src/libOggFLAC/stream_decoder.c

   1 /* libOggFLAC - Free Lossless Audio Codec + Ogg library
   2  * Copyright (C) 2002,2003  Josh Coalson
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * - Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  * - Redistributions in binary form must reproduce the above copyright
  12  * notice, this list of conditions and the following disclaimer in the
  13  * documentation and/or other materials provided with the distribution.
  14  *
  15  * - Neither the name of the Xiph.org Foundation nor the names of its
  16  * contributors may be used to endorse or promote products derived from
  17  * this software without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  23  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  26  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  27  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  28  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  29  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30  */
  31
  32 #include <stdlib.h> /* for calloc() */
  33 #include <string.h> /* for memset() */
  34 #include <ogg/ogg.h>
  35 #include "FLAC/assert.h"
  36 #include "protected/stream_decoder.h"
  37
  38 #ifdef min
  39 #undef min
  40 #endif
  41 #define min(x,y) ((x)<(y)?(x):(y))
  42
  43 /***********************************************************************
  44  *
  45  * Private class method prototypes
  46  *
  47  ***********************************************************************/
  48
  49 static void set_defaults_(OggFLAC__StreamDecoder *decoder);
  50 static FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *decoder, FLAC__byte buffer[], unsigned *bytes, void *client_data);
  51 static FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *decoder, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data);
  52 static void metadata_callback_(const FLAC__StreamDecoder *decoder, const FLAC__StreamMetadata *metadata, void *client_data);
  53 static void error_callback_(const FLAC__StreamDecoder *decoder, FLAC__StreamDecoderErrorStatus status, void *client_data);
  54
  55
  56 /***********************************************************************
  57  *
  58  * Private class data
  59  *
  60  ***********************************************************************/
  61
  62 typedef struct OggFLAC__StreamDecoderPrivate {
  63         OggFLAC__StreamDecoderReadCallback read_callback;
  64         OggFLAC__StreamDecoderWriteCallback write_callback;
  65         OggFLAC__StreamDecoderMetadataCallback metadata_callback;
  66         OggFLAC__StreamDecoderErrorCallback error_callback;
  67         void *client_data;
  68         FLAC__StreamDecoder *FLAC_stream_decoder;
  69         struct {
  70                 ogg_stream_state stream_state;
  71                 ogg_sync_state sync_state;
  72                 FLAC__bool need_serial_number;
  73         } ogg;
  74 } OggFLAC__StreamDecoderPrivate;
  75
  76 /***********************************************************************
  77  *
  78  * Public static class data
  79  *
  80  ***********************************************************************/
  81
  82 const OggFLAC_API char * const OggFLAC__StreamDecoderStateString[] = {
  83         "OggFLAC__STREAM_DECODER_OK",
  84         "OggFLAC__STREAM_DECODER_OGG_ERROR",
  85         "OggFLAC__STREAM_DECODER_READ_ERROR",
  86         "OggFLAC__STREAM_DECODER_FLAC_STREAM_DECODER_ERROR",
  87         "OggFLAC__STREAM_DECODER_INVALID_CALLBACK",
  88         "OggFLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR",
  89         "OggFLAC__STREAM_DECODER_ALREADY_INITIALIZED",
  90         "OggFLAC__STREAM_DECODER_UNINITIALIZED"
  91 };
  92
  93
  94 /***********************************************************************
  95  *
  96  * Class constructor/destructor
  97  *
  98  ***********************************************************************/
  99 OggFLAC_API OggFLAC__StreamDecoder *OggFLAC__stream_decoder_new()
 100 {
 101         OggFLAC__StreamDecoder *decoder;
 102
 103         decoder = (OggFLAC__StreamDecoder*)calloc(1, sizeof(OggFLAC__StreamDecoder));
 104         if(decoder == 0) {
