ffmpeg AAC Decoder

[senab]

Just saw that the ffmpeg GSoC project for a new AAC decoder has been commited to their SVN. It only supports LC-AAC at the mo, but HE-AAC and PS are being worked on now.

The thing about it is, it's about > 2x faster than FAAD. Obviously thats on my x86 machine and won't necessarily happen on Coldfire or ARM. I couldn't find a trac page on the patch so not sure on the details of the decoder.

[Lear]

I'm pretty sure it is floating point only, so a fairly large amount of work is required to get it ready for Rockbox...

[saratoga]

This is something we have been talking about on IRC for a while now.  There are two options:

1)  Fix FAAD.
2)  Try and integerize ffmpeg.

I've been working on #1 because from my point of view is probably a lot easier to fix FAAD then to convert ffmpeg. 

For reference, with FS#9285, FAAD is already faster then MP3 decoding on PP, although it remains quite slow on Coldfire.  That said, if ffmpeg does anything better then FAAD (and I suspect it must given the large list of problems with the design of FAAD), then using parts of it are not a bad idea.