[FFmpeg-cvslog] avfilter: add xcorrelate video filter

Paul B Mahol git at videolan.org
Wed Oct 13 20:10:19 EEST 2021


ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Thu Oct  7 19:33:54 2021 +0200| [933765aa0e07653307ff65a6af159a5922f1dc1d] | committer: Paul B Mahol

avfilter: add xcorrelate video filter

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=933765aa0e07653307ff65a6af159a5922f1dc1d
---

 Changelog                 |   1 +
 doc/filters.texi          |  18 +++
 libavfilter/Makefile      |   1 +
 libavfilter/allfilters.c  |   1 +
 libavfilter/version.h     |   2 +-
 libavfilter/vf_convolve.c | 370 ++++++++++++++++++++++++++++++++++++++++------
 6 files changed, 348 insertions(+), 45 deletions(-)

diff --git a/Changelog b/Changelog
index 76f53128ad..e357473893 100644
--- a/Changelog
+++ b/Changelog
@@ -27,6 +27,7 @@ version <next>:
 - asdr audio filter
 - speex decoder
 - limitdiff video filter
+- xcorrelate video filter
 
 
 version 4.4:
diff --git a/doc/filters.texi b/doc/filters.texi
index 653760932e..543df2ef8d 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -22563,6 +22563,24 @@ Set the scaling dimension: @code{2} for @code{2xBR}, @code{3} for
 Default is @code{3}.
 @end table
 
+ at section xcorrelate
+Apply normalized cross-correlation between first and second input video stream.
+
+Second input video stream dimensions must be lower than first input video stream.
+
+The filter accepts the following options:
+
+ at table @option
+ at item planes
+Set which planes to process.
+
+ at item secondary
+Set which secondary video frames will be processed from second input video stream,
+can be @var{first} or @var{all}. Default is @var{all}.
+ at end table
+
+The @code{xcorrelate} filter also supports the @ref{framesync} options.
+
 @section xfade
 
 Apply cross fade from one input video stream to another input video stream.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index ecfe060e1a..7987bf36c6 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -500,6 +500,7 @@ OBJS-$(CONFIG_W3FDIF_FILTER)                 += vf_w3fdif.o
 OBJS-$(CONFIG_WAVEFORM_FILTER)               += vf_waveform.o
 OBJS-$(CONFIG_WEAVE_FILTER)                  += vf_weave.o
 OBJS-$(CONFIG_XBR_FILTER)                    += vf_xbr.o
+OBJS-$(CONFIG_XCORRELATE_FILTER)             += vf_convolve.o framesync.o
 OBJS-$(CONFIG_XFADE_FILTER)                  += vf_xfade.o
 OBJS-$(CONFIG_XFADE_OPENCL_FILTER)           += vf_xfade_opencl.o opencl.o opencl/xfade.o
 OBJS-$(CONFIG_XMEDIAN_FILTER)                += vf_xmedian.o framesync.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 2127454aa9..d87c0ed981 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -477,6 +477,7 @@ extern const AVFilter ff_vf_w3fdif;
 extern const AVFilter ff_vf_waveform;
 extern const AVFilter ff_vf_weave;
 extern const AVFilter ff_vf_xbr;
+extern const AVFilter ff_vf_xcorrelate;
 extern const AVFilter ff_vf_xfade;
 extern const AVFilter ff_vf_xfade_opencl;
 extern const AVFilter ff_vf_xmedian;
diff --git a/libavfilter/version.h b/libavfilter/version.h
index dca5aacb45..8df0478465 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  13
+#define LIBAVFILTER_VERSION_MINOR  14
 #define LIBAVFILTER_VERSION_MICRO 100
 
 
diff --git a/libavfilter/vf_convolve.c b/libavfilter/vf_convolve.c
index 9d506d49dd..55afb582b4 100644
--- a/libavfilter/vf_convolve.c
+++ b/libavfilter/vf_convolve.c
@@ -47,6 +47,12 @@ typedef struct ConvolveContext {
     int planewidth[4];
     int planeheight[4];
 
+    int primarywidth[4];
+    int primaryheight[4];
+
+    int secondarywidth[4];
+    int secondaryheight[4];
+
     AVComplexFloat *fft_hdata_in[4];
     AVComplexFloat *fft_vdata_in[4];
     AVComplexFloat *fft_hdata_out[4];
@@ -63,6 +69,13 @@ typedef struct ConvolveContext {
     int nb_planes;
     int got_impulse[4];
 
