static int dump_extradata(AVBitStreamFilterContext *bsfc, AVCodecContext *avctx, const char *args,
                     uint8_t **poutbuf, int *poutbuf_size,
                     const uint8_t *buf, int buf_size, int keyframe){
    int cmd= args ? *args : 0;
    /* cast to avoid warning about discarding qualifiers */
    if(avctx->extradata){
        if(  (keyframe && (avctx->flags2 & CODEC_FLAG2_LOCAL_HEADER) && cmd=='a')
           ||(keyframe && (cmd=='k' || !cmd))
           ||(cmd=='e')
            /*||(? && (s->flags & PARSER_FLAG_DUMP_EXTRADATA_AT_BEGIN)*/){
            int size= buf_size + avctx->extradata_size;
            *poutbuf_size= size;
            *poutbuf= av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!*poutbuf)
                return AVERROR(ENOMEM);

            memcpy(*poutbuf, avctx->extradata, avctx->extradata_size);
            memcpy((*poutbuf) + avctx->extradata_size, buf, buf_size + FF_INPUT_BUFFER_PADDING_SIZE);
            return 1;
        }
    }
    return 0;
}