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         decoder->protected_->md5_checking = false;
 156
 157         return decoder;
 158 }
 159
 160 void FLAC__seekable_stream_decoder_delete(FLAC__SeekableStreamDecoder *decoder)
 161 {
 162         FLAC__ASSERT(decoder != 0);
 163         FLAC__ASSERT(decoder->protected_ != 0);
 164         FLAC__ASSERT(decoder->private_ != 0);
 165
 166         if(decoder->private_->stream_decoder != 0)
 167                 FLAC__stream_decoder_delete(decoder->private_->stream_decoder);
 168
 169         free(decoder->private_);
 170         free(decoder->protected_);
 171         free(decoder);
 172 }
 173
 174 /***********************************************************************
 175  *
 176  * Public class methods
 177  *
 178  ***********************************************************************/
 179
 180 FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_init(FLAC__SeekableStreamDecoder *decoder)
 181 {
 182         FLAC__ASSERT(decoder != 0);
 183
 184         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 185                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_ALREADY_INITIALIZED;
 186
 187         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_OK;
 188
 189         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)
 190                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;
 191
 192         if(0 == decoder->private_->write_callback || 0 == decoder->private_->metadata_callback || 0 == decoder->private_->error_callback)
 193                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_INVALID_CALLBACK;
 194
 195         decoder->private_->seek_table = 0;
 196
 197         /* We initialize the MD5Context even though we may never use it.  This is
 198          * because md5_checking may be turned on to start and then turned off if a
 199          * seek occurs.  So we always init the context here and finalize it in
 200          * FLAC__seekable_stream_decoder_finish() to make sure things are always
 201          * cleaned up properly.
 202          */
 203         MD5Init(&decoder->private_->md5context);
 204
 205         FLAC__stream_decoder_set_read_callback(decoder->private_->stream_decoder, read_callback_);
 206         FLAC__stream_decoder_set_write_callback(decoder->private_->stream_decoder, write_callback_);
 207         FLAC__stream_decoder_set_metadata_callback(decoder->private_->stream_decoder, metadata_callback_);
 208         FLAC__stream_decoder_set_error_callback(decoder->private_->stream_decoder, error_callback_);
 209         FLAC__stream_decoder_set_client_data(decoder->private_->stream_decoder, decoder);
 210
 211         if(FLAC__stream_decoder_init(decoder->private_->stream_decoder) != FLAC__STREAM_DECODER_SEARCH_FOR_METADATA)
 212                 return decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 213
 214         return decoder->protected_->state;
 215 }
 216
 217 FLAC__bool FLAC__seekable_stream_decoder_finish(FLAC__SeekableStreamDecoder *decoder)
 218 {
 219         FLAC__bool md5_failed = false;
 220
 221         FLAC__ASSERT(decoder != 0);
 222         FLAC__ASSERT(decoder->private_ != 0);
 223         FLAC__ASSERT(decoder->protected_ != 0);
 224
 225         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 226                 return true;
 227
 228         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 229
 230         /* see the comment in FLAC__seekable_stream_decoder_init() as to why we
 231          * always call MD5Final()
 232          */
 233         MD5Final(decoder->private_->computed_md5sum, &decoder->private_->md5context);
 234
 235         FLAC__stream_decoder_finish(decoder->private_->stream_decoder);
 236
 237         if(decoder->protected_->md5_checking) {
 238                 if(memcmp(decoder->private_->stored_md5sum, decoder->private_->computed_md5sum, 16))
 239                         md5_failed = true;
 240         }
 241
 242         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED;
 243
 244         return !md5_failed;
 245 }
 246
 247 FLAC__bool FLAC__seekable_stream_decoder_set_md5_checking(FLAC__SeekableStreamDecoder *decoder, FLAC__bool value)
 248 {
 249         FLAC__ASSERT(decoder != 0);
 250         FLAC__ASSERT(decoder->protected_ != 0);
 251         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 252                 return false;
 253         decoder->protected_->md5_checking = value;
 254         return true;
 255 }
 256
 257 FLAC__bool FLAC__seekable_stream_decoder_set_read_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderReadStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data))
 258 {
 259         FLAC__ASSERT(decoder != 0);
 260         FLAC__ASSERT(decoder->private_ != 0);
 261         FLAC__ASSERT(decoder->protected_ != 0);
 262         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 263                 return false;
