[Ffmpeg-devel] seek with duration for cutting: broken or changed?

Cyrus A lists
Mon Oct 30 23:37:25 CET 2006

Michael Niedermayer wrote:
> Hi
> On Mon, Oct 30, 2006 at 12:55:16PM -0500, Cyrus A wrote:
>> The following command used to work to cut a specific segment out of a 
>> video file on some FC3 machines I'm using with an old version of ffmpeg 
>> (still does work):
>> ffmpeg -acodec copy -vcodec copy -i fullvideo.avi -ss 60 -t 120 
>> choppedvideo.avi
>> But it doesn't work anymore with Fedora Core 5 on a 64-bit machine 
>> running today's SVN copy of ffmpeg. (Also doesn't work with freshrpms 
>> latest ffmpeg rpm, either.) I believe what it's doing is seeking, but 
>> the duration is completely ignored. It just returns the rest of the file 
>> from where the seek took it. The resulting file is also a little 
>> "chirpy"  -- the audio video sync is messed up somehow.
> could you find out when this problem was introduced into svn (see 
> binary search and svn up -r)
> [...]
Found it. The seek + duration option worked normally through revision 
4526 and then stopped working in 4527 and every other revision 
thereafter. It was August 15th, 2005.

The change notes read:

parse pict_type for streams in avi
fix mpeg4 parser so it outputs te pict_type
support header only parseing without repacking

That's interesting since I'm using mpeg4 for my vcodec and producing an 
AVI file.

Man, binary searching like that is not fun. Please let me know what you 


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