i++) {
1317                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &x, bps, read_callback_, decoder))
1318                         return false; /* the read_callback_ sets the state for us */
1319                 residual[i] = x;
1320         }
1321
1322         /* decode the subframe */
1323         memcpy(decoder->guts->output[channel], subframe->data, sizeof(int32) * decoder->guts->frame.header.blocksize);
1324
1325         return true;
1326 }
1327
1328 bool stream_decoder_read_residual_partitioned_rice_(FLAC__StreamDecoder *decoder, unsigned predictor_order, unsigned partition_order, int32 *residual)
1329 {
1330         uint32 rice_parameter;
1331         int i;
1332         unsigned partition, sample, u;
1333         const unsigned partitions = 1u << partition_order;
1334         const unsigned partition_samples = partition_order > 0? decoder->guts->frame.header.blocksize >> partition_order : decoder->guts->frame.header.blocksize - predictor_order;
1335
1336         sample = 0;
1337         for(partition = 0; partition < partitions; partition++) {
1338                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &rice_parameter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN, read_callback_, decoder))
1339                         return false; /* the read_callback_ sets the state for us */
1340                 if(rice_parameter < FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ESCAPE_PARAMETER) {
1341                         for(u = (partition_order == 0 || partition > 0)? 0 : predictor_order; u < partition_samples; u++, sample++) {
1342 #ifdef FLAC__SYMMETRIC_RICE
1343                                 if(!FLAC__bitbuffer_read_symmetric_rice_signed(&decoder->guts->input, &i, rice_parameter, read_callback_, decoder))
1344                                         return false; /* the read_callback_ sets the state for us */
1345 #else
1346                                 if(!FLAC__bitbuffer_read_rice_signed(&decoder->guts->input, &i, rice_parameter, read_callback_, decoder))
1347                                         return false; /* the read_callback_ sets the state for us */
1348 #endif
1349                                 residual[sample] = i;
1350                         }
1351                 }
1352                 else {
1353                         if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &rice_parameter, FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_RAW_LEN, read_callback_, decoder))
1354                                 return false; /* the read_callback_ sets the state for us */
1355                         for(u = (partition_order == 0 || partition > 0)? 0 : predictor_order; u < partition_samples; u++, sample++) {
1356                                 if(!FLAC__bitbuffer_read_raw_int32(&decoder->guts->input, &i, rice_parameter, read_callback_, decoder))
1357                                         return false; /* the read_callback_ sets the state for us */
1358                                 residual[sample] = i;
1359                         }
1360                 }
1361         }
1362
1363         return true;
1364 }
1365
1366 bool stream_decoder_read_zero_padding_(FLAC__StreamDecoder *decoder)
1367 {
1368         if(decoder->guts->input.consumed_bits != 0) {
1369                 uint32 zero = 0;
1370                 if(!FLAC__bitbuffer_read_raw_uint32(&decoder->guts->input, &zero, 8-decoder->guts->input.consumed_bits, read_callback_, decoder))
1371                         return false; /* the read_callback_ sets the state for us */
1372                 if(zero != 0) {
1373                         decoder->guts->error_callback(decoder, FLAC__STREAM_DECODER_ERROR_LOST_SYNC, decoder->guts->client_data);
1374                         decoder->state = FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC;
1375                 }
1376         }
1377         return true;
1378 }
1379
1380 bool read_callback_(byte buffer[], unsigned *bytes, void *client_data)
1381 {
1382         FLAC__StreamDecoder *decoder = (FLAC__StreamDecoder *)client_data;
1383         FLAC__StreamDecoderReadStatus status;
1384         status = decoder->guts->read_callback(decoder, buffer, bytes, decoder->guts->client_data);
1385         if(status == FLAC__STREAM_DECODER_READ_END_OF_STREAM)
1386                 decoder->state = FLAC__STREAM_DECODER_END_OF_STREAM;
1387         else if(status == FLAC__STREAM_DECODER_READ_ABORT)
1388                 decoder->state = FLAC__STREAM_DECODER_ABORTED;
1389         return status == FLAC__STREAM_DECODER_READ_CONTINUE;
1390 }