avfilter: add hsvkey and hsvhold video filters

6 files changed, 462 insertions, 1 deletions

diff --git a/Changelog b/Changelog
index 5a5b50eb66..20d71bed88 100644
--- a/Changelog
+++ b/Changelog
@@ -11,6 +11,7 @@ version <next>:
 - afwtdn audio filter
 - audio and video segment filters
 - Apple Graphics (SMC) encoder
+- hsvkey and hsvhold video filters
 
 
 version 4.4:
diff --git a/doc/filters.texi b/doc/filters.texi
index b902aca12d..47ceeb18c6 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -13519,6 +13519,82 @@ If set to 1, force the output to terminate when the shortest input
 terminates. Default value is 0.
 @end table
 
+@section hsvhold
+Turns a certain HSV range into gray values.
+
+This filter measures color difference between set HSV color in options
+and ones measured in video stream. Depending on options, output
+colors can be changed to be gray or not.
+
+The filter accepts the following options:
+
+@table @option
+@item hue
+Set the hue value which will be used if color difference calculation.
+Allowed range is from -360 to 360. Default value is 0.
+
+@item sat
+Set the saturation value which will be used if color difference calculation.
+Allowed range is from -1 to 1. Default value is 0.
+
+@item val
+Set the value which will be used if color difference calculation.
+Allowed range is from -1 to 1. Default value is 0.
+
+@item similarity
+Set similarity percentage with the key color.
+Allowed range is from 0 to 1. Default value is 0.01.
+
+0.00001 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+Allowed range is from 0 to 1. Default value is 0.
+
+0.0 makes pixels either fully gray, or not gray at all.
+
+Higher values result in more gray pixels, with a higher gray pixel
+the more similar the pixels color is to the key color.
+@end table
+
+@section hsvkey
+Turns a certain HSV range into transparency.
+
+This filter measures color difference between set HSV color in options
+and ones measured in video stream. Depending on options, output
+colors can be changed to transparent by adding alpha channel.
+
+The filter accepts the following options:
+
+@table @option
+@item hue
+Set the hue value which will be used if color difference calculation.
+Allowed range is from -360 to 360. Default value is 0.
+
+@item sat
+Set the saturation value which will be used if color difference calculation.
+Allowed range is from -1 to 1. Default value is 0.
+
+@item val
+Set the value which will be used if color difference calculation.
+Allowed range is from -1 to 1. Default value is 0.
+
+@item similarity
+Set similarity percentage with the key color.
+Allowed range is from 0 to 1. Default value is 0.01.
+
+0.00001 matches only the exact key color, while 1.0 matches everything.
+
+@item blend
+Blend percentage.
+Allowed range is from 0 to 1. Default value is 0.
+
+0.0 makes pixels either fully transparent, or not transparent at all.
+
+Higher values result in semi-transparent pixels, with a higher transparency
+the more similar the pixels color is to the key color.
+@end table
+
 @section hue
 
 Modify the hue and/or the saturation of the input.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 102ce7beff..3166e70b58 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -296,6 +296,8 @@ OBJS-$(CONFIG_HISTOGRAM_FILTER)              += vf_histogram.o
 OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
 OBJS-$(CONFIG_HQX_FILTER)                    += vf_hqx.o
 OBJS-$(CONFIG_HSTACK_FILTER)                 += vf_stack.o framesync.o
+OBJS-$(CONFIG_HSVHOLD_FILTER)                += vf_hsvkey.o
+OBJS-$(CONFIG_HSVKEY_FILTER)                 += vf_hsvkey.o
 OBJS-$(CONFIG_HUE_FILTER)                    += vf_hue.o
 OBJS-$(CONFIG_HWDOWNLOAD_FILTER)             += vf_hwdownload.o
 OBJS-$(CONFIG_HWMAP_FILTER)                  += vf_hwmap.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 73040d2824..c49c831203 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -281,6 +281,8 @@ extern const AVFilter ff_vf_histogram;
 extern const AVFilter ff_vf_hqdn3d;
 extern const AVFilter ff_vf_hqx;
 extern const AVFilter ff_vf_hstack;
+extern const AVFilter ff_vf_hsvhold;
+extern const AVFilter ff_vf_hsvkey;
 extern const AVFilter ff_vf_hue;
 extern const AVFilter ff_vf_hwdownload;
 extern const AVFilter ff_vf_hwmap;
diff --git a/libavfilter/version.h b/libavfilter/version.h