+    void (*get_input)(struct ConvolveContext *s, AVComplexFloat *fft_hdata,
+                      AVFrame *in, int w, int h, int n, int plane, float scale);
+
+    void (*get_output)(struct ConvolveContext *s, AVComplexFloat *input, AVFrame *out,
+                       int w, int h, int n, int plane, float scale);
+    void (*prepare_impulse)(AVFilterContext *ctx, AVFrame *impulsepic, int plane);
+
     int (*filter)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
 } ConvolveContext;
 
@@ -99,21 +112,22 @@ static const enum AVPixelFormat pixel_fmts_fftfilt[] = {
     AV_PIX_FMT_NONE
 };
 
-static int config_input_main(AVFilterLink *inlink)
+static int config_input(AVFilterLink *inlink)
 {
     ConvolveContext *s = inlink->dst->priv;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
-    int i;
+    const int w = inlink->w;
+    const int h = inlink->h;
 
-    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->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(w, desc->log2_chroma_w);
+    s->planewidth[0] = s->planewidth[3] = w;
+    s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(h, desc->log2_chroma_h);
+    s->planeheight[0] = s->planeheight[3] = h;
 
     s->nb_planes = desc->nb_components;
     s->depth = desc->comp[0].depth;
 
-    for (i = 0; i < s->nb_planes; i++) {
+    for (int i = 0; i < s->nb_planes; i++) {
         int w = s->planewidth[i];
         int h = s->planeheight[i];
         int n = FFMAX(w, h);
@@ -186,6 +200,98 @@ static int fft_horizontal(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
     return 0;
 }
 
+#define SQR(x) ((x) * (x))
+
+static void get_zeropadded_input(ConvolveContext *s,
+                                 AVComplexFloat *fft_hdata,
+                                 AVFrame *in, int w, int h,
+                                 int n, int plane, float scale)
+{
+    float sum = 0.f;
+    float mean, dev;
+    int y, x;
+
+    if (s->depth == 8) {
+        for (y = 0; y < h; y++) {
+            const uint8_t *src = in->data[plane] + in->linesize[plane] * y;
+
+            for (x = 0; x < w; x++)
+                sum += src[x];
+        }
+
+        mean = sum / (w * h);
+        sum = 0.f;
+        for (y = 0; y < h; y++) {
+            const uint8_t *src = in->data[plane] + in->linesize[plane] * y;
+
+            for (x = 0; x < w; x++)
+                sum += SQR(src[x] - mean);
+        }
+
+        dev = sqrtf(sum / (w * h));
+        scale /= dev;
+        for (y = 0; y < h; y++) {
+            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] - mean) * scale;
+                fft_hdata[y * n + x].im = 0;
+            }
+
+            for (x = w; x < n; x++) {
+                fft_hdata[y * n + x].re = 0;
+                fft_hdata[y * n + x].im = 0;
+            }
+        }
+
+        for (y = h; y < n; y++) {
+            for (x = 0; x < n; x++) {
+                fft_hdata[y * n + x].re = 0;
+                fft_hdata[y * n + x].im = 0;
+            }
+        }
+    } else {
+        for (y = 0; y < h; y++) {
+            const uint16_t *src = (const uint16_t *)(in->data[plane] + in->linesize[plane] * y);
+
+            for (x = 0; x < w; x++)
+                sum += src[x];
+        }
+
+        mean = sum / (w * h);
+        sum = 0.f;
+        for (y = 0; y < h; y++) {
+            const uint16_t *src = (const uint16_t *)(in->data[plane] + in->linesize[plane] * y);
+
+            for (x = 0; x < w; x++)
+                sum += SQR(src[x] - mean);
+        }
+
+        dev = sqrtf(sum / (w * h));
+        scale /= dev;
+        for (y = 0; y < h; y++) {
+            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] - mean) * scale;
+                fft_hdata[y * n + x].im = 0;
+            }
+
+            for (x = w; x < n; x++) {
+                fft_hdata[y * n + x].re = 0;
+                fft_hdata[y * n + x].im = 0;
+            }
+        }
+
+        for (y = h; y < n; y++) {
+            for (x = 0; x < n; x++) {
+                fft_hdata[y * n + x].re = 0;
+                fft_hdata[y * n + x].im = 0;
+            }
+        }
+    }
+}
+
 static void get_input(ConvolveContext *s, AVComplexFloat *fft_hdata,
                       AVFrame *in, int w, int h, int n, int plane, float scale)
 {
@@ -330,6 +436,27 @@ static int ifft_horizontal(AVFilterContext *ctx, void *arg, int jobnr, int nb_jo
     return 0;
 }
 
