[FFmpeg-user] Using the flags -movflags +faststart

Frank Tetzel s1445051 at mail.zih.tu-dresden.de
Sun Feb 26 17:22:28 EET 2017

> > The '+' sign in front of the flags is not going to work? I disagree.
> > ffmpeg's command line parser doesn't care whether the first flag is
> > prepended with a '+' or not:  
> Actually, I found this comment
> (http://stackoverflow.com/questions/23419351/ffmpeg-using-movflags-faststart#comment60936769_23440682):
>   The + sign indicates that ffmpeg should set the specified value in
>   addition to any values that the MOV/MP4 muxer will automatically set
>   during the course of executing the command. Omitting it means ffmpeg
>   will reset the flags to their default values, and only toggle the
>   state of faststart. Most MP4s generation doesn't involve the other
>   flags so usually it doesn't make a difference.
> I couldn't find this in ffmpeg's source or docs though.

Mhmm, maybe not anymore. I think I read about it some years ago in the
docs or wiki. In some of the examples it's still in, but no explanation.


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