--- /dev/null
+/*
+ * 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
+ */
+
+/**
+ * @todo
+ * - SIMD for compute_safe_ssd_integral_image
+ * - SIMD for final weighted averaging
+ * - better automatic defaults? see "Parameters" @ http://www.ipol.im/pub/art/2011/bcm_nlm/
+ * - temporal support (probably doesn't need any displacement according to
+ * "Denoising image sequences does not require motion estimation")
+ * - Bayer pixel format support for at least raw photos? (DNG support would be
+ * handy here)
+ * - FATE test (probably needs visual threshold test mechanism due to the use
+ * of floats)
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+struct weighted_avg {
+ double total_weight;
+ double sum;
+};
+
+#define WEIGHT_LUT_NBITS 9
+#define WEIGHT_LUT_SIZE (1<<WEIGHT_LUT_NBITS)
+
+typedef struct {
+ const AVClass *class;
+ int nb_planes;
+ int chroma_w, chroma_h;
+ double pdiff_scale; // invert of the filtering parameter (sigma*10) squared
+ double sigma; // denoising strength
+ int patch_size, patch_hsize; // patch size and half size
+ int patch_size_uv, patch_hsize_uv; // patch size and half size for chroma planes
+ int research_size, research_hsize; // research size and half size
+ int research_size_uv, research_hsize_uv; // research size and half size for chroma planes
+ uint32_t *ii_orig; // integral image
+ uint32_t *ii; // integral image starting after the 0-line and 0-column
+ int ii_w, ii_h; // width and height of the integral image
+ int ii_lz_32; // linesize in 32-bit units of the integral image
+ struct weighted_avg *wa; // weighted average of every pixel
+ int wa_linesize; // linesize for wa in struct size unit
+ double weight_lut[WEIGHT_LUT_SIZE]; // lookup table mapping (scaled) patch differences to their associated weights
+ double pdiff_lut_scale; // scale factor for patch differences before looking into the LUT
+ int max_meaningful_diff; // maximum difference considered (if the patch difference is too high we ignore the pixel)
+} NLMeansContext;
+
+#define OFFSET(x) offsetof(NLMeansContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption nlmeans_options[] = {
+ { "s", "denoising strength", OFFSET(sigma), AV_OPT_TYPE_DOUBLE, { .dbl = 1.0 }, 1.0, 30.0, FLAGS },
+ { "p", "patch size", OFFSET(patch_size), AV_OPT_TYPE_INT, { .i64 = 3*2+1 }, 0, 99, FLAGS },
+ { "pc", "patch size for chroma planes", OFFSET(patch_size_uv), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 99, FLAGS },
+ { "r", "research window", OFFSET(research_size), AV_OPT_TYPE_INT, { .i64 = 7*2+1 }, 0, 99, FLAGS },
+ { "rc", "research window for chroma planes", OFFSET(research_size_uv), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 99, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(nlmeans);
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pix_fmts[] = {
+ AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
+ AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
+ AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
+ AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+ AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+ AV_PIX_FMT_YUVJ411P,
+ AV_PIX_FMT_GRAY8, AV_PIX_FMT_GBRP,
+ AV_PIX_FMT_NONE
+ };
+
+ AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+ if (!fmts_list)
+ return AVERROR(ENOMEM);
+ 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 int get_integral_patch_value(const uint32_t *ii, int ii_lz_32, int x, int y, int p)
+{
+ const int e = ii[(y + p ) * ii_lz_32 + (x + p )];
+ const int d = ii[(y + p ) * ii_lz_32 + (x - p - 1)];
+ const int b = ii[(y - p - 1) * ii_lz_32 + (x + p )];
+ const int a = ii[(y - p - 1) * ii_lz_32 + (x - p - 1)];
+ 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
+ * 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.
+ *
+ * This C version computes the SSD integral image using a scalar accumulator,
+ * while for SIMD implementation it is likely more interesting to use the
+ * two-loops algorithm variant.
+ */
+static void compute_safe_ssd_integral_image_c(uint32_t *dst, int dst_linesize_32,
+ const uint8_t *s1, int linesize1,
+ const uint8_t *s2, int linesize2,
+ int w, int h)
+{
+ int x, y;
+
+ for (y = 0; y < h; y++) {
+ uint32_t acc = dst[-1] - dst[-dst_linesize_32 - 1];
+
+ for (x = 0; x < w; x++) {
+ const int d = s1[x] - s2[x];
+ acc += d * d;
+ dst[x] = dst[-dst_linesize_32 + x] + acc;
+ }
+ s1 += linesize1;
+ s2 += linesize2;
+ dst += dst_linesize_32;
+ }
+}
+
+/**
+ * Compute squared difference of an unsafe area (the zone nor s1 nor s2 could
+ * be readable).
