avfilter: add corr video filter

Changelog

@@ -26,6 +26,7 @@ version <next>:
 - QSV AV1 encoder
 - QSV decoding and encoding for 10/12bit 422, 10/12bit 444 HEVC and VP9
 - showcwt multimedia filter
+- corr video filter
 
 
 version 5.1:

doc/filters.texi

@@ -10110,6 +10110,30 @@ ffmpeg -f lavfi -i nullsrc=s=100x100,coreimage=filter=CIQRCodeGenerator@@inputMe
 @end example
 @end itemize
 
+@section corr
+
+Obtain the correlation between two input videos.
+
+This filter takes two input videos.
+
+Both input videos must have the same resolution and pixel format for
+this filter to work correctly. Also it assumes that both inputs
+have the same number of frames, which are compared one by one.
+
+The obtained per component, average, min and max correlation is printed through
+the logging system.
+
+The filter stores the calculated correlation of each frame in frame metadata.
+
+This filter also supports the @ref{framesync} options.
+
+In the below example the input file @file{main.mpg} being processed is compared
+with the reference file @file{ref.mpg}.
+
+@example
+ffmpeg -i main.mpg -i ref.mpg -lavfi corr -f null -
+@end example
+
 @section cover_rect
 
 Cover a rectangular object

libavfilter/Makefile

@@ -241,6 +241,7 @@ OBJS-$(CONFIG_CONVOLUTION_OPENCL_FILTER)     += vf_convolution_opencl.o opencl.o
 OBJS-$(CONFIG_CONVOLVE_FILTER)               += vf_convolve.o framesync.o
 OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o
 OBJS-$(CONFIG_COREIMAGE_FILTER)              += vf_coreimage.o
+OBJS-$(CONFIG_CORR_FILTER)                   += vf_corr.o framesync.o
 OBJS-$(CONFIG_COVER_RECT_FILTER)             += vf_cover_rect.o lavfutils.o
 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o
 OBJS-$(CONFIG_CROPDETECT_FILTER)             += vf_cropdetect.o

libavfilter/allfilters.c

@@ -221,6 +221,7 @@ extern const AVFilter ff_vf_convolution_opencl;
 extern const AVFilter ff_vf_convolve;
 extern const AVFilter ff_vf_copy;
 extern const AVFilter ff_vf_coreimage;
+extern const AVFilter ff_vf_corr;
 extern const AVFilter ff_vf_cover_rect;
 extern const AVFilter ff_vf_crop;
 extern const AVFilter ff_vf_cropdetect;

libavfilter/version.h

@@ -31,7 +31,7 @@
 
 #include "version_major.h"
 
-#define LIBAVFILTER_VERSION_MINOR  51
+#define LIBAVFILTER_VERSION_MINOR  52
 #define LIBAVFILTER_VERSION_MICRO 100
 
 