+static void get_xoutput(ConvolveContext *s, AVComplexFloat *input, AVFrame *out,
+                       int w, int h, int n, int plane, float scale)
+{
+    const int imax = (1 << s->depth) - 1;
+
+    scale *= imax * 16;
+    if (s->depth == 8) {
+        for (int y = 0; y < h; y++) {
+            uint8_t *dst = out->data[plane] + y * out->linesize[plane];
+            for (int x = 0; x < w; x++)
+                dst[x] = av_clip_uint8(input[y * n + x].re * scale);
+        }
+    } else {
+        for (int y = 0; y < h; y++) {
+            uint16_t *dst = (uint16_t *)(out->data[plane] + y * out->linesize[plane]);
+            for (int x = 0; x < w; x++)
+                dst[x] = av_clip(input[y * n + x].re * scale, 0, imax);
+        }
+    }
+}
+
 static void get_output(ConvolveContext *s, AVComplexFloat *input, AVFrame *out,
                        int w, int h, int n, int plane, float scale)
 {
@@ -414,6 +541,35 @@ static int complex_multiply(AVFilterContext *ctx, void *arg, int jobnr, int nb_j
     return 0;
 }
 
+static int complex_xcorrelate(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+    ThreadData *td = arg;
+    AVComplexFloat *input = td->hdata_in;
+    AVComplexFloat *filter = td->vdata_in;
+    const int n = td->n;
+    const float scale = 1.f / (n * n);
+    int start = (n * jobnr) / nb_jobs;
+    int end = (n * (jobnr+1)) / nb_jobs;
+
+    for (int y = start; y < end; y++) {
+        int yn = y * n;
+
+        for (int x = 0; x < n; x++) {
+            float re, im, ire, iim;
+
+            re = input[yn + x].re;
+            im = input[yn + x].im;
+            ire = filter[yn + x].re * scale;
+            iim = -filter[yn + x].im * scale;
+
+            input[yn + x].re = ire * re - iim * im;
+            input[yn + x].im = iim * re + ire * im;
+        }
+    }
+
+    return 0;
+}
+
 static int complex_divide(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ConvolveContext *s = ctx->priv;
@@ -446,13 +602,82 @@ static int complex_divide(AVFilterContext *ctx, void *arg, int jobnr, int nb_job
     return 0;
 }
 
+static void prepare_impulse(AVFilterContext *ctx, AVFrame *impulsepic, int plane)
+{
+    ConvolveContext *s = ctx->priv;
+    const int n = s->fft_len[plane];
+    const int w = s->secondarywidth[plane];
+    const int h = s->secondaryheight[plane];
+    ThreadData td;
+    float total = 0;
+
+    if (s->depth == 8) {
+        for (int y = 0; y < h; y++) {
+            const uint8_t *src = (const uint8_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
+            for (int x = 0; x < w; x++) {
+                total += src[x];
+            }
+        }
+    } else {
+        for (int y = 0; y < h; y++) {
+            const uint16_t *src = (const uint16_t *)(impulsepic->data[plane] + y * impulsepic->linesize[plane]) ;
+            for (int x = 0; x < w; x++) {
+                total += src[x];
+            }
+        }
+    }
+    total = FFMAX(1, total);
+
+    s->get_input(s, s->fft_hdata_impulse_in[plane], impulsepic, w, h, n, plane, 1.f / total);
+
+    td.n = n;
+    td.plane = plane;
+    td.hdata_in  = s->fft_hdata_impulse_in[plane];
+    td.vdata_in  = s->fft_vdata_impulse_in[plane];
+    td.hdata_out = s->fft_hdata_impulse_out[plane];
+    td.vdata_out = s->fft_vdata_impulse_out[plane];
+
+    ff_filter_execute(ctx, fft_horizontal, &td, NULL,
+                      FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
+    ff_filter_execute(ctx, fft_vertical, &td, NULL,
+                      FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
+
+    s->got_impulse[plane] = 1;
+}
+
+static void prepare_secondary(AVFilterContext *ctx, AVFrame *secondary, int plane)
+{
+    ConvolveContext *s = ctx->priv;
+    const int n = s->fft_len[plane];
+    ThreadData td;
+
+    s->get_input(s, s->fft_hdata_impulse_in[plane], secondary,
+                 s->secondarywidth[plane],
+                 s->secondaryheight[plane],
+                 n, plane, 1.f);
+
+    td.n = n;
+    td.plane = plane;
+    td.hdata_in  = s->fft_hdata_impulse_in[plane];
+    td.vdata_in  = s->fft_vdata_impulse_in[plane];
+    td.hdata_out = s->fft_hdata_impulse_out[plane];
+    td.vdata_out = s->fft_vdata_impulse_out[plane];
+
+    ff_filter_execute(ctx, fft_horizontal, &td, NULL,
+                      FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
+    ff_filter_execute(ctx, fft_vertical, &td, NULL,
+                      FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
+
+    s->got_impulse[plane] = 1;
+}
+
 static int do_convolve(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     AVFilterLink *outlink = ctx->outputs[0];
     ConvolveContext *s = ctx->priv;
     AVFrame *mainpic = NULL, *impulsepic = NULL;
-    int ret, y, x, plane;
+    int ret, plane;
 
