libavformat/oggparsetheora.c

   1 /**
   2       Copyright (C) 2005  Matthieu CASTET, Alex Beregszaszi
   3
   4       Permission is hereby granted, free of charge, to any person
   5       obtaining a copy of this software and associated documentation
   6       files (the "Software"), to deal in the Software without
   7       restriction, including without limitation the rights to use, copy,
   8       modify, merge, publish, distribute, sublicense, and/or sell copies
   9       of the Software, and to permit persons to whom the Software is
  10       furnished to do so, subject to the following conditions:
  11
  12       The above copyright notice and this permission notice shall be
  13       included in all copies or substantial portions of the Software.
  14
  15       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16       EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17       MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18       NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  19       HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  20       WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21       OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22       DEALINGS IN THE SOFTWARE.
  23 **/
  24
  25 #include <stdlib.h>
  26 #include "libavutil/bswap.h"
  27 #include "libavcodec/bitstream.h"
  28 #include "avformat.h"
  29 #include "oggdec.h"
  30
  31 typedef struct theora_params {
  32     int gpshift;
  33     int gpmask;
  34 } theora_params_t;
  35
  36 static int
  37 theora_header (AVFormatContext * s, int idx)
  38 {
  39     ogg_t *ogg = s->priv_data;
  40     ogg_stream_t *os = ogg->streams + idx;
  41     AVStream *st = s->streams[idx];
  42     theora_params_t *thp = os->private;
  43     int cds = st->codec->extradata_size + os->psize + 2;
  44     uint8_t *cdp;
  45
  46     if(!(os->buf[os->pstart] & 0x80))
  47         return 0;
  48
  49     if(!thp){
  50         thp = av_mallocz(sizeof(*thp));
  51         os->private = thp;
  52     }
  53
  54     if (os->buf[os->pstart] == 0x80) {
  55         GetBitContext gb;
  56         int width, height;
  57         int version;
  58
  59         init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
  60
  61         skip_bits(&gb, 7*8); /* 0x80"theora" */
  62
  63         version = get_bits_long(&gb, 24);
  64         if (version < 0x030100)
  65         {
  66             av_log(s, AV_LOG_ERROR,
  67                 "Too old or unsupported Theora (%x)\n", version);
  68             return -1;
  69         }
  70
  71         width  = get_bits(&gb, 16) << 4;
  72         height = get_bits(&gb, 16) << 4;
  73         avcodec_set_dimensions(st->codec, width, height);
  74
  75         if (version >= 0x030400)
  76             skip_bits(&gb, 100);
  77
  78         if (version >= 0x030200) {
  79             width  = get_bits_long(&gb, 24);
  80             height = get_bits_long(&gb, 24);
  81             if (   width  <= st->codec->width  && width  > st->codec->width-16
  82                 && height <= st->codec->height && height > st->codec->height-16)
  83                 avcodec_set_dimensions(st->codec, width, height);
  84
  85             skip_bits(&gb, 16);
  86         }
  87         st->codec->time_base.den = get_bits_long(&gb, 32);
  88         st->codec->time_base.num = get_bits_long(&gb, 32);
  89         st->time_base = st->codec->time_base;
  90
  91         st->sample_aspect_ratio.num = get_bits_long(&gb, 24);
  92         st->sample_aspect_ratio.den = get_bits_long(&gb, 24);
  93
  94         if (version >= 0x030200)
  95             skip_bits(&gb, 38);
  96         if (version >= 0x304000)
  97             skip_bits(&gb, 2);
  98
  99         thp->gpshift = get_bits(&gb, 5);
 100         thp->gpmask = (1 << thp->gpshift) - 1;
 101
 102         st->codec->codec_type = CODEC_TYPE_VIDEO;
 103         st->codec->codec_id = CODEC_ID_THEORA;
 104
 105     } else if (os->buf[os->pstart] == 0x83) {
 106         vorbis_comment (s, os->buf + os->pstart + 7, os->psize - 8);
 107     }
 108
 109     st->codec->extradata = av_realloc (st->codec->extradata, cds);
 110     cdp = st->codec->extradata + st->codec->extradata_size;
 111     *cdp++ = os->psize >> 8;
 112     *cdp++ = os->psize & 0xff;
 113     memcpy (cdp, os->buf + os->pstart, os->psize);
 114     st->codec->extradata_size = cds;
 115
 116     return 1;
 117 }
 118
 119 static uint64_t
 120 theora_gptopts(AVFormatContext *ctx, int idx, uint64_t gp)
 121 {
 122     ogg_t *ogg = ctx->priv_data;
 123     ogg_stream_t *os = ogg->streams + idx;
 124     theora_params_t *thp = os->private;
 125     uint64_t iframe = gp >> thp->gpshift;
 126     uint64_t pframe = gp & thp->gpmask;
 127
 128     if(!pframe)
 129         os->pflags |= PKT_FLAG_KEY;
 130
 131     return iframe + pframe;
 132 }
 133
 134 const ogg_codec_t ff_theora_codec = {
 135     .magic = "\200theora",
 136     .magicsize = 7,
 137     .header = theora_header,
 138     .gptopts = theora_gptopts
 139 };