[FFmpeg-devel] area changed: scdet filter

Previous observations:

 - Inconsistent code style with other filters. (Mostly using AVFilterLink*
link instead of AVFilterLink *link).
I hope it's fine now.	

 - Unrelated changes, please split trivial unrelated changes into separate
patches.
Removed trivial changes from this patch.

 - Can't tables be generated at .init/.config_props time? No point in
storing them into binary.
Done.

 - Adding extra delay is not backward compatible change, it should be
implemented properly by adding option for users to select mode: next & prev
frame or just next or prev frame.
Added legacy option to the mode parameter.

 - Could split frame clone change into earlier separate patch.
Cannot be done. It's either frame clone or 1 frame delay.

 - Where are results of improvements with accuracy so it can be confirmed?
Here are my test results with manual labeling of scene changes:
2379	Full length movie

Method	Threshold	TP	FP	FN		Precision
Recall	F
Cubic	7	2357	423	22		0.847841727	0.990752417
0.913742973
Cubic	10	2297	200	82		0.919903885	0.965531736
0.94216571
Cubic	12	2217	146	162		0.938214135	0.931904161
0.935048503
Cubic	15	2049	101	330		0.953023256	0.861286255
0.904835505
Linear	2.8	2357	1060	22		0.689786362	0.990752417
0.813319531
Linear	8	2099	236	280		0.898929336	0.882303489
0.890538821
Linear	10	1886	173	493		0.91597863	0.792770071
0.849932402
Legacy	5	2235	1260	144		0.639484979	0.939470366
0.760980592
Legacy	8	1998	414	381		0.828358209	0.839848676
0.83406387
Legacy	10	1743	193	636		0.900309917	0.732660782
0.80787949
								
15	HDR10Plus_PB_EAC3JOC
https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-viDc3zMj8ZHruHcWKyA

Method	Threshold	TP	FP	FN		Precision
Recall	F
Cubic	10	15	0	0		1	1	1
Linear	5	13	1	2		0.928571429	0.866666667
0.896551724
Legacy	5	12	2	3		0.857142857	0.8
0.827586207
								
21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47EhR2o

Method	Threshold	TP	FP	FN		Precision
Recall	F
Cubic	10	21	0	0		1	1	1
Linear	4	20	0	1		1	0.952380952
0.975609756
Legacy	4	19	0	2		1	0.904761905	0.95
								
94	Bieber Grammys
https://mega.nz/#!c9dhAaKA!MG5Yi-MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E

Method	Threshold	TP	FP	FN		Precision
Recall	F
Cubic	15	91	23	3		0.798245614	0.968085106
0.875
Cubic	18	85	9	9		0.904255319	0.904255319
0.904255319
Linear	7	79	49	15		0.6171875	0.840425532
0.711711712
Linear	8	74	28	20		0.725490196	0.787234043
0.755102041
Legacy	7	74	40	20		0.649122807	0.787234043
0.711538462
Legacy	8	71	26	23		0.731958763	0.755319149
0.743455497


Improve scene detection accuracy by comparing frame with both previous and
next frame (creates one frame delay).
Add new mode parameter and new method to compute the frame difference using
cubic square to increase the weight of small changes and new mean formula.
This improves accuracy significantly. Slightly improve performance by not
using frame clone.
Add legacy mode for backward compatibility.

Signed-off-by: raduct <radu.taraibuta@gmail.com>
---
 doc/filters.texi            |  16 ++++
 libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
 libavfilter/scene_sad.h     |   6 ++
 libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
 tests/fate/filter-video.mak |   3 +
 5 files changed, 284 insertions(+), 48 deletions(-)

+fate-filter-metadata-scdet1: SRC =
$(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
+fate-filter-metadata-scdet1: CMD = run $(FILTER_METADATA_COMMAND)
"sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1:t=6.5:mode=1"
 
