[FFmpeg-devel] [PATCH] avfilter: add colormap video filter
Paul B Mahol
onemda at gmail.com
Sat Apr 9 15:39:15 EEST 2022
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 24 ++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_colormap.c | 510 ++++++++++++++++++++++++++++++++++++++
4 files changed, 536 insertions(+)
create mode 100644 libavfilter/vf_colormap.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 6a66b0ed11..09bf5f8d32 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -8941,6 +8941,30 @@ colorlevels=romin=0.5:gomin=0.5:bomin=0.5
This filter supports the all above options as @ref{commands}.
+ at section colormap
+
+Apply color maps with custom color mappings.
+
+The filter accepts the following options:
+
+ at table @option
+ at item source
+Set the list of source colors that will be mapped to target colors.
+
+ at item target
+Set the list of target colors that will be mapped from source colors.
+
+ at item kernel
+Set the kernel used to measure color differences between mapped colors.
+
+The accepted values are:
+ at table @samp
+ at item absproduct
+ at item euclidean
+ at item logarithmic
+ at end table
+ at end table
+
@section colormatrix
Convert color matrix.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 3f905bced4..d9865ef25e 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -219,6 +219,7 @@ OBJS-$(CONFIG_COLORKEY_OPENCL_FILTER) += vf_colorkey_opencl.o opencl.o \
opencl/colorkey.o
OBJS-$(CONFIG_COLORHOLD_FILTER) += vf_colorkey.o
OBJS-$(CONFIG_COLORLEVELS_FILTER) += vf_colorlevels.o
+OBJS-$(CONFIG_COLORMAP_FILTER) += vf_colormap.o
OBJS-$(CONFIG_COLORMATRIX_FILTER) += vf_colormatrix.o
OBJS-$(CONFIG_COLORSPACE_FILTER) += vf_colorspace.o colorspace.o colorspacedsp.o
OBJS-$(CONFIG_COLORTEMPERATURE_FILTER) += vf_colortemperature.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index b278423884..8574d62e85 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -205,6 +205,7 @@ extern const AVFilter ff_vf_colorkey;
extern const AVFilter ff_vf_colorkey_opencl;
extern const AVFilter ff_vf_colorhold;
extern const AVFilter ff_vf_colorlevels;
+extern const AVFilter ff_vf_colormap;
extern const AVFilter ff_vf_colormatrix;
extern const AVFilter ff_vf_colorspace;
extern const AVFilter ff_vf_colortemperature;
diff --git a/libavfilter/vf_colormap.c b/libavfilter/vf_colormap.c
new file mode 100644
index 0000000000..6fcd1e34b5
--- /dev/null
+++ b/libavfilter/vf_colormap.c
@@ -0,0 +1,510 @@
+/*
+ * Copyright (c) 2022 Paul B Mahol
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Compute a look-up table from map of colors.
+ */
+
+#include "config_components.h"
+
+#include "libavutil/attributes.h"
+#include "libavutil/avstring.h"
+#include "libavutil/common.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#define MAX_SIZE 64
+
+enum KernelType {
+ ABSPRODUCT,
+ EUCLIDEAN,
+ LOGARITHMIC,
+ NB_KERNELS,
+};
+
+typedef struct ColorMapContext {
+ const AVClass *class;
+
+ int nb_maps;
+ char *source_str;
+ char *target_str;
+
+ float source[MAX_SIZE][4];
+ float target[MAX_SIZE][4];
+ float icoeff[4][4];
+ float coeff[MAX_SIZE][4];
+
+ int kernel_type;
+ float (*kernel)(const float *x, const float *y);
+} ColorMapContext;
+
+#define OFFSET(x) offsetof(ColorMapContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
+
+static const AVOption colormap_options[] = {
