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lavfi/nlmeans: inline integral patch value function

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This prevents redundant position computation and make the code faster
(1.1x faster overall).
This commit is contained in:
Clément Bœsch 2018-05-07 23:28:08 +02:00
parent 4278f79ef6
commit e6114d21ac
1 changed files with 41 additions and 39 deletions
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80
libavfilter/vf_nlmeans.c
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@ -100,44 +100,6 @@ static int query_formats(AVFilterContext *ctx)
return ff_set_common_formats(ctx, fmts_list);
}
/*
* M is a discrete map where every entry contains the sum of all the entries
* in the rectangle from the top-left origin of M to its coordinate. In the
* following schema, "i" contains the sum of the whole map:
*
* M = +----------+-----------------+----+
* | | | |
* | | | |
* | a| b| c|
* +----------+-----------------+----+
* | | | |
* | | | |
* | | X | |
* | | | |
* | d| e| f|
* +----------+-----------------+----+
* | | | |
* | g| h| i|
* +----------+-----------------+----+
*
* The sum of the X box can be calculated with:
* X = e-d-b+a
*
* See https://en.wikipedia.org/wiki/Summed_area_table
*
* The compute*_ssd functions compute the integral image M where every entry
* contains the sum of the squared difference of every corresponding pixels of
* two input planes of the same size as M.
*/
static inline uint32_t get_integral_patch_value(const uint32_t *ii, int ii_lz_32, int x, int y, int p)
{
const uint32_t a = ii[(y - p - 1) * ii_lz_32 + (x - p - 1)];
const uint32_t b = ii[(y - p - 1) * ii_lz_32 + (x + p )];
const uint32_t d = ii[(y + p ) * ii_lz_32 + (x - p - 1)];
const uint32_t e = ii[(y + p ) * ii_lz_32 + (x + p )];
return e - d - b + a;
}
/**
* Compute squared difference of the safe area (the zone where s1 and s2
* overlap). It is likely the largest integral zone, so it is interesting to do
@ -393,12 +355,51 @@ static int nlmeans_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs
const int slice_end = (process_h * (jobnr+1)) / nb_jobs;
const int starty = td->starty + slice_start;
const int endy = td->starty + slice_end;
const int p = td->p;
const uint32_t *ii = td->ii_start + (starty - p - 1) * s->ii_lz_32 - p - 1;
const int dist_b = 2*p + 1;
const int dist_d = dist_b * s->ii_lz_32;
const int dist_e = dist_d + dist_b;
for (y = starty; y < endy; y++) {
const uint8_t *src = td->src + y*src_linesize;
struct weighted_avg *wa = s->wa + y*s->wa_linesize;
for (x = td->startx; x < td->endx; x++) {
const uint32_t patch_diff_sq = get_integral_patch_value(td->ii_start, s->ii_lz_32, x, y, td->p);
/*
* M is a discrete map where every entry contains the sum of all the entries
* in the rectangle from the top-left origin of M to its coordinate. In the
* following schema, "i" contains the sum of the whole map:
*
* M = +----------+-----------------+----+
* | | | |
* | | | |
* | a| b| c|
* +----------+-----------------+----+
* | | | |
* | | | |
* | | X | |
* | | | |
* | d| e| f|
* +----------+-----------------+----+
* | | | |
* | g| h| i|
* +----------+-----------------+----+
*
* The sum of the X box can be calculated with:
* X = e-d-b+a
*
* See https://en.wikipedia.org/wiki/Summed_area_table
*
* The compute*_ssd functions compute the integral image M where every entry
* contains the sum of the squared difference of every corresponding pixels of
* two input planes of the same size as M.
*/
const uint32_t a = ii[x];
const uint32_t b = ii[x + dist_b];
const uint32_t d = ii[x + dist_d];
const uint32_t e = ii[x + dist_e];
const uint32_t patch_diff_sq = e - d - b + a;
if (patch_diff_sq < s->max_meaningful_diff) {
const unsigned weight_lut_idx = patch_diff_sq * s->pdiff_lut_scale;
const float weight = s->weight_lut[weight_lut_idx]; // exp(-patch_diff_sq * s->pdiff_scale)
@ -406,6 +407,7 @@ static int nlmeans_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs
wa[x].sum += weight * src[x];
}
}
ii += s->ii_lz_32;
}
return 0;
}