[FFmpeg-devel] [PATCH] avfilter: add colortemperature filter
Paul B Mahol
onemda at gmail.com
Tue Jan 26 13:16:31 EET 2021
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 22 +++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_colortemperature.c | 280 ++++++++++++++++++++++++++++++
4 files changed, 304 insertions(+)
create mode 100644 libavfilter/vf_colortemperature.c
diff --git a/doc/filters.texi b/doc/filters.texi
index 991f8d62c0..2a994e110b 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -8549,6 +8549,28 @@ For example to convert the input to SMPTE-240M, use the command:
colorspace=smpte240m
@end example
+ at section colortemperature
+Adjust color temperature in video to simulate variations in ambient color temperature.
+
+The filter accepts the following options:
+
+ at table @option
+ at item temperature
+Set the temperature in Kelvins. Allowed range is from 1000 to 40000.
+Default value is 6500 K.
+
+ at item mix
+Set mixing with filtered output. Allowed range is from 0 to 1.
+Default value is 1.
+
+ at item pl
+Set the amount of preserving lightness. Allowed range is from 0 to 1.
+Default value is 0.
+ at end table
+
+ at subsection Commands
+This filter supports same @ref{commands} as options.
+
@section convolution
Apply convolution of 3x3, 5x5, 7x7 or horizontal/vertical up to 49 elements.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index fbb4e29bd0..e1c364fbc6 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -203,6 +203,7 @@ OBJS-$(CONFIG_COLORHOLD_FILTER) += vf_colorkey.o
OBJS-$(CONFIG_COLORLEVELS_FILTER) += vf_colorlevels.o
OBJS-$(CONFIG_COLORMATRIX_FILTER) += vf_colormatrix.o
OBJS-$(CONFIG_COLORSPACE_FILTER) += vf_colorspace.o colorspace.o colorspacedsp.o
+OBJS-$(CONFIG_COLORTEMPERATURE_FILTER) += vf_colortemperature.o
OBJS-$(CONFIG_CONVOLUTION_FILTER) += vf_convolution.o
OBJS-$(CONFIG_CONVOLUTION_OPENCL_FILTER) += vf_convolution_opencl.o opencl.o \
opencl/convolution.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index d9d36554c4..1c1cc5b276 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -192,6 +192,7 @@ extern AVFilter ff_vf_colorhold;
extern AVFilter ff_vf_colorlevels;
extern AVFilter ff_vf_colormatrix;
extern AVFilter ff_vf_colorspace;
+extern AVFilter ff_vf_colortemperature;
extern AVFilter ff_vf_convolution;
extern AVFilter ff_vf_convolution_opencl;
extern AVFilter ff_vf_convolve;
diff --git a/libavfilter/vf_colortemperature.c b/libavfilter/vf_colortemperature.c
new file mode 100644
index 0000000000..11ab1d0cce
--- /dev/null
+++ b/libavfilter/vf_colortemperature.c
@@ -0,0 +1,280 @@
+/*
+ * Copyright (c) 2021 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
+ */
+
+#include <float.h>
+
+#include "libavutil/opt.h"
+#include "libavutil/imgutils.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct ColorTemperatureContext {
+ const AVClass *class;
+
+ float temperature;
+ float mix;
+ float preserve;
+
+ float color[3];
+
+ int depth;
+
+ int (*do_slice)(AVFilterContext *s, void *arg,
+ int jobnr, int nb_jobs);
+} ColorTemperatureContext;
+
+static float saturate(float input)
+{
+ return av_clipf(input, 0.f, 1.f);
+}
+
+static void kelvin2rgb(float k, float *rgb)
+{
+ float kelvin = k / 100.0f;
+
+ if (kelvin <= 66.0f) {
+ rgb[0] = 1.0f;
+ rgb[1] = saturate(0.39008157876901960784f * logf(kelvin) - 0.63184144378862745098f);
+ } else {
+ const float t = fmaxf(kelvin - 60.0f, 0.0f);
+ rgb[0] = saturate(1.29293618606274509804f * powf(t, -0.1332047592f));
+ rgb[1] = saturate(1.12989086089529411765f * powf(t, -0.0755148492f));
+ }
+
+ if (kelvin >= 66.0f)
+ rgb[2] = 1.0f;
+ else if (kelvin <= 19.0f)
+ rgb[2] = 0.0f;
+ else
+ rgb[2] = saturate(0.54320678911019607843f * logf(kelvin - 10.0f) - 1.19625408914f);
+}
+
+static float lerpf(float v0, float v1, float f)
+{
+ return v0 + (v1 - v0) * f;
+}
+
+static int temperature_slice8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorTemperatureContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int width = frame->width;
+ const int height = frame->height;
+ const float mix = s->mix;
+ const float preserve = s->preserve;
+ const float *color = s->color;
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+ const int glinesize = frame->linesize[0];
+ const int blinesize = frame->linesize[1];
+ const int rlinesize = frame->linesize[2];
+ uint8_t *gptr = frame->data[0] + slice_start * glinesize;
+ uint8_t *bptr = frame->data[1] + slice_start * blinesize;
+ uint8_t *rptr = frame->data[2] + slice_start * rlinesize;
+
+ for (int y = slice_start; y < slice_end; y++) {
+ for (int x = 0; x < width; x++) {
+ float g = gptr[x];
+ float b = bptr[x];
+ float r = rptr[x];
+ float nr, ng, nb;