+ *
+ * On the other hand, the line above dst and the column to its left are always
+ * readable.
+ *
+ * There is little point in having this function SIMDified as it is likely too
+ * complex and only handle small portions of the image.
+ *
+ * @param dst integral image
+ * @param dst_linesize_32 integral image linesize (in 32-bit integers unit)
+ * @param startx integral starting x position
+ * @param starty integral starting y position
+ * @param src source plane buffer
+ * @param linesize source plane linesize
+ * @param offx source offsetting in x
+ * @param offy source offsetting in y
+ * @paran r absolute maximum source offsetting
+ * @param sw source width
+ * @param sh source height
+ * @param w width to compute
+ * @param h height to compute
+ */
+static inline void compute_unsafe_ssd_integral_image(uint32_t *dst, int dst_linesize_32,
+ int startx, int starty,
+ const uint8_t *src, int linesize,
+ int offx, int offy, int r, int sw, int sh,
+ int w, int h)
+{
+ int x, y;
+
+ for (y = starty; y < starty + h; y++) {
+ uint32_t acc = dst[y*dst_linesize_32 + startx - 1] - dst[(y-1)*dst_linesize_32 + startx - 1];
+ const int s1y = av_clip(y - r, 0, sh - 1);
+ const int s2y = av_clip(y - (r + offy), 0, sh - 1);
+
+ for (x = startx; x < startx + w; x++) {
+ const int s1x = av_clip(x - r, 0, sw - 1);
+ const int s2x = av_clip(x - (r + offx), 0, sw - 1);
+ const uint8_t v1 = src[s1y*linesize + s1x];
+ const uint8_t v2 = src[s2y*linesize + s2x];
+ const int d = v1 - v2;
+ acc += d * d;
+ dst[y*dst_linesize_32 + x] = dst[(y-1)*dst_linesize_32 + x] + acc;
+ }
+ }
+}
+
+/*
+ * Compute the sum of squared difference integral image
+ * http://www.ipol.im/pub/art/2014/57/
+ * Integral Images for Block Matching - Gabriele Facciolo, Nicolas Limare, Enric Meinhardt-Llopis
+ *
+ * @param ii integral image of dimension (w+e*2) x (h+e*2) with
+ * an additional zeroed top line and column already
+ * "applied" to the pointer value
+ * @param ii_linesize_32 integral image linesize (in 32-bit integers unit)
+ * @param src source plane buffer
+ * @param linesize source plane linesize
+ * @param offx x-offsetting ranging in [-e;e]
+ * @param offy y-offsetting ranging in [-e;e]
+ * @param w source width
+ * @param h source height
+ * @param e research padding edge
+ */
+static void compute_ssd_integral_image(uint32_t *ii, int ii_linesize_32,
+ const uint8_t *src, int linesize, int offx, int offy,
+ int e, int w, int h)
+{
+ // ii has a surrounding padding of thickness "e"
+ const int ii_w = w + e*2;
+ const int ii_h = h + e*2;
+
+ // we center the first source
+ const int s1x = e;
+ const int s1y = e;
+
+ // 2nd source is the frame with offsetting
+ const int s2x = e + offx;
+ const int s2y = e + offy;
+
+ // get the dimension of the overlapping rectangle where it is always safe
+ // to compare the 2 sources pixels
+ const int startx_safe = FFMAX(s1x, s2x);
+ const int starty_safe = FFMAX(s1y, s2y);
+ const int endx_safe = FFMIN(s1x + w, s2x + w);
+ const int endy_safe = FFMIN(s1y + h, s2y + h);
+
+ // top part where only one of s1 and s2 is still readable, or none at all
+ compute_unsafe_ssd_integral_image(ii, ii_linesize_32,
+ 0, 0,
+ src, linesize,
+ offx, offy, e, w, h,
+ ii_w, starty_safe);
+
+ // fill the left column integral required to compute the central
+ // overlapping one
+ compute_unsafe_ssd_integral_image(ii, ii_linesize_32,
+ 0, starty_safe,
+ src, linesize,
+ offx, offy, e, w, h,
+ startx_safe, endy_safe - starty_safe);
+
+ // main and safe part of the integral
+ av_assert1(startx_safe - s1x >= 0); av_assert1(startx_safe - s1x < w);
+ av_assert1(starty_safe - s1y >= 0); av_assert1(starty_safe - s1y < h);
+ av_assert1(startx_safe - s2x >= 0); av_assert1(startx_safe - s2x < w);
+ av_assert1(starty_safe - s2y >= 0); av_assert1(starty_safe - s2y < h);
