[Ffmpeg-devel] Re: [PATCH] mov fourccs for handling FCP files

[Roberto Togni]

On Wed, 15 Feb 2006 11:23:40 -0800
Mike Melanson <mike at multimedia.cx> wrote:

> Roberto Togni wrote:
> > A sample for fl32 with enda atom is here
> > http://equinox.campus.ltu.se/samples/A-codecs/qtfl32/vb3.mov
> > MPlayer plays it as be float 32bit. I had no idea about the enda atom
> > when i added support for it, so i just considered all fl32 samples to be
> > be.
> 
> 	What I've always wondered about PCM is the range. What is the range of 
> the samples? -32768.0 -> 32767.0? -1.0 -> 1.0?
> 
Looking at MPlayer code they are in range -1.0 <--> +1.0

> > These files also seems to have an enda atom, but being mp3 i don't know
> > what's the meaning of it
> > http://equinox.campus.ltu.se/samples/mov/qtaudio/surge-2-16-B-.mp3.mov
> > http://equinox.campus.ltu.se/samples/mov/qtaudio/surge-2-16-B-ms55.mov
> 
> 	The 'B' or 'L' in the surge audio samples denotes that the decoded 
> 16-bit PCM data is in either big or little endian format ... hmm, you're 
> right, that doesn't make much sense in this context.

There were also other "surge" samples (in24/32, fl, ...) on
Openquicktime website in the past, but they are not there anymore. I
don't have them, if anybody downloaded them please contact me.

Ciao,
 Roberto