[Openquicktime-users] Determining Quicktime Aspect Ratio

[Roger M. <rog...@i2...>]

Hi

I'm trying to find some appropriate utility or source code that will =
enable my application to determine the aspect ratio of source quicktime =
files. My files might be 1:1, 4:3 or 16:9 and my application needs to =
know this in advance before processing the files.

I've been looking through the c source in ffmpeg / libquicktime / =
openquicktime / transcode and of course, the developer quicktime =
references at apple - but I am unable to find out how this information =
is coded in a .mov file.

When I use oqtinfo on a file known to be 16:9, it reports 720x576 as the =
size and yet quicktime itself is clearly finding aspect ratio info from =
somewhere as it sets the current size correctly as 720 x 432 (or =
something similar, I don't have it in front of me).

Can anyone help?

I'd like to know;

a) HOW is the aspect ratio information stored in a quicktime file
b) Pointers to any utility or source code that can help me extract this

Many thanks

Roger Moffatt
UK