index bcd27aa6e8..e9a76c5ac3 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR   8
-#define LIBAVFILTER_VERSION_MINOR   3
+#define LIBAVFILTER_VERSION_MINOR   4
 #define LIBAVFILTER_VERSION_MICRO 100
 
 
diff --git a/libavfilter/vf_hsvkey.c b/libavfilter/vf_hsvkey.c
new file mode 100644
index 0000000000..2f2f037714
--- /dev/null
+++ b/libavfilter/vf_hsvkey.c
@@ -0,0 +1,380 @@
+/*
+ * 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 "libavutil/intreadwrite.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct HSVKeyContext {
+    const AVClass *class;
+
+    float hue, hue_opt, sat, val;
+    float similarity;
+    float blend;
+
+    float scale;
+
+    float half;
+
+    int depth;
+    int max;
+
+    int hsub_log2;
+    int vsub_log2;
+
+    int (*do_slice)(AVFilterContext *ctx, void *arg,
+                    int jobnr, int nb_jobs);
+} HSVKeyContext;
+
+#define SQR(x) ((x)*(x))
+
+static int do_hsvkey_pixel(HSVKeyContext *s, int y, int u, int v,
+                           float hue_key, float sat_key, float val_key)
+{
+    const float similarity = s->similarity;
+    const float scale = s->scale;
+    const float blend = s->blend;
+    const int imax = s->max;
+    const float max = imax;
+    const float half = s->half;
+    const float uf = u - half;
+    const float vf = v - half;
+    const float hue = hue_key < 0.f ? -hue_key : atan2f(uf, vf) + M_PI;
+    const float sat = sat_key < 0.f ? -sat_key : sqrtf((uf * uf + vf * vf) / (half * half * 2.f));
+    const float val = val_key < 0.f ? -val_key : scale * y;
+    float diff;
+
+    hue_key = fabsf(hue_key);
+    sat_key = fabsf(sat_key);
+    val_key = fabsf(val_key);
+
+    diff = sqrtf(fmaxf(SQR(sat) * SQR(val) +
+                 SQR(sat_key) * SQR(val_key) -
+                 2.f * sat * val * sat_key * val_key * cosf(hue_key - hue) +
+                 SQR(val - val_key), 0.f));
+    if (diff < similarity) {
+        return 0;
+    } else if (blend > FLT_MIN) {
+        return av_clipf((diff - similarity) / blend, 0.f, 1.f) * max;
+    } else {
+        return imax;
+    }
+
+    return 0;
+}
+
+static int do_hsvkey_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
+{
+    HSVKeyContext *s = avctx->priv;
+    AVFrame *frame = arg;
+    const int slice_start = (frame->height * jobnr) / nb_jobs;
+    const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
+    const int hsub_log2 = s->hsub_log2;
+    const int vsub_log2 = s->vsub_log2;
+    const float hue = s->hue;
+    const float sat = s->sat;
+    const float val = s->val;
+
+    for (int y = slice_start; y < slice_end; y++) {
+        for (int x = 0; x < frame->width; x++) {
+            int Y = frame->data[0][frame->linesize[0] * y + x];
+            int u = frame->data[1][frame->linesize[1] * (y >> vsub_log2) + (x >> hsub_log2)];
+            int v = frame->data[2][frame->linesize[2] * (y >> vsub_log2) + (x >> hsub_log2)];
+
+            frame->data[3][frame->linesize[3] * y + x] = do_hsvkey_pixel(s, Y, u, v, hue, sat, val);
+        }
+    }
+
+    return 0;
+}
+
+static int do_hsvkey16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
+{
+    HSVKeyContext *s = avctx->priv;
+    AVFrame *frame = arg;
+    const int slice_start = (frame->height * jobnr) / nb_jobs;
+    const int slice_end = (frame->height * (jobnr + 1)) / nb_jobs;
+    const int hsub_log2 = s->hsub_log2;
+    const int vsub_log2 = s->vsub_log2;
+    const float hue = s->hue;
+    const float sat = s->sat;
+    const float val = s->val;
+
+    for (int y = slice_start; y < slice_end; ++y) {
+        for (int x = 0; x < frame->width; ++x) {
+            uint16_t *dst = (uint16_t *)(frame->data[3] + frame->linesize[3] * y);
+            int Y = AV_RN16(&frame->data[0][frame->linesize[0] * y + 2 * x]);
+            int u = AV_RN16(&frame->data[1][frame->linesize[1] * (y >> vsub_log2) + 2 * (x >> hsub_log2)]);
+            int v = AV_RN16(&frame->data[2][frame->linesize[2] * (y >> vsub_log2) + 2 * (x >> hsub_log2)]);
+
+            dst[x] = do_hsvkey_pixel(s, Y, u, v, hue, sat, val);
+        }
+    }
+
+    return 0;
+}
+
+static int do_hsvhold_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
+{
+    HSVKeyContext *s = avctx->priv;
+    AVFrame *frame = arg;
+    const int hsub_log2 = s->hsub_log2;
+    const int vsub_log2 = s->vsub_log2;
