FLAC/src/ogg_decoder_aspect.c

   1 /* libFLAC - Free Lossless Audio Codec
   2  * Copyright (C) 2002-2009  Josh Coalson
   3  * Copyright (C) 2011-2016  Xiph.Org Foundation
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  * notice, this list of conditions and the following disclaimer.
  11  *
  12  * - Redistributions in binary form must reproduce the above copyright
  13  * notice, this list of conditions and the following disclaimer in the
  14  * documentation and/or other materials provided with the distribution.
  15  *
  16  * - Neither the name of the Xiph.org Foundation nor the names of its
  17  * contributors may be used to endorse or promote products derived from
  18  * this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 #ifdef HAVE_CONFIG_H
  34 #  include <config.h>
  35 #endif
  36
  37 #include <string.h> /* for memcpy() */
  38 #include "FLAC/assert.h"
  39 #include "private/ogg_decoder_aspect.h"
  40 #include "private/ogg_mapping.h"
  41 #include "private/macros.h"
  42
  43
  44 /***********************************************************************
  45  *
  46  * Public class methods
  47  *
  48  ***********************************************************************/
  49
  50 FLAC__bool FLAC__ogg_decoder_aspect_init(FLAC__OggDecoderAspect *aspect)
  51 {
  52         /* we will determine the serial number later if necessary */
  53         if(ogg_stream_init(&aspect->stream_state, aspect->serial_number) != 0)
  54                 return false;
  55
  56         if(ogg_sync_init(&aspect->sync_state) != 0)
  57                 return false;
  58
  59         aspect->version_major = ~(0u);
  60         aspect->version_minor = ~(0u);
  61
  62         aspect->need_serial_number = aspect->use_first_serial_number;
  63
  64         aspect->end_of_stream = false;
  65         aspect->have_working_page = false;
  66
  67         return true;
  68 }
  69
  70 void FLAC__ogg_decoder_aspect_finish(FLAC__OggDecoderAspect *aspect)
  71 {
  72         (void)ogg_sync_clear(&aspect->sync_state);
  73         (void)ogg_stream_clear(&aspect->stream_state);
  74 }
  75
  76 void FLAC__ogg_decoder_aspect_set_serial_number(FLAC__OggDecoderAspect *aspect, long value)
  77 {
  78         aspect->use_first_serial_number = false;
  79         aspect->serial_number = value;
  80 }
  81
  82 void FLAC__ogg_decoder_aspect_set_defaults(FLAC__OggDecoderAspect *aspect)
  83 {
  84         aspect->use_first_serial_number = true;
  85 }
  86
  87 void FLAC__ogg_decoder_aspect_flush(FLAC__OggDecoderAspect *aspect)
  88 {
  89         (void)ogg_stream_reset(&aspect->stream_state);
  90         (void)ogg_sync_reset(&aspect->sync_state);
  91         aspect->end_of_stream = false;
  92         aspect->have_working_page = false;
  93 }
  94
  95 void FLAC__ogg_decoder_aspect_reset(FLAC__OggDecoderAspect *aspect)
  96 {
  97         FLAC__ogg_decoder_aspect_flush(aspect);
  98
  99         if(aspect->use_first_serial_number)
 100                 aspect->need_serial_number = true;
 101 }
 102
 103 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)
 104 {
 105         static const size_t OGG_BYTES_CHUNK = 8192;
 106         const size_t bytes_requested = *bytes;
 107
 108         /*
 109          * The FLAC decoding API uses pull-based reads, whereas Ogg decoding
 110          * is push-based.  In libFLAC, when you ask to decode a frame, the
 111          * decoder will eventually call the read callback to supply some data,
 112          * but how much it asks for depends on how much free space it has in
 113          * its internal buffer.  It does not try to grow its internal buffer
 114          * to accommodate a whole frame because then the internal buffer size
 115          * could not be limited, which is necessary in embedded applications.
 116          *
 117          * Ogg however grows its internal buffer until a whole page is present;
 118          * only then can you get decoded data out.  So we can't just ask for
 119          * the same number of bytes from Ogg, then pass what's decoded down to
 120          * libFLAC.  If what libFLAC is asking for will not contain a whole
 121          * page, then we will get no data from ogg_sync_pageout(), and at the
 122          * same time cannot just read more data from the client for the purpose
 123          * of getting a whole decoded page because the decoded size might be
 124          * larger than libFLAC's internal buffer.
 125          *
 126          * Instead, whenever this read callback wrapper is called, we will
 127          * continually request data from the client until we have at least one
 128          * page, and manage pages internally so that we can send pieces of
 129          * pages down to libFLAC in such a way that we obey its size
 130          * requirement.  To limit the amount of callbacks, we will always try
 131          * to read in enough pages to return the full number of bytes
 132          * requested.
