flvdec.c

ffmpeg移植到symbian的全部源代码

    keylen = 0;
    ioc = s->pb;

    //first object needs to be "onMetaData" string
    type = get_byte(ioc);
    if(type != AMF_DATA_TYPE_STRING || amf_get_string(ioc, buffer, sizeof(buffer)) < 0 || strcmp(buffer, "onMetaData"))
        return -1;

    //find the streams now so that amf_parse_object doesn't need to do the lookup every time it is called.
    for(i = 0; i < s->nb_streams; i++) {
        stream = s->streams[i];
        if     (stream->codec->codec_type == CODEC_TYPE_AUDIO) astream = stream;
        else if(stream->codec->codec_type == CODEC_TYPE_VIDEO) vstream = stream;
    }

    //parse the second object (we want a mixed array)
    if(amf_parse_object(s, astream, vstream, buffer, next_pos, 0) < 0)
        return -1;

    return 0;
}

static AVStream *create_stream(AVFormatContext *s, int is_audio){
    AVStream *st = av_new_stream(s, is_audio);
    if (!st)
        return NULL;
    st->codec->codec_type = is_audio ? CODEC_TYPE_AUDIO : CODEC_TYPE_VIDEO;
    av_set_pts_info(st, 32, 1, 1000); /* 32 bit pts in ms */
    return st;
}

static int flv_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
{
    int offset, flags;

    url_fskip(s->pb, 4);
    flags = get_byte(s->pb);
    /* old flvtool cleared this field */
    /* FIXME: better fix needed */
    if (!flags) {
        flags = FLV_HEADER_FLAG_HASVIDEO | FLV_HEADER_FLAG_HASAUDIO;
        av_log(s, AV_LOG_WARNING, "Broken FLV file, which says no streams present, this might fail\n");
    }

    if((flags & (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
             != (FLV_HEADER_FLAG_HASVIDEO|FLV_HEADER_FLAG_HASAUDIO))
        s->ctx_flags |= AVFMTCTX_NOHEADER;

    if(flags & FLV_HEADER_FLAG_HASVIDEO){
        if(!create_stream(s, 0))
            return AVERROR(ENOMEM);
    }
    if(flags & FLV_HEADER_FLAG_HASAUDIO){
        if(!create_stream(s, 1))
            return AVERROR(ENOMEM);
    }

    offset = get_be32(s->pb);
    url_fseek(s->pb, offset, SEEK_SET);

    s->start_time = 0;

    return 0;
}

static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
{
    av_free(st->codec->extradata);
    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!st->codec->extradata)
        return AVERROR(ENOMEM);
    st->codec->extradata_size = size;
    get_buffer(s->pb, st->codec->extradata, st->codec->extradata_size);
    return 0;
}

static int flv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int ret, i, type, size, flags, is_audio, next, pos;
    unsigned dts;
    AVStream *st = NULL;

 retry:
 for(;;){
    pos = url_ftell(s->pb);
    url_fskip(s->pb, 4); /* size of previous packet */
    type = get_byte(s->pb);
    size = get_be24(s->pb);
    dts = get_be24(s->pb);
    dts |= get_byte(s->pb) << 24;
//    av_log(s, AV_LOG_DEBUG, "type:%d, size:%d, dts:%d\n", type, size, dts);
    if (url_feof(s->pb))
        return AVERROR(EIO);
    url_fskip(s->pb, 3); /* stream id, always 0 */
    flags = 0;

    if(size == 0)
        continue;

    next= size + url_ftell(s->pb);

    if (type == FLV_TAG_TYPE_AUDIO) {
        is_audio=1;
        flags = get_byte(s->pb);
    } else if (type == FLV_TAG_TYPE_VIDEO) {
        is_audio=0;
        flags = get_byte(s->pb);
    } else {
        if (type == FLV_TAG_TYPE_META && size > 13+1+4)
            flv_read_metabody(s, next);
        else /* skip packet */
            av_log(s, AV_LOG_ERROR, "skipping flv packet: type %d, size %d, flags %d\n", type, size, flags);
        url_fseek(s->pb, next, SEEK_SET);
        continue;
    }

    /* now find stream */
    for(i=0;i<s->nb_streams;i++) {
        st = s->streams[i];
        if (st->id == is_audio)
            break;
    }
    if(i == s->nb_streams){
        av_log(NULL, AV_LOG_ERROR, "invalid stream\n");
        st= create_stream(s, is_audio);
        s->ctx_flags &= ~AVFMTCTX_NOHEADER;
    }
//    av_log(NULL, AV_LOG_DEBUG, "%d %X %d \n", is_audio, flags, st->discard);
    if(  (st->discard >= AVDISCARD_NONKEY && !((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY ||         is_audio))
       ||(st->discard >= AVDISCARD_BIDIR  &&  ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_DISP_INTER && !is_audio))
       || st->discard >= AVDISCARD_ALL
       ){
        url_fseek(s->pb, next, SEEK_SET);
        continue;
    }
    if ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY)
        av_add_index_entry(st, pos, dts, size, 0, AVINDEX_KEYFRAME);
    break;
 }

    // if not streamed and no duration from metadata then seek to end to find the duration from the timestamps
    if(!url_is_streamed(s->pb) && s->duration==AV_NOPTS_VALUE){
        int size;
        const int pos= url_ftell(s->pb);
        const int fsize= url_fsize(s->pb);
        url_fseek(s->pb, fsize-4, SEEK_SET);
        size= get_be32(s->pb);
        url_fseek(s->pb, fsize-3-size, SEEK_SET);
        if(size == get_be24(s->pb) + 11){
            s->duration= get_be24(s->pb) * (int64_t)AV_TIME_BASE / 1000;
        }
        url_fseek(s->pb, pos, SEEK_SET);
    }

    if(is_audio){
        if(!st->codec->sample_rate || !st->codec->bits_per_sample || (!st->codec->codec_id && !st->codec->codec_tag)) {
            st->codec->channels = (flags & FLV_AUDIO_CHANNEL_MASK) == FLV_STEREO ? 2 : 1;
            if((flags & FLV_AUDIO_CODECID_MASK) == FLV_CODECID_NELLYMOSER_8HZ_MONO)
                st->codec->sample_rate= 8000;
            else
                st->codec->sample_rate = (44100 << ((flags & FLV_AUDIO_SAMPLERATE_MASK) >> FLV_AUDIO_SAMPLERATE_OFFSET) >> 3);
            st->codec->bits_per_sample = (flags & FLV_AUDIO_SAMPLESIZE_MASK) ? 16 : 8;
            flv_set_audio_codec(s, st, flags & FLV_AUDIO_CODECID_MASK);
        }
    }else{
        size -= flv_set_video_codec(s, st, flags & FLV_VIDEO_CODECID_MASK);
    }

    if (st->codec->codec_id == CODEC_ID_AAC ||
        st->codec->codec_id == CODEC_ID_H264) {
        int type = get_byte(s->pb);
        size--;
        if (st->codec->codec_id == CODEC_ID_H264) {
            // cts offset ignored because it might to be signed
            // and would cause pts < dts
            get_be24(s->pb);
        }
        if (type == 0) {
            if ((ret = flv_get_extradata(s, st, size - 1)) < 0)
                return ret;
            goto retry;
        }
    }

    ret= av_get_packet(s->pb, pkt, size - 1);
    if (ret <= 0) {
        return AVERROR(EIO);
    }
    /* note: we need to modify the packet size here to handle the last
       packet */
    pkt->size = ret;
    pkt->dts = dts;
    pkt->stream_index = st->index;

    if (is_audio || ((flags & FLV_VIDEO_FRAMETYPE_MASK) == FLV_FRAME_KEY))
        pkt->flags |= PKT_FLAG_KEY;

    return ret;
}

AVInputFormat flv_demuxer = {
    "flv",
    NULL_IF_CONFIG_SMALL("FLV format"),
    0,
    flv_probe,
    flv_read_header,
    flv_read_packet,
#ifdef __CW32__
    0,
    0,
    0,
    0,
    "flv",
    CODEC_ID_FLV1,
#else
    .extensions = "flv",
    .value = CODEC_ID_FLV1,
#endif
};