src/libFLAC/seekable_stream_decoder.c

   1 /* libFLAC - Free Lossless Audio Codec library
   2  * Copyright (C) 2000,2001,2002  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 <stdio.h>
  21 #include <stdlib.h> /* for malloc() */
  22 #include <string.h> /* for memcpy()/memcmp() */
  23 #include "FLAC/assert.h"
  24 #include "protected/seekable_stream_decoder.h"
  25 #include "protected/stream_decoder.h"
  26 #include "private/md5.h"
  27
  28 /***********************************************************************
  29  *
  30  * Private class method prototypes
  31  *
  32  ***********************************************************************/
  33
  34 static FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data);
  35 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data);
  36 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
  37 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
  38 static FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample);
  39
  40 /***********************************************************************
  41  *
  42  * Private class data
  43  *
  44  ***********************************************************************/
  45
  46 typedef struct FLAC__SeekableStreamDecoderPrivate {
  47         FLAC__SeekableStreamDecoderReadStatus (*read_callback)(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data);
  48         FLAC__SeekableStreamDecoderSeekStatus (*seek_callback)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data);
  49         FLAC__SeekableStreamDecoderTellStatus (*tell_callback)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data);
  50         FLAC__SeekableStreamDecoderLengthStatus (*length_callback)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data);
  51         FLAC__bool (*eof_callback)(const FLAC__SeekableStreamDecoder *decoder, void *client_data);
  52         FLAC__StreamDecoderWriteStatus (*write_callback)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data);
  53         void (*metadata_callback)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data);
  54         void (*error_callback)(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
  55         void *client_data;
  56         FLAC__StreamDecoder *stream_decoder;
  57         struct MD5Context md5context;
  58         FLAC__byte stored_md5sum[16]; /* this is what is stored in the metadata */
  59         FLAC__byte computed_md5sum[16]; /* this is the sum we computed from the decoded data */
  60         /* the rest of these are only used for seeking: */
  61         FLAC__StreamMetaData_StreamInfo stream_info; /* we keep this around so we can figure out how to seek quickly */
  62         const FLAC__StreamMetaData_SeekTable *seek_table; /* we hold a pointer to the stream decoder's seek table for the same reason */
  63         FLAC__Frame last_frame; /* holds the info of the last frame we seeked to */
  64         FLAC__uint64 target_sample;
  65 } FLAC__SeekableStreamDecoderPrivate;
  66
  67 /***********************************************************************
  68  *
  69  * Public static class data
  70  *
  71  ***********************************************************************/
  72
  73 const char *FLAC__SeekableStreamDecoderStateString[] = {
  74         "FLAC__SEEKABLE_STREAM_DECODER_OK",
  75         "FLAC__SEEKABLE_STREAM_DECODER_SEEKING",
  76         "FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM",
  77         "FLAC__SEEKABLE_STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
  78         "FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR",
  79         "FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR",
  80         "FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR",
  81     "FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED",
  82     "FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK",
  83     "FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED"
  84 };
  85
  86 const char *FLAC__SeekableStreamDecoderReadStatusString[] = {
  87         "FLAC__STREAM_DECODER_READ_STATUS_OK",
  88         "FLAC__STREAM_DECODER_READ_STATUS_ERROR"
  89 };
  90
  91 const char *FLAC__SeekableStreamDecoderSeekStatusString[] = {
  92         "FLAC__STREAM_DECODER_SEEK_STATUS_OK",
  93         "FLAC__STREAM_DECODER_SEEK_STATUS_ERROR"
  94 };
  95
  96 const char *FLAC__SeekableStreamDecoderTellStatusString[] = {