 CROPDETECT_DEPS = LAVFI_INDEV FILE_PROTOCOL MOVIE_FILTER MOVIE_FILTER
MESTIMATE_FILTER CROPDETECT_FILTER \
                   SCALE_FILTER MOV_DEMUXER H264_DECODER

> -----Original Message-----
> From: radu.taraibuta@gmail.com <radu.taraibuta@gmail.com>
> Sent: luni, 13 mai 2024 18:52
> To: ffmpeg-devel@ffmpeg.org
> Subject: [PATCH] area changed: scdet filter
> 
> Previous observations:
> 
>  - Inconsistent code style with other filters. (Mostly using AVFilterLink*
> link instead of AVFilterLink *link).
> I hope it's fine now.
> 
>  - Unrelated changes, please split trivial unrelated changes into separate
> patches.
> Removed trivial changes from this patch.
> 
>  - Can't tables be generated at .init/.config_props time? No point in
> storing them into binary.
> Done.
> 
>  - Adding extra delay is not backward compatible change, it should be
> implemented properly by adding option for users to select mode: next &
prev
> frame or just next or prev frame.
> Added legacy option to the mode parameter.
> 
>  - Could split frame clone change into earlier separate patch.
> Cannot be done. It's either frame clone or 1 frame delay.
> 
>  - Where are results of improvements with accuracy so it can be confirmed?
> Here are my test results with manual labeling of scene changes:
> 2379	Full length movie
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	7	2357	423	22		0.847841727	0.990752417
> 0.913742973
> Cubic	10	2297	200	82		0.919903885	0.965531736
> 0.94216571
> Cubic	12	2217	146	162		0.938214135	0.931904161
> 0.935048503
> Cubic	15	2049	101	330		0.953023256	0.861286255
> 0.904835505
> Linear	2.8	2357	1060	22		0.689786362
0.990752417
> 0.813319531
> Linear	8	2099	236	280		0.898929336
0.882303489
> 0.890538821
> Linear	10	1886	173	493		0.91597863
0.792770071
> 0.849932402
> Legacy	5	2235	1260	144		0.639484979
0.939470366
> 0.760980592
> Legacy	8	1998	414	381		0.828358209
0.839848676
> 0.83406387
> Legacy	10	1743	193	636		0.900309917
0.732660782
> 0.80787949
> 
> 15	HDR10Plus_PB_EAC3JOC
> https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> viDc3zMj8ZHruHcWKyA
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	10	15	0	0		1	1	1
> Linear	5	13	1	2		0.928571429
0.866666667
> 0.896551724
> Legacy	5	12	2	3		0.857142857	0.8
> 0.827586207
> 
> 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47E
> hR2o
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	10	21	0	0		1	1	1
> Linear	4	20	0	1		1	0.952380952
> 0.975609756
> Legacy	4	19	0	2		1	0.904761905
0.95
> 
> 94	Bieber Grammys
> https://mega.nz/#!c9dhAaKA!MG5Yi-
> MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	15	91	23	3		0.798245614	0.968085106
> 0.875
> Cubic	18	85	9	9		0.904255319	0.904255319
> 0.904255319
> Linear	7	79	49	15		0.6171875
0.840425532
> 0.711711712
> Linear	8	74	28	20		0.725490196
0.787234043
> 0.755102041
> Legacy	7	74	40	20		0.649122807
0.787234043
> 0.711538462
> Legacy	8	71	26	23		0.731958763
0.755319149
> 0.743455497
> 
> 
> Improve scene detection accuracy by comparing frame with both previous and
> next frame (creates one frame delay).
> Add new mode parameter and new method to compute the frame difference
> using
> cubic square to increase the weight of small changes and new mean formula.
> This improves accuracy significantly. Slightly improve performance by not
> using frame clone.
