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lavfi/nlmeans: use a dynamic size for the weight LUT

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This commit is contained in:
Clément Bœsch 2019-02-01 20:50:34 +01:00
parent 65e61febc8
commit 1a9c6cc411
1 changed files with 6 additions and 10 deletions
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16
libavfilter/vf_nlmeans.c
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@ -43,13 +43,6 @@ struct weighted_avg {
float sum;
};
/*
* Note: WEIGHT_LUT_SIZE must be larger than max_meaningful_diff
* (log(255)*max(h)^2, which is approximately 500000 with the current
* maximum sigma of 30).
*/
#define WEIGHT_LUT_SIZE 500000
typedef struct NLMeansContext {
const AVClass *class;
int nb_planes;
@ -66,7 +59,7 @@ typedef struct NLMeansContext {
ptrdiff_t ii_lz_32; // linesize in 32-bit units of the integral image
struct weighted_avg *wa; // weighted average of every pixel
ptrdiff_t wa_linesize; // linesize for wa in struct size unit
float weight_lut[WEIGHT_LUT_SIZE]; // lookup table mapping (scaled) patch differences to their associated weights
float *weight_lut; // lookup table mapping (scaled) patch differences to their associated weights
uint32_t max_meaningful_diff; // maximum difference considered (if the patch difference is too high we ignore the pixel)
NLMeansDSPContext dsp;
} NLMeansContext;
@ -529,8 +522,10 @@ static av_cold int init(AVFilterContext *ctx)
s->pdiff_scale = 1. / (h * h);
s->max_meaningful_diff = log(255.) / s->pdiff_scale;
av_assert0((s->max_meaningful_diff - 1) < FF_ARRAY_ELEMS(s->weight_lut));
for (i = 0; i < WEIGHT_LUT_SIZE; i++)
s->weight_lut = av_calloc(s->max_meaningful_diff, sizeof(*s->weight_lut));
if (!s->weight_lut)
return AVERROR(ENOMEM);
for (i = 0; i < s->max_meaningful_diff; i++)
s->weight_lut[i] = exp(-i * s->pdiff_scale);
CHECK_ODD_FIELD(research_size, "Luma research window");
@ -559,6 +554,7 @@ static av_cold int init(AVFilterContext *ctx)
static av_cold void uninit(AVFilterContext *ctx)
{
NLMeansContext *s = ctx->priv;
av_freep(&s->weight_lut);
av_freep(&s->ii_orig);
av_freep(&s->wa);
}