[FFmpeg-user] format_whitelist and fFMPEG command

[Carl Eugen Hoyos]

Moritz Barsnick <barsnick <at> gmx.net> writes:

> > For mov, it will report "major_brand: qt", for 
> > mp4 it should be "major_brand: isom".
> 
> Ah, so ffmpeg does translate the atomic differences 
> into differing reports? I just noticed: ffprobe too 
> can display this as "TAG:major_brand=" ("-show_format").

I wouldn't say "translate". The files (mov, mp4 etc.) 
start with a "ftyp" atom and (I believe) the 
specifications call the content of the atom "major 
brand". At least qt, isom, mp42 exist, they are all 
compatible when reading, but need different handling 
when writing, that's why different muxers but only 
one demuxer exists.

Carl Eugen