> Add legacy mode for backward compatibility.
> 
> Signed-off-by: raduct <radu.taraibuta@gmail.com>
> ---
>  doc/filters.texi            |  16 ++++
>  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
>  libavfilter/scene_sad.h     |   6 ++
>  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
>  tests/fate/filter-video.mak |   3 +
>  5 files changed, 284 insertions(+), 48 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index bfa8ccec8b..53814e003b 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
>  @item sc_pass, s
>  Set the flag to pass scene change frames to the next filter. Default
value
> is @code{0}
>  You can enable it if you want to get snapshot of scene change frames
only.
> +
> +@item mode
> +Set the scene change detection method. Default value is @code{-1}
> +Available values are:
> +
> +@table @samp
> +@item -1
> +Legacy mode for sum of absolute linear differences. Compare frame with
> previous only and no delay.
> +
> +@item 0
> +Sum of absolute linear differences. Compare frame with both previous and
> next which introduces a 1 frame delay.
> +
> +@item 1
> +Sum of mean of cubic root differences. Compare frame with both previous
> and
> next which introduces a 1 frame delay.
> +
> +@end table
>  @end table
> 
>  @anchor{selectivecolor}
> diff --git a/libavfilter/scene_sad.c b/libavfilter/scene_sad.c
> index caf911eb5d..9b80d426bc 100644
> --- a/libavfilter/scene_sad.c
> +++ b/libavfilter/scene_sad.c
> @@ -21,6 +21,7 @@
>   * Scene SAD functions
>   */
> 
> +#include "libavutil/thread.h"
>  #include "scene_sad.h"
> 
>  void ff_scene_sad16_c(SCENE_SAD_PARAMS)
> @@ -71,3 +72,153 @@ ff_scene_sad_fn ff_scene_sad_get_fn(int depth)
>      return sad;
>  }
> 
> +static AVMutex cbrt_mutex = AV_MUTEX_INITIALIZER;
> +static uint8_t *cbrt_table[16] = { NULL };
> +static int cbrt_table_ref[16] = { 0 };
> +
> +int ff_init_cbrt(int bitdepth)
> +{
> +    if (bitdepth < 4 || bitdepth > 16)
> +        return AVERROR(EINVAL);
> +
> +    ff_mutex_lock(&cbrt_mutex);
> +
> +    uint8_t *table = cbrt_table[bitdepth];
> +    if (table) {
> +        cbrt_table_ref[bitdepth]++;
> +        goto end;
> +    }
> +
> +    table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> +    if (!table)
> +        goto end;
> +    cbrt_table[bitdepth] = table;
> +    cbrt_table_ref[bitdepth] = 1;
> +
> +    int size = 1 << bitdepth;
> +    double factor = pow(size - 1, 2. / 3.);
> +    if (bitdepth <= 8) {
> +        for (int i = 0; i < size; i++)
> +            table[i] = round(factor * pow(i, 1. / 3.));
> +    } else {
> +        uint16_t *tablew = (uint16_t*)table;
> +        for (int i = 0; i < size; i++)
> +            tablew[i] = round(factor * pow(i, 1. / 3.));
> +    }
> +
> +end:
> +    ff_mutex_unlock(&cbrt_mutex);
> +    return table != NULL;
> +}
> +
> +void ff_uninit_cbrt(int bitdepth)
> +{
> +    if (bitdepth < 4 || bitdepth > 16)
> +        return;
> +    ff_mutex_lock(&cbrt_mutex);
> +    if (!--cbrt_table_ref[bitdepth]) {
> +        av_free(cbrt_table[bitdepth]);
> +        cbrt_table[bitdepth] = NULL;
> +    }
> +    ff_mutex_unlock(&cbrt_mutex);
> +}
> +
> +void ff_scene_scrd_c(SCENE_SAD_PARAMS)
> +{
> +    uint64_t scrdPlus = 0;
> +    uint64_t scrdMinus = 0;
> +    int x, y;
> +
> +    uint8_t *table = cbrt_table[8];
> +    if (!table) {
> +        *sum = 0;
> +        return;
> +    }
> +
