Allows the AC3 parser to read the frame size and codec parameters from E-AC3 streams,

allowing them to be correctly demuxed.
Currently it only identifies the primary substream, and will skip over any additional
dependent or independent substreams.
Patch by Ian Caulfield % ian P caulfield A gmail P com %
Original thread:
date: Jan 19, 2007 9:55 AM
subject: Re: [Ffmpeg-devel] [PATCH] Correctly parse headers of E-AC3 streams

Originally committed as revision 7687 to svn://svn.ffmpeg.org/ffmpeg/trunk