[FFmpeg-devel] [PATCH] AAC: type puns for 16 bit floating point rounding

[Diego Biurrun]

On Sun, Feb 22, 2009 at 05:55:32PM -0500, Alex Converse wrote:
> On Sun, Feb 22, 2009 at 5:51 PM, Alex Converse <alex.converse at gmail.com> wrote:
> > On Mon, Feb 16, 2009 at 7:22 PM, Alex Converse <alex.converse at gmail.com> wrote:
> >> On Thu, Feb 12, 2009 at 9:29 AM, Robert Swain <robert.swain at gmail.com> wrote:
> >>> 2008/12/21 Robert Swain <robert.swain at gmail.com>:
> >>>> 2008/12/13 Guillaume POIRIER <poirierg at gmail.com>:
> >>>>> On Sat, Dec 13, 2008 at 3:54 PM, M?ns Rullg?rd <mans at mansr.com> wrote:
> >>>>>> Can you upload the file somewhere?  I'd rather not install mp4box just
> >>>>>> for this.
> >>>>>
> >>>>> Sure, here it is: http://natsuki.mplayerhq.hu/~ml-admin/type_puns.mp4
> >>>>
> >>>> M?ns?
> >>>
> >>> This thread seems to be mostly dead. Maybe Alex can do something to
> >>> make the speed testing that needs to be done easier so we can get
> >>> these optimisations merged into trunk, if indeed they do make decoding
> >>> faster.
> >>
> >> /MPlayer/incoming/aac-main/aac-main-long.adts,txt
> >>
> >> My system reports (Linux/amd64):
> >> before:
> >> real    0m7.602s
> >> user    0m7.568s
> >> sys     0m0.032s
> >>
> >> after:
> >> real    0m1.182s
> >> user    0m1.148s
> >> sys     0m0.040s
> >>
> >> I think we are looking for someone on ARM to test
> >
> > Let's try this one more time:
> >
> > We are looking for people on exotic architectures (non-x86) to
> > benchmark decoding a specific file on their systems before and after
> > the attached patch.
> >
> > The file: /MPlayer/incoming/aac-main/aac-main-long.adts,txt
> > Mirror: http://filer.case.edu/ajc30/pub/ffmpeg/
> 
> I'm aware that the #ifdefs in the patch should be #ifs but that
> shouldn't change the benchmarks. Still if anyone insists on the
> correct version it is attached.

On my PowerBook G4 with gcc 4.3 I get the following numbers, best run
of five, with no services stopped and the command line
time ./ffmpeg -v 0 -i aac-main-long.adts -f null /dev/null

before:

real    0m30.156s
user    0m30.060s
sys     0m0.083s

after:

real    0m4.401s
user    0m4.356s
sys     0m0.043s


We desperately need this :)

Diego