[FFmpeg-user] ffmpeg not syncing while using pipe

frank ernest doark at mail.com
Thu May 8 22:11:21 CEST 2014

>> ffmpeg -nostdin -loglevel debug -f video4linux2 -framerate 20 \
>> -s:v 640x480 -i /dev/video0 -ac 2 -f alsa -i hw:0 -ac 2 \
>> -c:a libvorbis -s:v 640x480 -b:v 100KiB -c:v libvpx -f nut \
>> -b:a 9000B -filter_complex volume=15 -
>(filter_complex seems unneeded.)

I wanted higher volume and as far as I can tell filter_complex is the
only choice to accomplish that.

> My question was:
> If you use only this command (as far as I pasted it), 
> does it allow to reproduce the sync-problem if you 
> redirect to a file?
> Or don't you agree the answer will significantly 
> reduce the number of possible reasons?

Sorry, I thought you ment to redirct the output through a file
(a fifo is a file.) It filp frames on me, sometimes. And I think
I see the problem. when encoding I get this message at the same
place that the video falls out of sync. "*** drop!"
I also tried playing back the file using vlc but it got stuck
on a video frame too.

>> Setting the logging level to debug
>> outputs more then 10000 lines
> Sorry, I am not a native speaker:
> How does "without loglevel fatal" imply debug level?

That was my idea, after all, I am trying to debug right?

>> ffmpeg version 2.1.1
> Please test current git head.

Ok, I'll download the latest version, but I'm not going to compile
ffmpeg now.

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