  97         "FLAC__STREAM_DECODER_TELL_STATUS_OK",
  98         "FLAC__STREAM_DECODER_TELL_STATUS_ERROR"
  99 };
 100
 101 const char *FLAC__SeekableStreamDecoderLengthStatusString[] = {
 102         "FLAC__STREAM_DECODER_LENGTH_STATUS_OK",
 103         "FLAC__STREAM_DECODER_LENGTH_STATUS_ERROR"
 104 };
 105
 106 /***********************************************************************
 107  *
 108  * Class constructor/destructor
 109  *
 110  ***********************************************************************/
 111
 112 FLAC__SeekableStreamDecoder *FLAC__seekable_stream_decoder_new()
 113 {
 114         FLAC__SeekableStreamDecoder *decoder;
 115
 116         FLAC__ASSERT(sizeof(int) >= 4); /* we want to die right away if this is not true */
 117
 118         decoder = (FLAC__SeekableStreamDecoder*)malloc(sizeof(FLAC__SeekableStreamDecoder));
 119         if(decoder == 0) {
 120                 return 0;
 121         }
 122         decoder->protected_ = (FLAC__SeekableStreamDecoderProtected*)malloc(sizeof(FLAC__SeekableStreamDecoderProtected));
 123         if(decoder->protected_ == 0) {
 124                 free(decoder);
 125                 return 0;
 126         }
 127         decoder->private_ = (FLAC__SeekableStreamDecoderPrivate*)malloc(sizeof(FLAC__SeekableStreamDecoderPrivate));
 128         if(decoder->private_ == 0) {
 129                 free(decoder->protected_);
 130                 free(decoder);
 131                 return 0;
 132         }
 133
 134         decoder->private_->stream_decoder = FLAC__stream_decoder_new();
 135
 136         if(0 == decoder->private_->stream_decoder) {
 137                 free(decoder->private_);
 138                 free(decoder->protected_);
 139                 free(decoder);
 140                 return 0;
 141         }
 142
 143         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED;
 144
 145         decoder->private_->read_callback = 0;
 146         decoder->private_->seek_callback = 0;
 147         decoder->private_->tell_callback = 0;
 148         decoder->private_->length_callback = 0;
 149         decoder->private_->eof_callback = 0;
 150         decoder->private_->write_callback = 0;
 151         decoder->private_->metadata_callback = 0;
 152         decoder->private_->error_callback = 0;
 153         decoder->private_->client_data = 0;
 154
 155         return decoder;
 156 }
 157
 158 void FLAC__seekable_stream_decoder_delete(FLAC__SeekableStreamDecoder *decoder)
 159 {
 160         FLAC__ASSERT(decoder != 0);
 161         FLAC__ASSERT(decoder->protected_ != 0);
 162         FLAC__ASSERT(decoder->private_ != 0);
 163
 164         if(decoder->private_->stream_decoder != 0)
 165                 FLAC__stream_decoder_delete(decoder->private_->stream_decoder);
 166
 167         free(decoder->private_);
 168         free(decoder->protected_);
 169         free(decoder);
 170 }
 171
 172 /***********************************************************************
 173  *
 174  * Public class methods
 175  *
 176  ***********************************************************************/
 177
 178 FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_init(FLAC__SeekableStreamDecoder *decoder)
 179 {
 180         FLAC__ASSERT(decoder != 0);
 181
 182         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 183                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED;
 184
 185         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_OK;
 186
 187         if(0 == decoder->private_->read_callback || 0 == decoder->private_->seek_callback || 0 == decoder->private_->tell_callback || 0 == decoder->private_->length_callback || 0 == decoder->private_->eof_callback)
 188                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;
 189
 190         if(0 == decoder->private_->write_callback || 0 == decoder->private_->metadata_callback || 0 == decoder->private_->error_callback)
 191                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;
 192
 193         decoder->private_->seek_table = 0;
 194
 195         /* We initialize the MD5Context even though we may never use it.  This is
 196          * because md5_checking may be turned on to start and then turned off if a
 197          * seek occurs.  So we always init the context here and finalize it in
 198          * FLAC__seekable_stream_decoder_finish() to make sure things are always
 199          * cleaned up properly.
