diff mbox

[FFmpeg-devel] avfilter: add generic FFT video convolve filter

Message ID 20170903105947.12926-1-onemda@gmail.com
State New
Headers show

Commit Message

Paul B Mahol Sept. 3, 2017, 10:59 a.m. UTC
Signed-off-by: Paul B Mahol <onemda@gmail.com>
---
 doc/filters.texi          |  14 ++
 libavfilter/Makefile      |   1 +
 libavfilter/allfilters.c  |   1 +
 libavfilter/vf_convolve.c | 513 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 529 insertions(+)
 create mode 100644 libavfilter/vf_convolve.c
diff mbox

Patch

diff --git a/doc/filters.texi b/doc/filters.texi
index afcb99d..0e595a6 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -5867,6 +5867,20 @@  For example to convert the input to SMPTE-240M, use the command:
 colorspace=smpte240m
 @end example
 
+@section convolve
+
+Apply 2D convolution of video stream in frequency domain using second stream as impulse.
+
+The filter accepts the following options:
+
+@table @option
+@item planes
+Set which planes to process.
+
+@item impulse
+Set which impulse will be processed, can be @var{first} or @var{all}. Default is @var{all}.
+@end table
+
 @section convolution
 
 Apply convolution 3x3 or 5x5 filter.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index ee840b0..d76d57c 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -149,6 +149,7 @@  OBJS-$(CONFIG_COLORLEVELS_FILTER)            += vf_colorlevels.o
 OBJS-$(CONFIG_COLORMATRIX_FILTER)            += vf_colormatrix.o
 OBJS-$(CONFIG_COLORSPACE_FILTER)             += vf_colorspace.o colorspacedsp.o
 OBJS-$(CONFIG_CONVOLUTION_FILTER)            += vf_convolution.o
+OBJS-$(CONFIG_CONVOLVE_FILTER)               += vf_convolve.o
 OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
 OBJS-$(CONFIG_COREIMAGE_FILTER)              += vf_coreimage.o
 OBJS-$(CONFIG_COVER_RECT_FILTER)             += vf_cover_rect.o lavfutils.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 8b9b9a4..890a7b8 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -161,6 +161,7 @@  static void register_all(void)
     REGISTER_FILTER(COLORMATRIX,    colormatrix,    vf);
     REGISTER_FILTER(COLORSPACE,     colorspace,     vf);
     REGISTER_FILTER(CONVOLUTION,    convolution,    vf);
+    REGISTER_FILTER(CONVOLVE,       convolve,       vf);
     REGISTER_FILTER(COPY,           copy,           vf);
     REGISTER_FILTER(COREIMAGE,      coreimage,      vf);
     REGISTER_FILTER(COVER_RECT,     cover_rect,     vf);
diff --git a/libavfilter/vf_convolve.c b/libavfilter/vf_convolve.c
new file mode 100644
index 0000000..2f3441e
--- /dev/null
+++ b/libavfilter/vf_convolve.c
@@ -0,0 +1,513 @@ 
+/*
+ * Copyright (c) 2017 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 "libavcodec/avfft.h"
+
+#include "avfilter.h"
+#include "formats.h"
+#include "framesync2.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct ConvolveContext {
+    const AVClass *class;
+    FFFrameSync fs;
+
+    FFTContext *fft[4];
+    FFTContext *ifft[4];
+
+    int fft_bits[4];
+    int fft_len[4];
+    int planewidth[4];
+    int planeheight[4];
+
+    FFTComplex *fft_hdata[4];
+    FFTComplex *fft_vdata[4];
+    FFTComplex *fft_hdata_impulse[4];
+    FFTComplex *fft_vdata_impulse[4];
+
+    int direct;
+    int depth;
+    int planes;
+    int impulse;
+    int nb_planes;
+    int got_impulse[4];
+} ConvolveContext;
+
+#define OFFSET(x) offsetof(ConvolveContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption convolve_options[] = {
+    { "planes",  "set planes to convolve",                  OFFSET(planes),   AV_OPT_TYPE_INT,   {.i64=7}, 0, 15, FLAGS },
+    { "impulse", "when to process impulses",                OFFSET(impulse),  AV_OPT_TYPE_INT,   {.i64=1}, 0,  1, FLAGS, "impulse" },
