[FFmpeg-user] Problem with instances of ffplay

Maziar Mehrabi maziar.mehrabi at gmail.com
Wed Nov 26 10:06:29 CET 2014

Hello everyone,

I'm not sure whether this problems relates to ffplay, ffmpeg or my system's
OS. I would appreciate any kind of comment, suggestion or solution.

here is the scenario:
I use ffmpeg to stream video files to UDP and then I use ffplay to play
these streams (all on the same machine using ffmpeg -re -i input1 -f mpegts
udp://localhost:port1 and ffplay udp://localhost:port1 and similar commands
for other streams). I first run the ffplay commands and they seem to be
waiting (or listening) to udp port for incoming streams, then I start
streaming with ffmpeg. This works fine in most of the cases and if I have
for example two streams of video then two instances of ffplay will start
playing these videos in separate windows right after the streaming starts.

The problem arises in some cases when I start ffmpeg streams shortly one
after another then the system does not open two separate instances of
ffplay in separate windows, instead both video streams get merged and
played in one ffplay instance and in one window. Although I dedicate two
different ports for each stream, but one of the players seems to be still
on the waiting mode showing the following in the console while the other
one plays both streams.
 nan    :  0.000 fd=   0 aq=    0KB vq=    0KB sq=    0B f=0/0

This problem appears more frequently when instantiations are somehow
automated (e.g. using bash). But also appears when I switch between console
tabs rapidly and run ffmpeg instances. What do you think about this? Is it
related to streaming with ffmpeg? or ffplay binding to udp ports? or OS's
inabilities to dedicate resources for each instance of ffplay? How can I
track it down and narrow this scope?

My ffmpeg version: ffmpeg version 2.3.git. Does it need upgrade? I was
simply waiting for 2.5 to be released.
OS: Ubuntu 14.04 LTS

Thanks a lot,

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