     ret = ff_framesync_dualinput_get(fs, &mainpic, &impulsepic);
     if (ret < 0)
@@ -464,9 +689,10 @@ static int do_convolve(FFFrameSync *fs)
         AVComplexFloat *filter = s->fft_vdata_impulse_out[plane];
         AVComplexFloat *input = s->fft_vdata_out[plane];
         const int n = s->fft_len[plane];
-        const int w = s->planewidth[plane];
-        const int h = s->planeheight[plane];
-        float total = 0;
+        const int w = s->primarywidth[plane];
+        const int h = s->primaryheight[plane];
+        const int ow = s->planewidth[plane];
+        const int oh = s->planeheight[plane];
         ThreadData td;
 
         if (!(s->planes & (1 << plane))) {
@@ -474,7 +700,7 @@ static int do_convolve(FFFrameSync *fs)
         }
 
         td.plane = plane, td.n = n;
-        get_input(s, s->fft_hdata_in[plane], mainpic, w, h, n, plane, 1.f);
+        s->get_input(s, s->fft_hdata_in[plane], mainpic, w, h, n, plane, 1.f);
 
         td.hdata_in  = s->fft_hdata_in[plane];
         td.vdata_in  = s->fft_vdata_in[plane];
@@ -487,36 +713,7 @@ static int do_convolve(FFFrameSync *fs)
                           FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
 
         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);
-
-            get_input(s, s->fft_hdata_impulse_in[plane], impulsepic, w, h, n, plane, 1.f / total);
-
-            td.hdata_in  = s->fft_hdata_impulse_in[plane];
-            td.vdata_in  = s->fft_vdata_impulse_in[plane];
-            td.hdata_out = s->fft_hdata_impulse_out[plane];
-            td.vdata_out = s->fft_vdata_impulse_out[plane];
-
-            ff_filter_execute(ctx, fft_horizontal, &td, NULL,
-                              FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
-            ff_filter_execute(ctx, fft_vertical, &td, NULL,
-                              FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
-
-            s->got_impulse[plane] = 1;
+            s->prepare_impulse(ctx, impulsepic, plane);
         }
 
         td.hdata_in = input;
@@ -539,7 +736,7 @@ static int do_convolve(FFFrameSync *fs)
         ff_filter_execute(ctx, ifft_horizontal, &td, NULL,
                           FFMIN3(MAX_THREADS, n, ff_filter_get_nb_threads(ctx)));
 
-        get_output(s, s->fft_hdata_out[plane], mainpic, w, h, n, plane, 1.f / (n * n));
+        s->get_output(s, s->fft_hdata_out[plane], mainpic, ow, oh, n, plane, 1.f / (n * n));
     }
 
     return ff_filter_frame(outlink, mainpic);
@@ -547,11 +744,23 @@ static int do_convolve(FFFrameSync *fs)
 
 static int config_output(AVFilterLink *outlink)
 {
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(outlink->format);
     AVFilterContext *ctx = outlink->src;
     ConvolveContext *s = ctx->priv;
     AVFilterLink *mainlink = ctx->inputs[0];
+    AVFilterLink *secondlink = ctx->inputs[1];
     int ret, i, j;
 
