[FFmpeg-user] -t option is ignored

Rodney Baker rodney.baker at iinet.net.au
Mon Mar 26 15:58:38 CEST 2012

On Mon, 26 Mar 2012 21:31:44 Martin G wrote:
> FFMPEG users,
> I am trying to edit a subclip from a larger movie. I just want a two
> minute section.
> This is the command I have been working with:
> ffmpeg -i input.avi -ss 01:05:16 -t 120 -vcodec copy -acodec copy
> output.avi

In my experience it is faster to put -ss and -t options before -i, otherwise 
ffmpeg parses the whole file up to -ss before starting conversion. With -ss 
first, it begins reading at that point (or the closest i-frame or reference 

Unless, of course, the behaviour has changed in recent versions but I have 
developed the habit of always putting the seek and duration options first.


> However, instead of getting a two minute (120 second) clip, I get a
> clip that starts at the selected time, and runs all the way to the end
> of the film (about 45 minutes long).
> What is wrong with this command?
> How can I get ffmpeg to only output a specific time length of video?
> Thank you.

Rodney Baker VK5ZTV
rodney.baker at iinet.net.au

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