+ compute_safe_ssd_integral_image_c(ii + starty_safe*ii_linesize_32 + startx_safe, ii_linesize_32,
+ src + (starty_safe - s1y) * linesize + (startx_safe - s1x), linesize,
+ src + (starty_safe - s2y) * linesize + (startx_safe - s2x), linesize,
+ endx_safe - startx_safe, endy_safe - starty_safe);
+
+ // right part of the integral
+ compute_unsafe_ssd_integral_image(ii, ii_linesize_32,
+ endx_safe, starty_safe,
+ src, linesize,
+ offx, offy, e, w, h,
+ ii_w - endx_safe, endy_safe - starty_safe);
+
+ // bottom part where only one of s1 and s2 is still readable, or none at all
+ compute_unsafe_ssd_integral_image(ii, ii_linesize_32,
+ 0, endy_safe,
+ src, linesize,
+ offx, offy, e, w, h,
+ ii_w, ii_h - endy_safe);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ NLMeansContext *s = ctx->priv;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+ const int e = FFMAX(s->research_hsize, s->research_hsize_uv)
+ + FFMAX(s->patch_hsize, s->patch_hsize_uv);
+
+ s->chroma_w = FF_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+ s->chroma_h = FF_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+ s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+
+ /* Allocate the integral image with extra edges of thickness "e"
+ *
+ * +_+-------------------------------+
+ * |0|0000000000000000000000000000000|
+ * +-x-------------------------------+
+ * |0|\ ^ |
+ * |0| ii | e |
+ * |0| v |
+ * |0| +-----------------------+ |
+ * |0| | | |
+ * |0|<->| | |
+ * |0| e | | |
+ * |0| | | |
+ * |0| +-----------------------+ |
+ * |0| |
+ * |0| |
+ * |0| |
+ * +-+-------------------------------+
+ */
+ s->ii_w = inlink->w + e*2;
+ s->ii_h = inlink->h + e*2;
+
+ // align to 4 the linesize, "+1" is for the space of the left 0-column
+ s->ii_lz_32 = FFALIGN(s->ii_w + 1, 4);
+
+ // "+1" is for the space of the top 0-line
+ s->ii_orig = av_mallocz_array(s->ii_h + 1, s->ii_lz_32 * sizeof(*s->ii_orig));
+ if (!s->ii_orig)
+ return AVERROR(ENOMEM);
+
+ // skip top 0-line and left 0-column
+ s->ii = s->ii_orig + s->ii_lz_32 + 1;
+
+ // allocate weighted average for every pixel
+ s->wa_linesize = inlink->w;
+ s->wa = av_malloc_array(s->wa_linesize, inlink->h * sizeof(*s->wa));
+ if (!s->wa)
+ return AVERROR(ENOMEM);
+
+ return 0;
+}
+
+struct thread_data {
+ const uint8_t *src;
+ int src_linesize;
+ int startx, starty;
+ int endx, endy;
+ const uint32_t *ii_start;
+ int p;
+};
+
+static int nlmeans_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ int x, y;
+ NLMeansContext *s = ctx->priv;
+ const struct thread_data *td = arg;
+ const uint8_t *src = td->src;
+ const int src_linesize = td->src_linesize;
+ const int process_h = td->endy - td->starty;
+ const int slice_start = (process_h * jobnr ) / 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;
+
+ for (y = starty; y < endy; y++) {
+ for (x = td->startx; x < td->endx; x++) {
+ const int patch_diff_sq = get_integral_patch_value(td->ii_start, s->ii_lz_32, x, y, td->p);
+ if (patch_diff_sq < s->max_meaningful_diff) {
+ struct weighted_avg *wa = &s->wa[y*s->wa_linesize + x];
+ const int weight_lut_idx = patch_diff_sq * s->pdiff_lut_scale;
+ const double weight = s->weight_lut[weight_lut_idx]; // exp(-patch_diff_sq * s->pdiff_scale)
+ wa->total_weight += weight;
+ wa->sum += weight * src[y*src_linesize + x];
+ }
+ }
+ }
+ return 0;
+}
+
+static int nlmeans_plane(AVFilterContext *ctx, int w, int h, int p, int r,
+ uint8_t *dst, int dst_linesize,
+ const uint8_t *src, int src_linesize)
+{
+ int x, y;
+ int offx, offy;
+ NLMeansContext *s = ctx->priv;
+ /* patches center points cover the whole research window so the patches
+ * themselves overflow the research window */
+ const int e = r + p;
+ /* focus an integral pointer on the centered image (s1) */
+ const uint32_t *centered_ii = s->ii + e*s->ii_lz_32 + e;
+
