我通过 ffmpeg 开始视频传输，如下所示：
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出现错误：
....
[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 …