ffmpeg生成带关键帧头信息的flv文件(三)

static int flv_write_trailer(AVFormatContext *s)

{

    int64_t file_size;

 

    AVIOContext *pb = s->pb;

    FLVContext *flv = (FLVContext*)s->priv_data;

    int i;

 

    /* Add EOS tag */

    for (i = 0; i < s->nb_streams; i++) {

        AVCodecContext *enc = s->streams[i]->codec;

        FLVStreamContext *sc = (FLVStreamContext*)s->streams[i]->priv_data;

        if (enc->codec_type == AVMEDIA_TYPE_VIDEO &&

                (enc->codec_id == CODEC_ID_H264 || enc->codec_id == CODEC_ID_MPEG4)) {

            put_avc_eos_tag(pb, sc->last_ts);

        }

    }

 

    file_size = avio_tell(pb);

    flv->datasize = file_size - flv->datastart_offset;

 

    /* update information */

    avio_seek(pb, flv->duration_offset, SEEK_SET);

    put_amf_double(pb, flv->duration / (double)1000);

 

    /********** Add KeyFrame Index ***********************************/

    avio_seek(pb, flv->datasize_offset, SEEK_SET);

    put_amf_double(pb, flv->datasize);

 

    avio_seek(pb, flv->videosize_offset, SEEK_SET);

    put_amf_double(pb, flv->videosize);

 

    avio_seek(pb, flv->audiosize_offset, SEEK_SET);

    put_amf_double(pb, flv->audiosize);

    /************************************************************************/

 

    avio_seek(pb, flv->filesize_offset, SEEK_SET);

    put_amf_double(pb, file_size);

 

    /********** Add KeyFrame Index ***********************************/

    avio_seek(pb, flv->lasttimestamp_offset, SEEK_SET);

    put_amf_double(pb, flv->lasttimestamp);

 

    avio_seek(pb, flv->lastkeyframetimestamp_offset, SEEK_SET);

    put_amf_double(pb, flv->lastkeyframetimestamp);

 

    avio_seek(pb, flv->lastkeyframelocation_offset, SEEK_SET);

    put_amf_double(pb, flv->lastkeyframelocation);

 

    int vKeyFrames = flv->filepositions.GetSize();

    if (vKeyFrames < MAX_FLV_KEY_FRAME)

    {

        DWORD vfilepositions = flv->filepositions.GetSize();

        avio_seek(pb, flv->filepositions_offset, SEEK_SET);

        put_amf_dword_array(pb, vfilepositions);

        for(int i = 0; i < vKeyFrames; i++)

        {

            double afilepositions = flv->filepositions.GetAt(i);

            put_amf_double(pb, afilepositions);

        }

 

        // times 向¨°前¡ã移°?动¡¥

        put_amf_string(pb, "times");

        flv->filetimes_offset = avio_tell(pb);

 

        DWORD vfiletimes = flv->filetimes.GetSize();

        avio_seek(pb, flv->filetimes_offset, SEEK_SET);

        put_amf_dword_array(pb, vfiletimes);

        for(int i = 0; i < vKeyFrames; i++)

        {

            double afiletimes = flv->filetimes.GetAt(i);

            put_amf_double(pb, afiletimes);

        }

 

        // 后¨®面?的Ì?数ºy据Y清?0

        int64_t vcurfile_Pos = avio_tell(pb);

        int vbytecount = flv->filetimesend_Pos - vcurfile_Pos;

        for (int i = 0; i < vbytecount; i++)

        {

            put_amf_byte(pb, 0);

        }

    }

    else

    {

        double  dbStep = 1.0 * vKeyFrames / MAX_FLV_KEY_FRAME;

 

        DWORD vfilepositions = MAX_FLV_KEY_FRAME;

        avio_seek(pb, flv->filepositions_offset, SEEK_SET);

        put_amf_dword_array(pb, vfilepositions);

        for(int i = 0; i < MAX_FLV_KEY_FRAME; i++)

        {

            int vIndex = int(dbStep * i);

            double afilepositions = flv->filepositions.GetAt(vIndex);

            put_amf_double(pb, afilepositions);

        }

 

        DWORD vfiletimes = MAX_FLV_KEY_FRAME;

        avio_seek(pb, flv->filetimes_offset, SEEK_SET);

        put_amf_dword_array(pb, vfiletimes);

        for(int i = 0; i < MAX_FLV_KEY_FRAME; i++)

        {

            int vIndex = int(dbStep * i);

            double afiletimes = flv->filetimes.GetAt(vIndex);

            put_amf_double(pb, afiletimes);

        }

    }

 

    flv->filepositions.RemoveAll();

    flv->filetimes.RemoveAll();

    /************************************************************************/

 

    avio_seek(pb, file_size, SEEK_SET);

    return 0;

}