[FFmpeg-user] Is there any good reason why FFmpeg doesn't do "-vcodec copy" automatically.

[Steven Kan]

> On Sep 30, 2023, at 12:07 PM, Reindl Harald <h.reindl at thelounge.net> wrote:
> 
> 
> Am 30.09.23 um 20:46 schrieb Stéphane Archer:
>> Is there any good reason why FFmpeg which sees that the video file input
>> and output match every single characteristic doesn't copy the stream to
>> avoid useless reencoding?
>> Basically doing "-vcodec copy" automatically.
> 
> is there a good reason to throw a video file through ffmpeg when you don't want to touch it?
> 
> yeah, there may be a few reasons, and for the really *few* reasons you are supposed to state that

Perhaps the user has an automated workflow that accepts X, Y, Z, and W, but always outputs W. If any particular incoming file happens to be W, it would be more efficient to not re-encode that particular file.