src/libFLAC/ogg_decoder_aspect.c

   1 /* libFLAC - Free Lossless Audio Codec
   2  * Copyright (C) 2002,2003,2004,2005,2006,2007,2008,2009  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 #if HAVE_CONFIG_H
  33 #  include <config.h>
  34 #endif
  35
  36 #include <string.h> /* for memcpy() */
  37 #include "FLAC/assert.h"
  38 #include "private/ogg_decoder_aspect.h"
  39 #include "private/ogg_mapping.h"
  40 #include "private/macros.h"
  41
  42
  43 /***********************************************************************
  44  *
  45  * Public class methods
  46  *
  47  ***********************************************************************/
  48
  49 FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
  50 {
  51         /* we will determine the serial number later if necessary */
  52         if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
  53                 return false;
  54
  55         if(ogg_sync_init(&aspect->sync_state) != 0)
  56                 return false;
  57
  58         aspect->version_major = ~(0u);
  59         aspect->version_minor = ~(0u);
  60
  61         aspect->need_serial_number = aspect->use_first_serial_number;
  62
  63         aspect->end_of_stream = false;
  64         aspect->have_working_page = false;
  65
  66         return true;
  67 }
  68
  69 void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
  70 {
  71         (void)ogg_sync_clear(&aspect->sync_state);
  72         (void)ogg_stream_clear(&aspect->stream_state);
  73 }
  74
  75 void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
  76 {
  77         aspect->use_first_serial_number = false;
  78         aspect->serial_number = value;
  79 }
  80
  81 void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
  82 {
  83         aspect->use_first_serial_number = true;
  84 }
  85
  86 void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
  87 {
  88         (void)ogg_stream_reset(&aspect->stream_state);
  89         (void)ogg_sync_reset(&aspect->sync_state);
  90         aspect->end_of_stream = false;
  91         aspect->have_working_page = false;
  92 }
  93
  94 void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
  95 {
  96         FLAC__ogg_decoder_aspect_flush(aspect);
  97
  98         if(aspect->use_first_serial_number)
  99                 aspect->need_serial_number = true;
 100 }
 101
 102 FLAC__OggDecoderAspectReadStatus FLAC__ogg_decoder_aspect_read_callback_wrapper(FLAC__OggDecoderAspect *aspect, FLAC__byte buffer[], size_t *bytes, FLAC__OggDecoderAspectReadCallbackProxy read_callback, const FLAC__StreamDecoder *decoder, void *client_data)
 103 {
 104         static const size_t OGG_BYTES_CHUNK = 8192;
 105         const size_t bytes_requested = *bytes;
 106
 107         /*
 108          * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
 109          * is push-based.  In libFLAC, when you ask to decode a frame, the
 110          * decoder will eventually call the read callback to supply some data,
 111          * but how much it asks for depends on how much free space it has in
 112          * its internal buffer.  It does not try to grow its internal buffer
 113          * to accomodate a whole frame because then the internal buffer size
 114          * could not be limited, which is necessary in embedded applications.
 115          *
 116          * Ogg however grows its internal buffer until a whole page is present;
 117          * only then can you get decoded data out.  So we can't just ask for
 118          * the same number of bytes from Ogg, then pass what's decoded down to
 119          * libFLAC.  If what libFLAC is asking for will not contain a whole
 120          * page, then we will get no data from ogg_sync_pageout(), and at the
 121          * same time cannot just read more data from the client for the purpose
 122          * of getting a whole decoded page because the decoded size might be
 123          * larger than libFLAC's internal buffer.
 124          *
 125          * Instead, whenever this read callback wrapper is called, we will
 126          * continually request data from the client until we have at least one
 127          * page, and manage pages internally so that we can send pieces of
 128          * pages down to libFLAC in such a way that we obey its size
 129          * requirement.  To limit the amount of callbacks, we will always try
 130          * to read in enough pages to return the full number of bytes
 131          * requested.
