PeerStreamer

/**

      Copyright (C) 2005  Matthieu CASTET, Alex Beregszaszi

      Permission is hereby granted, free of charge, to any person

      obtaining a copy of this software and associated documentation

      files (the "Software"), to deal in the Software without

      restriction, including without limitation the rights to use, copy,

      modify, merge, publish, distribute, sublicense, and/or sell copies

      of the Software, and to permit persons to whom the Software is

      furnished to do so, subject to the following conditions:

      The above copyright notice and this permission notice shall be

      included in all copies or substantial portions of the Software.

      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

      EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

      MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

      NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

      HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

      WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

      OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

      DEALINGS IN THE SOFTWARE.

**/

#include <stdlib.h>

#include "libavutil/bswap.h"

#include "libavcodec/get_bits.h"

#include "avformat.h"

#include "oggdec.h"

struct theora_params {

    int gpshift;

    int gpmask;

    unsigned version;

};

static int

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);

        if (!(st->codec->time_base.num > 0 && st->codec->time_base.den > 0)) {

            av_log(s, AV_LOG_WARNING, "Invalid time base in theora stream, assuming 25 FPS\n");

            st->codec->time_base.num = 1;

            st->codec->time_base.den = 25;

        }

        av_set_pts_info(st, 64, st->codec->time_base.num, st->codec->time_base.den);

        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 = AVMEDIA_TYPE_VIDEO;

        st->codec->codec_id = CODEC_ID_THEORA;

        st->need_parsing = AVSTREAM_PARSE_HEADERS;

    } else if (os->buf[os->pstart] == 0x83) {

        ff_vorbis_comment (s, &st->metadata, 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;

}

static uint64_t

theora_gptopts(AVFormatContext *ctx, int idx, uint64_t gp, int64_t *dts)

{

    struct ogg *ogg = ctx->priv_data;

    struct ogg_stream *os = ogg->streams + idx;

    struct theora_params *thp = os->private;

    uint64_t iframe = gp >> thp->gpshift;

    uint64_t pframe = gp & thp->gpmask;

    if (thp->version < 0x030201)

        iframe++;

    if(!pframe)

        os->pflags |= AV_PKT_FLAG_KEY;

    if (dts)

        *dts = iframe + pframe;

    return iframe + pframe;

}

const struct ogg_codec ff_theora_codec = {

    .magic = "\200theora",

    .magicsize = 7,

    .header = theora_header,

    .gptopts = theora_gptopts

};