> +    for (y = 0; y < height; y++) {
> +        for (x = 0; x < width; x++)
> +            if (src1[x] > src2[x])
> +                scrdMinus += table[src1[x] - src2[x]];
> +            else
> +                scrdPlus += table[src2[x] - src1[x]];
> +        src1 += stride1;
> +        src2 += stride2;
> +    }
> +
> +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> +    *sum = 2.0 * mean * mean;
> +}
> +
> +void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
> +{
> +    uint64_t scrdPlus = 0;
> +    uint64_t scrdMinus = 0;
> +    const uint16_t *src1w = (const uint16_t*)src1;
> +    const uint16_t *src2w = (const uint16_t*)src2;
> +    int x, y;
> +
> +    uint16_t *table = (uint16_t*)cbrt_table[bitdepth];
> +    if (!table) {
> +        *sum = 0;
> +        return;
> +    }
> +
> +    stride1 /= 2;
> +    stride2 /= 2;
> +
> +    for (y = 0; y < height; y++) {
> +        for (x = 0; x < width; x++)
> +            if (src1w[x] > src2w[x])
> +                scrdMinus += table[src1w[x] - src2w[x]];
> +            else
> +                scrdPlus += table[src2w[x] - src1w[x]];
> +        src1w += stride1;
> +        src2w += stride2;
> +    }
> +
> +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> +    *sum = 2.0 * mean * mean;
> +}
> +
> +void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum,
9);
> +}
> +
> +void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum,
> 10);
> +}
> +
> +void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum,
> 12);
> +}
> +
> +void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum,
> 14);
> +}
> +
> +void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum,
> 16);
> +}
> +
> +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth)
> +{
> +    ff_scene_sad_fn scrd = NULL;
> +    if (depth == 8)
> +        scrd = ff_scene_scrd_c;
> +    else if (depth == 9)
> +        scrd = ff_scene_scrd9_c;
> +    else if (depth == 10)
> +        scrd = ff_scene_scrd10_c;
> +    else if (depth == 12)
> +        scrd = ff_scene_scrd12_c;
> +    else if (depth == 14)
> +        scrd = ff_scene_scrd14_c;
> +    else if (depth == 16)
> +        scrd = ff_scene_scrd16_c;
> +    return scrd;
> +}
> diff --git a/libavfilter/scene_sad.h b/libavfilter/scene_sad.h
> index 173a051f2b..c294bd90f9 100644
> --- a/libavfilter/scene_sad.h
> +++ b/libavfilter/scene_sad.h
> @@ -41,4 +41,10 @@ ff_scene_sad_fn ff_scene_sad_get_fn_x86(int depth);
> 
>  ff_scene_sad_fn ff_scene_sad_get_fn(int depth);
> 
> +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth);
> +
> +int ff_init_cbrt(int bitdepth);
> +
> +void ff_uninit_cbrt(int bitdepth);
> +
>  #endif /* AVFILTER_SCENE_SAD_H */
> diff --git a/libavfilter/vf_scdet.c b/libavfilter/vf_scdet.c
> index 15399cfebf..93da5837b3 100644
> --- a/libavfilter/vf_scdet.c
> +++ b/libavfilter/vf_scdet.c
> @@ -31,6 +31,18 @@
>  #include "scene_sad.h"
>  #include "video.h"
> 
> +enum SCDETMode {
> +    MODE_LEGACY = -1,
> +    MODE_LINEAR = 0,
> +    MODE_MEAN_CBRT = 1
> +};
> +
> +typedef struct SCDETFrameInfo {
> +    AVFrame *picref;
> +    double mafd;
> +    double diff;
> +} SCDETFrameInfo;
> +
>  typedef struct SCDetContext {
>      const AVClass *class;
> 
> @@ -39,11 +51,12 @@ typedef struct SCDetContext {
>      int nb_planes;
>      int bitdepth;
>      ff_scene_sad_fn sad;
> -    double prev_mafd;
