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Diffstat (limited to 'libavfilter/vf_nlmeans_init.h')
-rw-r--r-- | libavfilter/vf_nlmeans_init.h | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/libavfilter/vf_nlmeans_init.h b/libavfilter/vf_nlmeans_init.h new file mode 100644 index 0000000000..04ad8801b6 --- /dev/null +++ b/libavfilter/vf_nlmeans_init.h @@ -0,0 +1,139 @@ +/* + * Copyright (c) 2016 Clément Bœsch <u pkh me> + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVFILTER_NLMEANS_INIT_H +#define AVFILTER_NLMEANS_INIT_H + +#include <stddef.h> +#include <stdint.h> + +#include "config.h" +#include "libavutil/avassert.h" +#include "libavutil/macros.h" +#include "vf_nlmeans.h" + +/** + * 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 + * as little checks as possible; contrary to the unsafe version of this + * function, we do not need any clipping here. + * + * The line above dst and the column to its left are always readable. + */ +static void compute_safe_ssd_integral_image_c(uint32_t *dst, ptrdiff_t dst_linesize_32, + const uint8_t *s1, ptrdiff_t linesize1, + const uint8_t *s2, ptrdiff_t linesize2, + int w, int h) +{ + const uint32_t *dst_top = dst - dst_linesize_32; + + /* SIMD-friendly assumptions allowed here */ + av_assert2(!(w & 0xf) && w >= 16 && h >= 1); + + for (int y = 0; y < h; y++) { + for (int x = 0; x < w; x += 4) { + const int d0 = s1[x ] - s2[x ]; + const int d1 = s1[x + 1] - s2[x + 1]; + const int d2 = s1[x + 2] - s2[x + 2]; + const int d3 = s1[x + 3] - s2[x + 3]; + + dst[x ] = dst_top[x ] - dst_top[x - 1] + d0*d0; + dst[x + 1] = dst_top[x + 1] - dst_top[x ] + d1*d1; + dst[x + 2] = dst_top[x + 2] - dst_top[x + 1] + d2*d2; + dst[x + 3] = dst_top[x + 3] - dst_top[x + 2] + d3*d3; + + dst[x ] += dst[x - 1]; + dst[x + 1] += dst[x ]; + dst[x + 2] += dst[x + 1]; + dst[x + 3] += dst[x + 2]; + } + s1 += linesize1; + s2 += linesize2; + dst += dst_linesize_32; + dst_top += dst_linesize_32; + } +} + +static void compute_weights_line_c(const uint32_t *const iia, + const uint32_t *const iib, + const uint32_t *const iid, + const uint32_t *const iie, + const uint8_t *const src, + float *total_weight, + float *sum, + const float *const weight_lut, + int max_meaningful_diff, + int startx, int endx) +{ + for (int x = startx; x < endx; x++) { + /* + * 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 = iia[x]; + const uint32_t b = iib[x]; + const uint32_t d = iid[x]; + const uint32_t e = iie[x]; + const uint32_t patch_diff_sq = FFMIN(e - d - b + a, max_meaningful_diff); + const float weight = weight_lut[patch_diff_sq]; // exp(-patch_diff_sq * s->pdiff_scale) + + total_weight[x] += weight; + sum[x] += weight * src[x]; + } +} + +static av_unused void ff_nlmeans_init(NLMeansDSPContext *dsp) +{ + dsp->compute_safe_ssd_integral_image = compute_safe_ssd_integral_image_c; + dsp->compute_weights_line = compute_weights_line_c; + + if (ARCH_AARCH64) + ff_nlmeans_init_aarch64(dsp); + + if (ARCH_X86) + ff_nlmeans_init_x86(dsp); +} + +#endif /* AVFILTER_NLMEANS_INIT_H */ |