 264         decoder->private_->read_callback = value;
 265         return true;
 266 }
 267
 268 FLAC__bool FLAC__seekable_stream_decoder_set_seek_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderSeekStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 absolute_byte_offset, void *client_data))
 269 {
 270         FLAC__ASSERT(decoder != 0);
 271         FLAC__ASSERT(decoder->private_ != 0);
 272         FLAC__ASSERT(decoder->protected_ != 0);
 273         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 274                 return false;
 275         decoder->private_->seek_callback = value;
 276         return true;
 277 }
 278
 279 FLAC__bool FLAC__seekable_stream_decoder_set_tell_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderTellStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *absolute_byte_offset, void *client_data))
 280 {
 281         FLAC__ASSERT(decoder != 0);
 282         FLAC__ASSERT(decoder->private_ != 0);
 283         FLAC__ASSERT(decoder->protected_ != 0);
 284         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 285                 return false;
 286         decoder->private_->tell_callback = value;
 287         return true;
 288 }
 289
 290 FLAC__bool FLAC__seekable_stream_decoder_set_length_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__SeekableStreamDecoderLengthStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 *stream_length, void *client_data))
 291 {
 292         FLAC__ASSERT(decoder != 0);
 293         FLAC__ASSERT(decoder->private_ != 0);
 294         FLAC__ASSERT(decoder->protected_ != 0);
 295         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 296                 return false;
 297         decoder->private_->length_callback = value;
 298         return true;
 299 }
 300
 301 FLAC__bool FLAC__seekable_stream_decoder_set_eof_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__bool (*value)(const FLAC__SeekableStreamDecoder *decoder, void *client_data))
 302 {
 303         FLAC__ASSERT(decoder != 0);
 304         FLAC__ASSERT(decoder->private_ != 0);
 305         FLAC__ASSERT(decoder->protected_ != 0);
 306         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 307                 return false;
 308         decoder->private_->eof_callback = value;
 309         return true;
 310 }
 311
 312 FLAC__bool FLAC__seekable_stream_decoder_set_write_callback(FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderWriteStatus (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data))
 313 {
 314         FLAC__ASSERT(decoder != 0);
 315         FLAC__ASSERT(decoder->private_ != 0);
 316         FLAC__ASSERT(decoder->protected_ != 0);
 317         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 318                 return false;
 319         decoder->private_->write_callback = value;
 320         return true;
 321 }
 322
 323 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_callback(FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data))
 324 {
 325         FLAC__ASSERT(decoder != 0);
 326         FLAC__ASSERT(decoder->private_ != 0);
 327         FLAC__ASSERT(decoder->protected_ != 0);
 328         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 329                 return false;
 330         decoder->private_->metadata_callback = value;
 331         return true;
 332 }
 333
 334 FLAC__bool FLAC__seekable_stream_decoder_set_error_callback(FLAC__SeekableStreamDecoder *decoder, void (*value)(const FLAC__SeekableStreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data))
 335 {
 336         FLAC__ASSERT(decoder != 0);
 337         FLAC__ASSERT(decoder->private_ != 0);
 338         FLAC__ASSERT(decoder->protected_ != 0);
 339         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 340                 return false;
 341         decoder->private_->error_callback = value;
 342         return true;
 343 }
 344
 345 FLAC__bool FLAC__seekable_stream_decoder_set_client_data(FLAC__SeekableStreamDecoder *decoder, void *value)
 346 {
 347         FLAC__ASSERT(decoder != 0);
 348         FLAC__ASSERT(decoder->private_ != 0);
 349         FLAC__ASSERT(decoder->protected_ != 0);
 350         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 351                 return false;
 352         decoder->private_->client_data = value;
 353         return true;
 354 }
 355
 356 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond(FLAC__SeekableStreamDecoder *decoder, FLAC__MetaDataType type)
 357 {
 358         FLAC__ASSERT(decoder != 0);
 359         FLAC__ASSERT(decoder->private_ != 0);
 360         FLAC__ASSERT(decoder->protected_ != 0);
 361         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 362         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 363                 return false;
 364         return FLAC__stream_decoder_set_metadata_respond(decoder->private_->stream_decoder, type);
 365 }
 366
