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/get_bits.h"
  28 #include "avformat.h"
  29 #include "oggdec.h"
  30
  31 struct theora_params {
  32     int gpshift;
  33     int gpmask;
  34     unsigned version;
  35 };
  36
  37 static int
  38 theora_header (AVFormatContext * s, int idx)
  39 {
  40     struct ogg *ogg = s->priv_data;
  41     struct ogg_stream *os = ogg->streams + idx;
  42     AVStream *st = s->streams[idx];
  43     struct theora_params *thp = os->private;
  44     int cds = st->codec->extradata_size + os->psize + 2;
  45     uint8_t *cdp;
  46
  47     if(!(os->buf[os->pstart] & 0x80))
  48         return 0;
  49
  50     if(!thp){
  51         thp = av_mallocz(sizeof(*thp));
  52         os->private = thp;
  53     }
  54
  55     if (os->buf[os->pstart] == 0x80) {
  56         GetBitContext gb;
  57         int width, height;
  58
  59         init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
  60
  61         skip_bits_long(&gb, 7*8); /* 0x80"theora" */
  62
  63         thp->version = get_bits_long(&gb, 24);
  64         if (thp->version < 0x030100)
  65         {
  66             av_log(s, AV_LOG_ERROR,
  67                 "Too old or unsupported Theora (%x)\n", thp->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 (thp->version >= 0x030400)
  76             skip_bits(&gb, 100);
  77
  78         if (thp->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         if (!(st->codec->time_base.num > 0 && st->codec->time_base.den > 0)) {
  90             av_log(s, AV_LOG_WARNING, "Invalid time base in theora stream, assuming 25 FPS\n");
  91             st->codec->time_base.num = 1;
  92             st->codec->time_base.den = 25;
  93         }
  94         st->time_base = st->codec->time_base;
  95
  96         st->sample_aspect_ratio.num = get_bits_long(&gb, 24);
  97         st->sample_aspect_ratio.den = get_bits_long(&gb, 24);
  98
  99         if (thp->version >= 0x030200)
 100             skip_bits_long(&gb, 38);
 101         if (thp->version >= 0x304000)
 102             skip_bits(&gb, 2);
 103
 104         thp->gpshift = get_bits(&gb, 5);
 105         thp->gpmask = (1 << thp->gpshift) - 1;
 106
 107         st->codec->codec_type = CODEC_TYPE_VIDEO;
 108         st->codec->codec_id = CODEC_ID_THEORA;
 109
 110     } else if (os->buf[os->pstart] == 0x83) {
 111         vorbis_comment (s, os->buf + os->pstart + 7, os->psize - 8);
 112     }
 113
 114     st->codec->extradata = av_realloc (st->codec->extradata,
 115                                        cds + FF_INPUT_BUFFER_PADDING_SIZE);
 116     cdp = st->codec->extradata + st->codec->extradata_size;
 117     *cdp++ = os->psize >> 8;
 118     *cdp++ = os->psize & 0xff;
 119     memcpy (cdp, os->buf + os->pstart, os->psize);
 120     st->codec->extradata_size = cds;
 121
 122     return 1;
 123 }
 124
 125 static uint64_t
 126 theora_gptopts(AVFormatContext *ctx, int idx, uint64_t gp)
 127 {
 128     struct ogg *ogg = ctx->priv_data;
 129     struct ogg_stream *os = ogg->streams + idx;
 130     struct theora_params *thp = os->private;
 131     uint64_t iframe = gp >> thp->gpshift;
 132     uint64_t pframe = gp & thp->gpmask;
 133
 134     if (thp->version < 0x030201)
 135         iframe++;
 136
 137     if(!pframe)
 138         os->pflags |= PKT_FLAG_KEY;
 139
 140     return iframe + pframe;
 141 }
 142
 143 const struct ogg_codec ff_theora_codec = {
 144     .magic = "\200theora",
 145     .magicsize = 7,
 146     .header = theora_header,
 147     .gptopts = theora_gptopts
 148 };