[FFmpeg-devel] Fixpoint FFT optimization, with MDCT and IMDCT wrappers for audio optimization
Michael Niedermayer
michaelni
Sun Jul 29 13:47:01 CEST 2007
Hi
On Sun, Jul 29, 2007 at 07:43:05AM -0400, Marc Hoffman wrote:
[...]
> > is this what you want?
> >
> > static FFTComplex16 *stwids (FFTComplex *w, int n) {
> > int i;
> > FFTComplex16 *v = av_malloc (sizeof (short)*n);
> > for (i = 0; i < n/2; i++) {
> > v[i].re = lrintf(w[i].re*32768);
> > v[i].im = lrintf(w[i].im*32768);
> > }
> > return v;
> > }
> >
>
> Thats what you want no problem sorry to be annoying.
>
> /**
> * Generate 16b coefficient table from a predefined floating point table.
> * @param w - floating point twiddle factors
> * Wparam n - number of twiddle factors
> */
> static FFTComplex16 *stwids (FFTComplex *w, int n) {
> int i;
> FFTComplex16 *v = av_malloc (sizeof (short)*n);
> for (i = 0; i < n/2; i++) {
> v[i].re = lrintf(FFMAX(FFMIN(w[i].re*32768,32767),-32768));
> v[i].im = lrintf(FFMAX(FFMIN(w[i].im*32768,32767),-32768));
> }
> return v;
> }
yes but i think the FFMAX is unneeded
[...]
--
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
it is not once nor twice but times without number that the same ideas make
their appearance in the world. -- Aristotle
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