 105                 return 0;
 106         }
 107
 108         decoder->protected_ = (OggFLAC__StreamDecoderProtected*)calloc(1, sizeof(OggFLAC__StreamDecoderProtected));
 109         if(decoder->protected_ == 0) {
 110                 free(decoder);
 111                 return 0;
 112         }
 113
 114         decoder->private_ = (OggFLAC__StreamDecoderPrivate*)calloc(1, sizeof(OggFLAC__StreamDecoderPrivate));
 115         if(decoder->private_ == 0) {
 116                 free(decoder->protected_);
 117                 free(decoder);
 118                 return 0;
 119         }
 120
 121         decoder->private_->FLAC_stream_decoder = FLAC__stream_decoder_new();
 122         if(0 == decoder->private_->FLAC_stream_decoder) {
 123                 free(decoder->private_);
 124                 free(decoder->protected_);
 125                 free(decoder);
 126                 return 0;
 127         }
 128
 129         set_defaults_(decoder);
 130
 131         decoder->protected_->state = OggFLAC__STREAM_DECODER_UNINITIALIZED;
 132
 133         return decoder;
 134 }
 135
 136 OggFLAC_API void OggFLAC__stream_decoder_delete(OggFLAC__StreamDecoder *decoder)
 137 {
 138         FLAC__ASSERT(0 != decoder);
 139         FLAC__ASSERT(0 != decoder->protected_);
 140         FLAC__ASSERT(0 != decoder->private_);
 141         FLAC__ASSERT(0 != decoder->private_->FLAC_stream_decoder);
 142
 143         OggFLAC__stream_decoder_finish(decoder);
 144
 145         FLAC__stream_decoder_delete(decoder->private_->FLAC_stream_decoder);
 146
 147         free(decoder->private_);
 148         free(decoder->protected_);
 149         free(decoder);
 150 }
 151
 152 /***********************************************************************
 153  *
 154  * Public class methods
 155  *
 156  ***********************************************************************/
 157
 158 OggFLAC_API OggFLAC__StreamDecoderState OggFLAC__stream_decoder_init(OggFLAC__StreamDecoder *decoder)
 159 {
 160         FLAC__ASSERT(0 != decoder);
 161
 162         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 163                 return decoder->protected_->state = OggFLAC__STREAM_DECODER_ALREADY_INITIALIZED;
 164
 165         if(0 == decoder->private_->read_callback || 0 == decoder->private_->write_callback || 0 == decoder->private_->metadata_callback || 0 == decoder->private_->error_callback)
 166                 return decoder->protected_->state = OggFLAC__STREAM_DECODER_INVALID_CALLBACK;
 167
 168         decoder->private_->ogg.need_serial_number = decoder->protected_->use_first_serial_number;
 169         /* we will determine the serial number later if necessary */
 170         if(ogg_stream_init(&decoder->private_->ogg.stream_state, decoder->protected_->serial_number) != 0)
 171                 return decoder->protected_->state = OggFLAC__STREAM_DECODER_OGG_ERROR;
 172
 173         if(ogg_sync_init(&decoder->private_->ogg.sync_state) != 0)
 174                 return decoder->protected_->state = OggFLAC__STREAM_DECODER_OGG_ERROR;
 175
 176         FLAC__stream_decoder_set_read_callback(decoder->private_->FLAC_stream_decoder, read_callback_);
 177         FLAC__stream_decoder_set_write_callback(decoder->private_->FLAC_stream_decoder, write_callback_);
 178         FLAC__stream_decoder_set_metadata_callback(decoder->private_->FLAC_stream_decoder, metadata_callback_);
 179         FLAC__stream_decoder_set_error_callback(decoder->private_->FLAC_stream_decoder, error_callback_);
 180         FLAC__stream_decoder_set_client_data(decoder->private_->FLAC_stream_decoder, decoder);
 181
 182         if(FLAC__stream_decoder_init(decoder->private_->FLAC_stream_decoder) != FLAC__STREAM_DECODER_SEARCH_FOR_METADATA)
 183                 return decoder->protected_->state = OggFLAC__STREAM_DECODER_FLAC_STREAM_DECODER_ERROR;
 184
 185         return decoder->protected_->state = OggFLAC__STREAM_DECODER_OK;
 186 }
 187
 188 OggFLAC_API void OggFLAC__stream_decoder_finish(OggFLAC__StreamDecoder *decoder)
 189 {
 190         FLAC__ASSERT(0 != decoder);
 191         FLAC__ASSERT(0 != decoder->private_);
 192         FLAC__ASSERT(0 != decoder->protected_);
 193
