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