[FFmpeg-user] HTTP playlist stream copy to an IP QAM modulator

Reuben Martin reuben.m at gmail.com
Wed Jul 20 06:56:00 EEST 2016

On Tuesday, July 19, 2016 10:16:03 PM CDT Anacelia Sarlo wrote:
> ffmpeg -re -y -i $stream  -c copy -f mpegts -map 0:0 -map 0:1
> -mpegts_pmt_start_pid 66 -streamid 1:71 -streamid 0:70 udp://
> When I watch the stream from the cable network,  the audio is OK but the
> video looks sometimes faltering and other times too fast, and out of sync.
> But when I received this same output with ffplay it runs OK.
> It seems there is a problem with the time base, I did many testings with
> (genpts, copyts, etc)  with no good results.

You might try and see what happens if you re-encode it rather than copying the 
media streams. Thing is with copying the stream you pass on any flaws that 
might be able to be corrected by ffmpeg, but are not as gracefully dealt with 
by other implementations.

At least that might help narrow the problem down a bit and determine if the 
problem is with the origional source, or with ffmpeg.

It would be nice to have a bit-stream filter to re-write time stamps when 
doing a stream copy, but sadly no such filter exists yet.


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