+    s->primarywidth[1]  = s->primarywidth[2]  = AV_CEIL_RSHIFT(mainlink->w, desc->log2_chroma_w);
+    s->primarywidth[0]  = s->primarywidth[3]  = mainlink->w;
+    s->primaryheight[1] = s->primaryheight[2] = AV_CEIL_RSHIFT(mainlink->h, desc->log2_chroma_h);
+    s->primaryheight[0] = s->primaryheight[3] = mainlink->h;
+
+    s->secondarywidth[1]  = s->secondarywidth[2]  = AV_CEIL_RSHIFT(secondlink->w, desc->log2_chroma_w);
+    s->secondarywidth[0]  = s->secondarywidth[3]  = secondlink->w;
+    s->secondaryheight[1] = s->secondaryheight[2] = AV_CEIL_RSHIFT(secondlink->h, desc->log2_chroma_h);
+    s->secondaryheight[0] = s->secondaryheight[3] = secondlink->h;
+
     s->fs.on_event = do_convolve;
     ret = ff_framesync_init_dualinput(&s->fs, ctx);
     if (ret < 0)
@@ -593,8 +802,19 @@ static av_cold int init(AVFilterContext *ctx)
 
     if (!strcmp(ctx->filter->name, "convolve")) {
         s->filter = complex_multiply;
+        s->prepare_impulse = prepare_impulse;
+        s->get_input = get_input;
+        s->get_output = get_output;
+    } else if (!strcmp(ctx->filter->name, "xcorrelate")) {
+        s->filter = complex_xcorrelate;
+        s->prepare_impulse = prepare_secondary;
+        s->get_input = get_zeropadded_input;
+        s->get_output = get_xoutput;
     } else if (!strcmp(ctx->filter->name, "deconvolve")) {
         s->filter = complex_divide;
+        s->prepare_impulse = prepare_impulse;
+        s->get_input = get_input;
+        s->get_output = get_output;
     } else {
         return AVERROR_BUG;
     }
@@ -630,7 +850,7 @@ static const AVFilterPad convolve_inputs[] = {
     {
         .name          = "main",
         .type          = AVMEDIA_TYPE_VIDEO,
-        .config_props  = config_input_main,
+        .config_props  = config_input,
     },{
         .name          = "impulse",
         .type          = AVMEDIA_TYPE_VIDEO,
@@ -698,3 +918,65 @@ const AVFilter ff_vf_deconvolve = {
 };
 
 #endif /* CONFIG_DECONVOLVE_FILTER */
+
+#if CONFIG_XCORRELATE_FILTER
+
+static const AVOption xcorrelate_options[] = {
+    { "planes",  "set planes to cross-correlate",     OFFSET(planes),   AV_OPT_TYPE_INT,   {.i64=7}, 0, 15, FLAGS },
+    { "secondary", "when to process secondary frame", OFFSET(impulse),  AV_OPT_TYPE_INT,   {.i64=1}, 0,  1, FLAGS, "impulse" },
+    {   "first", "process only first secondary frame, ignore rest", 0,  AV_OPT_TYPE_CONST, {.i64=0}, 0,  0, FLAGS, "impulse" },
+    {   "all",   "process all secondary frames",                    0,  AV_OPT_TYPE_CONST, {.i64=1}, 0,  0, FLAGS, "impulse" },
+    { NULL },
+};
+
+FRAMESYNC_DEFINE_PURE_CLASS(xcorrelate, "xcorrelate", convolve, xcorrelate_options);
+
+static int config_input_secondary(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 second input videos must be less than first input.\n");
+        return AVERROR(EINVAL);
+    }
+
+    return 0;
+}
+
+static const AVFilterPad xcorrelate_inputs[] = {
+    {
+        .name          = "primary",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_input,
+    },{
+        .name          = "secondary",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_input_secondary,
+    },
+};
+
+static const AVFilterPad xcorrelate_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+};
+
+const AVFilter ff_vf_xcorrelate = {
+    .name          = "xcorrelate",
+    .description   = NULL_IF_CONFIG_SMALL("Cross-correlate first video stream with second video stream."),
+    .preinit       = convolve_framesync_preinit,
+    .init          = init,
+    .uninit        = uninit,
+    .activate      = activate,
+    .priv_size     = sizeof(ConvolveContext),
+    .priv_class    = &xcorrelate_class,
+    FILTER_INPUTS(xcorrelate_inputs),
+    FILTER_OUTPUTS(xcorrelate_outputs),
+    FILTER_PIXFMTS_ARRAY(pixel_fmts_fftfilt),
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL | AVFILTER_FLAG_SLICE_THREADS,
+};
+
+#endif /* CONFIG_XCORRELATE_FILTER */



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