Question

我通过像这样的ffmpeg开始视频传输：

ffmpeg -f video4linux2 -i /dev/video0 -vcodec libx264 -preset ultrafast -crf 20 -tune zerolatency -s 800x600 -r 25 -b:v 0.9M -sdp_file video.sdp -f rtp rtp://192.168.10.24:5010

我以这种方式重现：

ffplay -protocol_whitelist file,udp,rtp video.sdp

一切正常。然后我中断传输，几秒钟后我恢复。 ffplay不会立即开始重现，但会发生错误：

....
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 14 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 33 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 41 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 49 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 33 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 27 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 14 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 48 times
[sdp @ 0x6ebf80] RTP: dropping old packet received too lateB f=1/1
    Last message repeated 34 times
......

一段时间后，播放恢复，但时间太长。有没有办法消除或最小化传入流被暂停，可以选择或其他什么时出现这种性质的错误？阅读手册ffmpeg没有什么值得的，这不是naryl ....（（（

Answer 1

好了，所以我有同样的问题，它花了好小时。深入研究ffmpeg代码；在libavformat/rtpdec.c

中

    if ((s->seq == 0 && !s->queue) || s->queue_size <= 1) {
    /* First packet, or no reordering */
    return rtp_parse_packet_internal(s, pkt, buf, len);
} else {
    uint16_t seq = AV_RB16(buf + 2);
    int16_t diff = seq - s->seq;
    if (diff < 0) {
        /* Packet older than the previously emitted one, drop */
        av_log(s->ic, AV_LOG_WARNING,
               "RTP: dropping old packet received too late\n");
        return -1;
    } else if (diff <= 1) {

它谈到no reordering。因此，我跟进了queue_size，并在libavformat/rtsp.c中谈到了reordering_queue_size，并在文档https://ffmpeg.org/ffmpeg-protocols.html#rtsp中展示了

-reorder_queue_size

    Set number of packets to buffer for handling of reordered packets.

它不是明确的，但是如果添加-reorder_queue_size 0可以解决此问题，因为它停止对数据包进行排序。我验证并解决了我的问题。我可以中断信号源... 2分钟后重启，它就可以正常工作

主要是因为为UDP和实时我不需要任何命令，它应该只是扮演什么样的来通过

希望这也可以解决您的问题

ffmpeg rtp流错误：RTP：丢弃收到的旧数据包太晚

1 个答案: