avfilter: add multiply video filter

Changelog

@@ -14,6 +14,7 @@ version 5.1:
 - colormap video filter
 - colorchart video source filter
 - blurdetect filter
+- multiply video filter
 
 
 version 5.0:

doc/filters.texi

@@ -16638,6 +16638,29 @@ with the reference file @file{ref.mpg}.
 ffmpeg -i main.mpg -i ref.mpg -lavfi msad -f null -
 @end example
 
+@section multiply
+Multiply first video stream pixels values with second video stream pixels values.
+
+The filter accepts the following options:
+
+@table @option
+@item scale
+Set the scale applied to second video stream. By default is @code{1}.
+Allowed range is from @code{0} to @code{9}.
+
+@item offset
+Set the offset applied to second video stream. By default is @code{0.5}.
+Allowed range is from @code{-1} to @code{1}.
+
+@item planes
+Specify planes from input video stream that will be processed.
+By default all planes are processed.
+@end table
+
+@subsection Commands
+
+This filter supports same @ref{commands} as options.
+
 @section negate
 
 Negate (invert) the input video.

libavfilter/Makefile

@@ -366,6 +366,7 @@ OBJS-$(CONFIG_MIX_FILTER)                    += vf_mix.o framesync.o
 OBJS-$(CONFIG_MONOCHROME_FILTER)             += vf_monochrome.o
 OBJS-$(CONFIG_MORPHO_FILTER)                 += vf_morpho.o
 OBJS-$(CONFIG_MPDECIMATE_FILTER)             += vf_mpdecimate.o
+OBJS-$(CONFIG_MULTIPLY_FILTER)               += vf_multiply.o
 OBJS-$(CONFIG_NEGATE_FILTER)                 += vf_negate.o
 OBJS-$(CONFIG_NLMEANS_FILTER)                += vf_nlmeans.o
 OBJS-$(CONFIG_NLMEANS_OPENCL_FILTER)         += vf_nlmeans_opencl.o opencl.o opencl/nlmeans.o

libavfilter/allfilters.c

@@ -350,6 +350,7 @@ extern const AVFilter ff_vf_monochrome;
 extern const AVFilter ff_vf_morpho;
 extern const AVFilter ff_vf_mpdecimate;
 extern const AVFilter ff_vf_msad;
+extern const AVFilter ff_vf_multiply;
 extern const AVFilter ff_vf_negate;
 extern const AVFilter ff_vf_nlmeans;
 extern const AVFilter ff_vf_nlmeans_opencl;

libavfilter/version.h

@@ -31,7 +31,7 @@
 
 #include "version_major.h"
 
-#define LIBAVFILTER_VERSION_MINOR  37
+#define LIBAVFILTER_VERSION_MINOR  38
 #define LIBAVFILTER_VERSION_MICRO 100
 
 