 200          */
 201         MD5Init(&decoder->private_->md5context);
 202
 203         FLAC__stream_decoder_set_read_callback(decoder->private_->stream_decoder, read_callback_);
 204         FLAC__stream_decoder_set_write_callback(decoder->private_->stream_decoder, write_callback_);
 205         FLAC__stream_decoder_set_metadata_callback(decoder->private_->stream_decoder, metadata_callback_);
 206         FLAC__stream_decoder_set_error_callback(decoder->private_->stream_decoder, error_callback_);
 207         FLAC__stream_decoder_set_client_data(decoder->private_->stream_decoder, decoder);
 208
 209         if(FLAC__stream_decoder_init(decoder->private_->stream_decoder) != FLAC__STREAM_DECODER_SEARCH_FOR_METADATA)
 210                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 211
 212         return decoder->protected_->state;
 213 }
 214
 215 FLAC__bool FLAC__seekable_stream_decoder_finish(FLAC__SeekableStreamDecoder *decoder)
 216 {
 217         FLAC__bool md5_failed = false;
 218
 219         FLAC__ASSERT(decoder != 0);
 220         FLAC__ASSERT(decoder->private_ != 0);
 221         FLAC__ASSERT(decoder->protected_ != 0);
 222
 223         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 224                 return true;
 225
 226         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 227
 228         /* see the comment in FLAC__seekable_stream_decoder_init() as to why we
 229          * always call MD5Final()
 230          */
 231         MD5Final(decoder->private_->computed_md5sum, &decoder->private_->md5context);
 232
 233         FLAC__stream_decoder_finish(decoder->private_->stream_decoder);
 234
 235         if(decoder->protected_->md5_checking) {
 236                 if(memcmp(decoder->private_->stored_md5sum, decoder->private_->computed_md5sum, 16))
 237                         md5_failed = true;
 238         }
 239
 240         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED;
 241
 242         return !md5_failed;
 243 }
 244
 245 FLAC__bool FLAC__seekable_stream_decoder_set_md5_checking(const FLAC__SeekableStreamDecoder *decoder, FLAC__bool value)
 246 {
 247         FLAC__ASSERT(decoder != 0);
 248         FLAC__ASSERT(decoder->protected_ != 0);
 249         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 250                 return false;
 251         decoder->protected_->md5_checking = value;
 252         return true;
 253 }
 254
 255 FLAC__bool FLAC__seekable_stream_decoder_set_read_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderReadStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data))
 256 {
 257         FLAC__ASSERT(decoder != 0);
 258         FLAC__ASSERT(decoder->private_ != 0);
 259         FLAC__ASSERT(decoder->protected_ != 0);
 260         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 261                 return false;
 262         decoder->private_->read_callback = value;
 263         return true;
 264 }
 265
 266 FLAC__bool FLAC__seekable_stream_decoder_set_seek_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderSeekStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data))
 267 {
 268         FLAC__ASSERT(decoder != 0);
 269         FLAC__ASSERT(decoder->private_ != 0);
 270         FLAC__ASSERT(decoder->protected_ != 0);
 271         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 272                 return false;
 273         decoder->private_->seek_callback = value;
 274         return true;
 275 }
 276
 277 FLAC__bool FLAC__seekable_stream_decoder_set_tell_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderTellStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data))
 278 {
 279         FLAC__ASSERT(decoder != 0);
 280         FLAC__ASSERT(decoder->private_ != 0);
 281         FLAC__ASSERT(decoder->protected_ != 0);
 282         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 283                 return false;
 284         decoder->private_->tell_callback = value;
 285         return true;
 286 }
 287
 288 FLAC__bool FLAC__seekable_stream_decoder_set_length_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderLengthStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data))
 289 {
 290         FLAC__ASSERT(decoder != 0);
 291         FLAC__ASSERT(decoder->private_ != 0);
 292         FLAC__ASSERT(decoder->protected_ != 0);
 293         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 294                 return false;
 295         decoder->private_->length_callback = value;
 296         return true;
 297 }
 298
 299 FLAC__bool FLAC__seekable_stream_decoder_set_eof_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__bool (*value)(const FLAC__SeekableStreamDecoder *decoder, void *client_data))
 300 {
 301         FLAC__ASSERT(decoder != 0);
 302         FLAC__ASSERT(decoder->private_ != 0);
 303         FLAC__ASSERT(decoder->protected_ != 0);
 304         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 305                 return false;
 306         decoder->private_->eof_callback = value;
 307         return true;
 308 }
 309
 310 FLAC__bool FLAC__seekable_stream_decoder_set_write_callback(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderWriteStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data))
 311 {
 312         FLAC__ASSERT(decoder != 0);
 313         FLAC__ASSERT(decoder->private_ != 0);
 314         FLAC__ASSERT(decoder->protected_ != 0);
