[FFmpeg-devel] [PATCH] avfilter: add monochrome video filter
Paul B Mahol
onemda at gmail.com
Mon Feb 8 13:08:17 EET 2021
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
doc/filters.texi | 27 ++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_monochrome.c | 239 ++++++++++++++++++++++++++++++++++++
4 files changed, 268 insertions(+)
create mode 100644 libavfilter/vf_monochrome.c
diff --git a/doc/filters.texi b/doc/filters.texi
index f50a776897..45afc7efb1 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -14794,6 +14794,33 @@ This filter supports the following commands:
Syntax is same as option with same name.
@end table
+ at section monochrome
+Convert video to gray using custom color filter.
+
+A description of the accepted options follows.
+
+ at table @option
+ at item cb
+Set the chroma blue spot. Allowed range is from -1 to 1.
+Default value is 0.
+
+ at item cr
+Set the chroma red spot. Allowed range is from -1 to 1.
+Default value is 0.
+
+ at item size
+Set the color filter size. Allowed range is from .25 to 3.
+Default value is 1.
+
+ at item high
+Set the highlights strength. Allowed range is from 0 to 1.
+Default value is 0.
+ at end table
+
+ at subsection Commands
+
+This filter supports the all above options as @ref{commands}.
+
@section mpdecimate
Drop frames that do not differ greatly from the previous frame in
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 5a611e7a9e..3333ad16ef 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -332,6 +332,7 @@ OBJS-$(CONFIG_METADATA_FILTER) += f_metadata.o
OBJS-$(CONFIG_MIDEQUALIZER_FILTER) += vf_midequalizer.o framesync.o
OBJS-$(CONFIG_MINTERPOLATE_FILTER) += vf_minterpolate.o motion_estimation.o
OBJS-$(CONFIG_MIX_FILTER) += vf_mix.o framesync.o
+OBJS-$(CONFIG_MONOCHROME_FILTER) += vf_monochrome.o
OBJS-$(CONFIG_MPDECIMATE_FILTER) += vf_mpdecimate.o
OBJS-$(CONFIG_NEGATE_FILTER) += vf_lut.o
OBJS-$(CONFIG_NLMEANS_FILTER) += vf_nlmeans.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 31546c268d..7fa01ff139 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -317,6 +317,7 @@ extern AVFilter ff_vf_metadata;
extern AVFilter ff_vf_midequalizer;
extern AVFilter ff_vf_minterpolate;
extern AVFilter ff_vf_mix;
+extern AVFilter ff_vf_monochrome;
extern AVFilter ff_vf_mpdecimate;
extern AVFilter ff_vf_negate;
extern AVFilter ff_vf_nlmeans;
diff --git a/libavfilter/vf_monochrome.c b/libavfilter/vf_monochrome.c
new file mode 100644
index 0000000000..105b0e98ce
--- /dev/null
+++ b/libavfilter/vf_monochrome.c
@@ -0,0 +1,239 @@
+/*
+ * 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 MonochromeContext {
+ const AVClass *class;
+
+ float b, r;
+ float size;
+ float high;
+
+ int depth;
+
+ int (*do_slice)(AVFilterContext *s, void *arg,
+ int jobnr, int nb_jobs);
+} MonochromeContext;
+
+static float envelope(const float x)
+{
+ const float beta = 0.6f;
+
+ if (x < beta) {
+ const float tmp = fabsf(x / beta - 1.f);
+
+ return 1.f - tmp * tmp;
+ } else {
+ const float tmp = (1.f - x) / (1.f - beta);
+
+ return tmp * tmp * (3.f - 2.f * tmp);
+ }
+}
+
+static float filter(float b, float r, float u, float v, float size)
+{
+ return expf(-av_clipf(((b - u) * (b - u) +
+ (r - v) * (r - v)) /
+ size, 0.f, 1.f));
+}
+
+#define PROCESS() \
+ float y = yptr[x] * imax; \
+ float u = uptr[x] * imax - .5f; \
+ float v = vptr[x] * imax - .5f; \
+ float tt, t, ny; \
+ \
+ ny = filter(b, r, u, v, size); \
+ tt = envelope(y); \
+ t = tt + (1.f - tt) * (1.f - high); \
+ ny = (1.f - t) * y + t * ny * y;
+
+static int monochrome_slice8(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ MonochromeContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int depth = s->depth;
+ const int half = (1 << (depth - 1));
+ const float max = (1 << depth) - 1;
+ const float imax = 1.f / max;
+ const int width = frame->width;
+ const int height = frame->height;