> -    double scene_score;
> -    AVFrame *prev_picref;
> +    SCDETFrameInfo curr_frame;
> +    SCDETFrameInfo prev_frame;
> +
>      double threshold;
>      int sc_pass;
> +    enum SCDETMode mode;
>  } SCDetContext;
> 
>  #define OFFSET(x) offsetof(SCDetContext, x)
> @@ -55,6 +68,7 @@ static const AVOption scdet_options[] = {
>      { "t",           "set scene change detect threshold",
> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F
},
>      { "sc_pass",     "Set the flag to pass scene change frames",
> OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,  V|F
},
>      { "s",           "Set the flag to pass scene change frames",
> OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,  V|F
},
> +    { "mode",        "scene change detection method",
> OFFSET(mode),       AV_OPT_TYPE_INT,      {.i64 = MODE_LEGACY},
> MODE_LEGACY,
> MODE_MEAN_CBRT, V|F },
>      {NULL}
>  };
> 
> @@ -91,7 +105,14 @@ static int config_input(AVFilterLink *inlink)
>          s->height[plane] = inlink->h >> ((plane == 1 || plane == 2) ?
> desc->log2_chroma_h : 0);
>      }
> 
> -    s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> +    if (s->mode == MODE_LINEAR || s->mode == MODE_LEGACY)
> +        s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> +    else if (s->mode == MODE_MEAN_CBRT) {
> +        int ret = ff_init_cbrt(s->bitdepth);
> +        if (ret < 0)
> +            return ret;
> +        s->sad = ff_scene_scrd_get_fn(s->bitdepth);
> +    }
>      if (!s->sad)
>          return AVERROR(EINVAL);
> 
> @@ -101,46 +122,97 @@ static int config_input(AVFilterLink *inlink)
>  static av_cold void uninit(AVFilterContext *ctx)
>  {
>      SCDetContext *s = ctx->priv;
> -
> -    av_frame_free(&s->prev_picref);
> +    if (s->mode == MODE_LEGACY)
> +        av_frame_free(&s->prev_frame.picref);
> +    if (s->mode == MODE_MEAN_CBRT)
> +        ff_uninit_cbrt(s->bitdepth);
>  }
> 
> -static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
> +static void compute_diff(AVFilterContext *ctx)
>  {
> -    double ret = 0;
>      SCDetContext *s = ctx->priv;
> -    AVFrame *prev_picref = s->prev_picref;
> +    AVFrame *prev_picref = s->prev_frame.picref;
> +    AVFrame *curr_picref = s->curr_frame.picref;
> 
> -    if (prev_picref && frame->height == prev_picref->height
> -                    && frame->width  == prev_picref->width) {
> -        uint64_t sad = 0;
> -        double mafd, diff;
> -        uint64_t count = 0;
> +    if (prev_picref && curr_picref
> +            && curr_picref->height == prev_picref->height
> +            && curr_picref->width  == prev_picref->width) {
> 
> +        uint64_t sum = 0;
> +        uint64_t count = 0;
>          for (int plane = 0; plane < s->nb_planes; plane++) {
> -            uint64_t plane_sad;
> +            uint64_t plane_sum;
>              s->sad(prev_picref->data[plane],
prev_picref->linesize[plane],
> -                    frame->data[plane], frame->linesize[plane],
> -                    s->width[plane], s->height[plane], &plane_sad);
> -            sad += plane_sad;
> +                    curr_picref->data[plane],
curr_picref->linesize[plane],
> +                    s->width[plane], s->height[plane], &plane_sum);
> +            sum += plane_sum;
>              count += s->width[plane] * s->height[plane];
>          }
> 
