[FFmpeg-devel] [PATCH 1/2] colorbalance filter

Paul B Mahol onemda at gmail.com
Tue Apr 16 14:23:30 CEST 2013


Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 doc/filters.texi              |  27 +++++
 libavfilter/Makefile          |   1 +
 libavfilter/allfilters.c      |   1 +
 libavfilter/vf_colorbalance.c | 222 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 251 insertions(+)
 create mode 100644 libavfilter/vf_colorbalance.c

diff --git a/doc/filters.texi b/doc/filters.texi
index 5c2a54a..87811df 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2051,6 +2051,33 @@ boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chrom
 @end example
 @end itemize
 
+ at section colorbalance
+Modify intensity of primary colors (red, green and blue) of input image.
+
+The filter allows an image to be adjusted in the shadows, midtones or highlights
+regions for the red-cyan, green-magenta or blue-yellow balance.
+
+The filter accepts the following options:
+
+ at table @option
+ at item rs
+ at item gs
+ at item bs
+Adjust red, green and blue shadows (darkest pixels).
+
+ at item rm
+ at item gm
+ at item bm
+Adjust red, green and blue midtones (medium pixels).
+
+ at item rh
+ at item gh
+ at item bh
+Adjust red, green and blue highlights (brightest pixels).
+
+Allowed range is from -100 to 100, default is 0.
+ at end table
+
 @section colormatrix
 
 Convert color matrix.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 949972d..0927986 100644
--- a/libavfilter/Makefile
+++ b/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
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 95bd270..bebbf2b 100644
--- a/libavfilter/allfilters.c
+++ b/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);
diff --git a/libavfilter/vf_colorbalance.c b/libavfilter/vf_colorbalance.c
new file mode 100644
index 0000000..e9ecab6
--- /dev/null
+++ b/libavfilter/vf_colorbalance.c
@@ -0,0 +1,222 @@
+/*
+ * 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"
+
+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 lookup[3][256];
+
+    uint8_t rgba_map[4];
+    int nb_components;
+} 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}, -100, 100, FLAGS },
+    { "gs", "set green shadows",     OFFSET(magenta_green.shadows),    AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "bs", "set blue shadows",      OFFSET(yellow_blue.shadows),      AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "rm", "set red midtones",      OFFSET(cyan_red.midtones),        AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "gm", "set green midtones",    OFFSET(magenta_green.midtones),   AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "bm", "set blue midtones",     OFFSET(yellow_blue.midtones),     AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "rh", "set red hightlights",   OFFSET(cyan_red.highlights),      AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "gh", "set green hightlights", OFFSET(magenta_green.highlights), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, FLAGS },
+    { "bh", "set blue hightlights",  OFFSET(yellow_blue.highlights),   AV_OPT_TYPE_DOUBLE, {.dbl=0}, -100, 100, 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 *add[3], *sub[3];
+    double *coeff[3][3];
+    double *buffer;
+    int i, r, g, b;
+
+    buffer = av_malloc(256 * 3 * 2 * sizeof(double));
+    if (!buffer)
+        return AVERROR(ENOMEM);
+
+    for (i = 0; i < 3; i++) {
+        add[i] = buffer + 256 * i;
+        sub[i] = buffer + 256 * (3 + i);
+    }
+
+    for (i = 0; i < 256; i++) {
+        double low = (1.075 - 1 / (i / 16.0 + 1));
+        double mid = 2.0 / 3.0 * (1 - ((i - 127.0) / 127.0) * ((i - 127.0) / 127.0));
+
+        add[0][i] = low;
+        add[1][i] = mid;
+        add[2][255 - i] = low;
+        sub[0][255 - i] = low;
+        sub[1][i] = mid;
+        sub[2][i] = low;
+    }
+
+    coeff[0][0] = cb->cyan_red.shadows > 0 ? add[0] : sub[0];
+    coeff[1][0] = cb->magenta_green.shadows > 0 ? add[0] : sub[0];
+    coeff[2][0] = cb->yellow_blue.shadows > 0 ? add[0] : sub[0];
+    coeff[0][1] = cb->cyan_red.midtones > 0 ? add[1] : sub[1];
+    coeff[1][1] = cb->magenta_green.midtones > 0 ? add[1] : sub[1];
+    coeff[2][1] = cb->yellow_blue.midtones > 0 ? add[1] : sub[1];
+    coeff[0][2] = cb->cyan_red.highlights > 0 ? add[2] : sub[2];
+    coeff[1][2] = cb->magenta_green.highlights > 0 ? add[2] : sub[2];
+    coeff[2][2] = cb->yellow_blue.highlights > 0 ? add[2] : sub[2];
+
+    for (i = 0; i < 256; i++) {
+        r = g = b = i;
+
+        r = av_clip_uint8(r + cb->cyan_red.shadows * coeff[0][0][r]);
+        r = av_clip_uint8(r + cb->cyan_red.midtones * coeff[0][1][r]);
+        r = av_clip_uint8(r + cb->cyan_red.highlights * coeff[0][2][r]);
+
+        g = av_clip_uint8(g + cb->magenta_green.shadows * coeff[1][0][g]);
+        g = av_clip_uint8(g + cb->magenta_green.midtones * coeff[1][1][g]);
+        g = av_clip_uint8(g + cb->magenta_green.highlights * coeff[1][2][g]);
+
+        b = av_clip_uint8(b + cb->yellow_blue.shadows * coeff[2][0][b]);
+        b = av_clip_uint8(b + cb->yellow_blue.midtones * coeff[2][1][b]);
+        b = av_clip_uint8(b + cb->yellow_blue.highlights * coeff[2][2][b]);
+
+        cb->lookup[0][i] = r;
+        cb->lookup[1][i] = g;
+        cb->lookup[2][i] = b;
+    }
+
+    av_free(buffer);
+
+    ff_fill_rgba_map(cb->rgba_map, outlink->format);
+    cb->nb_components = 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[0];
+    const uint8_t goffset = cb->rgba_map[1];
+    const uint8_t boffset = cb->rgba_map[2];
+    const uint8_t aoffset = cb->rgba_map[3];
+    const int comp = cb->nb_components;
+    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 * comp; j += comp) {
+            dst[j + roffset] = cb->lookup[0][src[j + roffset]];
+            dst[j + goffset] = cb->lookup[1][src[j + goffset]];
+            dst[j + boffset] = cb->lookup[2][src[j + boffset]];
+            if (in != out && comp == 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),
+    .query_formats = query_formats,
+    .inputs        = colorbalance_inputs,
+    .outputs       = colorbalance_outputs,
+    .priv_class    = &colorbalance_class,
+};
-- 
1.7.11.2



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