+    {   "first", "process only first impulse, ignore rest", 0,                AV_OPT_TYPE_CONST, {.i64=0}, 0,  0, FLAGS, "impulse" },
+    {   "all",   "process all impulses",                    0,                AV_OPT_TYPE_CONST, {.i64=1}, 0,  0, FLAGS, "impulse" },
+    { NULL },
+};
+
+FRAMESYNC_DEFINE_CLASS(convolve, ConvolveContext, fs);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pixel_fmts_fftfilt[] = {
+        AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P,
+        AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P,
+        AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUV420P,
+        AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
+        AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+        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_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV440P12,
+        AV_PIX_FMT_YUV420P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV444P14,
+        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_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,
+        AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
+        AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
+        AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP16,
+        AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY16,
+        AV_PIX_FMT_NONE
+    };
+
+    AVFilterFormats *fmts_list = ff_make_format_list(pixel_fmts_fftfilt);
+    if (!fmts_list)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, fmts_list);
+}
+
+static int config_input_main(AVFilterLink *inlink)
+{
+    ConvolveContext *s = inlink->dst->priv;
+    int fft_bits, i;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+
+    s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
+    s->planewidth[0] = s->planewidth[3] = inlink->w;
+    s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
+    s->planeheight[0] = s->planeheight[3] = inlink->h;
+
+    s->nb_planes = desc->nb_components;
+    s->depth = desc->comp[0].depth;
+
+    for (i = 0; i < s->nb_planes; i++) {
+        int w = s->planewidth[i];
+        int h = s->planeheight[i];
+        int n = FFMAX(w, h);
+
+        for (fft_bits = 1; 1 << fft_bits < n; fft_bits++);
+
+        s->fft_bits[i] = fft_bits;
+        s->fft_len[i] = 1 << s->fft_bits[i];
+
+        if (!(s->fft_hdata[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
+            return AVERROR(ENOMEM);
+
+        if (!(s->fft_vdata[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
+            return AVERROR(ENOMEM);
+
+        if (!(s->fft_hdata_impulse[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
+            return AVERROR(ENOMEM);
+
+        if (!(s->fft_vdata_impulse[i] = av_calloc(s->fft_len[i], s->fft_len[i] * sizeof(FFTComplex))))
+            return AVERROR(ENOMEM);
+    }
+
+    s->direct = !(s->planewidth[0] == s->planeheight[0] && s->fft_len[0] == s->planeheight[0]);
+
+    return 0;
+}
+
+static int config_input_impulse(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx  = inlink->dst;
+
+    if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
+        ctx->inputs[0]->h != ctx->inputs[1]->h) {
+        av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
+        return AVERROR(EINVAL);
+    }
+    if (ctx->inputs[0]->format != ctx->inputs[1]->format) {
+        av_log(ctx, AV_LOG_ERROR, "Inputs must be of same pixel format.\n");
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}
+
+static void fft_horizontal(ConvolveContext *s, FFTComplex *fft_hdata,
+                           AVFrame *in, int w, int h, int n, int plane, float scale)