 315         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 316                 return false;
 317         decoder->private_->write_callback = value;
 318         return true;
 319 }
 320
 321 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_callback(const FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data))
 322 {
 323         FLAC__ASSERT(decoder != 0);
 324         FLAC__ASSERT(decoder->private_ != 0);
 325         FLAC__ASSERT(decoder->protected_ != 0);
 326         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 327                 return false;
 328         decoder->private_->metadata_callback = value;
 329         return true;
 330 }
 331
 332 FLAC__bool FLAC__seekable_stream_decoder_set_error_callback(const FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data))
 333 {
 334         FLAC__ASSERT(decoder != 0);
 335         FLAC__ASSERT(decoder->private_ != 0);
 336         FLAC__ASSERT(decoder->protected_ != 0);
 337         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 338                 return false;
 339         decoder->private_->error_callback = value;
 340         return true;
 341 }
 342
 343 FLAC__bool FLAC__seekable_stream_decoder_set_client_data(const FLAC__SeekableStreamDecoder *decoder, void *value)
 344 {
 345         FLAC__ASSERT(decoder != 0);
 346         FLAC__ASSERT(decoder->private_ != 0);
 347         FLAC__ASSERT(decoder->protected_ != 0);
 348         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 349                 return false;
 350         decoder->private_->client_data = value;
 351         return true;
 352 }
 353
 354 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond(const FLAC__SeekableStreamDecoder *decoder, FLAC__MetaDataType type)
 355 {
 356         FLAC__ASSERT(decoder != 0);
 357         FLAC__ASSERT(decoder->private_ != 0);
 358         FLAC__ASSERT(decoder->protected_ != 0);
 359         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 360         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 361                 return false;
 362         return FLAC__stream_decoder_set_metadata_respond(decoder->private_->stream_decoder, type);
 363 }
 364
 365 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_application(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte id[4])
 366 {
 367         FLAC__ASSERT(decoder != 0);
 368         FLAC__ASSERT(decoder->private_ != 0);
 369         FLAC__ASSERT(decoder->protected_ != 0);
 370         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 371         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 372                 return false;
 373         return FLAC__stream_decoder_set_metadata_respond_application(decoder->private_->stream_decoder, id);
 374 }
 375
 376 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_all(const FLAC__SeekableStreamDecoder *decoder)
 377 {
 378         FLAC__ASSERT(decoder != 0);
 379         FLAC__ASSERT(decoder->private_ != 0);
 380         FLAC__ASSERT(decoder->protected_ != 0);
 381         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 382         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 383                 return false;
 384         return FLAC__stream_decoder_set_metadata_respond_all(decoder->private_->stream_decoder);
 385 }
 386
 387 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore(const FLAC__SeekableStreamDecoder *decoder, FLAC__MetaDataType type)
 388 {
 389         FLAC__ASSERT(decoder != 0);
 390         FLAC__ASSERT(decoder->private_ != 0);
 391         FLAC__ASSERT(decoder->protected_ != 0);
 392         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 393         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 394                 return false;
 395         return FLAC__stream_decoder_set_metadata_ignore(decoder->private_->stream_decoder, type);
 396 }
 397
 398 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_application(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte id[4])
 399 {
 400         FLAC__ASSERT(decoder != 0);
 401         FLAC__ASSERT(decoder->private_ != 0);
 402         FLAC__ASSERT(decoder->protected_ != 0);
 403         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 404         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 405                 return false;
 406         return FLAC__stream_decoder_set_metadata_ignore_application(decoder->private_->stream_decoder, id);
 407 }
 408
 409 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_all(const FLAC__SeekableStreamDecoder *decoder)
 410 {
 411         FLAC__ASSERT(decoder != 0);
 412         FLAC__ASSERT(decoder->private_ != 0);
 413         FLAC__ASSERT(decoder->protected_ != 0);
 414         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 415         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 416                 return false;
 417         return FLAC__stream_decoder_set_metadata_ignore_all(decoder->private_->stream_decoder);
 418 }
 419
 420 FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_get_state(const FLAC__SeekableStreamDecoder *decoder)
 421 {
 422         FLAC__ASSERT(decoder != 0);
 423         FLAC__ASSERT(decoder->protected_ != 0);
 424         return decoder->protected_->state;
 425 }
 426
 427 FLAC__bool FLAC__seekable_stream_decoder_get_md5_checking(const FLAC__SeekableStreamDecoder *decoder)
 428 {
 429         FLAC__ASSERT(decoder != 0);
 430         FLAC__ASSERT(decoder->protected_ != 0);