 367 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_application(FLAC__SeekableStreamDecoder *decoder, const FLAC__byte id[4])
 368 {
 369         FLAC__ASSERT(decoder != 0);
 370         FLAC__ASSERT(decoder->private_ != 0);
 371         FLAC__ASSERT(decoder->protected_ != 0);
 372         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 373         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 374                 return false;
 375         return FLAC__stream_decoder_set_metadata_respond_application(decoder->private_->stream_decoder, id);
 376 }
 377
 378 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_respond_all(FLAC__SeekableStreamDecoder *decoder)
 379 {
 380         FLAC__ASSERT(decoder != 0);
 381         FLAC__ASSERT(decoder->private_ != 0);
 382         FLAC__ASSERT(decoder->protected_ != 0);
 383         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 384         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 385                 return false;
 386         return FLAC__stream_decoder_set_metadata_respond_all(decoder->private_->stream_decoder);
 387 }
 388
 389 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore(FLAC__SeekableStreamDecoder *decoder, FLAC__MetaDataType type)
 390 {
 391         FLAC__ASSERT(decoder != 0);
 392         FLAC__ASSERT(decoder->private_ != 0);
 393         FLAC__ASSERT(decoder->protected_ != 0);
 394         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 395         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 396                 return false;
 397         return FLAC__stream_decoder_set_metadata_ignore(decoder->private_->stream_decoder, type);
 398 }
 399
 400 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_application(FLAC__SeekableStreamDecoder *decoder, const FLAC__byte id[4])
 401 {
 402         FLAC__ASSERT(decoder != 0);
 403         FLAC__ASSERT(decoder->private_ != 0);
 404         FLAC__ASSERT(decoder->protected_ != 0);
 405         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 406         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 407                 return false;
 408         return FLAC__stream_decoder_set_metadata_ignore_application(decoder->private_->stream_decoder, id);
 409 }
 410
 411 FLAC__bool FLAC__seekable_stream_decoder_set_metadata_ignore_all(FLAC__SeekableStreamDecoder *decoder)
 412 {
 413         FLAC__ASSERT(decoder != 0);
 414         FLAC__ASSERT(decoder->private_ != 0);
 415         FLAC__ASSERT(decoder->protected_ != 0);
 416         FLAC__ASSERT(decoder->private_->stream_decoder != 0);
 417         if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_UNINITIALIZED)
 418                 return false;
 419         return FLAC__stream_decoder_set_metadata_ignore_all(decoder->private_->stream_decoder);
 420 }
 421
 422 FLAC__SeekableStreamDecoderState FLAC__seekable_stream_decoder_get_state(const FLAC__SeekableStreamDecoder *decoder)
 423 {
 424         FLAC__ASSERT(decoder != 0);
 425         FLAC__ASSERT(decoder->protected_ != 0);
 426         return decoder->protected_->state;
 427 }
 428
 429 FLAC__bool FLAC__seekable_stream_decoder_get_md5_checking(const FLAC__SeekableStreamDecoder *decoder)
 430 {
 431         FLAC__ASSERT(decoder != 0);
 432         FLAC__ASSERT(decoder->protected_ != 0);
 433         return decoder->protected_->md5_checking;
 434 }
 435
 436 FLAC__bool FLAC__seekable_stream_decoder_process_whole_stream(FLAC__SeekableStreamDecoder *decoder)
 437 {
 438         FLAC__bool ret;
 439         FLAC__ASSERT(decoder != 0);
 440
 441         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 442                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 443
 444         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 445                 return true;
 446
 447         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 448
 449         ret = FLAC__stream_decoder_process_whole_stream(decoder->private_->stream_decoder);
 450         if(!ret)
 451                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 452
 453         return ret;
 454 }
 455
 456 FLAC__bool FLAC__seekable_stream_decoder_process_metadata(FLAC__SeekableStreamDecoder *decoder)
 457 {
 458         FLAC__bool ret;
 459         FLAC__ASSERT(decoder != 0);
 460
 461         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 462                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 463
 464         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 465                 return true;
 466
 467         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 468
 469         ret = FLAC__stream_decoder_process_metadata(decoder->private_->stream_decoder);
 470         if(!ret)
 471                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 472
 473         return ret;
 474 }
 475
 476 FLAC__bool FLAC__seekable_stream_decoder_process_one_frame(FLAC__SeekableStreamDecoder *decoder)
 477 {
 478         FLAC__bool ret;