+{
+    int y, x;
+
+    for (y = 0; y < h; y++) {
+        if (s->depth == 8) {
+            const uint8_t *src = in->data[plane] + in->linesize[plane] * y;
+
+            for (x = 0; x < w; x++) {
+                fft_hdata[(y) * n + x].re = src[x] * scale;
+                fft_hdata[(y) * n + x].im = 0;
+            }
+        } else {
+            const uint16_t *src = (const uint16_t *)(in->data[plane] + in->linesize[plane] * y);
+
+            for (x = 0; x < w; x++) {
+                fft_hdata[(y) * n + x].re = src[x] * scale;
+                fft_hdata[(y) * n + x].im = 0;
+            }
+        }
+        for (; x < n; x++) {
+            fft_hdata[y * n + x].re = 0;
+            fft_hdata[y * n + x].im = 0;
+        }
+    }
+
+    for (; y < n; y++) {
+        for (x = 0; x < n; x++) {
+            fft_hdata[y * n + x].re = 0;
+            fft_hdata[y * n + x].im = 0;
+        }
+    }
+
+    for (y = 0; y < n; y++) {
+        av_fft_permute(s->fft[plane], fft_hdata + y * n);
+        av_fft_calc(s->fft[plane], fft_hdata + y * n);
+    }
+}
+
+static void fft_vertical(ConvolveContext *s, FFTComplex *fft_hdata, FFTComplex *fft_vdata,
+                         int n, int plane)
+{
+    int y, x;
+
+    for (y = 0; y < n; y++) {
+        for (x = 0; x < n; x++) {
+            fft_vdata[y * n + x].re = fft_hdata[x * n + y].re;
+            fft_vdata[y * n + x].im = fft_hdata[x * n + y].im;
+        }
+        for (; x < n; x++) {
+            fft_vdata[y * n + x].re = 0;
+            fft_vdata[y * n + x].im = 0;
+        }
+        av_fft_permute(s->fft[plane], fft_vdata + y * n);
+        av_fft_calc(s->fft[plane], fft_vdata + y * n);
+    }
+}
+
+static void ifft_vertical(ConvolveContext *s, int n, int plane)
+{
+    int y, x;
+
+    for (y = 0; y < n; y++) {
+        av_fft_permute(s->ifft[plane], s->fft_vdata[plane] + y * n);
+        av_fft_calc(s->ifft[plane], s->fft_vdata[plane] + y * n);
+        for (x = 0; x < n; x++) {
+            s->fft_hdata[plane][x * n + y].re = s->fft_vdata[plane][y * n + x].re;
+            s->fft_hdata[plane][x * n + y].im = s->fft_vdata[plane][y * n + x].im;
+        }
+    }
+}
+
+static void ifft_horizontal(ConvolveContext *s, AVFrame *out,
+                            int w, int h, int n, int plane)
+{
+    const float scale = 1.f / (n * n);
+    const int max = (1 << s->depth) - 1;
+    const int oh = w == h && n == w ? 0 : h / 2;
+    const int ow = w == h && n == w ? 0 : w / 2;
+    int y, x;
+
+    for (y = 0; y < n; y++) {
+        av_fft_permute(s->ifft[plane], s->fft_hdata[plane] + y * n);
+        av_fft_calc(s->ifft[plane], s->fft_hdata[plane] + y * n);
+    }
+
+    if (s->depth == 8) {
+        for (y = 0; y < h; y++) {
+            uint8_t *dst = out->data[plane] + y * out->linesize[plane];
+            for (x = 0; x < w; x++)
+                dst[x] = av_clip(s->fft_hdata[plane][(y+oh) * n + x+ow].re * scale, 0, 255);
+        }
+    } else {
+        for (y = 0; y < h; y++) {
+            uint16_t *dst = (uint16_t *)(out->data[plane] + y * out->linesize[plane]);
+            for (x = 0; x < w; x++)
+                dst[x] = av_clip(s->fft_hdata[plane][(y+oh) * n + x+ow].re * scale, 0, max);
+        }
+    }
+}
+
+static void fftshift8(uint8_t *out, ptrdiff_t out_linesize,
+                      const uint8_t *in, ptrdiff_t in_linesize,
+                      int w, int h)
+{
+    int hw = (w >> 1), hh = (h >> 1);
+    int y, x;
+
+    for (x = 0; x < hw; x++)
+        out[x+1] = in[(h-hh) * in_linesize + x + hw];
+    for (; x < w-1; x++)
+        out[x+1] = in[(h-hh) * in_linesize + x - hw];
+    out[0] = in[(h-hh) * in_linesize + x - hw];
