[FFmpeg-user] Are pipe's slow?

Carl Zwanzig cpz at tuunq.com
Thu Sep 10 19:33:47 EEST 2020

On 9/10/2020 1:28 AM, Simon Brown wrote:
> Equally, if I
> run myTestOnDemandRTSPServer from a file then it can play it without
> issue.  It seems to be the combination of the two that causes the problem.

Are you sure that the server is actually reading from the pipe? That is-

cat myfile | ./myTestOnDemandRTSPServer

is myTestOnDemandRTSPServer a script or an executable?
does it read from stdin?
is myTestOnDemandRTSPServer silently crashing when it connects to the pipe?
is it expecting the same format as the other device produces?

(it's not clear how you've tried things or which OS you're using.... the 
command output is always wanted here, as is using the most recent build)

*nix pipes should should have very little latency, so if you manage to stuff 
15 seconds of video into one it's probably not being emptied

You can exercise the pipe mechanism itself with

ffmpeg -i udp://:61120 -c:v copy -an -f h264 pipe:1 | cat - >/dev/null
That should run basically forever.


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