 479         FLAC__ASSERT(decoder != 0);
 480
 481         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 482                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 483
 484         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 485                 return true;
 486
 487         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 488
 489         ret = FLAC__stream_decoder_process_one_frame(decoder->private_->stream_decoder);
 490         if(!ret)
 491                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 492
 493         return ret;
 494 }
 495
 496 FLAC__bool FLAC__seekable_stream_decoder_process_remaining_frames(FLAC__SeekableStreamDecoder *decoder)
 497 {
 498         FLAC__bool ret;
 499         FLAC__ASSERT(decoder != 0);
 500
 501         if(decoder->private_->stream_decoder->protected_->state == FLAC__STREAM_DECODER_END_OF_STREAM)
 502                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 503
 504         if(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM)
 505                 return true;
 506
 507         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK);
 508
 509         ret = FLAC__stream_decoder_process_remaining_frames(decoder->private_->stream_decoder);
 510         if(!ret)
 511                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 512
 513         return ret;
 514 }
 515
 516 FLAC__bool FLAC__seekable_stream_decoder_seek_absolute(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 sample)
 517 {
 518         FLAC__uint64 length;
 519
 520         FLAC__ASSERT(decoder != 0);
 521         FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK || decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM);
 522
 523         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEKING;
 524
 525         /* turn off md5 checking if a seek is attempted */
 526         decoder->protected_->md5_checking = false;
 527
 528         if(!FLAC__stream_decoder_reset(decoder->private_->stream_decoder)) {
 529                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 530                 return false;
 531         }
 532         /* get the file length */
 533         if(decoder->private_->length_callback(decoder, &length, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_LENGTH_STATUS_OK) {
 534                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 535                 return false;
 536         }
 537         /* rewind */
 538         if(decoder->private_->seek_callback(decoder, 0, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) {
 539                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 540                 return false;
 541         }
 542         if(!FLAC__stream_decoder_process_metadata(decoder->private_->stream_decoder)) {
 543                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 544                 return false;
 545         }
 546         if(sample > decoder->private_->stream_info.total_samples) {
 547                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 548                 return false;
 549         }
 550
 551         return seek_to_absolute_sample_(decoder, length, sample);
 552 }
 553
 554 /***********************************************************************
 555  *
 556  * Private class methods
 557  *
 558  ***********************************************************************/
 559
 560 FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data)
 561 {
 562         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 563         (void)decoder;
 564         if(seekable_stream_decoder->private_->eof_callback(seekable_stream_decoder, seekable_stream_decoder->private_->client_data)) {
 565                 seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 566                 return FLAC__STREAM_DECODER_READ_END_OF_STREAM;
 567         }
 568         else if(*bytes > 0) {
 569                 unsigned bytes_read = *bytes;
 570                 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) {
 571                         seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_READ_ERROR;
 572                         return FLAC__STREAM_DECODER_READ_ABORT;
 573                 }
 574                 if(bytes_read == 0) {
 575                         if(seekable_stream_decoder->private_->eof_callback(seekable_stream_decoder, seekable_stream_decoder->private_->client_data)) {
 576                                 seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM;
 577                                 return FLAC__STREAM_DECODER_READ_END_OF_STREAM;
 578                         }
 579                         else
 580                                 return FLAC__STREAM_DECODER_READ_CONTINUE;
 581                 }
 582                 else {
 583                         *bytes = bytes_read;
 584                         return FLAC__STREAM_DECODER_READ_CONTINUE;
