avcodec on C，定格图像

Question

我将视频数据包从视频流写入缓冲区。然后我试着把它们写到文件中。

            av_init_packet( &pkt );
            int bufer_size=250;

            while ( av_read_frame( ifcx, &pkt ) >= 0 && start_flag==0 && stop_flag==0){
                printf("reading packet - %i \n", pkg_index);
                if ( pkt.stream_index == i_index ) {
                    pkt.stream_index = ost->id;
                    pkt.pts = av_rescale_q_rnd(pkt.pts, ist->time_base, ost->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
                    pkt.dts = av_rescale_q_rnd(pkt.dts, ist->time_base, ost->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
                    pkt.duration = av_rescale_q(pkt.duration, ist->time_base, ost->time_base);
                    pkt.pos = -1;
                    av_copy_packet(&pkt_arr[pkg_index],&pkt);
                }
                av_free_packet( &pkt );
                av_init_packet( &pkt );
                pkg_index++;

                if(pkg_index>=bufer_size){

                    int ret = avformat_write_header(ofcx, NULL);
                    av_dump_format( ofcx, 0, ofcx->filename, 1 );

                        int i;
                        int start_frame=0;
                        for(i=start_frame; i<bufer_size; i++){
                            av_interleaved_write_frame( ofcx, &pkt_arr[i] );
                        }

                          av_write_trailer( ofcx );
                          avio_close( ofcx->pb );
                          printf("END \n");
                          return 0;

                }
            }

现在的问题是:如果start_frame=0一切正常，我有10秒的视频文件。但如果start_frame=125 (例如)在resault中，我有5秒冻结图片和5秒视频的视频文件。

怎么啦？

同样在最后，我也有错误：

[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 1
[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 2
[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 3
[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 4
[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 5
[avi @ 0x287a9f0] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 6 >= 6

也许你知道它是什么。

Answer 1

这说明你必须重新调整数据包pts/dts，以适应+125帧的变化。尝试在av_interleaved_write_frame之前重新标记pt/dts。对于pts，这个简单的公式可能适用于pkt.pts = frame_count * pkt.duration。dts更复杂，但对于测试推送，请尝试pkt.dts = pkt.pts。希望这能有所帮助。