[Libav-user] High CPU load for parsing MPEG-TS

Andrea3000 andrea3000 at email.it
Thu Nov 17 21:48:15 CET 2011

I use latest git version of FFmpeg API as parser in my 
media player app (not as decoder).
It works great with every format/codec/muxer/ecc..

The only annoying thing is that with around 50%-60% of 
MPEG-TS file that I've tested, CPU stays over 60% just 
for parsing data.
If I remux the movie file with tsMuxer 
(without re-encoding and using the same container), 
the problem disappears and CPU usage is below 5%.

I've never seen this issue with FFmpeg-mt versions 
prior to 0.6. I don't know about versions in beetwen 
because I jumped from FFmpeg-mt 0.5.x to latest
FFmpeg git repository.
And this is not the only strange thing. If I don't allow 
FFmpeg to seek through the file to correctly allocate 
AVFormatContext and to identify all the available 
streams, it does find only the first streams 
(main video track and audio tracks) and not all the PGS
subtitles tracks and secondary video track, but the 
high CPU usage problem does not appear!

What is going on here? Am I missing something? 



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