 431         return decoder->protected_->md5_checking;
 432 }
 433
 434 FLAC__bool FLAC__seekable_stream_decoder_process_whole_stream(FLAC__SeekableStreamDecoder *decoder)
 435 {
 436         FLAC__bool ret;
 437         FLAC__ASSERT(decoder != 0);
 438
 439         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 440                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 441
 442         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 443                 return true;
 444
 445         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 446
 447         ret = FLAC__stream_decoder_process_whole_stream(decoder->private_->stream_decoder);
 448         if(!ret)
 449                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 450
 451         return ret;
 452 }
 453
 454 FLAC__bool FLAC__seekable_stream_decoder_process_metadata(FLAC__SeekableStreamDecoder *decoder)
 455 {
 456         FLAC__bool ret;
 457         FLAC__ASSERT(decoder != 0);
 458
 459         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 460                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 461
 462         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 463                 return true;
 464
 465         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 466
 467         ret = FLAC__stream_decoder_process_metadata(decoder->private_->stream_decoder);
 468         if(!ret)
 469                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 470
 471         return ret;
 472 }
 473
 474 FLAC__bool FLAC__seekable_stream_decoder_process_one_frame(FLAC__SeekableStreamDecoder *decoder)
 475 {
 476         FLAC__bool ret;
 477         FLAC__ASSERT(decoder != 0);
 478
 479         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 480                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 481
 482         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 483                 return true;
 484
 485         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 486
 487         ret = FLAC__stream_decoder_process_one_frame(decoder->private_->stream_decoder);
 488         if(!ret)
 489                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 490
 491         return ret;
 492 }
 493
 494 FLAC__bool FLAC__seekable_stream_decoder_process_remaining_frames(FLAC__SeekableStreamDecoder *decoder)
 495 {
 496         FLAC__bool ret;
 497         FLAC__ASSERT(decoder != 0);
 498
 499         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 500                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 501
 502         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 503                 return true;
 504
 505         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 506
 507         ret = FLAC__stream_decoder_process_remaining_frames(decoder->private_->stream_decoder);
 508         if(!ret)
 509                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 510
 511         return ret;
 512 }
 513
 514 FLAC__bool FLAC__seekable_stream_decoder_seek_absolute(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 sample)
 515 {
 516         FLAC__uint64 length;
 517
 518         FLAC__ASSERT(decoder != 0);
 519         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK || decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM);
 520
 521         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEKING;
 522
 523         /* turn off md5 checking if a seek is attempted */
 524         decoder->protected_->md5_checking = false;
 525
 526         if(!FLAC__stream_decoder_reset(decoder->private_->stream_decoder)) {
 527                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 528                 return false;
 529         }
 530         /* get the file length */
 531         if(decoder->private_->length_callback(decoder, &length, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK) {
 532                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 533                 return false;
 534         }
 535         /* rewind */
 536         if(decoder->private_->seek_callback(decoder, 0, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) {
 537                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 538                 return false;
 539         }
 540         if(!FLAC__stream_decoder_process_metadata(decoder->private_->stream_decoder)) {
 541                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 542                 return false;
 543         }
 544         if(sample > decoder->private_->stream_info.total_samples) {
 545                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 546                 return false;
 547         }
 548
 549         return seek_to_absolute_sample_(decoder, length, sample);
 550 }
 551
 552 /***********************************************************************
 553  *
 554  * Private class methods
 555  *
 556  ***********************************************************************/
 557
 558 FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data)
 559 {
 560         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 561         (void)decoder;
 562         if(seekable_stream_decoder->private_->eof_callback(seekable_stream_decoder, seekable_stream_decoder->private_->client_data)) {
