[FFmpeg-user] "-acodec copy -vcodec copy" output smaller than original

Moritz Barsnick barsnick at gmx.net
Fri Sep 16 20:29:20 EEST 2016

On Fri, Sep 16, 2016 at 05:25:07 +0000, Olexandr Melnyk wrote:
> ffmpeg -i Svalbard2016_g04033.mp4 -acodec copy -vcodec copy -map 0
> output.mp4
> Here, the output file I'm getting is 5MB smaller than the source file. And
> if I do the same for a bigger source file, the size difference is bigger as
> well.

Please do show us the complete, uncut console output of your command.

> Any thoughts why this is happening?

Many things to speculate about. Less speculation if we see the valuable
information ffmpeg prints to console. ;-) For example it could be
dropping other streams (unknown data), it could be dropping padding,

> I'm going to delete the source files eventually, hence I'm afraid if I'm
> losing anything (metadata?) in the process.

Metadata you could check.

> https://dl.dropboxusercontent.com/u/30369146/Svalbard2016_g04033.mp4 (produced
> with an original SJ5000+ camera, if that's of any help)

I'll check later, my download asks me to be patient for another 30


P.S.: Svalbard! <3

More information about the ffmpeg-user mailing list