[CELT-dev] FIXED_POINT

[Jean-Marc Valin]

Quoting Wessel Lubberhuizen <wessel at lubberhuizen.nl>:

> Hi Jean-Marc,
>
> I'm trying to compile with the settings below, for a target that has no
> floating point support whatsoever.
> Compilation fails because there are constants #defined in arch.h that
> appear to be float, e.g.
>
> #ifdef FIXED_POINT
> <...>
> #define DB_SCALING 256.f
> #define DB_SCALING_1 (1.f/256.f)
> <..>
> #else
> <..>
> #endif
>
> DB_SCALING_1 appears not to be used. Is it safe to remove the .f?

It should be safe to remove SCALING and the .f from SCALING. Let me know if that
causes a problem.

   Jean-Marc

> Regards
>
> Wessel
>
>
> Jean-Marc Valin wrote:
> > Note that for fixed-point to work, you need to define the following:
> >
> > #define FIXED_POINT
> > #define DOUBLE_PRECISION
> > #define MIXED_PRECISION
> >
> > otherwise you'll get strange results.
> >
> >    Jean-Marc
> >
> > Quoting Gregory Maxwell <gmaxwell at gmail.com>:
> >
> >
> >> On Tue, Sep 15, 2009 at 5:12 AM, Elston Sa <jose at rebaca.com> wrote:
> >>
> >>> I have build celt with FIXED_POINT option (latest 0.6.1 as well as from
> the
> >>> git repo) on windows. However I am not getting a valid output (all
> samples
> >>> are saturated) when I try to decode with this version. Â The input file
> was
> >>> encoded with the same fixed point version. Does fixed point version work
> at
> >>> all?
> >>>
> >> Yes, fixed point it tested in parallel with floating point. Since you
> >> say you're building on windows, is it possible that you haven't setup
> >> the correct defines for fixed point mode? Or is this a cygwin build
> >> configured through autotools?
> >>
> >>
> >>> Following are the command line settings;
> >>> Samplerate; 48000
> >>> Channels: 2
> >>> Framesize: 256
> >>> Bytesperpacket: 1024
> >>> Complexity: 10
> >>>
> >> You're asking CELT for 1.536Mbit/sec output, it's also possible that
> >> you're triggering a fixed-point specific bug. I don't to regular
> >> testing at rates that high.  Does it work at more typical rates such
> >> as 128 bytes per packet?
> >> _______________________________________________
> >> celt-dev mailing list
> >> celt-dev at xiph.org
> >> http://lists.xiph.org/mailman/listinfo/celt-dev
> >>
> >>
> >
> >
> >
> > _______________________________________________
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> > celt-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/celt-dev
> >
> >
>
>
>