 585                 }
 586         }
 587         else
 588                 return FLAC__STREAM_DECODER_READ_ABORT; /* abort to avoid a deadlock */
 589 }
 590
 591 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 *buffer[], void *client_data)
 592 {
 593         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 594         (void)decoder;
 595
 596         if(seekable_stream_decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_SEEKING) {
 597                 FLAC__uint64 this_frame_sample = frame->header.number.sample_number;
 598                 FLAC__uint64 next_frame_sample = this_frame_sample + (FLAC__uint64)frame->header.blocksize;
 599                 FLAC__uint64 target_sample = seekable_stream_decoder->private_->target_sample;
 600
 601                 FLAC__ASSERT(frame->header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
 602
 603                 seekable_stream_decoder->private_->last_frame = *frame; /* save the frame */
 604                 if(this_frame_sample <= target_sample && target_sample < next_frame_sample) { /* we hit our target frame */
 605                         unsigned delta = (unsigned)(target_sample - this_frame_sample);
 606                         /* kick out of seek mode */
 607                         seekable_stream_decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_OK;
 608                         /* shift out the samples before target_sample */
 609                         if(delta > 0) {
 610                                 unsigned channel;
 611                                 const FLAC__int32 *newbuffer[FLAC__MAX_CHANNELS];
 612                                 for(channel = 0; channel < frame->header.channels; channel++)
 613                                         newbuffer[channel] = buffer[channel] + delta;
 614                                 seekable_stream_decoder->private_->last_frame.header.blocksize -= delta;
 615                                 seekable_stream_decoder->private_->last_frame.header.number.sample_number += (FLAC__uint64)delta;
 616                                 /* write the relevant samples */
 617                                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, &seekable_stream_decoder->private_->last_frame, newbuffer, seekable_stream_decoder->private_->client_data);
 618                         }
 619                         else {
 620                                 /* write the relevant samples */
 621                                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, frame, buffer, seekable_stream_decoder->private_->client_data);
 622                         }
 623                 }
 624                 else {
 625                         return FLAC__STREAM_DECODER_WRITE_CONTINUE;
 626                 }
 627         }
 628         else {
 629                 if(seekable_stream_decoder->protected_->md5_checking) {
 630                         if(!FLAC__MD5Accumulate(&seekable_stream_decoder->private_->md5context, buffer, frame->header.channels, frame->header.blocksize, (frame->header.bits_per_sample+7) / 8))
 631                                 return FLAC__STREAM_DECODER_WRITE_ABORT;
 632                 }
 633                 return seekable_stream_decoder->private_->write_callback(seekable_stream_decoder, frame, buffer, seekable_stream_decoder->private_->client_data);
 634         }
 635 }
 636
 637 void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetaData *metadata, void *client_data)
 638 {
 639         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 640         (void)decoder;
 641
 642         if(metadata->type == FLAC__METADATA_TYPE_STREAMINFO) {
 643                 seekable_stream_decoder->private_->stream_info = metadata->data.stream_info;
 644                 /* save the MD5 signature for comparison later */
 645                 memcpy(seekable_stream_decoder->private_->stored_md5sum, metadata->data.stream_info.md5sum, 16);
 646                 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))
 647                         seekable_stream_decoder->protected_->md5_checking = false;
 648         }
 649         else if(metadata->type == FLAC__METADATA_TYPE_SEEKTABLE) {
 650                 seekable_stream_decoder->private_->seek_table = &metadata->data.seek_table;
 651         }
 652
 653         if(seekable_stream_decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING)
 654                 seekable_stream_decoder->private_->metadata_callback(seekable_stream_decoder, metadata, seekable_stream_decoder->private_->client_data);
 655 }
 656
 657 void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data)
 658 {
 659         FLAC__SeekableStreamDecoder *seekable_stream_decoder = (FLAC__SeekableStreamDecoder *)client_data;
 660         (void)decoder;
 661
 662         if(seekable_stream_decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING)