+ { "source", "set source map color values", OFFSET(source_str), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+ { "target", "set target map color values", OFFSET(target_str), AV_OPT_TYPE_STRING, { .str = "0" }, .flags = FLAGS },
+ { "kernel", "set the kernel used for measuring color difference", OFFSET(kernel_type), AV_OPT_TYPE_INT, {.i64=1}, 0, NB_KERNELS-1, FLAGS, "kernel" },
+ { "absproduct", "absolute product of differences", 0, AV_OPT_TYPE_CONST, {.i64=ABSPRODUCT}, 0, 0, FLAGS, "kernel" },
+ { "euclidean", "square root of sum of squared differences", 0, AV_OPT_TYPE_CONST, {.i64=EUCLIDEAN}, 0, 0, FLAGS, "kernel" },
+ { "logarithmic", "modified euclidean with logarithmic factor", 0, AV_OPT_TYPE_CONST, {.i64=LOGARITHMIC}, 0, 0, FLAGS, "kernel" },
+ { NULL }
+};
+
+static int parse_color_str(AVFilterContext *ctx, float colors[64][4], char *str, int *N)
+{
+ char *p, *arg, *saveptr;
+ int n = MAX_SIZE;
+
+ p = str;
+ for (int i = 0; i < MAX_SIZE; i++) {
+ float r, g, b;
+
+ if (!(arg = av_strtok(p, "|", &saveptr))) {
+ n = i;
+ break;
+ }
+
+ p = NULL;
+
+ if (av_sscanf(arg, "%f %f %f", &r, &g, &b) != 3) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid syntax for color.\n");
+ return AVERROR(EINVAL);
+ }
+
+ colors[i][0] = r;
+ colors[i][1] = g;
+ colors[i][2] = b;
+ }
+
+ *N = n;
+
+ return 0;
+}
+
+static int gauss_make_triangular(double *A, int *p, int n)
+{
+ p[n - 1] = n - 1;
+ for (int k = 0; k < n; k++) {
+ double t1;
+ int m = k;
+
+ for (int i = k + 1; i < n; i++)
+ if (fabs(A[k + n * i]) > fabs(A[k + n * m]))
+ m = i;
+ p[k] = m;
+ t1 = A[k + n * m];
+ A[k + n * m] = A[k + n * k];
+ A[k + n * k] = t1;
+ if (t1 != 0) {
+ for (int i = k + 1; i < n; i++)
+ A[k + n * i] /= -t1;
+ if (k != m)
+ for (int i = k + 1; i < n; i++) {
+ double t2 = A[i + n * m];
+ A[i + n * m] = A[i + n * k];
+ A[i + n * k] = t2;
+ }
+ for (int j = k + 1; j < n; j++)
+ for (int i = k + 1; i < n; i++)
+ A[i + n * j] += A[k + j * n] * A[i + k * n];
+ } else {
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+static void gauss_solve_triangular(const double *A, const int *p, double *b, int n)
+{
+ for(int k = 0; k < n - 1; k++) {
+ int m = p[k];
+ double t = b[m];
+ b[m] = b[k];
+ b[k] = t;
+ for (int i = k + 1; i < n; i++)
+ b[i] += A[k + n * i] * t;
+ }
+
+ for(int k = n - 1; k > 0; k--) {
+ b[k] /= A[k + n * k];
+ double t = b[k];
+ for (int i = 0; i < k; i++)
+ b[i] -= A[k + n * i] * t;
+ }
+
+ b[0] /= A[0 + 0 * n];
+}
+
+static int gauss_solve(double *A, double *b, int n)
+{
+ int *p = av_calloc(n, sizeof(*p));
+
+ if (!p)
+ return 1;
+
+ if (!gauss_make_triangular(A, p, n)) {
+ av_freep(&p);
+ return 1;
+ }
+
+ gauss_solve_triangular(A, p, b, n);
+
+ av_freep(&p);
+
+ return 0;
+}
+
+#define P2(x) ((x)*(x))
+
+static float absproduct(const float *x, const float *y)
+{
+ const float d = (x[0]-y[0]) *
+ (x[1]-y[1]) *
+ (x[2]-y[2]);
+ return fabsf(d);
+}
+
+static float euclidean_kernel(const float *x, const float *y)
+{
+ const float d2 = P2(x[0]-y[0]) +
+ P2(x[1]-y[1]) +
+ P2(x[2]-y[2]);
+ return sqrtf(d2);
+}
+
+static float logarithmic_kernel(const float *x, const float *y)
+{
+ const float d2 = P2(x[0]-y[0]) +
+ P2(x[1]-y[1]) +
+ P2(x[2]-y[2]);
+ return sqrtf(d2) * log(fmaxf(1e-8f, d2));
+}
+
+static int config_props(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ColorMapContext *s = ctx->priv;
+ int ret, n = 0;
+
+ switch (s->kernel_type) {
+ case ABSPRODUCT:
+ s->kernel = absproduct;
+ break;
+ case EUCLIDEAN:
+ s->kernel = euclidean_kernel;
+ break;
+ case LOGARITHMIC:
+ s->kernel = logarithmic_kernel;
