libavformat/oggparseflac.c

   1 /*
   2  *    Copyright (C) 2005  Matthieu CASTET
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <stdlib.h>
  22 #include "libavcodec/bitstream.h"
  23 #include "avformat.h"
  24 #include "oggdec.h"
  25
  26 #define FLAC_STREAMINFO_SIZE 0x22
  27
  28 static int
  29 flac_header (AVFormatContext * s, int idx)
  30 {
  31     ogg_t *ogg = s->priv_data;
  32     ogg_stream_t *os = ogg->streams + idx;
  33     AVStream *st = s->streams[idx];
  34     GetBitContext gb;
  35     int mdt;
  36
  37     if (os->buf[os->pstart] == 0xff)
  38         return 0;
  39
  40     init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
  41     get_bits(&gb, 1); /* metadata_last */
  42     mdt = get_bits(&gb, 7);
  43
  44     if (mdt == 0x7f) {
  45         skip_bits(&gb, 4*8); /* "FLAC" */
  46         if(get_bits(&gb, 8) != 1) /* unsupported major version */
  47             return -1;
  48         skip_bits(&gb, 8 + 16);      /* minor version + header count */
  49         skip_bits(&gb, 4*8); /* "fLaC" */
  50
  51         /* METADATA_BLOCK_HEADER */
  52         if (get_bits_long(&gb, 32) != FLAC_STREAMINFO_SIZE)
  53             return -1;
  54
  55         skip_bits(&gb, 16*2+24*2);
  56
  57         st->codec->sample_rate = get_bits_long(&gb, 20);
  58         st->codec->channels = get_bits(&gb, 3) + 1;
  59
  60         st->codec->codec_type = CODEC_TYPE_AUDIO;
  61         st->codec->codec_id = CODEC_ID_FLAC;
  62
  63         st->codec->extradata =
  64             av_malloc(FLAC_STREAMINFO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
  65         memcpy (st->codec->extradata, os->buf + os->pstart + 5 + 4 + 4 + 4,
  66                 FLAC_STREAMINFO_SIZE);
  67         st->codec->extradata_size = FLAC_STREAMINFO_SIZE;
  68
  69         st->time_base.num = 1;
  70         st->time_base.den = st->codec->sample_rate;
  71     } else if (mdt == 4) {
  72         vorbis_comment (s, os->buf + os->pstart + 4, os->psize - 4);
  73     }
  74
  75     return 1;
  76 }
  77
  78 static int
  79 old_flac_header (AVFormatContext * s, int idx)
  80 {
  81     AVStream *st = s->streams[idx];
  82     st->codec->codec_type = CODEC_TYPE_AUDIO;
  83     st->codec->codec_id = CODEC_ID_FLAC;
  84
  85     return 0;
  86 }
  87
  88 ogg_codec_t flac_codec = {
  89     .magic = "\177FLAC",
  90     .magicsize = 5,
  91     .header = flac_header
  92 };
  93
  94 ogg_codec_t old_flac_codec = {
  95     .magic = "fLaC",
  96     .magicsize = 4,
  97     .header = old_flac_header
  98 };