 132          */
 133         *bytes = 0;
 134         while (*bytes < bytes_requested && !aspect->end_of_stream) {
 135                 if (aspect->have_working_page) {
 136                         if (aspect->have_working_packet) {
 137                                 size_t n = bytes_requested - *bytes;
 138                                 if ((size_t)aspect->working_packet.bytes <= n) {
 139                                         /* the rest of the packet will fit in the buffer */
 140                                         n = aspect->working_packet.bytes;
 141                                         memcpy(buffer, aspect->working_packet.packet, n);
 142                                         *bytes += n;
 143                                         buffer += n;
 144                                         aspect->have_working_packet = false;
 145                                 }
 146                                 else {
 147                                         /* only n bytes of the packet will fit in the buffer */
 148                                         memcpy(buffer, aspect->working_packet.packet, n);
 149                                         *bytes += n;
 150                                         buffer += n;
 151                                         aspect->working_packet.packet += n;
 152                                         aspect->working_packet.bytes -= n;
 153                                 }
 154                         }
 155                         else {
 156                                 /* try and get another packet */
 157                                 const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
 158                                 if (ret > 0) {
 159                                         aspect->have_working_packet = true;
 160                                         /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
 161                                         if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
 162                                                 const FLAC__byte *b = aspect->working_packet.packet;
 163                                                 const unsigned header_length =
 164                                                         FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
 165                                                         FLAC__OGG_MAPPING_MAGIC_LENGTH +
 166                                                         FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
 167                                                         FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
 168                                                         FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
 169                                                 if (aspect->working_packet.bytes < (long)header_length)
 170                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
 171                                                 b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
 172                                                 if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
 173                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
 174                                                 b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
 175                                                 aspect->version_major = (unsigned)(*b);
 176                                                 b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
 177                                                 aspect->version_minor = (unsigned)(*b);
 178                                                 if (aspect->version_major != 1)
 179                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
 180                                                 aspect->working_packet.packet += header_length;
 181                                                 aspect->working_packet.bytes -= header_length;
 182                                         }
 183                                 }
 184                                 else if (ret == 0) {
 185                                         aspect->have_working_page = false;
 186                                 }
 187                                 else { /* ret < 0 */
 188                                         /* lost sync, we'll leave the working page for the next call */
 189                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
 190                                 }
 191                         }
 192                 }
 193                 else {
 194                         /* try and get another page */
 195                         const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
 196                         if (ret > 0) {
 197                                 /* got a page, grab the serial number if necessary */
 198                                 if(aspect->need_serial_number) {
 199                                         aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
 200                                         aspect->need_serial_number = false;
 201                                 }
 202                                 if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
 203                                         aspect->have_working_page = true;
 204                                         aspect->have_working_packet = false;
 205                                 }
 206                                 /* else do nothing, could be a page from another stream */
 207                         }
 208                         else if (ret == 0) {
 209                                 /* need more data */
 210                                 const size_t ogg_bytes_to_read = flac_max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
 211                                 char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
 212
 213                                 if(0 == oggbuf) {
 214                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
 215                                 }
 216                                 else {
 217                                         size_t ogg_bytes_read = ogg_bytes_to_read;
 218
 219                                         switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
 220                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
 221                                                         break;
 222                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
 223                                                         aspect->end_of_stream = true;
 224                                                         break;
 225                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
 226                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
 227                                                 default:
 228                                                         FLAC__ASSERT(0);
 229                                         }
 230
 231                                         if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
 232                                                 /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
 233                                                 FLAC__ASSERT(0);
 234                                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
 235                                         }
 236                                 }
 237                         }
 238                         else { /* ret < 0 */
 239                                 /* lost sync, bail out */
 240                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
 241                         }
 242                 }
 243         }
 244
 245         if (aspect->end_of_stream && *bytes == 0) {
 246                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
 247         }
 248
 249         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
 250 }