libavfilter/vf_multiply.c

@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2022 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/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+#include "framesync.h"
+
+typedef struct MultiplyContext {
+    const AVClass *class;
+
+    float offset;
+    float scale;
+    int planes;
+
+    int linesize[4];
+    int nb_planes;
+
+    FFFrameSync fs;
+} MultiplyContext;
+
+#define OFFSET(x) offsetof(MultiplyContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_RUNTIME_PARAM
+
+typedef struct ThreadData {
+    AVFrame *src, *ref, *dst;
+} ThreadData;
+
+static const AVOption multiply_options[] = {
+    { "scale",  "set scale",  OFFSET(scale),  AV_OPT_TYPE_FLOAT, {.dbl=1},     0., 9., FLAGS },
+    { "offset", "set offset", OFFSET(offset), AV_OPT_TYPE_FLOAT, {.dbl=0.5},  -1., 1., FLAGS },
+    { "planes", "set planes", OFFSET(planes), AV_OPT_TYPE_FLAGS, {.i64=0xF},   0., 0xF, FLAGS },
+    { NULL }
+};
+
+static const enum AVPixelFormat pix_fmts[] = {
+    AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32,
+    AV_PIX_FMT_NONE
+};
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    MultiplyContext *s = ctx->priv;
+    int ret;
+
+    s->nb_planes = av_pix_fmt_count_planes(inlink->format);
+    if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
+        return ret;
+
+    return 0;
+}
+
+static void multiply(const uint8_t *ssrc, const uint8_t *rref, uint8_t *ddst,
+                     float scale, float offset, int w)
+{
+    const float *src = (const float *)ssrc;
+    const float *ref = (const float *)rref;
+    float *dst = (float *)ddst;
+
+    for (int x = 0; x < w; x++) {
+        const float factor = (ref[x] + offset) * scale;
+
+        dst[x] = src[x] * factor;
+    }
+}
+
+static int multiply_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+    MultiplyContext *s = ctx->priv;
+    const float offset = s->offset;
+    const float scale = s->scale;
+    ThreadData *td = arg;
+
+    for (int p = 0; p < s->nb_planes; p++) {
+        const ptrdiff_t src_linesize = td->src->linesize[p];
+        const ptrdiff_t ref_linesize = td->ref->linesize[p];
+        const ptrdiff_t dst_linesize = td->dst->linesize[p];
+        const int w = td->src->width;
+        const int h = td->src->height;
+        const int slice_start = (h * jobnr) / nb_jobs;
+        const int slice_end = (h * (jobnr+1)) / nb_jobs;
+        const uint8_t *src = td->src->data[p] + slice_start * src_linesize;
+        const uint8_t *ref = td->ref->data[p] + slice_start * ref_linesize;
+        uint8_t *dst = td->dst->data[p] + slice_start * dst_linesize;
+
+        if (!((1 << p) & s->planes)) {
+            av_image_copy_plane(dst, dst_linesize, ref, ref_linesize,
+                                s->linesize[p], slice_end - slice_start);
+            continue;
+        }
+
+        for (int y = slice_start; y < slice_end; y++) {
+            multiply(src, ref, dst, scale, offset, w);
+
+            dst += dst_linesize;
+            src += src_linesize;
+            ref += ref_linesize;
+        }
+    }
+
+    return 0;
+}
+
+static int process_frame(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    MultiplyContext *s = fs->opaque;
+    AVFilterLink *outlink = ctx->outputs[0];
+    AVFrame *out, *src, *ref;
+    int ret;
+
+    if ((ret = ff_framesync_get_frame(&s->fs, 0, &src, 0)) < 0 ||
+        (ret = ff_framesync_get_frame(&s->fs, 1, &ref, 0)) < 0)
+        return ret;
+
+    if (ctx->is_disabled) {
+        out = av_frame_clone(src);
+        if (!out)
+            return AVERROR(ENOMEM);
+    } else {
+        ThreadData td;
+
+        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!out)
+            return AVERROR(ENOMEM);
+        av_frame_copy_props(out, src);
+
+        td.src = src;
+        td.ref = ref;
+        td.dst = out;
+
+        ff_filter_execute(ctx, multiply_slice, &td, NULL,
+                          FFMIN(outlink->h, ff_filter_get_nb_threads(ctx)));
+    }
+    out->pts = av_rescale_q(s->fs.pts, s->fs.time_base, outlink->time_base);
+
+    return ff_filter_frame(outlink, out);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    MultiplyContext *s = ctx->priv;
+    AVFilterLink *source = ctx->inputs[0];
+    AVFilterLink *ref = ctx->inputs[1];
+    FFFrameSyncIn *in;
+    int ret;
+
+    if (source->w != ref->w || source->h != ref->h) {
+        av_log(ctx, AV_LOG_ERROR, "First input link %s parameters "
+               "(size %dx%d) do not match the corresponding "
+               "second input link %s parameters (%dx%d)\n",
+               ctx->input_pads[0].name, source->w, source->h,
+               ctx->input_pads[1].name, ref->w, ref->h);
+        return AVERROR(EINVAL);
+    }
+
+    outlink->w = source->w;
+    outlink->h = source->h;
+    outlink->sample_aspect_ratio = source->sample_aspect_ratio;
+    outlink->frame_rate = source->frame_rate;
+
+    if ((ret = ff_framesync_init(&s->fs, ctx, 2)) < 0)
+        return ret;
+
+    in = s->fs.in;
+    in[0].time_base = source->time_base;
+    in[1].time_base = ref->time_base;
+    in[0].sync   = 1;
+    in[0].before = EXT_STOP;
+    in[0].after  = EXT_INFINITY;
+    in[1].sync   = 1;
+    in[1].before = EXT_STOP;
+    in[1].after  = EXT_INFINITY;
+    s->fs.opaque   = s;
+    s->fs.on_event = process_frame;
+
+    ret = ff_framesync_configure(&s->fs);
+    outlink->time_base = s->fs.time_base;
+
+    return ret;
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    MultiplyContext *s = ctx->priv;
+    return ff_framesync_activate(&s->fs);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    MultiplyContext *s = ctx->priv;
+
+    ff_framesync_uninit(&s->fs);
+}
+
+static const AVFilterPad multiply_inputs[] = {
+    {
+        .name         = "source",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_input,
+    },
+    {
+        .name         = "factor",
+        .type         = AVMEDIA_TYPE_VIDEO,
+    },
+};
+
+static const AVFilterPad multiply_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+};
+
+AVFILTER_DEFINE_CLASS(multiply);
+
+const AVFilter ff_vf_multiply = {
+    .name          = "multiply",
+    .description   = NULL_IF_CONFIG_SMALL("Multiply first video stream with second video stream."),
+    .priv_class    = &multiply_class,
+    .priv_size     = sizeof(MultiplyContext),
+    .uninit        = uninit,
+    .activate      = activate,
+    FILTER_INPUTS(multiply_inputs),
+    FILTER_OUTPUTS(multiply_outputs),
+    FILTER_PIXFMTS_ARRAY(pix_fmts),
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL | AVFILTER_FLAG_SLICE_THREADS,
+    .process_command = ff_filter_process_command,
+};