[MPlayer-users] Feature Request / A humble wish: Optimize libfaad2 / AAC+ decoder for MMX/i586

[Jason Garrett-Glaser]

On Thu, Oct 9, 2008 at 9:58 AM, Urja Rannikko <urjaman at gmail.com> wrote:
> Hi,
>
> I'm not sure whether this mail should go to devel or users, but i
> think it could be classified as a feature request, so sending to
> users.
>
> I'm just using my old Pentium 233 MMX box to play some 24kbps AAC+
> stream and it takes 69% of CPU to play that,
>  compared to ~13-15% for 128kbps-320kbps MP3.
> (libmp3 seems to have pretty good optimizations, just compare "ls
> libfaad2" and "ls mp3lib" in the mplayer source tree?).
>
> Even if AAC+ is a more advanced coding than MP3, it seems clear to me
> that this could be optimized,
> i'm just not a decoder expert and wish not to spend lots of time just
> to get to know the codebase etc.
>
> If someone wants to take on this, i could help by testing and maybe
> some mmx coding?

No point; ffmpeg's built-in aac decoder is already 130% faster than
libfaad (and counting).  This is mostly due to Loren Merritt's
incredibly fast FFT code, but also due to other nice optimizations.
It doesn't support HE-AAC yet, but I suspect adding that will be much
easier than speeding up libfaad to a respectable level.

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