 194         if(decoder->protected_->state == OggFLAC__STREAM_DECODER_UNINITIALIZED)
 195                 return;
 196
 197         FLAC__ASSERT(0 != decoder->private_->FLAC_stream_decoder);
 198
 199         FLAC__stream_decoder_finish(decoder->private_->FLAC_stream_decoder);
 200
 201         (void)ogg_sync_clear(&decoder->private_->ogg.sync_state);
 202         (void)ogg_stream_clear(&decoder->private_->ogg.stream_state);
 203
 204         set_defaults_(decoder);
 205
 206         decoder->protected_->state = OggFLAC__STREAM_DECODER_UNINITIALIZED;
 207 }
 208
 209 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_read_callback(OggFLAC__StreamDecoder *decoder, OggFLAC__StreamDecoderReadCallback value)
 210 {
 211         FLAC__ASSERT(0 != decoder);
 212         FLAC__ASSERT(0 != decoder->private_);
 213         FLAC__ASSERT(0 != decoder->protected_);
 214         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 215                 return false;
 216         decoder->private_->read_callback = value;
 217         return true;
 218 }
 219
 220 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_write_callback(OggFLAC__StreamDecoder *decoder, OggFLAC__StreamDecoderWriteCallback value)
 221 {
 222         FLAC__ASSERT(0 != decoder);
 223         FLAC__ASSERT(0 != decoder->private_);
 224         FLAC__ASSERT(0 != decoder->protected_);
 225         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 226                 return false;
 227         decoder->private_->write_callback = value;
 228         return true;
 229 }
 230
 231 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_callback(OggFLAC__StreamDecoder *decoder, OggFLAC__StreamDecoderMetadataCallback value)
 232 {
 233         FLAC__ASSERT(0 != decoder);
 234         FLAC__ASSERT(0 != decoder->private_);
 235         FLAC__ASSERT(0 != decoder->protected_);
 236         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 237                 return false;
 238         decoder->private_->metadata_callback = value;
 239         return true;
 240 }
 241
 242 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_error_callback(OggFLAC__StreamDecoder *decoder, OggFLAC__StreamDecoderErrorCallback value)
 243 {
 244         FLAC__ASSERT(0 != decoder);
 245         FLAC__ASSERT(0 != decoder->private_);
 246         FLAC__ASSERT(0 != decoder->protected_);
 247         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 248                 return false;
 249         decoder->private_->error_callback = value;
 250         return true;
 251 }
 252
 253 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_client_data(OggFLAC__StreamDecoder *decoder, void *value)
 254 {
 255         FLAC__ASSERT(0 != decoder);
 256         FLAC__ASSERT(0 != decoder->private_);
 257         FLAC__ASSERT(0 != decoder->protected_);
 258         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 259                 return false;
 260         decoder->private_->client_data = value;
 261         return true;
 262 }
 263
 264 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_serial_number(OggFLAC__StreamDecoder *decoder, long value)
 265 {
 266         FLAC__ASSERT(0 != decoder);
 267         FLAC__ASSERT(0 != decoder->private_);
 268         FLAC__ASSERT(0 != decoder->protected_);
 269         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 270                 return false;
 271         decoder->protected_->use_first_serial_number = false;
 272         decoder->protected_->serial_number = value;
 273         return true;
 274 }
 275
 276 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_respond(OggFLAC__StreamDecoder *decoder, FLAC__MetadataType type)
 277 {
 278         FLAC__ASSERT(0 != decoder);
 279         FLAC__ASSERT(0 != decoder->private_);
 280         FLAC__ASSERT(0 != decoder->protected_);
 281         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 282                 return false;
 283         return FLAC__stream_decoder_set_metadata_respond(decoder->private_->FLAC_stream_decoder, type);
 284 }
 285
 286 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_respond_application(OggFLAC__StreamDecoder *decoder, const FLAC__byte id[4])
 287 {
 288         FLAC__ASSERT(0 != decoder);