 663                 seekable_stream_decoder->private_->error_callback(seekable_stream_decoder, status, seekable_stream_decoder->private_->client_data);
 664 }
 665
 666 FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__uint64 stream_length, FLAC__uint64 target_sample)
 667 {
 668         FLAC__uint64 first_frame_offset, lower_bound, upper_bound;
 669         FLAC__int64 pos = -1, last_pos = -1;
 670         int i, lower_seek_point = -1, upper_seek_point = -1;
 671         unsigned approx_bytes_per_frame;
 672         FLAC__uint64 last_frame_sample = 0xffffffffffffffff;
 673         FLAC__bool needs_seek;
 674         const FLAC__bool is_variable_blocksize_stream = (decoder->private_->stream_info.min_blocksize != decoder->private_->stream_info.max_blocksize);
 675
 676         /* we are just guessing here, but we want to guess high, not low */
 677         if(decoder->private_->stream_info.max_framesize > 0) {
 678                 approx_bytes_per_frame = decoder->private_->stream_info.max_framesize;
 679         }
 680         else if(!is_variable_blocksize_stream) {
 681                 /* note there are no () around 'decoder->private_->stream_info.bits_per_sample/8' to keep precision up since it's an integer calulation */
 682                 approx_bytes_per_frame = decoder->private_->stream_info.min_blocksize * decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample/8 + 64;
 683         }
 684         else
 685                 approx_bytes_per_frame = 1152 * decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample/8 + 64;
 686
 687         /*
 688          * The stream position is currently at the first frame plus any read
 689          * ahead data, so first we get the stream position, then subtract
 690          * uncomsumed bytes to get the position of the first frame in the
 691          * stream.
 692          */
 693         if(decoder->private_->tell_callback(decoder, &first_frame_offset, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
 694                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 695                 return false;
 696         }
 697         FLAC__ASSERT(first_frame_offset >= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder));
 698         first_frame_offset -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
 699
 700         /*
 701          * First, we set an upper and lower bound on where in the
 702          * stream we will search.  For now we assume the worst case
 703          * scenario, which is our best guess at the beginning of
 704          * the first and last frames.
 705          */
 706         lower_bound = first_frame_offset;
 707
 708         /* calc the upper_bound, beyond which we never want to seek */
 709         if(decoder->private_->stream_info.max_framesize > 0)
 710                 upper_bound = stream_length - (decoder->private_->stream_info.max_framesize + 128 + 2); /* 128 for a possible ID3V1 tag, 2 for indexing differences */
 711         else
 712                 upper_bound = stream_length - ((decoder->private_->stream_info.channels * decoder->private_->stream_info.bits_per_sample * FLAC__MAX_BLOCK_SIZE) / 8 + 128 + 2);
 713
 714         /*
 715          * Now we refine the bounds if we have a seektable with
 716          * suitable points.  Note that according to the spec they
 717          * must be ordered by ascending sample number.
 718          */
 719         if(0 != decoder->private_->seek_table) {
 720                 /* find the closest seek point <= target_sample, if it exists */
 721                 for(i = (int)decoder->private_->seek_table->num_points - 1; i >= 0; i--) {
 722                         if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number <= target_sample)
 723                                 break;
 724                 }
 725                 if(i >= 0) { /* i.e. we found a suitable seek point... */
 726                         lower_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
 727                         lower_seek_point = i;
 728                 }
 729
 730                 /* find the closest seek point > target_sample, if it exists */
 731                 for(i = 0; i < (int)decoder->private_->seek_table->num_points; i++) {
 732                         if(decoder->private_->seek_table->points[i].sample_number != FLAC__STREAM_METADATA_SEEKPOINT_PLACEHOLDER && decoder->private_->seek_table->points[i].sample_number > target_sample)
 733                                 break;
 734                 }
 735                 if(i < (int)decoder->private_->seek_table->num_points) { /* i.e. we found a suitable seek point... */
 736                         upper_bound = first_frame_offset + decoder->private_->seek_table->points[i].stream_offset;
 737                         upper_seek_point = i;
 738                 }
 739         }
 740
 741         /*
 742          * Now guess at where within those bounds our target
 743          * sample will be.
