[FFmpeg-devel] [PATCH] avfilter: add colorhold filter
Paul B Mahol
onemda at gmail.com
Sat May 4 17:13:38 EEST 2019
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 18 +++++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_colorkey.c | 102 +++++++++++++++++++++++++++++++++++++-
4 files changed, 121 insertions(+), 1 deletion(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index cd82869849..1ac37a32b8 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -6723,6 +6723,24 @@ ffmpeg -i background.png -i video.mp4 -filter_complex "[1:v]colorkey=0x3BBD1E:0.
@end example
@end itemize
+ at section colorhold
+Remove all color information for all RGB colors except for certain one.
+
+The filter accepts the following options:
+
+ at table @option
+ at item color
+The color which will not be replaced with neutral gray.
+
+ at item similarity
+Similarity percentage with the above color.
+0.01 matches only the exact key color, while 1.0 matches everything.
+
+ at item blend
+Blend percentage. 0.0 makes pixels fully gray.
+Higher values result in more preserved color.
+ at end table
+
@section colorlevels
Adjust video input frames using levels.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 59d12ce069..b41304d480 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -179,6 +179,7 @@ OBJS-$(CONFIG_COLORCHANNELMIXER_FILTER) += vf_colorchannelmixer.o
OBJS-$(CONFIG_COLORKEY_FILTER) += vf_colorkey.o
OBJS-$(CONFIG_COLORKEY_OPENCL_FILTER) += vf_colorkey_opencl.o opencl.o \
opencl/colorkey.o
+OBJS-$(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
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index ae725cb0e0..9bdfa7d1bc 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -167,6 +167,7 @@ extern AVFilter ff_vf_colorbalance;
extern AVFilter ff_vf_colorchannelmixer;
extern AVFilter ff_vf_colorkey;
extern AVFilter ff_vf_colorkey_opencl;
+extern AVFilter ff_vf_colorhold;
extern AVFilter ff_vf_colorlevels;
extern AVFilter ff_vf_colormatrix;
extern AVFilter ff_vf_colorspace;
diff --git a/libavfilter/vf_colorkey.c b/libavfilter/vf_colorkey.c
index 3d65e59d42..b546cd4122 100644
--- a/libavfilter/vf_colorkey.c
+++ b/libavfilter/vf_colorkey.c
@@ -34,6 +34,9 @@ typedef struct ColorkeyContext {
uint8_t colorkey_rgba[4];
float similarity;
float blend;
+
+ int (*do_slice)(AVFilterContext *ctx, void *arg,
+ int jobnr, int nb_jobs);
} ColorkeyContext;
static uint8_t do_colorkey_pixel(ColorkeyContext *ctx, uint8_t r, uint8_t g, uint8_t b)
@@ -77,15 +80,65 @@ static int do_colorkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int n
return 0;
}
+static int do_colorhold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
+{
+ AVFrame *frame = arg;
+
+ const int slice_start = (frame->height * jobnr) / nb_jobs;
+ const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
+
+ ColorkeyContext *ctx = avctx->priv;
+
+ int o, x, y;
+
+ for (y = slice_start; y < slice_end; ++y) {
+ for (x = 0; x < frame->width; ++x) {
+ int t, r, g, b;
+
+ o = frame->linesize[0] * y + x * 4;
+ r = frame->data[0][o + ctx->co[0]];
+ g = frame->data[0][o + ctx->co[1]];
+ b = frame->data[0][o + ctx->co[2]];
+
+ t = do_colorkey_pixel(ctx, r, g, b);
+
+ if (t > 0) {
+ int a = (r + g + b) / 3;
+ int rt = 255 - t;
+
+ frame->data[0][o + ctx->co[0]] = (a * t + r * rt + 127) >> 8;
+ frame->data[0][o + ctx->co[1]] = (a * t + g * rt + 127) >> 8;
+ frame->data[0][o + ctx->co[2]] = (a * t + b * rt + 127) >> 8;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static av_cold int init_filter(AVFilterContext *avctx)
+{
+ ColorkeyContext *ctx = avctx->priv;
+
+ if (!strcmp(avctx->filter->name, "colorkey")) {
+ ctx->do_slice = do_colorkey_slice;
+ } else {
+ ctx->do_slice = do_colorhold_slice;
+ }
+
+ return 0;
+}
+
static int filter_frame(AVFilterLink *link, AVFrame *frame)
{
AVFilterContext *avctx = link->dst;
+ ColorkeyContext *ctx = avctx->priv;
int res;
if (res = av_frame_make_writable(frame))
return res;
- if (res = avctx->internal->execute(avctx, do_colorkey_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
+ if (res = avctx->internal->execute(avctx, ctx->do_slice, frame, NULL, FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
return res;
return ff_filter_frame(avctx->outputs[0], frame);
@@ -148,6 +201,8 @@ static const AVFilterPad colorkey_outputs[] = {
#define OFFSET(x) offsetof(ColorkeyContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+#if CONFIG_COLORKEY_FILTER
+
static const AVOption colorkey_options[] = {
{ "color", "set the colorkey key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
{ "similarity", "set the colorkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
@@ -163,7 +218,52 @@ AVFilter ff_vf_colorkey = {
.priv_size = sizeof(ColorkeyContext),
.priv_class = &colorkey_class,
.query_formats = query_formats,
+ .init = init_filter,
.inputs = colorkey_inputs,
.outputs = colorkey_outputs,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};
+
+#endif /* CONFIG_COLORKEY_FILTER */
+#if CONFIG_COLORHOLD_FILTER
+
+static const AVFilterPad colorhold_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad colorhold_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output,
+ },
+ { NULL }
+};
+
+static const AVOption colorhold_options[] = {
+ { "color", "set the colorhold key color", OFFSET(colorkey_rgba), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
+ { "similarity", "set the colorhold similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.01, 1.0, FLAGS },
+ { "blend", "set the colorhold blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(colorhold);
+
+AVFilter ff_vf_colorhold = {
+ .name = "colorhold",
+ .description = NULL_IF_CONFIG_SMALL("Turns a certain color range into gray. Operates on RGB colors."),
+ .priv_size = sizeof(ColorkeyContext),
+ .priv_class = &colorhold_class,
+ .query_formats = query_formats,
+ .init = init_filter,
+ .inputs = colorhold_inputs,
+ .outputs = colorhold_outputs,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+};
+
+#endif /* CONFIG_COLORHOLD_FILTER */
--
2.17.1
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