> -        mafd = (double)sad * 100. / count / (1ULL << s->bitdepth);
> -        diff = fabs(mafd - s->prev_mafd);
> -        ret  = av_clipf(FFMIN(mafd, diff), 0, 100.);
> -        s->prev_mafd = mafd;
> -        av_frame_free(&prev_picref);
> +        s->curr_frame.mafd = (double)sum * 100. / count / (1ULL <<
> s->bitdepth);
> +        if (s->mode == MODE_LEGACY)
> +            s->curr_frame.diff = fabs(s->curr_frame.mafd -
> s->prev_frame.mafd);
> +        else
> +            s->curr_frame.diff = s->curr_frame.mafd - s->prev_frame.mafd;
> +    } else {
> +        s->curr_frame.mafd = 0;
> +        s->curr_frame.diff = 0;
>      }
> -    s->prev_picref = av_frame_clone(frame);
> -    return ret;
>  }
> 
> -static int set_meta(SCDetContext *s, AVFrame *frame, const char *key,
const
> char *value)
> +static int set_meta(AVFrame *frame, const char *key, const char *value)
>  {
>      return av_dict_set(&frame->metadata, key, value, 0);
>  }
> 
> +static int filter_frame(AVFilterContext *ctx, AVFrame *frame)
> +{
> +    AVFilterLink *inlink = ctx->inputs[0];
> +    AVFilterLink *outlink = ctx->outputs[0];
> +    SCDetContext *s = ctx->priv;
> +
> +    s->prev_frame = s->curr_frame;
> +    s->curr_frame.picref = frame;
> +
> +    if ((s->mode != MODE_LEGACY && s->prev_frame.picref) || (s->mode ==
> MODE_LEGACY && frame != NULL)) {
> +        compute_diff(ctx);
> +
> +        if (s->mode == MODE_LEGACY) {
> +            av_frame_free(&s->prev_frame.picref);
> +            s->prev_frame = s->curr_frame;
> +            s->curr_frame.picref = av_frame_clone(s->curr_frame.picref);
> +        } else if (s->prev_frame.diff < -s->curr_frame.diff) {
> +            s->prev_frame.diff = -s->curr_frame.diff;
> +            s->prev_frame.mafd = s->curr_frame.mafd;
> +        }
> +        double scene_score = av_clipf(s->mode == MODE_LEGACY ?
> FFMIN(s->prev_frame.mafd, s->prev_frame.diff) : FFMAX(s->prev_frame.diff,
> 0), 0, 100.);
> +
> +        char buf[64];
> +        snprintf(buf, sizeof(buf), "%0.3f", s->prev_frame.mafd);
> +        set_meta(s->prev_frame.picref, "lavfi.scd.mafd", buf);
> +        snprintf(buf, sizeof(buf), "%0.3f", scene_score);
> +        set_meta(s->prev_frame.picref, "lavfi.scd.score", buf);
> +
> +        if (scene_score >= s->threshold) {
> +            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
lavfi.scd.time:
> %s\n",
> +                scene_score, av_ts2timestr(s->prev_frame.picref->pts,
> &inlink->time_base));
> +            set_meta(s->prev_frame.picref, "lavfi.scd.time",
> +                av_ts2timestr(s->prev_frame.picref->pts,
> &inlink->time_base));
> +        }
> +
> +        if (s->sc_pass) {
> +            if (scene_score >= s->threshold)
> +                return ff_filter_frame(outlink, s->prev_frame.picref);
> +            else
> +                av_frame_free(&s->prev_frame.picref);
> +        }
> +        else
> +            return ff_filter_frame(outlink, s->prev_frame.picref);
> +    }
> +
> +    return 0;
> +}
> +
>  static int activate(AVFilterContext *ctx)
>  {
>      int ret;
> @@ -148,6 +220,8 @@ static int activate(AVFilterContext *ctx)
>      AVFilterLink *outlink = ctx->outputs[0];
>      SCDetContext *s = ctx->priv;
>      AVFrame *frame;
> +    int64_t pts;
> +    int status;
> 
>      FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
> 
