[Ffmpeg-devel] closed captioning bug?

Luca Abeni lucabe72
Mon Apr 24 08:23:36 CEST 2006


On Sun, 2006-04-23 at 23:50 -0400, Cyrus A wrote:
> More info here: I downgraded (wiped and reinstalled) to FC3. An old 
> version of ffmpeg (probably early 2005) seems to work (at least for a 
> while) when trying to capture closed captions.*
I know this is a lot of work, but can you try a dichotomic search to
find out which commit is responsible for the breakage you are seeing?
My experience is that this commit
might cause problems when capturing audio and video simultaneously
(note: the commit is perfectly fine and correct. The problem is that the
grab.c and audio.c inputs are a little bit "special").
But if early 2005 works ok for you this commit is not the problem...

> * The caps will work fine for up to 5 minutes (maybe more) with ffmpeg 
> driving /dev/audio and /dev/video0. However, they eventually get garbled 
> again for some reason. Maybe the caps go bad when I use my USB KVM 
> switch? I have no idea. I'm going to try doing them without KDE or GNOME 
> running and no USB switching over the next 24 hours. We'll see how they 
> turn out.
I think the output of "dmesg" and "lsmod" could be useful for finding
the problem.

Also,try execution ffmpeg alone (without closed captioning) but adding
"-v 5" to the command line, and see if duplicated/dropped frames are

Proud to be "coglione"

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