[FFmpeg-devel] [PATCH] split-radix FFT

Diego Biurrun diego
Thu Aug 7 10:19:17 CEST 2008


On Wed, Aug 06, 2008 at 01:36:08PM +0300, Siarhei Siamashka wrote:
> On Tue, Aug 5, 2008 at 11:51 PM, matthieu castet wrote:
> > Siarhei Siamashka wrote:
> >> On Tue, Aug 5, 2008 at 9:10 PM, M?ns Rullg?rd wrote:
> >>> matthieu castet <castet.matthieu at free.fr> writes:
> >>>
> >
> >> Generally the source of ARM11 floating point slowness rumors are the
> >> blogs like this:
> >> http://etrunko.blogspot.com/2008/05/ogg-support-on-canola2.html
> >>
> >> They typically compare libvorbis performance with tremor, get much
> >> better results with tremor and make a conclusion that the difference
> >> is caused by slow floating point hardware. But they don't take into
> >> account that libvorbis itself is slow (on x86 too). I benchmarked
> >> ffvorbis vs. tremor in MPlayer on ARM11 and even in its current state,
> >> ffvorbis was slightly faster (that was before the recent ffvorbis
> >> performance optimizations done by Loren Merritt).
> > Did you tried tremolo (http://wss.co.uk/pinknoise/tremolo/index.html) ?
> 
> No, I have not tried it. If you are intersted in this stuff, you can
> get all the performance patches for tremor (tremor SVN head, rockbox,
> tremolo, have a look at armv6 macros from 'armv4l/mathops.h' ), ensure
> that there are no license conflicts and submit a patch to MPlayer.
> Beware that there was some activity trying to drop internal tremor
> decoder from MPlayer some time ago and this contribution may cause
> another round of flames.

The problem with MPlayer's tremor decoder is that it is outdated and
largely redundant, it stopped being the default decoder a long time ago.
Thus I see little point in keeping it around forever.  If someone were
to update it and/or provide support for external tremor, then we could
talk...

Diego




More information about the ffmpeg-devel mailing list