colorbalance filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -23,6 +23,7 @@ version <next>:
 - new interlace filter
 - smptehdbars source
 - inverse telecine filters (fieldmatch and decimate)
+- colorbalance filter
 
 
 version 1.2:

doc/filters.texi

@@ -2051,6 +2051,46 @@ boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chrom
 @end example
 @end itemize
 
+@section colorbalance
+Modify intensity of primary colors (red, green and blue) of input frames.
+
+The filter allows an input frame to be adjusted in the shadows, midtones or highlights
+regions for the red-cyan, green-magenta or blue-yellow balance.
+
+A positive adjustment value shifts the balance towards the primary color, a negative
+value towards the complementary color.
+
+The filter accepts the following options:
+
+@table @option
+@item rs
+@item gs
+@item bs
+Adjust red, green and blue shadows (darkest pixels).
+
+@item rm
+@item gm
+@item bm
+Adjust red, green and blue midtones (medium pixels).
+
+@item rh
+@item gh
+@item bh
+Adjust red, green and blue highlights (brightest pixels).
+
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Add red color cast to shadows:
+@example
+colorbalance=rs=.3
+@end example
+@end itemize
+
 @section colormatrix
 
 Convert color matrix.

libavfilter/Makefile

@@ -104,6 +104,7 @@ OBJS-$(CONFIG_BLACKDETECT_FILTER)            += vf_blackdetect.o
 OBJS-$(CONFIG_BLACKFRAME_FILTER)             += vf_blackframe.o
 OBJS-$(CONFIG_BLEND_FILTER)                  += vf_blend.o
 OBJS-$(CONFIG_BOXBLUR_FILTER)                += vf_boxblur.o
+OBJS-$(CONFIG_COLORBALANCE_FILTER)           += vf_colorbalance.o
 OBJS-$(CONFIG_COLORMATRIX_FILTER)            += vf_colormatrix.o
 OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o

libavfilter/allfilters.c

@@ -102,6 +102,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(BLACKFRAME,     blackframe,     vf);
     REGISTER_FILTER(BLEND,          blend,          vf);
     REGISTER_FILTER(BOXBLUR,        boxblur,        vf);
+    REGISTER_FILTER(COLORBALANCE,   colorbalance,   vf);
     REGISTER_FILTER(COLORMATRIX,    colormatrix,    vf);
     REGISTER_FILTER(COPY,           copy,           vf);
     REGISTER_FILTER(CROP,           crop,           vf);

libavfilter/version.h

@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  56
+#define LIBAVFILTER_VERSION_MINOR  57
-#define LIBAVFILTER_VERSION_MICRO 103
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

