[Ffmpeg-devel] Fixed vs. Floating Point AAC

Michel Lespinasse walken
Fri Mar 10 00:36:35 CET 2006

On Wed, Mar 08, 2006 at 05:32:53PM -0800, Mike Melanson wrote:
> 	Okay, so we need to start tracking these requests:
> * pure float implementation
> * fast, low-precision, strictly 32-bit integer implementation
> * slower, higher-precision 32-bit integer implementation
> * pure 64-bit integer implementation
> Anyone else have a request while we're in the planning phases? :)

Double precision float implementation (not to be used in production,
but nice to have at the development stage to have a reference to compare
the others precision against).

Floats are definitely easiest to start with. In my experience, they are
also fastest on about every <10 years old desktop hardware - though they
are very slow on some embedded chips that do not have hardware support.

If someone is looking for a benchmark, liba52 CVS supports both floats
and ints as a configure option - with the same code base and algorithms
otherwise. You can even switch between the 3 above mentionned integer
support modes by just changing a few ifdefs at the end of a52_internal.h

Hope this helps, though I'd be surprised if integer supporters changed
their mind about this. In my opinion, they've been ignoring the evidence
for 10 years already.

Michel "Walken" Lespinasse
"Bill Gates is a monocle and a Persian cat away from being the villain
in a James Bond movie." -- Dennis Miller

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