+ float l0, l1, l;
+
+ nr = r * color[0];
+ ng = g * color[1];
+ nb = b * color[2];
+
+ nr = lerpf(r, nr, mix);
+ ng = lerpf(g, ng, mix);
+ nb = lerpf(b, nb, mix);
+
+ l0 = (FFMAX3(r, g, b) + FFMIN3(r, g, b)) + FLT_EPSILON;
+ l1 = (FFMAX3(nr, ng, nb) + FFMIN3(nr, ng, nb)) + FLT_EPSILON;
+ l = l0 / l1;
+
+ r = nr * l;
+ g = ng * l;
+ b = nb * l;
+
+ nr = lerpf(nr, r, preserve);
+ ng = lerpf(ng, g, preserve);
+ nb = lerpf(nb, b, preserve);
+
+ gptr[x] = av_clip_uint8(ng);
+ bptr[x] = av_clip_uint8(nb);
+ rptr[x] = av_clip_uint8(nr);
+ }
+
+ gptr += glinesize;
+ bptr += blinesize;
+ rptr += rlinesize;
+ }
+
+ return 0;
+}
+
+static int temperature_slice16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ColorTemperatureContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int depth = s->depth;
+ const int width = frame->width;
+ const int height = frame->height;
+ const float preserve = s->preserve;
+ const float mix = s->mix;
+ const float *color = s->color;
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+ const int glinesize = frame->linesize[0] / sizeof(uint16_t);
+ const int blinesize = frame->linesize[1] / sizeof(uint16_t);
+ const int rlinesize = frame->linesize[2] / sizeof(uint16_t);
+ uint16_t *gptr = (uint16_t *)frame->data[0] + slice_start * glinesize;
+ uint16_t *bptr = (uint16_t *)frame->data[1] + slice_start * blinesize;
+ uint16_t *rptr = (uint16_t *)frame->data[2] + slice_start * rlinesize;
+
+ for (int y = slice_start; y < slice_end; y++) {
+ for (int x = 0; x < width; x++) {
+ float g = gptr[x];
+ float b = bptr[x];
+ float r = rptr[x];
+ float nr, ng, nb;
+ float l0, l1, l;
+
+ nr = r * color[0];
+ ng = g * color[1];
+ nb = b * color[2];
+
+ nr = lerpf(r, nr, mix);
+ ng = lerpf(g, ng, mix);
+ nb = lerpf(b, nb, mix);
+
+ l0 = (FFMAX3(r, g, b) + FFMIN3(r, g, b)) + FLT_EPSILON;
+ l1 = (FFMAX3(nr, ng, nb) + FFMIN3(nr, ng, nb)) + FLT_EPSILON;
+ l = l0 / l1;
+
+ r = nr * l;
+ g = ng * l;
+ b = nb * l;
+
+ nr = lerpf(nr, r, preserve);
+ ng = lerpf(ng, g, preserve);
+ nb = lerpf(nb, b, preserve);
+
+ gptr[x] = av_clip_uintp2(ng, depth);
+ bptr[x] = av_clip_uintp2(nb, depth);
+ rptr[x] = av_clip_uintp2(nr, depth);
+ }
+
+ gptr += glinesize;
+ bptr += blinesize;
+ rptr += rlinesize;
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ColorTemperatureContext *s = ctx->priv;
+
+ kelvin2rgb(s->temperature, s->color);
+
+ ctx->internal->execute(ctx, s->do_slice, frame, NULL,
+ FFMIN(frame->height, ff_filter_get_nb_threads(ctx)));
+
+ return ff_filter_frame(ctx->outputs[0], frame);
+}
+
+static av_cold int query_formats(AVFilterContext *ctx)
+{
+ static const enum AVPixelFormat pixel_fmts[] = {
+ AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
+ AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10, AV_PIX_FMT_GBRP12,
+ AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
+ AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
+ AV_PIX_FMT_NONE
+ };
+
+ AVFilterFormats *formats = NULL;
+
+ formats = ff_make_format_list(pixel_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+
+ return ff_set_common_formats(ctx, formats);
+}
+
+static av_cold int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ColorTemperatureContext *s = ctx->priv;
+ const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+ s->depth = desc->comp[0].depth;
+ s->do_slice = s->depth <= 8 ? temperature_slice8 : temperature_slice16;
+
+ return 0;
+}
+
+static const AVFilterPad inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ .needs_writable = 1,
+ },
+ { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+#define OFFSET(x) offsetof(ColorTemperatureContext, x)
+#define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
+
+static const AVOption colortemperature_options[] = {
+ { "temperature", "set the temperature in Kelvins", OFFSET(temperature), AV_OPT_TYPE_FLOAT, {.dbl=6500}, 1000, 40000, VF },
+ { "mix", "set the mix with filtered output", OFFSET(mix), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 1, VF },
+ { "pl", "set the amount of preserving lightness", OFFSET(preserve), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, 1, VF },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(colortemperature);
+
+AVFilter ff_vf_colortemperature = {
+ .name = "colortemperature",
+ .description = NULL_IF_CONFIG_SMALL("Adjust color temperature of video."),
+ .priv_size = sizeof(ColorTemperatureContext),
+ .priv_class = &colortemperature_class,
+ .query_formats = query_formats,
+ .inputs = inputs,
+ .outputs = outputs,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+ .process_command = ff_filter_process_command,
+};
--
2.17.1
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