+    out += out_linesize;
+    for (y = 0; y < hh; y++) {
+        for (x = 0; x < hw; x++)
+            out[x+1] = in[(y+hh) * in_linesize + x + hw];
+        for (; x < w-1; x++)
+            out[x+1] = in[(y+hh) * in_linesize + x - hw];
+        out[0] = in[(y+hh) * in_linesize + x - hw];
+
+        out += out_linesize;
+    }
+    for (; y < h-1; y++) {
+        for (x = 0; x < hw; x++)
+            out[x+1] = in[(y-hh) * in_linesize + x + hw];
+        for (; x < w-1; x++)
+            out[x+1] = in[(y-hh) * in_linesize + x - hw];
+        out[0] = in[(y-hh) * in_linesize + x - hw];
+
+        out += out_linesize;
+    }
+}
+
+static void fftshift16(uint8_t *dst, ptrdiff_t out_linesize,
+                       const uint8_t *src, ptrdiff_t in_linesize,
+                       int w, int h)
+{
+    const uint16_t *in = (const uint16_t *)src;
+    uint16_t *out = (uint16_t *)dst;
+    int hw = (w >> 1), hh = (h >> 1);
+    int y, x;
+
+    out_linesize /= 2;
+    in_linesize /= 2;
+
+    for (x = 0; x < hw; x++)
+        out[x+1] = in[(h-hh) * in_linesize + x + hw];
+    for (; x < w-1; x++)
+        out[x+1] = in[(h-hh) * in_linesize + x - hw];
+    out[0] = in[(h-hh) * in_linesize + x - hw];
+    out += out_linesize;
+    for (y = 0; y < hh; y++) {
+        for (x = 0; x < hw; x++)
+            out[x+1] = in[(y+hh) * in_linesize + x + hw];
+        for (; x < w-1; x++)
+            out[x+1] = in[(y+hh) * in_linesize + x - hw];
+        out[0] = in[(y+hh) * in_linesize + x - hw];
+
+        out += out_linesize;
+    }
+    for (; y < h-1; y++) {
+        for (x = 0; x < hw; x++)
+            out[x+1] = in[(y-hh) * in_linesize + x + hw];
+        for (; x < w-1; x++)
+            out[x+1] = in[(y-hh) * in_linesize + x - hw];
+        out[0] = in[(y-hh) * in_linesize + x - hw];
+
+        out += out_linesize;
+    }
+}
+
+static int do_convolve(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    AVFilterLink *outlink = ctx->outputs[0];
+    ConvolveContext *s = ctx->priv;
+    AVFrame *out, *mainpic = NULL, *impulsepic = NULL;
+    int ret, y, x, plane;
+
+    ret = ff_framesync2_dualinput_get(fs, &mainpic, &impulsepic);
+    if (ret < 0)
+        return ret;
+    if (!impulsepic)
+        return ff_filter_frame(ctx->outputs[0], mainpic);
+
+    if (!s->direct) {
+        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!out) {
+            av_frame_free(&mainpic);
+            av_frame_free(&impulsepic);
+            return AVERROR(ENOMEM);
+        }
+        av_frame_copy_props(out, mainpic);
+    }
+
+    for (plane = 0; plane < s->nb_planes; plane++) {
+        const int n = s->fft_len[plane];
+        const int w = s->planewidth[plane];
+        const int h = s->planeheight[plane];
+        float total = 0;
+
+        if (!(s->planes & (1 << plane)))
+            continue;
+
+        fft_horizontal(s, s->fft_hdata[plane], mainpic, w, h, n, plane, 1.f);
+        fft_vertical(s, s->fft_hdata[plane], s->fft_vdata[plane],
+                     n, plane);
+
+        if ((!s->impulse && !s->got_impulse[plane]) || s->impulse) {
+            if (s->depth == 8) {
+                for (y = 0; y < h; y++) {
+                    const uint8_t *src = (const uint8_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
+                    for (x = 0; x < w; x++) {
+                        total += src[x];
+                    }
+                }
+            } else {
+                for (y = 0; y < h; y++) {
+                    const uint16_t *src = (const uint16_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
+                    for (x = 0; x < w; x++) {
+                        total += src[x];
+                    }