 289         FLAC__ASSERT(0 != decoder->private_);
 290         FLAC__ASSERT(0 != decoder->protected_);
 291         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 292                 return false;
 293         return FLAC__stream_decoder_set_metadata_respond_application(decoder->private_->FLAC_stream_decoder, id);
 294 }
 295
 296 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_respond_all(OggFLAC__StreamDecoder *decoder)
 297 {
 298         FLAC__ASSERT(0 != decoder);
 299         FLAC__ASSERT(0 != decoder->private_);
 300         FLAC__ASSERT(0 != decoder->protected_);
 301         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 302                 return false;
 303         return FLAC__stream_decoder_set_metadata_respond_all(decoder->private_->FLAC_stream_decoder);
 304 }
 305
 306 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_ignore(OggFLAC__StreamDecoder *decoder, FLAC__MetadataType type)
 307 {
 308         FLAC__ASSERT(0 != decoder);
 309         FLAC__ASSERT(0 != decoder->private_);
 310         FLAC__ASSERT(0 != decoder->protected_);
 311         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 312                 return false;
 313         return FLAC__stream_decoder_set_metadata_ignore(decoder->private_->FLAC_stream_decoder, type);
 314 }
 315
 316 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_ignore_application(OggFLAC__StreamDecoder *decoder, const FLAC__byte id[4])
 317 {
 318         FLAC__ASSERT(0 != decoder);
 319         FLAC__ASSERT(0 != decoder->private_);
 320         FLAC__ASSERT(0 != decoder->protected_);
 321         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 322                 return false;
 323         return FLAC__stream_decoder_set_metadata_ignore_application(decoder->private_->FLAC_stream_decoder, id);
 324 }
 325
 326 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_set_metadata_ignore_all(OggFLAC__StreamDecoder *decoder)
 327 {
 328         FLAC__ASSERT(0 != decoder);
 329         FLAC__ASSERT(0 != decoder->private_);
 330         FLAC__ASSERT(0 != decoder->protected_);
 331         if(decoder->protected_->state != OggFLAC__STREAM_DECODER_UNINITIALIZED)
 332                 return false;
 333         return FLAC__stream_decoder_set_metadata_ignore_all(decoder->private_->FLAC_stream_decoder);
 334 }
 335
 336 OggFLAC_API OggFLAC__StreamDecoderState OggFLAC__stream_decoder_get_state(const OggFLAC__StreamDecoder *decoder)
 337 {
 338         FLAC__ASSERT(0 != decoder);
 339         FLAC__ASSERT(0 != decoder->protected_);
 340         return decoder->protected_->state;
 341 }
 342
 343 OggFLAC_API FLAC__StreamDecoderState OggFLAC__stream_decoder_get_FLAC_stream_decoder_state(const OggFLAC__StreamDecoder *decoder)
 344 {
 345         FLAC__ASSERT(0 != decoder);
 346         FLAC__ASSERT(0 != decoder->private_);
 347         return FLAC__stream_decoder_get_state(decoder->private_->FLAC_stream_decoder);
 348 }
 349
 350 OggFLAC_API unsigned OggFLAC__stream_decoder_get_channels(const OggFLAC__StreamDecoder *decoder)
 351 {
 352         FLAC__ASSERT(0 != decoder);
 353         FLAC__ASSERT(0 != decoder->private_);
 354         return FLAC__stream_decoder_get_channels(decoder->private_->FLAC_stream_decoder);
 355 }
 356
 357 OggFLAC_API FLAC__ChannelAssignment OggFLAC__stream_decoder_get_channel_assignment(const OggFLAC__StreamDecoder *decoder)
 358 {
 359         FLAC__ASSERT(0 != decoder);
 360         FLAC__ASSERT(0 != decoder->private_);
 361         return FLAC__stream_decoder_get_channel_assignment(decoder->private_->FLAC_stream_decoder);
 362 }
 363
 364 OggFLAC_API unsigned OggFLAC__stream_decoder_get_bits_per_sample(const OggFLAC__StreamDecoder *decoder)
 365 {
 366         FLAC__ASSERT(0 != decoder);
 367         FLAC__ASSERT(0 != decoder->private_);
 368         return FLAC__stream_decoder_get_bits_per_sample(decoder->private_->FLAC_stream_decoder);
 369 }
 370
 371 OggFLAC_API unsigned OggFLAC__stream_decoder_get_sample_rate(const OggFLAC__StreamDecoder *decoder)
 372 {
 373         FLAC__ASSERT(0 != decoder);
 374         FLAC__ASSERT(0 != decoder->private_);
 375         return FLAC__stream_decoder_get_sample_rate(decoder->private_->FLAC_stream_decoder);
