libavformat/oggparseogm.c

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#include <stdlib.h>
#include "libavutil/intreadwrite.h"
#include "libavcodec/bitstream.h"
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "oggdec.h"
#include "riff.h"

static int
ogm_header(AVFormatContext *s, int idx)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    AVStream *st = s->streams[idx];
    const uint8_t *p = os->buf + os->pstart;
    uint64_t time_unit;
    uint64_t spu;
    uint32_t default_len;

    if(!(*p & 1))
        return 0;
    if(*p != 1)
        return 1;

    p++;

    if(*p == 'v'){
        int tag;
        st->codec->codec_type = CODEC_TYPE_VIDEO;
        p += 8;
        tag = bytestream_get_le32(&p);
        st->codec->codec_id = codec_get_id(codec_bmp_tags, tag);
        st->codec->codec_tag = tag;
    } else if (*p == 't') {
        st->codec->codec_type = CODEC_TYPE_SUBTITLE;
        st->codec->codec_id = CODEC_ID_TEXT;
        p += 12;
    } else {
        uint8_t acid[5];
        int cid;
        st->codec->codec_type = CODEC_TYPE_AUDIO;
        p += 8;
        bytestream_get_buffer(&p, acid, 4);
        acid[4] = 0;
        cid = strtol(acid, NULL, 16);
        st->codec->codec_id = codec_get_id(codec_wav_tags, cid);
        st->need_parsing = AVSTREAM_PARSE_FULL;
    }

    p += 4;                     /* useless size field */

    time_unit   = bytestream_get_le64(&p);
    spu         = bytestream_get_le64(&p);
    default_len = bytestream_get_le32(&p);

    p += 8;                     /* buffersize + bits_per_sample */

    if(st->codec->codec_type == CODEC_TYPE_VIDEO){
        st->codec->width = bytestream_get_le32(&p);
        st->codec->height = bytestream_get_le32(&p);
        st->codec->time_base.den = spu * 10000000;
        st->codec->time_base.num = time_unit;
        st->time_base = st->codec->time_base;
    } else {
        st->codec->channels = bytestream_get_le16(&p);
        p += 2;                 /* block_align */
        st->codec->bit_rate = bytestream_get_le32(&p) * 8;
        st->codec->sample_rate = spu * 10000000 / time_unit;
        st->time_base.num = 1;
        st->time_base.den = st->codec->sample_rate;
    }

    return 1;
}

static int
ogm_dshow_header(AVFormatContext *s, int idx)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    AVStream *st = s->streams[idx];
    uint8_t *p = os->buf + os->pstart;
    uint32_t t;

    if(!(*p & 1))
        return 0;
    if(*p != 1)
        return 1;

    t = AV_RL32(p + 96);

    if(t == 0x05589f80){
        st->codec->codec_type = CODEC_TYPE_VIDEO;
        st->codec->codec_id = codec_get_id(codec_bmp_tags, AV_RL32(p + 68));
        st->codec->time_base.den = 10000000;
        st->codec->time_base.num = AV_RL64(p + 164);
        st->codec->width = AV_RL32(p + 176);
        st->codec->height = AV_RL32(p + 180);
    } else if(t == 0x05589f81){
        st->codec->codec_type = CODEC_TYPE_AUDIO;
        st->codec->codec_id = codec_get_id(codec_wav_tags, AV_RL16(p + 124));
        st->codec->channels = AV_RL16(p + 126);
        st->codec->sample_rate = AV_RL32(p + 128);
        st->codec->bit_rate = AV_RL32(p + 132) * 8;
    }

    return 1;
}

static int
ogm_packet(AVFormatContext *s, int idx)
{
    struct ogg *ogg = s->priv_data;
    struct ogg_stream *os = ogg->streams + idx;
    uint8_t *p = os->buf + os->pstart;
    int lb;

    if(*p & 8)
        os->pflags |= PKT_FLAG_KEY;

    lb = ((*p & 2) << 1) | ((*p >> 6) & 3);
    os->pstart += lb + 1;
    os->psize -= lb + 1;

    return 0;
}

const struct ogg_codec ff_ogm_video_codec = {
    .magic = "\001video",
    .magicsize = 6,
    .header = ogm_header,
    .packet = ogm_packet
};

const struct ogg_codec ff_ogm_audio_codec = {
    .magic = "\001audio",
    .magicsize = 6,
    .header = ogm_header,
    .packet = ogm_packet
};

const struct ogg_codec ff_ogm_text_codec = {
    .magic = "\001text",
    .magicsize = 5,
    .header = ogm_header,
    .packet = ogm_packet
};

const struct ogg_codec ff_ogm_old_codec = {
    .magic = "\001Direct Show Samples embedded in Ogg",
    .magicsize = 35,
    .header = ogm_dshow_header,
    .packet = ogm_packet
};

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