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+ const int ylinesize = frame->linesize[0];
+ const int ulinesize = frame->linesize[1];
+ const int vlinesize = frame->linesize[2];
+ uint8_t *yptr = frame->data[0] + slice_start * ylinesize;
+ uint8_t *uptr = frame->data[1] + slice_start * ulinesize;
+ uint8_t *vptr = frame->data[2] + slice_start * vlinesize;
+ const float high = s->high;
+ const float size = s->size;
+ const float b = s->b * .5f;
+ const float r = s->r * .5f;
+
+ for (int y = slice_start; y < slice_end; y++) {
+ for (int x = 0; x < width; x++) {
+ PROCESS()
+
+ yptr[x] = av_clip_uint8(ny * max);
+ uptr[x] = half;
+ vptr[x] = half;
+ }
+
+ yptr += ylinesize;
+ uptr += ulinesize;
+ vptr += vlinesize;
+ }
+
+ return 0;
+}
+
+static int monochrome_slice16(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ MonochromeContext *s = ctx->priv;
+ AVFrame *frame = arg;
+ const int depth = s->depth;
+ const int half = (1 << (depth - 1));
+ const float max = (1 << depth) - 1;
+ const float imax = 1.f / max;
+ const int width = frame->width;
+ const int height = frame->height;
+ const int slice_start = (height * jobnr) / nb_jobs;
+ const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+ const int ylinesize = frame->linesize[0] / 2;
+ const int ulinesize = frame->linesize[1] / 2;
+ const int vlinesize = frame->linesize[2] / 2;
+ uint16_t *yptr = (uint16_t *)frame->data[0] + slice_start * ylinesize;
+ uint16_t *uptr = (uint16_t *)frame->data[1] + slice_start * ulinesize;
+ uint16_t *vptr = (uint16_t *)frame->data[2] + slice_start * vlinesize;
+ const float high = s->high;
+ const float size = s->size;
+ const float b = s->b * .5f;
+ const float r = s->r * .5f;
+
+ for (int y = slice_start; y < slice_end; y++) {
+ for (int x = 0; x < width; x++) {
+ PROCESS()
+
+ yptr[x] = av_clip_uintp2_c(ny * max, depth);
+ uptr[x] = half;
+ vptr[x] = half;
+ }
+
+ yptr += ylinesize;
+ uptr += ulinesize;
+ vptr += vlinesize;
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+ AVFilterContext *ctx = inlink->dst;
+ MonochromeContext *s = ctx->priv;
+
+ 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_YUV444P, AV_PIX_FMT_YUVJ444P,
+ AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV444P16,
+ AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_YUVA444P16,
+ 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;
+ MonochromeContext *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 ? monochrome_slice8 : monochrome_slice16;
+
+ return 0;
+}
+
+static const AVFilterPad monochrome_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .needs_writable = 1,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+ { NULL }
+};
+
+static const AVFilterPad monochrome_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+#define OFFSET(x) offsetof(MonochromeContext, x)
+#define VF AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
+
+static const AVOption monochrome_options[] = {
+ { "cb", "set the chroma blue spot", OFFSET(b), AV_OPT_TYPE_FLOAT, {.dbl=0},-1, 1, VF },
+ { "cr", "set the chroma red spot", OFFSET(r), AV_OPT_TYPE_FLOAT, {.dbl=0},-1, 1, VF },
+ { "size", "set the color filter size", OFFSET(size), AV_OPT_TYPE_FLOAT, {.dbl=1},.25, 3, VF },
+ { "high", "set the highlights strength", OFFSET(high), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, 1, VF },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(monochrome);
+
+AVFilter ff_vf_monochrome = {
+ .name = "monochrome",
+ .description = NULL_IF_CONFIG_SMALL("Convert video to gray using custom color filter."),
+ .priv_size = sizeof(MonochromeContext),
+ .priv_class = &monochrome_class,
+ .query_formats = query_formats,
+ .inputs = monochrome_inputs,
+ .outputs = monochrome_outputs,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+ .process_command = ff_filter_process_command,
+};
--
2.17.1
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