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aacenc: use the decoder's lcg PRNG

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Using lfg was an overkill in this case where the random numbers
were only used for encoder descisions. Should increase result
uniformity between different FPUs and gives a slight speedup.

Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
This commit is contained in:
Rostislav Pehlivanov
2016-10-08 01:47:04 +01:00
parent cfa3c2655a
commit 230178dfe2
4 changed files with 17 additions and 8 deletions
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8
libavcodec/aaccoder.c
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@@ -643,11 +643,9 @@ static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChanne
float band_energy, scale, pns_senergy;
const int start_c = (w+w2)*128+sce->ics.swb_offset[g];
band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
for (i = 0; i < sce->ics.swb_sizes[g]; i+=2) {
double rnd[2];
av_bmg_get(&s->lfg, rnd);
PNS[i+0] = (float)rnd[0];
PNS[i+1] = (float)rnd[1];
for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
s->random_state = lcg_random(s->random_state);
PNS[i] = s->random_state;
}
band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
scale = noise_amp/sqrtf(band_energy);