theora_header (AVFormatContext * s, int idx) { struct ogg *ogg = s->priv_data; struct ogg_stream *os = ogg->streams + idx; AVStream *st = s->streams[idx]; struct theora_params *thp = os->private; int cds = st->codec->extradata_size + os->psize + 2; uint8_t *cdp; if(!(os->buf[os->pstart] & 0x80)) return 0; if(!thp){ thp = av_mallocz(sizeof(*thp)); os->private = thp; if (os->buf[os->pstart] == 0x80) { GetBitContext gb; int width, height; init_get_bits(&gb, os->buf + os->pstart, os->psize*8); skip_bits_long(&gb, 7*8); /* 0x80"theora" */ thp->version = get_bits_long(&gb, 24); if (thp->version < 0x030100) { av_log(s, AV_LOG_ERROR, "Too old or unsupported Theora (%x)\n", thp->version); return -1; width = get_bits(&gb, 16) << 4; height = get_bits(&gb, 16) << 4; avcodec_set_dimensions(st->codec, width, height); if (thp->version >= 0x030400) skip_bits(&gb, 100); if (thp->version >= 0x030200) { width = get_bits_long(&gb, 24); height = get_bits_long(&gb, 24); if ( width <= st->codec->width && width > st->codec->width-16 && height <= st->codec->height && height > st->codec->height-16) avcodec_set_dimensions(st->codec, width, height); skip_bits(&gb, 16); st->codec->time_base.den = get_bits_long(&gb, 32); st->codec->time_base.num = get_bits_long(&gb, 32); st->time_base = st->codec->time_base; st->sample_aspect_ratio.num = get_bits_long(&gb, 24); st->sample_aspect_ratio.den = get_bits_long(&gb, 24); if (thp->version >= 0x030200) skip_bits_long(&gb, 38); if (thp->version >= 0x304000) skip_bits(&gb, 2); thp->gpshift = get_bits(&gb, 5); thp->gpmask = (1 << thp->gpshift) - 1; st->codec->codec_type = CODEC_TYPE_VIDEO; st->codec->codec_id = CODEC_ID_THEORA; } else if (os->buf[os->pstart] == 0x83) { vorbis_comment (s, os->buf + os->pstart + 7, os->psize - 8); st->codec->extradata = av_realloc (st->codec->extradata, cds + FF_INPUT_BUFFER_PADDING_SIZE); cdp = st->codec->extradata + st->codec->extradata_size; *cdp++ = os->psize >> 8; *cdp++ = os->psize & 0xff; memcpy (cdp, os->buf + os->pstart, os->psize); st->codec->extradata_size = cds; return 1;