 744          */
 745         if(lower_seek_point >= 0) {
 746                 /* first see if our sample is within a few frames of the lower seekpoint */
 747                 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)) {
 748                         pos = (FLAC__int64)lower_bound;
 749                 }
 750                 else if(upper_seek_point >= 0) {
 751                         const FLAC__uint64 target_offset = target_sample - decoder->private_->seek_table->points[lower_seek_point].sample_number;
 752                         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;
 753                         const FLAC__uint64 range_bytes = upper_bound - lower_bound;
 754 #if defined _MSC_VER || defined __MINGW32__
 755                         /* with VC++ you have to spoon feed it the casting */
 756                         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;
 757 #else
 758                         pos = (FLAC__int64)lower_bound + (FLAC__int64)((double)target_offset / (double)range_samples * (double)(range_bytes-1)) - approx_bytes_per_frame;
 759 #endif
 760                 }
 761         }
 762         if(pos < 0) {
 763                 /* We need to use the metadata and the filelength to estimate the position of the frame with the correct sample */
 764 #if defined _MSC_VER || defined __MINGW32__
 765                 /* with VC++ you have to spoon feed it the casting */
 766                 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;
 767 #else
 768                 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;
 769 #endif
 770         }
 771
 772         /* clip the position to the bounds, lower bound takes precedence */
 773         if(pos >= (FLAC__int64)upper_bound)
 774                 pos = (FLAC__int64)upper_bound-1;
 775         if(pos < (FLAC__int64)lower_bound)
 776                 pos = (FLAC__int64)lower_bound;
 777         needs_seek = true;
 778
 779         decoder->private_->target_sample = target_sample;
 780         while(1) {
 781                 if(needs_seek) {
 782                         if(decoder->private_->seek_callback(decoder, (FLAC__uint64)pos, decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_SEEK_STATUS_OK) {
 783                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 784                                 return false;
 785                         }
 786                         if(!FLAC__stream_decoder_flush(decoder->private_->stream_decoder)) {
 787                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_ERROR;
 788                                 return false;
 789                         }
 790                 }
 791                 if(!FLAC__stream_decoder_process_one_frame(decoder->private_->stream_decoder)) {
 792                         decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 793                         return false;
 794                 }
 795                 /* our write callback will change the state when it gets to the target frame */
 796                 if(decoder->protected_->state != FLAC__SEEKABLE_STREAM_DECODER_SEEKING) {
 797                         break;
 798                 }
 799                 else { /* we need to narrow the search */
 800                         FLAC__uint64 this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
 801                         FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
 802                         if(this_frame_sample == last_frame_sample) {
 803                                 /* our last move backwards wasn't big enough */
 804                                 pos -= (last_pos - pos);
 805                                 needs_seek = true;
 806                         }
 807                         else {
 808                                 if(target_sample < this_frame_sample) {
 809                                         last_pos = pos;
 810                                         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;
 811                                         pos -= approx_bytes_per_frame;
 812                                         needs_seek = true;
 813                                 }
 814                                 else { /* target_sample >= this_frame_sample + this frame's blocksize */
 815                                         last_pos = pos;
 816                                         if(decoder->private_->tell_callback(decoder, (FLAC__uint64*)(&pos), decoder->private_->client_data) != FLAC__SEEKABLE_STREAM_DECODER_TELL_STATUS_OK) {
 817                                                 decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
 818                                                 return false;
 819                                         }
 820                                         pos -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
 821                                         needs_seek = false;
 822                                 }
 823                         }
 824                         if(pos < (FLAC__int64)lower_bound)
 825                                 pos = (FLAC__int64)lower_bound;
 826                         last_frame_sample = this_frame_sample;
 827                 }
 828         }
 829
 830         return true;
 831 }