[Openquicktime-devel] Re: Audio Codecs Added to CVS

[Nicholas H. <nj...@ec...>]

>endianess problem: on i386-linux, twos should do byte swapping and 
>sowt should not.

I put put a fix for this in CVS - hopefully it will work... there are 
a few other endian bugs around the place... I don't think 
oqtextractaudio works on little endian - and there is a problem with 
the encoder on Big Endian...

Also added 'alaw' and 'agsm' audio codecs. Real Quicktime can't even 
encode GSM 06.10... ;-)  I have managed to stream live audio using 
it. Not very useful for anything apart from speech. Almost got all 
the audio codecs done this weekend :)

I have been looking at the Ogg Vorbis codec. 
http://qtcomponents.sourceforge.net/ do a plugin to let you use Ogg 
Vorbis in real quicktime - I was looking at the headers in the Sound 
Samples Description - and they are doing something quite odd - a very 
long header... might take a bit more work than I thought. Oh well it 
is open source at least...

I think encoding is still broken - something odd happened to the 
oqt_encode_audio function ;-) and it is generating the 
Sample/Chunk/Offset tables correctly...

Also I think the arguments for the oqt_encode_audio function should 
be changed so that it takes interleaved 16-bit samples as its input - 
rather than array of channels... there is code on both sides for the 
call that converts between the two formats :)

Unfortunately I have a report (thesis) to write now - so there will 
be less check-ins to CVS for a bit...


nj.
-- 
Nicholas Humfrey

Undergraduate, BSc Computer Science
University of Southampton, UK
nj...@ec...
http://www.ecs.soton.ac.uk/~njh399/