 563                 seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 564                 return FLAC__STREAM_DECODER_READ_END_OF_STREAM;
 565         }
 566         else if(*bytes > 0) {
 567                 unsigned bytes_read = *bytes;
 568                 if(seekable_stream_decoder->private_->read_callback(seekable_stream_decoder, buffer, &bytes_read, seekable_stream_decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_READ_STATUS_OK) {
 569                         seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR;
 570                         return FLAC__STREAM_DECODER_READ_ABORT;
 571                 }
 572                 if(bytes_read == 0) {
 573                         if(seekable_stream_decoder->private_->eof_callback(seekable_stream_decoder, seekable_stream_decoder->private_->client_data)) {
 574                                 seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 575                                 return FLAC__STREAM_DECODER_READ_END_OF_STREAM;
 576                         }
 577                         else
 578                                 return FLAC__STREAM_DECODER_READ_CONTINUE;
 579                 }
 580                 else {
 581                         *bytes = bytes_read;
 582                         return FLAC__STREAM_DECODER_READ_CONTINUE;
 583                 }
 584         }
 585         else
 586                 return FLAC__STREAM_DECODER_READ_ABORT; /* abort to avoid a deadlock */
 587 }
 588
 589 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data)
 590 {
 591         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 592         (void)decoder;
 593
 594         if(seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_SEEKING) {
 595                 FLAC__uint64 this_frame_sample = frame->header.number.sample_number;
 596                 FLAC__uint64 next_frame_sample = this_frame_sample + (FLAC__uint64)frame->header.blocksize;
 597                 FLAC__uint64 target_sample = seekable_stream_decoder->private_->target_sample;
 598
 599                 FLAC__ASSERT(frame->header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
 600
 601                 seekable_stream_decoder->private_->last_frame = *frame; /* save the frame */
 602                 if(this_frame_sample <= target_sample && target_sample < next_frame_sample) { /* we hit our target frame */
 603                         unsigned delta = (unsigned)(target_sample - this_frame_sample);
 604                         /* kick out of seek mode */
 605                         seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_OK;
 606                         /* shift out the samples before target_sample */
 607                         if(delta > 0) {
 608                                 unsigned channel;
 609                                 const FLAC__int32 *newbuffer[FLAC__MAX_CHANNELS];
 610                                 for(channel = 0; channel < frame->header.channels; channel++)
 611                                         newbuffer[channel] = buffer[channel] + delta;
 612                                 seekable_stream_decoder->private_->last_frame.header.blocksize -= delta;
 613                                 seekable_stream_decoder->private_->last_frame.header.number.sample_number += (FLAC__uint64)delta;
 614                                 /* write the relevant samples */
 615                                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, &seekable_stream_decoder->private_->last_frame, newbuffer, seekable_stream_decoder->private_->client_data);
 616                         }
 617                         else {
 618                                 /* write the relevant samples */
 619                                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, frame, buffer, seekable_stream_decoder->private_->client_data);
 620                         }
 621                 }
 622                 else {
 623                         return FLAC__STREAM_DECODER_WRITE_CONTINUE;
 624                 }
 625         }
 626         else {
 627                 if(seekable_stream_decoder->protected_->md5_checking) {
 628                         if(!FLAC__MD5Accumulate(&seekable_stream_decoder->private_->md5context, buffer, frame->header.channels, frame->header.blocksize, (frame->header.bits_per_sample+7) / 8))
 629                                 return FLAC__STREAM_DECODER_WRITE_ABORT;
 630                 }
 631                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, frame, buffer, seekable_stream_decoder->private_->client_data);
 632         }
 633 }
 634
 635 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data)
 636 {
 637         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 638         (void)decoder;
 639
 640         if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO) {
 641                 seekable_stream_decoder->private_->stream_info = metadata->data.stream_info;
 642                 /* save the MD5 signature for comparison later */
 643                 memcpy(seekable_stream_decoder->private_->stored_md5sum, metadata->data.stream_info.md5sum, 16);
 644                 if(0 == memcmp(seekable_stream_decoder->private_->stored_md5sum, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", 16))
 645                         seekable_stream_decoder->protected_->md5_checking = false;
 646         }
 647         else if(metadata->type == FLAC__METADATA_TYPE_SEEKTABLE) {