+ memset(s->wa, 0, s->wa_linesize * h * sizeof(*s->wa));
+
+ for (offy = -r; offy <= r; offy++) {
+ for (offx = -r; offx <= r; offx++) {
+ if (offx || offy) {
+ struct thread_data td = {
+ .src = src + offy*src_linesize + offx,
+ .src_linesize = src_linesize,
+ .startx = FFMAX(0, -offx),
+ .starty = FFMAX(0, -offy),
+ .endx = FFMIN(w, w - offx),
+ .endy = FFMIN(h, h - offy),
+ .ii_start = centered_ii + offy*s->ii_lz_32 + offx,
+ .p = p,
+ };
+
+ compute_ssd_integral_image(s->ii, s->ii_lz_32,
+ src, src_linesize,
+ offx, offy, e, w, h);
+ ctx->internal->execute(ctx, nlmeans_slice, &td, NULL,
+ FFMIN(td.endy - td.starty, ff_filter_get_nb_threads(ctx)));
+ }
+ }
+ }
+ for (y = 0; y < h; y++) {
+ for (x = 0; x < w; x++) {
+ struct weighted_avg *wa = &s->wa[y*s->wa_linesize + x];
+
+ // Also weight the centered pixel
+ wa->total_weight += 1.0;
+ wa->sum += 1.0 * src[y*src_linesize + x];
+
+ dst[y*dst_linesize + x] = av_clip_uint8(wa->sum / wa->total_weight);
+ }
+ }
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ int i;
+ AVFilterContext *ctx = inlink->dst;
+ NLMeansContext *s = ctx->priv;
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+ if (!out) {
+ av_frame_free(&in);
+ return AVERROR(ENOMEM);
+ }
+ av_frame_copy_props(out, in);
+
+ for (i = 0; i < s->nb_planes; i++) {
+ const int w = i ? s->chroma_w : inlink->w;
+ const int h = i ? s->chroma_h : inlink->h;
+ const int p = i ? s->patch_hsize_uv : s->patch_hsize;
+ const int r = i ? s->research_hsize_uv : s->research_hsize;
+ nlmeans_plane(ctx, w, h, p, r,
+ out->data[i], out->linesize[i],
+ in->data[i], in->linesize[i]);
+ }
+
+ av_frame_free(&in);
+ return ff_filter_frame(outlink, out);
+}
+
+#define CHECK_ODD_FIELD(field, name) do { \
+ if (!(s->field & 1)) { \
+ s->field |= 1; \
+ av_log(ctx, AV_LOG_WARNING, name " size must be odd, " \
+ "setting it to %d\n", s->field); \
+ } \
+} while (0)
+
+static av_cold int init(AVFilterContext *ctx)
+{
+ int i;
+ NLMeansContext *s = ctx->priv;
+ const double h = s->sigma * 10.;
+
+ s->pdiff_scale = 1. / (h * h);
+ s->max_meaningful_diff = -log(1/255.) / s->pdiff_scale;
+ s->pdiff_lut_scale = 1./s->max_meaningful_diff * WEIGHT_LUT_SIZE;
+ av_assert0((s->max_meaningful_diff - 1) * s->pdiff_lut_scale < FF_ARRAY_ELEMS(s->weight_lut));
+ for (i = 0; i < WEIGHT_LUT_SIZE; i++)
+ s->weight_lut[i] = exp(-i / s->pdiff_lut_scale * s->pdiff_scale);
+
+ CHECK_ODD_FIELD(research_size, "Luma research window");
+ CHECK_ODD_FIELD(patch_size, "Luma patch");
+
+ if (!s->research_size_uv) s->research_size_uv = s->research_size;
+ if (!s->patch_size_uv) s->patch_size_uv = s->patch_size;
+
+ CHECK_ODD_FIELD(research_size_uv, "Chroma research window");
+ CHECK_ODD_FIELD(patch_size_uv, "Chroma patch");
+
+ s->research_hsize = s->research_size / 2;
+ s->research_hsize_uv = s->research_size_uv / 2;
+ s->patch_hsize = s->patch_size / 2;
+ s->patch_hsize_uv = s->patch_size_uv / 2;
+
+ av_log(ctx, AV_LOG_INFO, "Research window: %dx%d / %dx%d, patch size: %dx%d / %dx%d\n",
+ s->research_size, s->research_size, s->research_size_uv, s->research_size_uv,
+ s->patch_size, s->patch_size, s->patch_size_uv, s->patch_size_uv);
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ NLMeansContext *s = ctx->priv;
+ av_freep(&s->ii_orig);
+ av_freep(&s->wa);
+}
+
+static const AVFilterPad nlmeans_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_input,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad nlmeans_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_nlmeans = {
+ .name = "nlmeans",
+ .description = NULL_IF_CONFIG_SMALL("Non-local means denoiser."),
+ .priv_size = sizeof(NLMeansContext),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .inputs = nlmeans_inputs,
+ .outputs = nlmeans_outputs,
+ .priv_class = &nlmeans_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+};