avfilter: add colortemperature filter

Changelog

@@ -60,6 +60,7 @@ version <next>:
 - Dolby E parser
 - shear filter
 - kirsch filter
+- colortemperature filter
 
 
 version 4.3:

doc/filters.texi

@@ -8550,6 +8550,28 @@ For example to convert the input to SMPTE-240M, use the command:
 colorspace=smpte240m
 @end example
 
+@section colortemperature
+Adjust color temperature in video to simulate variations in ambient color temperature.
+
+The filter accepts the following options:
+
+@table @option
+@item temperature
+Set the temperature in Kelvin. Allowed range is from 1000 to 40000.
+Default value is 6500 K.
+
+@item mix
+Set mixing with filtered output. Allowed range is from 0 to 1.
+Default value is 1.
+
+@item pl
+Set the amount of preserving lightness. Allowed range is from 0 to 1.
+Default value is 0.
+@end table
+
+@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.

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

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;

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   7
-#define LIBAVFILTER_VERSION_MINOR  99
+#define LIBAVFILTER_VERSION_MINOR 100
 #define LIBAVFILTER_VERSION_MICRO 100
 
 

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_c(ng, depth);
+            bptr[x] = av_clip_uintp2_c(nb, depth);
+            rptr[x] = av_clip_uintp2_c(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,
+};