 648                 seekable_stream_decoder->private_->seek_table = &metadata->data.seek_table;
 649         }
 650
 651         if(seekable_stream_decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING)
 652                 seekable_stream_decoder->private_->metadata_callback(seekable_stream_decoder, metadata, seekable_stream_decoder->private_->client_data);
 653 }
 654
 655 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 656 {
 657         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 658         (void)decoder;
 659
 660         if(seekable_stream_decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING)
 661                 seekable_stream_decoder->private_->error_callback(seekable_stream_decoder, status, seekable_stream_decoder->private_->client_data);
 662 }
 663
 664 FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample)
 665 {
 666         FLAC__uint64 first_frame_offset, lower_bound, upper_bound;
 667         FLAC__int64 pos = -1, last_pos = -1;
 668         int i, lower_seek_point = -1, upper_seek_point = -1;
 669         unsigned approx_bytes_per_frame;
 670         FLAC__uint64 last_frame_sample = 0xffffffffffffffff;
 671         FLAC__bool needs_seek;
 672         const FLAC__bool is_variable_blocksize_stream = (decoder->private_->stream_info.min_blocksize != decoder->private_->stream_info.max_blocksize);
 673
 674         /* we are just guessing here, but we want to guess high, not low */
 675         if(decoder->private_->stream_info.max_framesize > 0) {
 676                 approx_bytes_per_frame = decoder->private_->stream_info.max_framesize;
 677         }
 678         else if(!is_variable_blocksize_stream) {
 679                 /* note there are no () around 'decoder->private_->stream_info.bits_per_sample/8' to keep precision up since it's an integer calulation */
 680                 approx_bytes_per_frame = decoder->private_->stream_info.min_blocksize * decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample/8 + 64;
 681         }
 682         else
 683                 approx_bytes_per_frame = 1152 * decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample/8 + 64;
 684
 685         /*
 686          * The stream position is currently at the first frame plus any read
 687          * ahead data, so first we get the stream position, then subtract
 688          * uncomsumed bytes to get the position of the first frame in the
 689          * stream.
 690          */
 691         if(decoder->private_->tell_callback(decoder, &first_frame_offset, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
 692                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 693                 return false;
 694         }
 695         FLAC__ASSERT(first_frame_offset >= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder));
 696         first_frame_offset -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
 697
 698         /*
 699          * First, we set an upper and lower bound on where in the
 700          * stream we will search.  For now we assume the worst case
 701          * scenario, which is our best guess at the beginning of
 702          * the first and last frames.
 703          */
 704         lower_bound = first_frame_offset;
 705
 706         /* calc the upper_bound, beyond which we never want to seek */
 707         if(decoder->private_->stream_info.max_framesize > 0)
 708                 upper_bound = stream_length - (decoder->private_->stream_info.max_framesize + 128 + 2); /* 128 for a possible ID3V1 tag, 2 for indexing differences */
 709         else
 710                 upper_bound = stream_length - ((decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample * FLAC__MAX_BLOCK_SIZE) / 8 + 128 + 2);
 711
 712         /*
 713          * Now we refine the bounds if we have a seektable with
 714          * suitable points.  Note that according to the spec they
 715          * must be ordered by ascending sample number.
 716          */
 717         if(0 != decoder->private_->seek_table) {
 718                 /* find the closest seek point <= target_sample, if it exists */
 719                 for(i = (int)decoder->private_->seek_table->num_points - 1; i >= 0; i--) {
 720                         if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number <= target_sample)
 721                                 break;
 722                 }
 723                 if(i >= 0) { /* i.e. we found a suitable seek point... */
 724                         lower_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
 725                         lower_seek_point = i;
 726                 }
 727
 728                 /* find the closest seek point > target_sample, if it exists */
 729                 for(i = 0; i < (int)decoder->private_->seek_table->num_points; i++) {
 730                         if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number > target_sample)
 731                                 break;
 732                 }
 733                 if(i < (int)decoder->private_->seek_table->num_points) { /* i.e. we found a suitable seek point... */
 734                         upper_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
 735                         upper_seek_point = i;
 736                 }
 737         }
 738
 739         /*
 740          * Now guess at where within those bounds our target
 741          * sample will be.
