lavfi: add colorlevels filter

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

Changelog

@@ -4,6 +4,7 @@ releases are sorted from youngest to oldest.
 version <next>:
 - nvenc encoder
 - 10bit spp filter
+- colorlevels filter
 
 
 version 2.5:

doc/filters.texi

@@ -2934,6 +2934,75 @@ colorbalance=rs=.3
 @end example
 @end itemize
 
+@section colorlevels
+
+Adjust video input frames using levels.
+
+The filter accepts the following options:
+
+@table @option
+@item rimin
+@item gimin
+@item bimin
+@item aimin
+Adjust red, green, blue and alpha input black point.
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{0}.
+
+@item rimax
+@item gimax
+@item bimax
+@item aimax
+Adjust red, green, blue and alpha input white point.
+Allowed ranges for options are @code{[-1.0, 1.0]}. Defaults are @code{1}.
+
+Input levels are used to lighten highlights (bright tones), darken shadows
+(dark tones), change the balance of bright and dark tones.
+
+@item romin
+@item gomin
+@item bomin
+@item aomin
+Adjust red, green, blue and alpha output black point.
+Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{0}.
+
+@item romax
+@item gomax
+@item bomax
+@item aomax
+Adjust red, green, blue and alpha output white point.
+Allowed ranges for options are @code{[0, 1.0]}. Defaults are @code{1}.
+
+Output levels allows manual selection of a constrained output level range.
+@end table
+
+@subsection Examples
+
+@itemize
+@item
+Make video output darker:
+@example
+colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
+@end example
+
+@item
+Increase contrast:
+@example
+colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
+@end example
+
+@item
+Make video output lighter:
+@example
+colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
+@end example
+
+@item
+Increase brightness:
+@example
+colorlevels=romin=0.5:gomin=0.5:bomin=0.5
+@end example
+@end itemize
+
 @section colorchannelmixer
 
 Adjust video input frames by re-mixing color channels.

libavfilter/Makefile

@@ -100,6 +100,7 @@ OBJS-$(CONFIG_BOXBLUR_FILTER)                += vf_boxblur.o
 OBJS-$(CONFIG_CODECVIEW_FILTER)              += vf_codecview.o
 OBJS-$(CONFIG_COLORBALANCE_FILTER)           += vf_colorbalance.o
 OBJS-$(CONFIG_COLORCHANNELMIXER_FILTER)      += vf_colorchannelmixer.o
+OBJS-$(CONFIG_COLORLEVELS_FILTER)            += vf_colorlevels.o
 OBJS-$(CONFIG_COLORMATRIX_FILTER)            += vf_colormatrix.o
 OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o

libavfilter/allfilters.c

@@ -116,6 +116,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(CODECVIEW,      codecview,      vf);
     REGISTER_FILTER(COLORBALANCE,   colorbalance,   vf);
     REGISTER_FILTER(COLORCHANNELMIXER, colorchannelmixer, vf);
+    REGISTER_FILTER(COLORLEVELS,    colorlevels,    vf);
     REGISTER_FILTER(COLORMATRIX,    colormatrix,    vf);
     REGISTER_FILTER(COPY,           copy,           vf);
     REGISTER_FILTER(CROP,           crop,           vf);

libavfilter/version.h

@@ -30,8 +30,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  5
-#define LIBAVFILTER_VERSION_MINOR  3
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MINOR  4
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

