[Ffmpeg-devel] [Ss][Nn][Oo][Ww] spelling^wbranding

[Måns Rullgård]

Rich Felker <dalias at aerifal.cx> writes:

>> A great advantage from strings are that they're very extensible.
>> You can easily have sub-type and whatever, like "MPEG-4 / level 1" or 
>> "MPEG-4 (ffmpeg x.y.z)" just like HTTP does for browser identification.
>> Danger for name collisions is low and there is little need for central 
>> registry, like for fourccs.
>
> This is a disadvantage because idiots are more likely to use random
> variants on the basic string, and then all player apps need to be
> updated to know about every single stupid variant someone uses.
> Fourccs have the advantage of being a fairly limited space without
> room for alternate spellings, misspellings, typos, etc.

OK, my list of fourccs used for mpeg4 currently contains no less than
16 variations:

\004\0\0\0
BLZ0
DIV1
DIVX
divx
DX50
FMP4
M4S2
m4s2
M4S2
mp4s
MP4S
mp4v
UMP4
XVID
xvid

This covers all the files I've come across, but I'm sure there are
more out there.

Even if we stick to alphanumeric characters, there's still room for
14776336 different fourccs, which should be plenty enough for idiots
to screw things up.

-- 
M?ns Rullg?rd
mru at inprovide.com