+                }
+            }
+            total = FFMAX(1, total);
+
+            fft_horizontal(s, s->fft_hdata_impulse[plane], impulsepic, w, h, n, plane, 1 / total);
+            fft_vertical(s, s->fft_hdata_impulse[plane], s->fft_vdata_impulse[plane],
+                         n, plane);
+
+            s->got_impulse[plane] = 1;
+        }
+
+        for (y = 0; y < n; y++) {
+            for (x = 0; x < n; x++) {
+                FFTSample re, im, ire, iim;
+
+                re = s->fft_vdata[plane][y*n + x].re;
+                im = s->fft_vdata[plane][y*n + x].im;
+                ire = s->fft_vdata_impulse[plane][y*n + x].re;
+                iim = s->fft_vdata_impulse[plane][y*n + x].im;
+
+                s->fft_vdata[plane][y*n + x].re = ire * re - iim * im;
+                s->fft_vdata[plane][y*n + x].im = iim * re + ire * im;
+            }
+        }
+
+        ifft_vertical(s, n, plane);
+        ifft_horizontal(s, mainpic, w, h, n, plane);
+
+        if (!s->direct) {
+            if (s->depth == 8)
+                fftshift8(out->data[plane], out->linesize[plane],
+                          mainpic->data[plane], mainpic->linesize[plane], w, h);
+            else
+                fftshift16(out->data[plane], out->linesize[plane],
+                           mainpic->data[plane], mainpic->linesize[plane], w, h);
+        }
+    }
+
+    if (!s->direct) {
+        av_frame_free(&mainpic);
+        mainpic = out;
+    }
+
+    return ff_filter_frame(outlink, mainpic);
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    ConvolveContext *s = ctx->priv;
+    AVFilterLink *mainlink = ctx->inputs[0];
+    int ret, i;
+
+    s->fs.on_event = do_convolve;
+    ret = ff_framesync2_init_dualinput(&s->fs, ctx);
+    if (ret < 0)
+        return ret;
+    outlink->w = mainlink->w;
+    outlink->h = mainlink->h;
+    outlink->time_base = mainlink->time_base;
+    outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
+    outlink->frame_rate = mainlink->frame_rate;
+
+    if ((ret = ff_framesync2_configure(&s->fs)) < 0)
+        return ret;
+
+    for (i = 0; i < 4; i++) {
+        s->fft[i]  = av_fft_init(s->fft_bits[i], 0);
+        s->ifft[i] = av_fft_init(s->fft_bits[i], 1);
+    }
+
+    return 0;
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    ConvolveContext *s = ctx->priv;
+    return ff_framesync2_activate(&s->fs);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    ConvolveContext *s = ctx->priv;
+    int i;
+
+    for (i = 0; i < 4; i++) {
+        av_freep(&s->fft_hdata[i]);
+        av_freep(&s->fft_vdata[i]);
+        av_freep(&s->fft_hdata_impulse[i]);
+        av_freep(&s->fft_vdata_impulse[i]);
+        av_fft_end(s->fft[i]);
+        av_fft_end(s->ifft[i]);
+    }
+
+    ff_framesync2_uninit(&s->fs);
+}
+
+static const AVFilterPad convolve_inputs[] = {
+    {
+        .name          = "main",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_input_main,
+    },{
+        .name          = "impulse",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_input_impulse,
+    },
+    { NULL }
+};
+
+static const AVFilterPad convolve_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_convolve = {
+    .name          = "convolve",
+    .description   = NULL_IF_CONFIG_SMALL("Convolve first video stream with second video stream."),
+    .preinit       = convolve_framesync_preinit,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .activate      = activate,
+    .priv_size     = sizeof(ConvolveContext),
+    .priv_class    = &convolve_class,
+    .inputs        = convolve_inputs,
+    .outputs       = convolve_outputs,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+};