 376 }
 377
 378 OggFLAC_API unsigned OggFLAC__stream_decoder_get_blocksize(const OggFLAC__StreamDecoder *decoder)
 379 {
 380         FLAC__ASSERT(0 != decoder);
 381         FLAC__ASSERT(0 != decoder->private_);
 382         return FLAC__stream_decoder_get_blocksize(decoder->private_->FLAC_stream_decoder);
 383 }
 384
 385 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_flush(OggFLAC__StreamDecoder *decoder)
 386 {
 387         FLAC__ASSERT(0 != decoder);
 388         FLAC__ASSERT(0 != decoder->private_);
 389         FLAC__ASSERT(0 != decoder->protected_);
 390
 391         (void)ogg_sync_clear(&decoder->private_->ogg.sync_state);
 392
 393         if(!FLAC__stream_decoder_flush(decoder->private_->FLAC_stream_decoder)) {
 394                 decoder->protected_->state = OggFLAC__STREAM_DECODER_FLAC_STREAM_DECODER_ERROR;
 395                 return false;
 396         }
 397
 398         decoder->protected_->state = OggFLAC__STREAM_DECODER_OK;
 399
 400         return true;
 401 }
 402
 403 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_reset(OggFLAC__StreamDecoder *decoder)
 404 {
 405         FLAC__ASSERT(0 != decoder);
 406         FLAC__ASSERT(0 != decoder->private_);
 407         FLAC__ASSERT(0 != decoder->protected_);
 408
 409         if(!OggFLAC__stream_decoder_flush(decoder)) {
 410                 decoder->protected_->state = OggFLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR;
 411                 return false;
 412         }
 413
 414         if(!FLAC__stream_decoder_reset(decoder->private_->FLAC_stream_decoder)) {
 415                 decoder->protected_->state = OggFLAC__STREAM_DECODER_FLAC_STREAM_DECODER_ERROR;
 416                 return false;
 417         }
 418
 419         decoder->protected_->state = OggFLAC__STREAM_DECODER_OK;
 420
 421         return true;
 422 }
 423
 424 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_process_single(OggFLAC__StreamDecoder *decoder)
 425 {
 426         FLAC__ASSERT(0 != decoder);
 427         FLAC__ASSERT(0 != decoder->private_);
 428         return FLAC__stream_decoder_process_single(decoder->private_->FLAC_stream_decoder);
 429 }
 430
 431 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_process_until_end_of_metadata(OggFLAC__StreamDecoder *decoder)
 432 {
 433         FLAC__ASSERT(0 != decoder);
 434         FLAC__ASSERT(0 != decoder->private_);
 435         return FLAC__stream_decoder_process_until_end_of_metadata(decoder->private_->FLAC_stream_decoder);
 436 }
 437
 438 OggFLAC_API FLAC__bool OggFLAC__stream_decoder_process_until_end_of_stream(OggFLAC__StreamDecoder *decoder)
 439 {
 440         FLAC__ASSERT(0 != decoder);
 441         FLAC__ASSERT(0 != decoder->private_);
 442         return FLAC__stream_decoder_process_until_end_of_stream(decoder->private_->FLAC_stream_decoder);
 443 }
 444
 445
 446 /***********************************************************************
 447  *
 448  * Private class methods
 449  *
 450  ***********************************************************************/
 451
 452 void set_defaults_(OggFLAC__StreamDecoder *decoder)
 453 {
 454         decoder->private_->read_callback = 0;
 455         decoder->private_->write_callback = 0;
 456         decoder->private_->metadata_callback = 0;
 457         decoder->private_->error_callback = 0;
 458         decoder->private_->client_data = 0;
 459         decoder->protected_->use_first_serial_number = true;
 460 }
 461
 462 FLAC__StreamDecoderReadStatus read_callback_(const FLAC__StreamDecoder *unused, FLAC__byte buffer[], unsigned *bytes, void *client_data)
 463 {
 464         static const unsigned OGG_BYTES_CHUNK = 8192;
 465         OggFLAC__StreamDecoder *decoder = (OggFLAC__StreamDecoder*)client_data;
 466         unsigned ogg_bytes_to_read, ogg_bytes_read;
 467         ogg_page page;
 468         char *oggbuf;
 469
 470         (void)unused;
 471
 472         /*
 473          * We have to be careful not to read in more than the
 474          * FLAC__StreamDecoder says it has room for.  We know
 475          * that the size of the decoded data must be no more
 476          * than the encoded data we will read.
