Requests For Features

Peter S Kirk peter.kirk at
Fri Jul 24 12:50:49 PDT 2015

On 23 Jul 2015 at 21:56, Colin Law Colin Law <clanlaw at> wrote:

> On 23 July 2015 at 09:59, Jim web <web at> wrote:
> > ...
> > FWIW I tend to use this to 'snip' files
> >
> > ffmpeg -ss "hh:mm:ss" -i infile.<ext> -acodec copy -vcodec copy -t
> > "hh:mm:ss" output.<ext>
> You might occasionally find this gives strange effects at the start of
> the new file.  If you switch the options round so -i infile appears
> before -ss ".." then it stops this happening.  I think putting them
> this way round makes sure it scans the input file from the start so
> that the first frames of the output file are complete, whereas with
> them the other way round it just jumps in at the start point which can
> lead to strange artefacts.  Something like that anyway.


Useful info, thanks. If ffmpeg is starting the cut at the exact time if -ss 
before -i that implies it misses the necessary "key frame". The arefcats 
are a result of frames between key frames only containing changes from 
previous frame.

I use mkvtoolnix to split videos - with much laborious altering of split 
time to find +/- ss key frame - then remux mkv back to mp4 through ffmpeg 

Is there any quick way to find key frame times?



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