+    const int width = frame->width >> hsub_log2;
+    const int height = frame->height >> vsub_log2;
+    const int slice_start = (height * jobnr) / nb_jobs;
+    const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+    const float scale = s->scale;
+    const float hue = s->hue;
+    const float sat = s->sat;
+    const float val = s->val;
+
+    for (int y = slice_start; y < slice_end; ++y) {
+        for (int x = 0; x < width; ++x) {
+            uint8_t *dstu = frame->data[1] + frame->linesize[1] * y;
+            uint8_t *dstv = frame->data[2] + frame->linesize[2] * y;
+            int Y = frame->data[0][frame->linesize[0] * (y << vsub_log2) + (x << hsub_log2)];
+            int u = frame->data[1][frame->linesize[1] * y + x];
+            int v = frame->data[2][frame->linesize[2] * y + x];
+            int t = do_hsvkey_pixel(s, Y, u, v, hue, sat, val);
+
+            if (t > 0) {
+                float f = 1.f - t * scale;
+
+                dstu[x] = 128 + (u - 128) * f;
+                dstv[x] = 128 + (v - 128) * f;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int do_hsvhold16_slice(AVFilterContext *avctx, void *arg, int jobnr, int nb_jobs)
+{
+    HSVKeyContext *s = avctx->priv;
+    AVFrame *frame = arg;
+    const int hsub_log2 = s->hsub_log2;
+    const int vsub_log2 = s->vsub_log2;
+    const int width = frame->width >> hsub_log2;
+    const int height = frame->height >> vsub_log2;
+    const int slice_start = (height * jobnr) / nb_jobs;
+    const int slice_end = (height * (jobnr + 1)) / nb_jobs;
+    const float scale = s->scale;
+    const float half = s->half;
+    const float hue = s->hue;
+    const float sat = s->sat;
+    const float val = s->val;
+
+    for (int y = slice_start; y < slice_end; ++y) {
+        for (int x = 0; x < width; ++x) {
+            uint16_t *dstu = (uint16_t *)(frame->data[1] + frame->linesize[1] * y);
+            uint16_t *dstv = (uint16_t *)(frame->data[2] + frame->linesize[2] * y);
+            int Y = AV_RN16(&frame->data[0][frame->linesize[0] * (y << vsub_log2) + 2 * (x << hsub_log2)]);
+            int u = AV_RN16(&frame->data[1][frame->linesize[1] * y + 2 * x]);
+            int v = AV_RN16(&frame->data[2][frame->linesize[2] * y + 2 * x]);
+            int t = do_hsvkey_pixel(s, Y, u, v, hue, sat, val);
+
+            if (t > 0) {
+                float f = 1.f - t * scale;
+
+                dstu[x] = half + (u - half) * f;
+                dstv[x] = half + (v - half) * f;
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *link, AVFrame *frame)
+{
+    AVFilterContext *avctx = link->dst;
+    HSVKeyContext *s = avctx->priv;
+    int res;
+
+    s->hue = FFSIGN(s->hue_opt) *M_PI * fmodf(526.f - fabsf(s->hue_opt), 360.f) / 180.f;
+    if (res = ff_filter_execute(avctx, s->do_slice, frame, NULL,
+                                FFMIN(frame->height, ff_filter_get_nb_threads(avctx))))
+        return res;
+
+    return ff_filter_frame(avctx->outputs[0], frame);
+}
+
+static av_cold int config_output(AVFilterLink *outlink)
+{
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
+    AVFilterContext *avctx = outlink->src;
+    HSVKeyContext *s = avctx->priv;
+
+    s->depth = desc->comp[0].depth;
+    s->max = (1 << s->depth) - 1;
+    s->half = 0.5f * s->max;
+    s->scale = 1.f / s->max;
+
+    if (!strcmp(avctx->filter->name, "hsvkey")) {
+        s->do_slice = s->depth <= 8 ? do_hsvkey_slice : do_hsvkey16_slice;
+    } else {
+        s->do_slice = s->depth <= 8 ? do_hsvhold_slice: do_hsvhold16_slice;
+    }
+
+    return 0;
+}
+
+static av_cold int query_formats(AVFilterContext *avctx)
+{
+    static const enum AVPixelFormat pixel_fmts[] = {
+        AV_PIX_FMT_YUVA420P,
+        AV_PIX_FMT_YUVA422P,
+        AV_PIX_FMT_YUVA444P,
+        AV_PIX_FMT_YUVA420P9,  AV_PIX_FMT_YUVA422P9,  AV_PIX_FMT_YUVA444P9,
+        AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
+        AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
+        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+        AV_PIX_FMT_NONE
+    };
+
+    static const enum AVPixelFormat hold_pixel_fmts[] = {
+        AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUV422P,
+        AV_PIX_FMT_YUV444P,
+        AV_PIX_FMT_YUVA420P,
+        AV_PIX_FMT_YUVA422P,
+        AV_PIX_FMT_YUVA444P,
