[FFmpeg-user] Need help; willing to pay

Moritz Barsnick barsnick at gmx.net
Tue Jan 5 21:08:10 CET 2016

On Tue, Jan 05, 2016 at 13:30:07 -0600, Matthew Adams wrote:
> I pulled the files off of the iPhone using iExplorer, a nice little tool to
> get at the iOS filesystem.

Hmm. Something tells me this isn't the raw video as it comes from your
device, but it was manipulated by Google (Drive) after your upload:

$ sha1sum variable-bitrate-sample.mov
3820bb93784835f2257299008fed2fafeaacd5c5  variable-bitrate-sample.mov
$ ffmpeg -i variable-bitrate-sample.mov 
ffmpeg version 2.6.5 Copyright (c) 2000-2015 the FFmpeg developers
      creation_time   : 2016-01-03 05:53:31
      handler_name    : IsoMedia File Produced by Google, 5-11-2011

I don't think any Apple product inserts such metadata. ;-)

Googl(ouch!)ing a bit, it does seem iOS creates variable frame rate
videos. But usually, they are detected as such, or in other words, the
headers and timestamps properly reflect that.

So I think Google Drive ruined your video by doing some bad CFR magic
to it.

The video as *I* get it from your Google drive is not fixable without
manual analysis of the timeline. Likely the original video which is (or
has remained) on your iPhone is different. If it doesn't play fine
there either, the video recording software fooled you, or did this
effect on purpose due to some configuration. If it does play correctly
on the iPhone though, you may need to find a different way to get that
file to us. You probably wouldn't even need to fix it if Google Drive
(your way to share the videos with others?) didn't mess it up.

ffmpeg *can* convert VFR to CFR if need be (for the sake of players
which can't handle the former).


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