Commit 395e8a53 authored by Paul B Mahol's avatar Paul B Mahol

avfilter/af_anlmdn: use lut table to calculate weights

parent dcae5ba3
......@@ -29,6 +29,10 @@
#include "af_anlmdndsp.h"
#define MAX_DIFF 11.f
#define WEIGHT_LUT_NBITS 20
#define WEIGHT_LUT_SIZE (1<<WEIGHT_LUT_NBITS)
#define SQR(x) ((x) * (x))
typedef struct AudioNLMeansContext {
......@@ -38,6 +42,9 @@ typedef struct AudioNLMeansContext {
int64_t pd;
int64_t rd;
float pdiff_lut_scale;
float weight_lut[WEIGHT_LUT_SIZE];
int K;
int S;
int N;
......@@ -150,6 +157,13 @@ static int config_output(AVFilterLink *outlink)
if (!s->fifo)
return AVERROR(ENOMEM);
s->pdiff_lut_scale = 1.f / MAX_DIFF * WEIGHT_LUT_SIZE;
for (int i = 0; i < WEIGHT_LUT_SIZE; i++) {
float w = -i / s->pdiff_lut_scale;
s->weight_lut[i] = expf(w);
}
ff_anlmdn_init(&s->dsp);
return 0;
......@@ -183,13 +197,16 @@ static int filter_channel(AVFilterContext *ctx, void *arg, int ch, int nb_jobs)
for (int j = 0; j < 2 * S; j++) {
const float distance = cache[j];
unsigned weight_lut_idx;
float w;
av_assert0(distance >= 0.f);
w = -distance * sw;
if (w < -11.f)
av_assert2(distance >= 0.f);
w = distance * sw;
if (w >= MAX_DIFF)
continue;
w = expf(w);
weight_lut_idx = w * s->pdiff_lut_scale;
av_assert2(weight_lut_idx < WEIGHT_LUT_SIZE);
w = s->weight_lut[weight_lut_idx];
P += w * f[i - S + j + (j >= S)];
Q += w;
}
......
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