libavfilter/vf_corr.c

+/*
+ * 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
+ */
+
+/**
+ * @file
+ * Calculate the correlation between two input videos.
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "drawutils.h"
+#include "formats.h"
+#include "framesync.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct CorrContext {
+    const AVClass *class;
+    FFFrameSync fs;
+    double score, min_score, max_score, score_comp[4];
+    uint64_t nb_frames;
+    int is_rgb;
+    uint8_t rgba_map[4];
+    int max[4];
+    char comps[4];
+    int nb_components;
+    int planewidth[4];
+    int planeheight[4];
+    int (*filter_slice)(AVFilterContext *ctx, void *arg,
+                        int jobnr, int nb_jobs);
+} CorrContext;
+
+#define OFFSET(x) offsetof(CorrContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static void set_meta(AVFilterContext *ctx,
+                     AVDictionary **metadata, const char *key, char comp, float d)
+{
+    char value[128];
+    snprintf(value, sizeof(value), "%f", d);
+    if (comp) {
+        char key2[128];
+        snprintf(key2, sizeof(key2), "lavfi.%s.%s%s%c",
+                 ctx->filter->name, ctx->filter->name, key, comp);
+        av_dict_set(metadata, key2, value, 0);
+    } else {
+        char key2[128];
+        snprintf(key2, sizeof(key2), "lavfi.%s.%s%s",
+                 ctx->filter->name, ctx->filter->name, key);
+        av_dict_set(metadata, key2, value, 0);
+    }
+}
+
+#define CORR(type, name)                                     \
+static void f##name(AVFilterContext *ctx, AVFrame *master,   \
+                   AVFrame *ref, double *comp_score)         \
+{                                                            \
+    CorrContext *s = ctx->priv;                              \
+                                                             \
+    for (int c = 0; c < s->nb_components; c++) {             \
+        const ptrdiff_t linesize1 = master->linesize[c] /    \
+                                    sizeof(type);            \
+        const ptrdiff_t linesize2 = ref->linesize[c] /       \
+                                    sizeof(type);            \
+        const type *src1 = (const type *)master->data[c];    \
+        const type *src2 = (const type *)ref->data[c];       \
+        const int h = s->planeheight[c];                     \
+        const int w = s->planewidth[c];                      \
+        const float scale = 1.f / s->max[c];                 \
+        uint64_t sum1 = 0, sum2 = 0;                         \
+        float sum12, sum1q, sum2q;                           \
+        float sumq, mean1, mean2;                            \
+                                                             \
+        for (int y = 0; y < h; y++) {                        \
+            for (int x = 0; x < w; x++) {                    \
+                sum1 += src1[x];                             \
+                sum2 += src2[x];                             \
+            }                                                \
+                                                             \
+            src1 += linesize1;                               \
+            src2 += linesize2;                               \
+        }                                                    \
+                                                             \
+        mean1 = scale * (sum1 /(double)(w * h));             \
+        mean2 = scale * (sum2 /(double)(w * h));             \
+                                                             \
+        src1 = (const type *)master->data[c];                \
+        src2 = (const type *)ref->data[c];                   \
+                                                             \
+        sum12 = 0.f;                                         \
+        sum1q = 0.f;                                         \
+        sum2q = 0.f;                                         \
+                                                             \
+        for (int y = 0; y < h; y++) {                        \
+            for (int x = 0; x < w; x++) {                    \
+                const float f1 = scale * src1[x] - mean1;    \
+                const float f2 = scale * src2[x] - mean2;    \
+                                                             \
+                sum12 += f1 * f2;                            \
+                sum1q += f1 * f1;                            \
+                sum2q += f2 * f2;                            \
+            }                                                \
+                                                             \
+            src1 += linesize1;                               \
+            src2 += linesize2;                               \
+        }                                                    \
+                                                             \
+        sumq = sqrtf(sum1q * sum2q);                         \
+        if (sumq > 0.f) {                                    \
+            comp_score[c] = av_clipf(sum12 / sumq,-1.f,1.f); \
+        } else {                                             \
+            comp_score[c] = sum1q == sum2q ? 1.f : 0.f;      \
+        }                                                    \
+    }                                                        \
+}
+
+CORR(uint8_t, corr8)
+CORR(uint16_t, corr16)
+
+static int do_corr(FFFrameSync *fs)
+{
+    AVFilterContext *ctx = fs->parent;
+    CorrContext *s = ctx->priv;