libavfilter/vf_colorbalance.c

@@ -0,0 +1,212 @@
+/*
+ * Copyright (c) 2013 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 "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "drawutils.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+#define R 0
+#define G 1
+#define B 2
+#define A 3
+
+typedef struct {
+    double shadows;
+    double midtones;
+    double highlights;
+} Range;
+
+typedef struct {
+    const AVClass *class;
+    Range cyan_red;
+    Range magenta_green;
+    Range yellow_blue;
+
+    uint8_t lut[3][256];
+
+    uint8_t rgba_map[4];
+    int step;
+} ColorBalanceContext;
+
+#define OFFSET(x) offsetof(ColorBalanceContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption colorbalance_options[] = {
+    { "rs", "set red shadows",      OFFSET(cyan_red.shadows),         AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "gs", "set green shadows",    OFFSET(magenta_green.shadows),    AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "bs", "set blue shadows",     OFFSET(yellow_blue.shadows),      AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "rm", "set red midtones",     OFFSET(cyan_red.midtones),        AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "gm", "set green midtones",   OFFSET(magenta_green.midtones),   AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "bm", "set blue midtones",    OFFSET(yellow_blue.midtones),     AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "rh", "set red highlights",   OFFSET(cyan_red.highlights),      AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "gh", "set green highlights", OFFSET(magenta_green.highlights), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "bh", "set blue highlights",  OFFSET(yellow_blue.highlights),   AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(colorbalance);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pix_fmts[] = {
+        AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
+        AV_PIX_FMT_RGBA,  AV_PIX_FMT_BGRA,
+        AV_PIX_FMT_ABGR,  AV_PIX_FMT_ARGB,
+        AV_PIX_FMT_0BGR,  AV_PIX_FMT_0RGB,
+        AV_PIX_FMT_RGB0,  AV_PIX_FMT_BGR0,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    ColorBalanceContext *cb = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
+    double *shadows, *midtones, *highlights, *buffer;
+    int i, r, g, b;
+
+    buffer = av_malloc(256 * 3 * sizeof(*buffer));
+    if (!buffer)
+        return AVERROR(ENOMEM);
+
+    shadows    = buffer + 256 * 0;
+    midtones   = buffer + 256 * 1;
+    highlights = buffer + 256 * 2;
+
+    for (i = 0; i < 256; i++) {
+        double low = av_clipd((i - 85.0) / -64.0 + 0.5, 0, 1) * 178.5;
+        double mid = av_clipd((i - 85.0) /  64.0 + 0.5, 0, 1) *
+                     av_clipd((i + 85.0 - 255.0) / -64.0 + 0.5, 0, 1) * 178.5;
+
+        shadows[i] = low;
+        midtones[i] = mid;
+        highlights[255 - i] = low;
+    }
+
+    for (i = 0; i < 256; i++) {
+        r = g = b = i;
+
+        r = av_clip_uint8(r + cb->cyan_red.shadows         * shadows[r]);
+        r = av_clip_uint8(r + cb->cyan_red.midtones        * midtones[r]);
+        r = av_clip_uint8(r + cb->cyan_red.highlights      * highlights[r]);
+
+        g = av_clip_uint8(g + cb->magenta_green.shadows    * shadows[g]);
+        g = av_clip_uint8(g + cb->magenta_green.midtones   * midtones[g]);
+        g = av_clip_uint8(g + cb->magenta_green.highlights * highlights[g]);
+
+        b = av_clip_uint8(b + cb->yellow_blue.shadows      * shadows[b]);
+        b = av_clip_uint8(b + cb->yellow_blue.midtones     * midtones[b]);
+        b = av_clip_uint8(b + cb->yellow_blue.highlights   * highlights[b]);
+
+        cb->lut[R][i] = r;
+        cb->lut[G][i] = g;
+        cb->lut[B][i] = b;
+    }
+
+    av_free(buffer);
+
+    ff_fill_rgba_map(cb->rgba_map, outlink->format);
+    cb->step = av_get_padded_bits_per_pixel(desc) >> 3;
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    ColorBalanceContext *cb = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    const uint8_t roffset = cb->rgba_map[R];
+    const uint8_t goffset = cb->rgba_map[G];
+    const uint8_t boffset = cb->rgba_map[B];
+    const uint8_t aoffset = cb->rgba_map[A];
+    const int step = cb->step;
+    const uint8_t *srcrow = in->data[0];
+    uint8_t *dstrow;
+    AVFrame *out;
+    int i, j;
+
+    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);
+    }
+
+    dstrow = out->data[0];
+    for (i = 0; i < outlink->h; i++) {
+        const uint8_t *src = srcrow;
+        uint8_t *dst = dstrow;
+
+        for (j = 0; j < outlink->w * step; j += step) {
+            dst[j + roffset] = cb->lut[R][src[j + roffset]];
+            dst[j + goffset] = cb->lut[G][src[j + goffset]];
+            dst[j + boffset] = cb->lut[B][src[j + boffset]];
+            if (in != out && step == 4)
+                dst[j + aoffset] = src[j + aoffset];
+        }
+
+        srcrow += in->linesize[0];
+        dstrow += out->linesize[0];
+    }
+
+    if (in != out)
+        av_frame_free(&in);
+    return ff_filter_frame(ctx->outputs[0], out);
+}
+
+static const AVFilterPad colorbalance_inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .filter_frame   = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad colorbalance_outputs[] = {
+     {
+         .name         = "default",
+         .type         = AVMEDIA_TYPE_VIDEO,
+         .config_props = config_output,
+     },
+     { NULL }
+};
+
+AVFilter avfilter_vf_colorbalance = {
+    .name          = "colorbalance",
+    .description   = NULL_IF_CONFIG_SMALL("Adjust the color balance."),
+    .priv_size     = sizeof(ColorBalanceContext),
+    .priv_class    = &colorbalance_class,
+    .query_formats = query_formats,
+    .inputs        = colorbalance_inputs,
+    .outputs       = colorbalance_outputs,
+};