[FFmpeg-user] usage of fifo_size option while receiving udp stream hangs ffmpeg itself

Simon Thelen ffmpeg-user at c-14.de
Mon Sep 29 11:53:01 CEST 2014

On 29/09/14 at 17:10, ajay parashar wrote:
> ajay parashar <ajay_382000-at-yahoo.co.in <at> ffmpeg.org> writes:
> > “ffmpeg –i udp:// -map 0:v:1 -map 0:a:0 
> > -acodec copy -f mp4 2909_3v.ts” 
> > 
> > My concern is that the output file 2909_3v.ts is 
> > neither playable by vlc nor by ffplay.
> Carl Eugen Hoyos <cehoyos at ag.or.at> writes:
> >>Remove "-f mp4".
>       My video is MPEG4 encoded in transport stream and it is live video. I 
> want to capture mpeg4 encoded data so i am using mp4 format , is ther 
> any    othet format that can be use to receiving AVC codec data and will 
> resolve this issue
Use -f mpegts, MPEG4 in this case is the video codec and not the format.
> >>As said here from time to time, I suspect FFmpeg is not 
> >>the best tool to dump transport streams: I suggest you 
> >>pipe the udp stream to a file and use FFmpeg later 
> >>to convert the file to whatever format you need if you 
> >>don't want to keep the transport stream.
> As it is live video is it possible that first it dump  to file then simultaneously stream video data to end user ?
Sure, just use something like tee to pipe the stream to a file and some
program/fifo for viewing.

Simon Thelen

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