（一）mplayer与ffmpeg的调用过程

mplayer调用ffmpeg解码视频流过程

mplayer播放视频硬解码流程
update_video(int *blit_frame)
    generate_video_frame(sh_video_t *sh_video, demux_stream_t *d_video) === mplayer：mplayer.c
        decode_video(sh_video, start, in_size, drop_frame, pts, NULL);  === mplayer：mplayer.c +1822
         *decode(sh_video_t *sh, void *data, int len, int flags)
            avcodec_decode_video2(avctx, pic, &got_picture, &pkt); === mplayer：libmpcodecs/vd_ffmpeg.c
                compat_decode(AVCodecContext *avctx, AVFrame *frame,int *got_frame, const AVPacket *pkt)
                    avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
                         decode_receive_frame_internal(avctx, avci->buffer_frame);
                            ret = avctx->codec->receive_frame(avctx, frame);
                                hantrocodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
                
                    avcodec_receive_frame(avctx, frame);
                        decode_receive_frame_internal(avctx, avci->buffer_frame);
                                ret = avctx->codec->receive_frame(avctx, frame);
                                   硬解码接口
                    if (ret < 0) {
                             if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                                 ret = 0;
                              goto finish;
                     }