libavfilter/vf_colorlevels.c

+/*
+ * 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/imgutils.h"
+#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 in_min, in_max;
+    double out_min, out_max;
+} Range;
+
+typedef struct {
+    const AVClass *class;
+    Range range[4];
+    int nb_comp;
+    int bpp;
+    int step;
+    uint8_t rgba_map[4];
+    int linesize;
+} ColorLevelsContext;
+
+#define OFFSET(x) offsetof(ColorLevelsContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption colorlevels_options[] = {
+    { "rimin", "set input red black point",    OFFSET(range[R].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "gimin", "set input green black point",  OFFSET(range[G].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "bimin", "set input blue black point",   OFFSET(range[B].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "aimin", "set input alpha black point",  OFFSET(range[A].in_min),  AV_OPT_TYPE_DOUBLE, {.dbl=0}, -1, 1, FLAGS },
+    { "rimax", "set input red white point",    OFFSET(range[R].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
+    { "gimax", "set input green white point",  OFFSET(range[G].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
+    { "bimax", "set input blue white point",   OFFSET(range[B].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
+    { "aimax", "set input alpha white point",  OFFSET(range[A].in_max),  AV_OPT_TYPE_DOUBLE, {.dbl=1}, -1, 1, FLAGS },
+    { "romin", "set output red black point",   OFFSET(range[R].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
+    { "gomin", "set output green black point", OFFSET(range[G].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
+    { "bomin", "set output blue black point",  OFFSET(range[B].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
+    { "aomin", "set output alpha black point", OFFSET(range[A].out_min), AV_OPT_TYPE_DOUBLE, {.dbl=0},  0, 1, FLAGS },
+    { "romax", "set output red white point",   OFFSET(range[R].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
+    { "gomax", "set output green white point", OFFSET(range[G].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
+    { "bomax", "set output blue white point",  OFFSET(range[B].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
+    { "aomax", "set output alpha white point", OFFSET(range[A].out_max), AV_OPT_TYPE_DOUBLE, {.dbl=1},  0, 1, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(colorlevels);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pix_fmts[] = {
+        AV_PIX_FMT_0RGB,  AV_PIX_FMT_0BGR,
+        AV_PIX_FMT_ARGB,  AV_PIX_FMT_ABGR,
+        AV_PIX_FMT_RGB0,  AV_PIX_FMT_BGR0,
+        AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
+        AV_PIX_FMT_RGB48, AV_PIX_FMT_BGR48,
+        AV_PIX_FMT_RGBA64, AV_PIX_FMT_BGRA64,
+        AV_PIX_FMT_RGBA,  AV_PIX_FMT_BGRA,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+    return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    ColorLevelsContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+    s->nb_comp = desc->nb_components;
+    s->bpp = (desc->comp[0].depth_minus1 + 1) >> 3;
+    s->step = (av_get_padded_bits_per_pixel(desc) >> 3) / s->bpp;
+    s->linesize = inlink->w * s->step;
+    ff_fill_rgba_map(s->rgba_map, inlink->format);
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    ColorLevelsContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    const int step = s->step;
+    AVFrame *out;
+    int x, y, i;
+
+    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);
+    }
+
+    switch (s->bpp) {
+    case 1:
+        for (i = 0; i < s->nb_comp; i++) {
+            Range *r = &s->range[i];
+            const uint8_t offset = s->rgba_map[i];
+            const uint8_t *srcrow = in->data[0];
+            uint8_t *dstrow = out->data[0];
+            int imin = round(r->in_min  * UINT8_MAX);
+            int imax = round(r->in_max  * UINT8_MAX);
+            int omin = round(r->out_min * UINT8_MAX);
+            int omax = round(r->out_max * UINT8_MAX);
+            double coeff;
+
+            if (imin < 0) {
+                imin = UINT8_MAX;
+                for (y = 0; y < inlink->h; y++) {
+                    const uint8_t *src = srcrow;
+
+                    for (x = 0; x < s->linesize; x += step)
+                        imin = FFMIN(imin, src[x + offset]);
+                    srcrow += in->linesize[0];
+                }
+            }
+            if (imax < 0) {
+                srcrow = in->data[0];
+                imax = 0;
+                for (y = 0; y < inlink->h; y++) {
+                    const uint8_t *src = srcrow;
+
+                    for (x = 0; x < s->linesize; x += step)
+                        imax = FFMAX(imax, src[x + offset]);
+                    srcrow += in->linesize[0];
+                }
+            }
+
+            srcrow = in->data[0];
+            coeff = (omax - omin) / (double)(imax - imin);
+            for (y = 0; y < inlink->h; y++) {
+                const uint8_t *src = srcrow;
+                uint8_t *dst = dstrow;
+
+                for (x = 0; x < s->linesize; x += step)
+                    dst[x + offset] = av_clip_uint8((src[x + offset] - imin) * coeff + omin);
+                dstrow += out->linesize[0];
+                srcrow += in->linesize[0];
+            }
+        }
+        break;
+    case 2:
+        for (i = 0; i < s->nb_comp; i++) {
+            Range *r = &s->range[i];
+            const uint8_t offset = s->rgba_map[i];
+            const uint8_t *srcrow = in->data[0];
+            uint8_t *dstrow = out->data[0];
+            int imin = round(r->in_min  * UINT16_MAX);
+            int imax = round(r->in_max  * UINT16_MAX);
+            int omin = round(r->out_min * UINT16_MAX);
+            int omax = round(r->out_max * UINT16_MAX);
+            double coeff;
+
+            if (imin < 0) {
+                imin = UINT16_MAX;
+                for (y = 0; y < inlink->h; y++) {
+                    const uint16_t *src = (const uint16_t *)srcrow;
+
+                    for (x = 0; x < s->linesize; x += step)
+                        imin = FFMIN(imin, src[x + offset]);
+                    srcrow += in->linesize[0];
+                }
+            }
+            if (imax < 0) {
+                srcrow = in->data[0];
+                imax = 0;
+                for (y = 0; y < inlink->h; y++) {
+                    const uint16_t *src = (const uint16_t *)srcrow;
+
+                    for (x = 0; x < s->linesize; x += step)
+                        imax = FFMAX(imax, src[x + offset]);
+                    srcrow += in->linesize[0];
+                }
+            }
+
+            srcrow = in->data[0];
+            coeff = (omax - omin) / (double)(imax - imin);
+            for (y = 0; y < inlink->h; y++) {
+                const uint16_t *src = (const uint16_t*)srcrow;
+                uint16_t *dst = (uint16_t *)dstrow;
+
+                for (x = 0; x < s->linesize; x += step)
+                    dst[x + offset] = av_clip_uint16((src[x + offset] - imin) * coeff + omin);
+                dstrow += out->linesize[0];
+                srcrow += in->linesize[0];
+            }
+        }
+    }
+
+    if (in != out)
+        av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+static const AVFilterPad colorlevels_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+        .config_props = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad colorlevels_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_colorlevels = {
+    .name          = "colorlevels",
+    .description   = NULL_IF_CONFIG_SMALL("Adjust the color levels."),
+    .priv_size     = sizeof(ColorLevelsContext),
+    .priv_class    = &colorlevels_class,
+    .query_formats = query_formats,
+    .inputs        = colorlevels_inputs,
+    .outputs       = colorlevels_outputs,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};