public static extern void avcodec_register(ref AVCodec pAVCodec);
public static extern void register_avcodec(ref AVCodec pAVCodec);
public static extern int avcodec_open(ref AVCodecContext pAVCodecContext, AVCodec* pAVCodec);
public static extern int av_bitstream_filter_filter(ref AVBitStreamFilterContext pAVBitStreamFilterContext, ref AVCodec pAVCodecContext, string args, ref byte[] poutbuf, ref int poutbuf_size, byte[] buf, int buf_size, int keyframe);