 133          */
 134         *bytes = 0;
 135         while (*bytes < bytes_requested && !aspect->end_of_stream) {
 136                 if (aspect->have_working_page) {
 137                         if (aspect->have_working_packet) {
 138                                 size_t n = bytes_requested - *bytes;
 139                                 if ((size_t)aspect->working_packet.bytes <= n) {
 140                                         /* the rest of the packet will fit in the buffer */
 141                                         n = aspect->working_packet.bytes;
 142                                         memcpy(buffer, aspect->working_packet.packet, n);
 143                                         *bytes += n;
 144                                         buffer += n;
 145                                         aspect->have_working_packet = false;
 146                                 }
 147                                 else {
 148                                         /* only n bytes of the packet will fit in the buffer */
 149                                         memcpy(buffer, aspect->working_packet.packet, n);
 150                                         *bytes += n;
 151                                         buffer += n;
 152                                         aspect->working_packet.packet += n;
 153                                         aspect->working_packet.bytes -= n;
 154                                 }
 155                         }
 156                         else {
 157                                 /* try and get another packet */
 158                                 const int ret = ogg_stream_packetout(&aspect->stream_state, &aspect->working_packet);
 159                                 if (ret > 0) {
 160                                         aspect->have_working_packet = true;
 161                                         /* if it is the first header packet, check for magic and a supported Ogg FLAC mapping version */
 162                                         if (aspect->working_packet.bytes > 0 && aspect->working_packet.packet[0] == FLAC__OGG_MAPPING_FIRST_HEADER_PACKET_TYPE) {
 163                                                 const FLAC__byte *b = aspect->working_packet.packet;
 164                                                 const uint32_t header_length =
 165                                                         FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH +
 166                                                         FLAC__OGG_MAPPING_MAGIC_LENGTH +
 167                                                         FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH +
 168                                                         FLAC__OGG_MAPPING_VERSION_MINOR_LENGTH +
 169                                                         FLAC__OGG_MAPPING_NUM_HEADERS_LENGTH;
 170                                                 if (aspect->working_packet.bytes < (long)header_length)
 171                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
 172                                                 b += FLAC__OGG_MAPPING_PACKET_TYPE_LENGTH;
 173                                                 if (memcmp(b, FLAC__OGG_MAPPING_MAGIC, FLAC__OGG_MAPPING_MAGIC_LENGTH))
 174                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_NOT_FLAC;
 175                                                 b += FLAC__OGG_MAPPING_MAGIC_LENGTH;
 176                                                 aspect->version_major = (uint32_t)(*b);
 177                                                 b += FLAC__OGG_MAPPING_VERSION_MAJOR_LENGTH;
 178                                                 aspect->version_minor = (uint32_t)(*b);
 179                                                 if (aspect->version_major != 1)
 180                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_UNSUPPORTED_MAPPING_VERSION;
 181                                                 aspect->working_packet.packet += header_length;
 182                                                 aspect->working_packet.bytes -= header_length;
 183                                         }
 184                                 }
 185                                 else if (ret == 0) {
 186                                         aspect->have_working_page = false;
 187                                 }
 188                                 else { /* ret < 0 */
 189                                         /* lost sync, we'll leave the working page for the next call */
 190                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
 191                                 }
 192                         }
 193                 }
 194                 else {
 195                         /* try and get another page */
 196                         const int ret = ogg_sync_pageout(&aspect->sync_state, &aspect->working_page);
 197                         if (ret > 0) {
 198                                 /* got a page, grab the serial number if necessary */
 199                                 if(aspect->need_serial_number) {
 200                                         aspect->stream_state.serialno = aspect->serial_number = ogg_page_serialno(&aspect->working_page);
 201                                         aspect->need_serial_number = false;
 202                                 }
 203                                 if(ogg_stream_pagein(&aspect->stream_state, &aspect->working_page) == 0) {
 204                                         aspect->have_working_page = true;
 205                                         aspect->have_working_packet = false;
 206                                 }
 207                                 /* else do nothing, could be a page from another stream */
 208                         }
 209                         else if (ret == 0) {
 210                                 /* need more data */
 211                                 const size_t ogg_bytes_to_read = flac_max(bytes_requested - *bytes, OGG_BYTES_CHUNK);
 212                                 char *oggbuf = ogg_sync_buffer(&aspect->sync_state, ogg_bytes_to_read);
 213
 214                                 if(0 == oggbuf) {
 215                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_MEMORY_ALLOCATION_ERROR;
 216                                 }
 217                                 else {
 218                                         size_t ogg_bytes_read = ogg_bytes_to_read;
 219
 220                                         switch(read_callback(decoder, (FLAC__byte*)oggbuf, &ogg_bytes_read, client_data)) {
 221                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK:
 222                                                         break;
 223                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM:
 224                                                         aspect->end_of_stream = true;
 225                                                         break;
 226                                                 case FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT:
 227                                                         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ABORT;
 228                                                 default:
 229                                                         FLAC__ASSERT(0);
 230                                         }
 231
 232                                         if(ogg_sync_wrote(&aspect->sync_state, ogg_bytes_read) < 0) {
 233                                                 /* double protection; this will happen if the read callback returns more bytes than the max requested, which would overflow Ogg's internal buffer */
 234                                                 FLAC__ASSERT(0);
 235                                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_ERROR;
 236                                         }
 237                                 }
 238                         }
 239                         else { /* ret < 0 */
 240                                 /* lost sync, bail out */
 241                                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_LOST_SYNC;
 242                         }
 243                 }
 244         }
 245
 246         if (aspect->end_of_stream && *bytes == 0) {
 247                 return FLAC__OGG_DECODER_ASPECT_READ_STATUS_END_OF_STREAM;
 248         }
 249
 250         return FLAC__OGG_DECODER_ASPECT_READ_STATUS_OK;
 251 }