+ break;
+ default:
+ return AVERROR_BUG;
+ }
+
+ ret = parse_color_str(ctx, s->source, s->source_str, &n);
+ if (ret < 0)
+ return ret;
+
+ ret = parse_color_str(ctx, s->target, s->target_str, &n);
+ if (ret < 0)
+ return ret;
+
+ s->nb_maps = n;
+
+ for (int c = 0; c < 3; c++) {
+ for (int j = 0; j < s->nb_maps; j++)
+ s->coeff[j][c] = 0.f;
+
+ for (int j = 0; j < 4; j++) {
+ s->icoeff[j][c] = 0;
+ s->icoeff[j][c] = 0;
+ s->icoeff[j][c] = 0;
+ }
+
+ s->icoeff[c+1][c] = 1.f;
+
+ switch (n) {
+ case 1:
+ {
+ float div = fabsf(s->source[0][c]) < 1e-6f ? 1e-6f : s->source[0][c];
+ s->icoeff[c][1+c] = s->target[0][c] / div;
+ }
+ break;
+ case 2:
+ {
+ double A[2 * 2] = { 1, s->source[0][c],
+ 1, s->source[1][c] };
+ double b[2] = { s->target[0][c], s->target[1][c] };
+
+ if (gauss_solve(A, b, 2))
+ continue;
+
+ s->icoeff[0 ][c] = b[0];
+ s->icoeff[1+c][c] = b[1];
+ }
+ break;
+ case 3:
+ {
+ const uint8_t idx[3][3] = {{ 0, 1, 2 },
+ { 1, 0, 2 },
+ { 2, 0, 1 }};
+ const uint8_t didx[3][4] = {{ 0, 1, 2, 2 },
+ { 0, 2, 1, 2 },
+ { 0, 2, 2, 1 }};
+ const int C0 = idx[c][0];
+ const int C1 = idx[c][1];
+ const int C2 = idx[c][2];
+ double A[3 * 3] = { 1, s->source[0][C0], s->source[0][C1] + s->source[0][C2],
+ 1, s->source[1][C0], s->source[1][C1] + s->source[1][C2],
+ 1, s->source[2][C0], s->source[2][C1] + s->source[2][C2] };
+ double b[3] = { s->target[0][c], s->target[1][c], s->target[2][c] };
+
+ if (gauss_solve(A, b, 3))
+ continue;
+
+ s->icoeff[0][c] = b[didx[c][0]];
+ s->icoeff[1][c] = b[didx[c][1]];
+ s->icoeff[2][c] = b[didx[c][2]];
+ s->icoeff[3][c] = b[didx[c][3]];
+ }
+ break;
+ case 4:
+ {
+ double A[4 * 4] = { 1, s->source[0][0], s->source[0][1], s->source[0][2],
+ 1, s->source[1][0], s->source[1][1], s->source[1][2],
+ 1, s->source[2][0], s->source[2][1], s->source[2][2],
+ 1, s->source[3][0], s->source[3][1], s->source[3][2] };
+ double b[4] = { s->target[0][c], s->target[1][c], s->target[2][c], s->target[3][c] };
+ int pivot[4];
+
+ if (!gauss_make_triangular(A, pivot, 4))
+ continue;
+ gauss_solve_triangular(A, pivot, b, 4);
+
+ s->icoeff[0][c] = b[0];
+ s->icoeff[1][c] = b[1];
+ s->icoeff[2][c] = b[2];
+ s->icoeff[3][c] = b[3];
+ }
+ break;
+ default:
+ {
+ const int N = s->nb_maps;
+ const int N4 = N + 4;
+ double *A = av_calloc(sizeof(*A), N4 * N4);
+ double *b = av_calloc(sizeof(*b), N4);
+ int *pivot = NULL;
+
+ if (!A || !b)
+ goto error;
+
+ for (int j = 0; j < N; j++)
+ for (int i = j; i < N; i++)
+ A[j*N4+i] = A[i*N4+j] = s->kernel(s->source[i], s->source[j]);
+
+ for (int i = 0; i < N; i++)
+ A[i*N4+N+0] = A[(N+0)*N4+i] = 1;
+ for (int i = 0; i < N; i++)
+ A[i*N4+N+1] = A[(N+1)*N4+i] = s->source[i][0];
+ for (int i = 0; i < N; i++)
+ A[i*N4+N+2] = A[(N+2)*N4+i] = s->source[i][1];
+ for (int i = 0; i < N; i++)
+ A[i*N4+N+3] = A[(N+3)*N4+i] = s->source[i][2];
+
+ for (int j = N; j < N4; j++)
+ for (int i = N;i < N4; i++)
+ A[j * N4 + i] = 0.;
+
+ pivot = av_calloc(N4, sizeof(*pivot));
+ if (!pivot)
+ goto error;
+
+ if (gauss_make_triangular(A, pivot, N4)) {
+ for (int i = 0;i < N; i++)
+ b[i] = s->target[i][c];
+ for (int i = N; i < N + 4; i++)
+ b[i] = 0;
+
+ gauss_solve_triangular(A, pivot, b, N4);
+
+ for (int i = 0; i < N; i++)
+ s->coeff[i][c] = b[i];
+
+ for (int i = 0; i < 4; i++)
+ s->icoeff[i][c] = b[N + i];
+ }
+error:
+ av_free(pivot);
+ av_free(b);
+ av_free(A);
+ }
+ }
+ }
+
+ return 0;
+}
+
+typedef struct ThreadData {
+ AVFrame *in, *out;
