On poniedziałek, 7 lipca 2008, Michael Niedermayer wrote:
> On Mon, Jul 07, 2008 at 10:55:16PM +0200, Reimar Döffinger wrote:
> > Hello,
> >
> > On Mon, Jul 07, 2008 at 10:21:38PM +0200, Bartlomiej Wolowiec wrote:
> > > On poniedziałek, 7 lipca 2008, Robert Swain wrote:
> > > > 2008/7/7 bwolowiec <[EMAIL PROTECTED]>:
> > > > > Author: bwolowiec
> > > > > Date: Mon Jul 7 16:41:50 2008
> > > > > New Revision: 2719
> > > > >
> > > > > Log:
> > > > > use ff_sine_window_init
> > > > >
> > > > >
> > > > > Modified:
> > > > > nellyenc/nellymoserenc.c
> > > > >
> > > > > Modified: nellyenc/nellymoserenc.c
> > > > > ===================================================================
> > > > >====== ===== --- nellyenc/nellymoserenc.c (original)
> > > > > +++ nellyenc/nellymoserenc.c Mon Jul 7 16:41:50 2008
> > > > > @@ -116,10 +116,13 @@ static av_cold int encode_init(AVCodecCo
> > > > > dsputil_init(&s->dsp, avctx);
> > > > >
> > > > > /* Generate overlap window */
> > > > > - if (!sine_window[0])
> > > > > - for (i=0 ; i<256; i++) {
> > > > > - sine_window[i] = sin((i + 0.5) / 256.0 * M_PI) /8;
> > > > > + if (!sine_window[0]){
> > > > > + ff_sine_window_init(sine_window, 128);
> > > > > + for (i=0; i<128; i++) {
> > > > > + sine_window[i] /= 8.0;
> > > >
> > > > This isn't thread safe. You must merge the /8 into some other
> > > > calculation.
> > >
> > > Hmm.. yes, you're right. Unfortunately, I don't see now where it can be
> > > calculated. If I don't calculate it in init I will have to calculate it
> > > additionally in every encode_tag, it isn't a good idea. Maybe it's
> > > better to use previous version and don't use ff_sine_window_init...? or
> > > maybe (in my opinion a bit unnatural) such a solution:
> > > ff_sine_window_init(tmp_sine_window, 128);
> > > for (i=0; i<128; i++) {
> > > sine_window[i] = tmp_sine_window[i] / 8.0;
> > > sine_window[255-i] = sine_window[i];
> > > }
> >
> > Just use your original code on some per-thread buffer (stack or heap
> > depending on size) and then memcpy it over.
>
> Please everyone stop scaring me ...
>
> pval = -pow(2, pows[j]/2048);
> tmp = s->mdct_out[i*NELLY_BUF_LEN + j] / pval;
>
> above is in the current code, that will happily take a /8
> besides it obviously should be a * not a / pval, / is slow
>
> [...]
Do you think of something like this?
Or maybe instead of this additional calculations it can be better calculated
once while initialization... ?
--
Bartlomiej Wolowiec
Index: nellymoserenc.c
===================================================================
--- nellymoserenc.c (wersja 2719)
+++ nellymoserenc.c (kopia robocza)
@@ -119,7 +119,6 @@
if (!sine_window[0]){
ff_sine_window_init(sine_window, 128);
for (i=0; i<128; i++) {
- sine_window[i] /= 8.0;
sine_window[255-i] = sine_window[i];
}
}
@@ -189,7 +188,7 @@
stmp += tmp*tmp;
}
}
- tmp = log(FFMAX(1.0, stmp/(ff_nelly_band_sizes_table[i]<<1))) *
+ tmp = ( log(FFMAX(64.0, stmp/(ff_nelly_band_sizes_table[i]<<1))) - log(64.0)) *
M_LOG2E * 1024.0;
if(i){
@@ -217,8 +216,8 @@
for (j = 0; j < NELLY_FILL_LEN; j++) {
bs+=bits[j];
if (bits[j] > 0) {
- pval = -pow(2, pows[j]/2048);
- tmp = s->mdct_out[i*NELLY_BUF_LEN + j] / pval;
+ pval = -pow(2, -pows[j]/2048 - 3.0);
+ tmp = s->mdct_out[i*NELLY_BUF_LEN + j] * pval;
find_best_value(tmp,
(ff_nelly_dequantization_table + (1<<bits[j])-1),
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