[FFmpeg-user] understanding copy flag

Mike Scheutzow mike.scheutzow at alcatel-lucent.com
Mon May 16 18:09:22 CEST 2011

Rick C. wrote:
> Hello,
> I was making a few tests using the following syntax:
> ffmpeg -i original.avi -acodec copy -vcodec copy output.avi
> To my surprise the results were not very good (mainly just the audio side I believe).  Am I wrong in thinking this should work as a passthrough?  I tried the same with .mp4 and .mpg and the results were what I expected.  I didn't notice anything significant from the output log so I didn't post anything.  Any advice would be great.  Thanks!

If you want our help, you need to be more descriptive about the problem 
you have. "not very good" is too vague. Did you hear clicks? Is lip-sync 

Also, show us the *complete* output from 'ffmpeg -i original.avi'.

Mike Scheutzow

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