 477          */
 478         ogg_bytes_to_read = min(*bytes, OGG_BYTES_CHUNK);
 479         oggbuf = ogg_sync_buffer(&decoder->private_->ogg.sync_state, ogg_bytes_to_read);
 480
 481         if(decoder->private_->read_callback(decoder, oggbuf, &ogg_bytes_to_read, decoder->private_->client_data) != FLAC__STREAM_DECODER_READ_STATUS_CONTINUE) {
 482                 decoder->protected_->state = OggFLAC__STREAM_DECODER_READ_ERROR;
 483                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
 484         }
 485         ogg_bytes_read = ogg_bytes_to_read;
 486
 487         if(ogg_sync_wrote(&decoder->private_->ogg.sync_state, ogg_bytes_read) < 0) {
 488                 decoder->protected_->state = OggFLAC__STREAM_DECODER_READ_ERROR;
 489                 return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
 490         }
 491
 492         *bytes = 0;
 493         while(ogg_sync_pageout(&decoder->private_->ogg.sync_state, &page) == 1) {
 494                 /* grab the serial number if necessary */
 495                 if(decoder->private_->ogg.need_serial_number) {
 496                         decoder->private_->ogg.stream_state.serialno = decoder->protected_->serial_number = ogg_page_serialno(&page);
 497                         decoder->private_->ogg.need_serial_number = false;
 498                 }
 499                 if(ogg_stream_pagein(&decoder->private_->ogg.stream_state, &page) == 0) {
 500                         ogg_packet packet;
 501
 502                         while(ogg_stream_packetout(&decoder->private_->ogg.stream_state, &packet) == 1) {
 503                                 memcpy(buffer, packet.packet, packet.bytes);
 504                                 *bytes += packet.bytes;
 505                                 buffer += packet.bytes;
 506                         }
 507                 } else {
 508                         decoder->protected_->state = OggFLAC__STREAM_DECODER_READ_ERROR;
 509                         return FLAC__STREAM_DECODER_READ_STATUS_ABORT;
 510                 }
 511         }
 512
 513         return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;
 514 }
 515
 516 FLAC__StreamDecoderWriteStatus write_callback_(const FLAC__StreamDecoder *unused, const FLAC__Frame *frame, const FLAC__int32 * const buffer[], void *client_data)
 517 {
 518         OggFLAC__StreamDecoder *decoder = (OggFLAC__StreamDecoder*)client_data;
 519         (void)unused;
 520         return decoder->private_->write_callback(decoder, frame, buffer, decoder->private_->client_data);
 521 }
 522
 523 void metadata_callback_(const FLAC__StreamDecoder *unused, const FLAC__StreamMetadata *metadata, void *client_data)
 524 {
 525         OggFLAC__StreamDecoder *decoder = (OggFLAC__StreamDecoder*)client_data;
 526         (void)unused;
 527         decoder->private_->metadata_callback(decoder, metadata, decoder->private_->client_data);
 528 }
 529
 530 void error_callback_(const FLAC__StreamDecoder *unused, FLAC__StreamDecoderErrorStatus status, void *client_data)
 531 {
 532         OggFLAC__StreamDecoder *decoder = (OggFLAC__StreamDecoder*)client_data;
 533         (void)unused;
 534         decoder->private_->error_callback(decoder, status, decoder->private_->client_data);
 535 }