+} ThreadData;
+
+static int colormap_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorMapContext *s = ctx->priv;
+ ThreadData *td = arg;
+ AVFrame *in = td->in;
+ AVFrame *out = td->out;
+ const int maps = s->nb_maps;
+ const int width = out->width;
+ const int height = out->height;
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+ const int sr_linesize = in->linesize[2] / 4;
+ const int dr_linesize = out->linesize[2] / 4;
+ const int sg_linesize = in->linesize[0] / 4;
+ const int dg_linesize = out->linesize[0] / 4;
+ const int sb_linesize = in->linesize[1] / 4;
+ const int db_linesize = out->linesize[1] / 4;
+ const float *sr = (float *)in->data[2] + slice_start * sr_linesize;
+ const float *sg = (float *)in->data[0] + slice_start * sg_linesize;
+ const float *sb = (float *)in->data[1] + slice_start * sb_linesize;
+ float *r = (float *)out->data[2] + slice_start * dr_linesize;
+ float *g = (float *)out->data[0] + slice_start * dg_linesize;
+ float *b = (float *)out->data[1] + slice_start * db_linesize;
+
+ for (int y = slice_start; y < slice_end; y++) {
+ for (int x = 0; x < width; x++) {
+ const float input[3] = { sr[x], sg[x], sb[x] };
+ float srv, sgv, sbv;
+ float rv, gv, bv;
+
+ srv = sr[x];
+ sgv = sg[x];
+ sbv = sb[x];
+
+ rv = s->icoeff[0][0];
+ gv = s->icoeff[0][1];
+ bv = s->icoeff[0][2];
+
+ rv += s->icoeff[1][0] * srv + s->icoeff[2][0] * sgv + s->icoeff[3][0] * sbv;
+ gv += s->icoeff[1][1] * srv + s->icoeff[2][1] * sgv + s->icoeff[3][1] * sbv;
+ bv += s->icoeff[1][2] * srv + s->icoeff[2][2] * sgv + s->icoeff[3][2] * sbv;
+
+ for (int z = 0; z < maps && maps > 4; z++) {
+ const float cr = s->coeff[z][0];
+ const float cg = s->coeff[z][1];
+ const float cb = s->coeff[z][2];
+ const float f = s->kernel(input, s->source[z]);
+
+ rv += f * cr;
+ gv += f * cg;
+ bv += f * cb;
+ }
+
+ r[x] = rv;
+ g[x] = gv;
+ b[x] = bv;
+ }
+
+ sg += sg_linesize;
+ g += dg_linesize;
+ sb += sb_linesize;
+ b += db_linesize;
+ sr += sr_linesize;
+ r += dr_linesize;
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ ThreadData td;
+ AVFrame *out;
+
+ if (av_frame_is_writable(in)) {
+ out = in;
+ } else {
+ 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);
+ }
+
+ td.in = in;
+ td.out = out;
+ ff_filter_execute(ctx, colormap_slice, &td, NULL,
+ FFMIN(in->height, ff_filter_get_nb_threads(ctx)));
+
+ if (out != in)
+ av_frame_free(&in);
+
+ return ff_filter_frame(outlink, out);
+}
+
+static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
+ char *res, int res_len, int flags)
+{
+ int ret = ff_filter_process_command(ctx, cmd, args, res, res_len, flags);
+
+ if (ret < 0)
+ return ret;
+
+ return config_props(ctx->inputs[0]);
+}
+
+static const AVFilterPad inputs[] = {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_props,
+ },
+};
+
+static const AVFilterPad outputs[] = {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+};
+
+AVFILTER_DEFINE_CLASS(colormap);
+
+const AVFilter ff_vf_colormap = {
+ .name = "colormap",
+ .description = NULL_IF_CONFIG_SMALL("Apply custom Color Maps to video stream."),
+ .priv_class = &colormap_class,
+ .priv_size = sizeof(ColorMapContext),
+ FILTER_INPUTS(inputs),
+ FILTER_OUTPUTS(outputs),
+ FILTER_PIXFMTS(AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32),
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC |
+ AVFILTER_FLAG_SLICE_THREADS,
+ .process_command = process_command,
+};
--
2.35.1
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