+    AVFrame *master, *ref;
+    double comp_score[4], score = 0.;
+    AVDictionary **metadata;
+    int ret;
+
+    ret = ff_framesync_dualinput_get(fs, &master, &ref);
+    if (ret < 0)
+        return ret;
+    if (ctx->is_disabled || !ref)
+        return ff_filter_frame(ctx->outputs[0], master);
+    metadata = &master->metadata;
+
+    if (s->max[0] > 255) {
+        fcorr16(ctx, master, ref, comp_score);
+    } else {
+        fcorr8(ctx, master, ref, comp_score);
+    }
+
+    for (int c = 0; c < s->nb_components; c++)
+        score += comp_score[c];
+    score /= s->nb_components;
+    s->score += score;
+
+    s->min_score = fmin(s->min_score, score);
+    s->max_score = fmax(s->max_score, score);
+
+    for (int c = 0; c < s->nb_components; c++)
+        s->score_comp[c] += comp_score[c];
+    s->nb_frames++;
+
+    for (int j = 0; j < s->nb_components; j++) {
+        int c = s->is_rgb ? s->rgba_map[j] : j;
+        set_meta(ctx, metadata, ".", s->comps[j], comp_score[c]);
+    }
+    set_meta(ctx, metadata, "_avg", 0, score);
+
+    return ff_filter_frame(ctx->outputs[0], master);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    CorrContext *s = ctx->priv;
+
+    s->fs.on_event = do_corr;
+
+    return 0;
+}
+
+static const enum AVPixelFormat pix_fmts[] = {
+    AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
+#define PF_NOALPHA(suf) AV_PIX_FMT_YUV420##suf,  AV_PIX_FMT_YUV422##suf,  AV_PIX_FMT_YUV444##suf
+#define PF_ALPHA(suf)   AV_PIX_FMT_YUVA420##suf, AV_PIX_FMT_YUVA422##suf, AV_PIX_FMT_YUVA444##suf
+#define PF(suf)         PF_NOALPHA(suf), PF_ALPHA(suf)
+    PF(P), PF(P9), PF(P10), PF_NOALPHA(P12), PF_NOALPHA(P14), PF(P16),
+    AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
+    AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
+    AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
+    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_NONE
+};
+
+static int config_input_ref(AVFilterLink *inlink)
+{
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    AVFilterContext *ctx  = inlink->dst;
+    CorrContext *s = ctx->priv;
+
+    s->nb_components = desc->nb_components;
+    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);
+    }
+
+    s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
+    s->comps[0] = s->is_rgb ? 'R' : 'Y' ;
+    s->comps[1] = s->is_rgb ? 'G' : 'U' ;
+    s->comps[2] = s->is_rgb ? 'B' : 'V' ;
+    s->comps[3] = 'A';
+
+    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(inlink->w, desc->log2_chroma_w);
+    s->planewidth[0]  = s->planewidth[3]  = inlink->w;
+
+    s->min_score = +INFINITY;
+    s->max_score = -INFINITY;
+
+    s->max[0] = (1 << desc->comp[0].depth) - 1;
+    s->max[1] = (1 << desc->comp[1].depth) - 1;
+    s->max[2] = (1 << desc->comp[2].depth) - 1;
+    s->max[3] = (1 << desc->comp[3].depth) - 1;
+
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    CorrContext *s = ctx->priv;
+    AVFilterLink *mainlink = ctx->inputs[0];
+    int ret;
+
+    ret = ff_framesync_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_framesync_configure(&s->fs)) < 0)
+        return ret;
+
+    outlink->time_base = s->fs.time_base;
+
+    if (av_cmp_q(mainlink->time_base, outlink->time_base) ||
+        av_cmp_q(ctx->inputs[1]->time_base, outlink->time_base))
+        av_log(ctx, AV_LOG_WARNING, "not matching timebases found between first input: %d/%d and second input %d/%d, results may be incorrect!\n",
+               mainlink->time_base.num, mainlink->time_base.den,
+               ctx->inputs[1]->time_base.num, ctx->inputs[1]->time_base.den);
+
+    return 0;
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    CorrContext *s = ctx->priv;
+    return ff_framesync_activate(&s->fs);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    CorrContext *s = ctx->priv;
+
+    if (s->nb_frames > 0) {
+        char buf[256];
+
+        buf[0] = 0;
+        for (int j = 0; j < s->nb_components; j++) {
+            int c = s->is_rgb ? s->rgba_map[j] : j;
+            av_strlcatf(buf, sizeof(buf), " %c:%f", s->comps[j], s->score_comp[c] / s->nb_frames);
+        }
+
+        av_log(ctx, AV_LOG_INFO, "%s%s average:%f min:%f max:%f\n",
+               ctx->filter->name,
+               buf,
+               s->score / s->nb_frames,
+               s->min_score,
+               s->max_score);
+    }
+
+    ff_framesync_uninit(&s->fs);
+}
+
+static const AVFilterPad corr_inputs[] = {
+    {
+        .name         = "main",
+        .type         = AVMEDIA_TYPE_VIDEO,
+    },{
+        .name         = "reference",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_input_ref,
+    },
+};
+
+static const AVFilterPad corr_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+        .config_props  = config_output,
+    },
+};
+
+static const AVOption options[] = {
+    { NULL }
+};
+
+#define corr_options options
+FRAMESYNC_DEFINE_CLASS(corr, CorrContext, fs);
+
+const AVFilter ff_vf_corr = {
+    .name          = "corr",
+    .description   = NULL_IF_CONFIG_SMALL("Calculate the correlation between two video streams."),
+    .preinit       = corr_framesync_preinit,
+    .init          = init,
+    .uninit        = uninit,
+    .activate      = activate,
+    .priv_size     = sizeof(CorrContext),
+    .priv_class    = &corr_class,
+    FILTER_INPUTS(corr_inputs),
+    FILTER_OUTPUTS(corr_outputs),
+    FILTER_PIXFMTS_ARRAY(pix_fmts),
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
+                     AVFILTER_FLAG_METADATA_ONLY,
+};