 742          */
 743         if(lower_seek_point >= 0) {
 744                 /* first see if our sample is within a few frames of the lower seekpoint */
 745                 if(decoder->private_->seek_table->points[lower_seek_point].sample_number <= target_sample && target_sample < decoder->private_->seek_table->points[lower_seek_point].sample_number + (decoder->private_->seek_table->points[lower_seek_point].frame_samples * 4)) {
 746                         pos = (FLAC__int64)lower_bound;
 747                 }
 748                 else if(upper_seek_point >= 0) {
 749                         const FLAC__uint64 target_offset = target_sample - decoder->private_->seek_table->points[lower_seek_point].sample_number;
 750                         const FLAC__uint64 range_samples = decoder->private_->seek_table->points[upper_seek_point].sample_number - decoder->private_->seek_table->points[lower_seek_point].sample_number;
 751                         const FLAC__uint64 range_bytes = upper_bound - lower_bound;
 752 #if defined _MSC_VER || defined __MINGW32__
 753                         /* with VC++ you have to spoon feed it the casting */
 754                         pos = (FLAC__int64)lower_bound + (FLAC__int64)((double)(FLAC__int64)target_offset / (double)(FLAC__int64)range_samples * (double)(FLAC__int64)(range_bytes-1)) - approx_bytes_per_frame;
 755 #else
 756                         pos = (FLAC__int64)lower_bound + (FLAC__int64)((double)target_offset / (double)range_samples * (double)(range_bytes-1)) - approx_bytes_per_frame;
 757 #endif
 758                 }
 759         }
 760         if(pos < 0) {
 761                 /* We need to use the metadata and the filelength to estimate the position of the frame with the correct sample */
 762 #if defined _MSC_VER || defined __MINGW32__
 763                 /* with VC++ you have to spoon feed it the casting */
 764                 pos = (FLAC__int64)first_frame_offset + (FLAC__int64)((double)(FLAC__int64)target_sample / (double)(FLAC__int64)decoder->private_->stream_info.total_samples * (double)(FLAC__int64)(stream_length-first_frame_offset-1)) - approx_bytes_per_frame;
 765 #else
 766                 pos = (FLAC__int64)first_frame_offset + (FLAC__int64)((double)target_sample / (double)decoder->private_->stream_info.total_samples * (double)(stream_length-first_frame_offset-1)) - approx_bytes_per_frame;
 767 #endif
 768         }
 769
 770         /* clip the position to the bounds, lower bound takes precedence */
 771         if(pos >= (FLAC__int64)upper_bound)
 772                 pos = (FLAC__int64)upper_bound-1;
 773         if(pos < (FLAC__int64)lower_bound)
 774                 pos = (FLAC__int64)lower_bound;
 775         needs_seek = true;
 776
 777         decoder->private_->target_sample = target_sample;
 778         while(1) {
 779                 if(needs_seek) {
 780                         if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) {
 781                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 782                                 return false;
 783                         }
 784                         if(!FLAC__stream_decoder_flush(decoder->private_->stream_decoder)) {
 785                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 786                                 return false;
 787                         }
 788                 }
 789                 if(!FLAC__stream_decoder_process_one_frame(decoder->private_->stream_decoder)) {
 790                         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 791                         return false;
 792                 }
 793                 /* our write callback will change the state when it gets to the target frame */
 794                 if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING) {
 795                         break;
 796                 }
 797                 else { /* we need to narrow the search */
 798                         FLAC__uint64 this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
 799                         FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
 800                         if(this_frame_sample == last_frame_sample) {
 801                                 /* our last move backwards wasn't big enough */
 802                                 pos -= (last_pos - pos);
 803                                 needs_seek = true;
 804                         }
 805                         else {
 806                                 if(target_sample < this_frame_sample) {
 807                                         last_pos = pos;
 808                                         approx_bytes_per_frame = decoder->private_->last_frame.header.blocksize * decoder->private_->last_frame.header.channels * decoder->private_->last_frame.header.bits_per_sample/8 + 64;
 809                                         pos -= approx_bytes_per_frame;
 810                                         needs_seek = true;
 811                                 }
 812                                 else { /* target_sample >= this_frame_sample + this frame's blocksize */
 813                                         last_pos = pos;
 814                                         if(decoder->private_->tell_callback(decoder, (FLAC__uint64*)(&pos), decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
 815                                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 816                                                 return false;
 817                                         }
 818                                         pos -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
 819                                         needs_seek = false;
 820                                 }
 821                         }
 822                         if(pos < (FLAC__int64)lower_bound)
 823                                 pos = (FLAC__int64)lower_bound;
 824                         last_frame_sample = this_frame_sample;
 825                 }
 826         }
 827
 828         return true;
 829 }