[maemo-developers] [maemo-developers] Ogg Vorbis and the N800

From: Krischan Keitsch krischan.keitsch at alumni.tu-berlin.de
Date: Tue Feb 6 22:29:00 EET 2007
Am Mittwoch, 31. Januar 2007 schrieb Simon Pickering:
> > > Hi
> > >
> > > as far as I can tell the n800 with the OMAP2420 processor has a vfp
> > > (vector floating point unit; see [1] ) Based on this I wanted to find
> > > out if vorbis could take advantage of this unit by default.
> > >
> > > To make it short: Yes it works - BUT it is just painful!
> >
> > [...]

> Just using the "-mfpu=vfp -mfloat-abi=softfp" flags (I couldn't remember
> the exact -mcpu setting), produces a gstreamer vorbis plugin with a CPU
> load of ~30% playing the same file. So better, but still not too good. 

I just wanted to confirm that "-mfpu=vfp -mfloat-abi=softfp" flags for 
compiling libvorbis works without any error with cpu load ~25%.
Using the "-mcpu=arm1136j-s" flag ends up in compiling errors.

>I wonder why this is so slow compared with the integer version 

Have you had any chance findig out why integer based tremor decoder takes half 
the cpu load of the floating point codec? 

> (does the integer version produce worse sound?).

I don't know. My ears are not (yet) optimized ;-)

Regards Krischan
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