From (other) encoding GUIs I know that I can specify (for AVC/H.264 encoding) a maximum key frame interval (e.g. max 200).
How do I do this at the ffmpeg command line?
Furthermore I would like to resize the output video to lets say 640*400 pixel.
How do I specify this new resolution at the cmdline for ffmpeg?
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Ok, thank you.
Do I have to enter these option in a two-pass encoding (for H.264) in BOTH steps or only the last (second pass) command?
Thank you but sorry I have still a special question:
Assume I have a source video with an unknown resolution and unknown aspect ratio.
Now I want to shrink the video to a width of 800. The height should be automatically adjusted so that the aspect ratio of the source is kept.
How can I specify that?
work (mind the missing height value)?
It gets tricky with different PAR (pixel aspect ratio) values (also called SAR, or sample aspect ratio), you need some equations with padding (for letterbox/pillarbox) , I'm not sure how to do it exactly in ffmpeg . Selur probably knows , he probably has something implemented in his hybrid GUI program
But for simple square pixel example , use "-1" to calculate dimension from source
EDIT: maybe this will help for the different AR examples, but it needs to be modified
Last edited by poisondeathray; 17th Sep 2013 at 12:18.