+        AV_PIX_FMT_YUV420P9,   AV_PIX_FMT_YUV422P9,   AV_PIX_FMT_YUV444P9,
+        AV_PIX_FMT_YUV420P10,  AV_PIX_FMT_YUV422P10,  AV_PIX_FMT_YUV444P10,
+        AV_PIX_FMT_YUV444P12,  AV_PIX_FMT_YUV422P12,  AV_PIX_FMT_YUV420P12,
+        AV_PIX_FMT_YUV444P14,  AV_PIX_FMT_YUV422P14,  AV_PIX_FMT_YUV420P14,
+        AV_PIX_FMT_YUV420P16,  AV_PIX_FMT_YUV422P16,  AV_PIX_FMT_YUV444P16,
+        AV_PIX_FMT_YUVA420P9,  AV_PIX_FMT_YUVA422P9,  AV_PIX_FMT_YUVA444P9,
+        AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA444P10,
+        AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA444P12,
+        AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+        AV_PIX_FMT_NONE
+    };
+    const enum AVPixelFormat *pix_fmts;
+
+    pix_fmts = !strcmp(avctx->filter->name, "hsvhold") ? hold_pixel_fmts : pixel_fmts;
+
+    return ff_set_common_formats_from_list(avctx, pix_fmts);
+}
+
+static av_cold int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *avctx = inlink->dst;
+    HSVKeyContext *s = avctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+    s->hsub_log2 = desc->log2_chroma_w;
+    s->vsub_log2 = desc->log2_chroma_h;
+
+    return 0;
+}
+
+static const AVFilterPad hsvkey_inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .flags          = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
+        .filter_frame   = filter_frame,
+        .config_props   = config_input,
+    },
+};
+
+static const AVFilterPad hsvkey_outputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .config_props   = config_output,
+    },
+};
+
+#define OFFSET(x) offsetof(HSVKeyContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
+
+static const AVOption hsvkey_options[] = {
+    { "hue", "set the hue value", OFFSET(hue_opt), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -360, 360, FLAGS },
+    { "sat", "set the saturation value", OFFSET(sat), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -1, 1, FLAGS },
+    { "val", "set the value value", OFFSET(val), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -1, 1, FLAGS },
+    { "similarity", "set the hsvkey similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01}, 0.00001, 1.0, FLAGS },
+    { "blend", "set the hsvkey blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(hsvkey);
+
+const AVFilter ff_vf_hsvkey = {
+    .name          = "hsvkey",
+    .description   = NULL_IF_CONFIG_SMALL("Turns a certain HSV range into transparency. Operates on YUV colors."),
+    .priv_size     = sizeof(HSVKeyContext),
+    .priv_class    = &hsvkey_class,
+    .query_formats = query_formats,
+    FILTER_INPUTS(hsvkey_inputs),
+    FILTER_OUTPUTS(hsvkey_outputs),
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+    .process_command = ff_filter_process_command,
+};
+
+static const AVOption hsvhold_options[] = {
+    { "hue", "set the hue value", OFFSET(hue_opt), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -360, 360, FLAGS },
+    { "sat", "set the saturation value", OFFSET(sat), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -1, 1, FLAGS },
+    { "val", "set the value value", OFFSET(val), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, -1, 1, FLAGS },
+    { "similarity", "set the hsvhold similarity value", OFFSET(similarity), AV_OPT_TYPE_FLOAT, { .dbl = 0.01 }, 0.00001, 1.0, FLAGS },
+    { "blend", "set the hsvhold blend value", OFFSET(blend), AV_OPT_TYPE_FLOAT, { .dbl = 0.0 }, 0.0, 1.0, FLAGS },
+    { NULL }
+};
+
+static const AVFilterPad hsvhold_inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .flags          = AVFILTERPAD_FLAG_NEEDS_WRITABLE,
+        .filter_frame   = filter_frame,
+        .config_props   = config_input,
+    },
+};
+
+static const AVFilterPad hsvhold_outputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .config_props   = config_output,
+    },
+};
+
+AVFILTER_DEFINE_CLASS(hsvhold);
+
+const AVFilter ff_vf_hsvhold = {
+    .name          = "hsvhold",
+    .description   = NULL_IF_CONFIG_SMALL("Turns a certain HSV range into gray."),
+    .priv_size     = sizeof(HSVKeyContext),
+    .priv_class    = &hsvhold_class,
+    .query_formats = query_formats,
+    FILTER_INPUTS(hsvhold_inputs),
+    FILTER_OUTPUTS(hsvhold_outputs),
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+    .process_command = ff_filter_process_command,
+};