ffmpeg RTSP error while decoding MB

Question

I\'m using ffmpeg to read an h264 RTSP stream from a Cisco 3050 IP camera and reencode it to disk as h264 (there are reasons why I\'m not just using -codec:copy).

Answer 1

Looking at the initial error message:

[rtsp @ 0x7f268c5e9220] max delay reached. need to consume packet
[rtsp @ 0x7f268c5e9220] RTP: missed 40 packets

I guess that you are loosing UDP packets. The rest of the H.264 error messages are caused by receiving an incomplete bitstream. Now key is to isolate the issue. Is your network dropping packets? Or is your sever too slow or overloaded receiving the UDP (RTP).

First I'd check the UDP buffer size of your OS. https://access.redhat.com/documentation/en-US/JBoss_Enterprise_Web_Platform/5/html/Administration_And_Configuration_Guide/jgroups-perf-udpbuffer.html

If increasing the UDP buffer size doesn't help - use ffmpeg with -codec:copy to lower the CPU load. Do you still get errors? Since you want to reencode consider using Intel Quicksync -vcodec h264_qsv or some other hardware encoder lowering your CPU load.

The question is not so much about if the PC has enough CPU. But more about identifying the bottle neck in the processing pipeline. Your H.264 encoder (x264) may over subscribe your CPU so that you get momentary peak loads that result in packet drops. Try limiting the number of threads for x264 and/or lower the quality to 'fast' or 'faster'.