> @@ -155,31 +229,17 @@ static int activate(AVFilterContext *ctx)
>      if (ret < 0)
>          return ret;
> 
> -    if (frame) {
> -        char buf[64];
> -        s->scene_score = get_scene_score(ctx, frame);
> -        snprintf(buf, sizeof(buf), "%0.3f", s->prev_mafd);
> -        set_meta(s, frame, "lavfi.scd.mafd", buf);
> -        snprintf(buf, sizeof(buf), "%0.3f", s->scene_score);
> -        set_meta(s, frame, "lavfi.scd.score", buf);
> +    if (ret > 0)
> +        return filter_frame(ctx, frame);
> 
> -        if (s->scene_score >= s->threshold) {
> -            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
lavfi.scd.time:
> %s\n",
> -                    s->scene_score, av_ts2timestr(frame->pts,
> &inlink->time_base));
> -            set_meta(s, frame, "lavfi.scd.time",
> -                    av_ts2timestr(frame->pts, &inlink->time_base));
> -        }
> -        if (s->sc_pass) {
> -            if (s->scene_score >= s->threshold)
> -                return ff_filter_frame(outlink, frame);
> -            else {
> -                av_frame_free(&frame);
> -            }
> -        } else
> -            return ff_filter_frame(outlink, frame);
> +    if (ff_inlink_acknowledge_status(inlink, &status, &pts)) {
> +        if (status == AVERROR_EOF)
> +            ret = filter_frame(ctx, NULL);
> +
> +        ff_outlink_set_status(outlink, status, pts);
> +        return ret;
>      }
> 
> -    FF_FILTER_FORWARD_STATUS(inlink, outlink);
>      FF_FILTER_FORWARD_WANTED(outlink, inlink);
> 
>      return FFERROR_NOT_READY;
> diff --git a/tests/fate/filter-video.mak b/tests/fate/filter-video.mak
> index ee9f0f5e40..cff48e33d9 100644
> --- a/tests/fate/filter-video.mak
> +++ b/tests/fate/filter-video.mak
> @@ -672,6 +672,9 @@ SCDET_DEPS = LAVFI_INDEV FILE_PROTOCOL
> MOVIE_FILTER
> SCDET_FILTER SCALE_FILTER \
>  FATE_METADATA_FILTER-$(call ALLYES, $(SCDET_DEPS)) +=
> fate-filter-metadata-scdet
>  fate-filter-metadata-scdet: SRC =
> $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
>  fate-filter-metadata-scdet: CMD = run $(FILTER_METADATA_COMMAND)
> "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1"
> +FATE_METADATA_FILTER-$(call ALLYES, $(SCDET_DEPS)) +=
> fate-filter-metadata-scdet1
> +fate-filter-metadata-scdet1: SRC =
> $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
> +fate-filter-metadata-scdet1: CMD = run $(FILTER_METADATA_COMMAND)
> "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1:t=6.5:mode=1"
> 
>  CROPDETECT_DEPS = LAVFI_INDEV FILE_PROTOCOL MOVIE_FILTER
> MOVIE_FILTER
> MESTIMATE_FILTER CROPDETECT_FILTER \
>                    SCALE_FILTER MOV_DEMUXER H264_DECODER
> --
> 2.43.0.windows.1
> 

So what's next? Is there anything else I should do?

> -----Original Message-----
> From: radu.taraibuta@gmail.com <radu.taraibuta@gmail.com>
> Sent: duminică, 19 mai 2024 19:05
> To: ffmpeg-devel@ffmpeg.org
> Subject: RE: [PATCH] area changed: scdet filter
> 
> 
> > -----Original Message-----
> > From: radu.taraibuta@gmail.com <radu.taraibuta@gmail.com>
> > Sent: luni, 13 mai 2024 18:52
> > To: ffmpeg-devel@ffmpeg.org
> > Subject: [PATCH] area changed: scdet filter
> >
> > Previous observations:
> >
> >  - Inconsistent code style with other filters. (Mostly using
> > AVFilterLink* link instead of AVFilterLink *link).
> > I hope it's fine now.
> >
> >  - Unrelated changes, please split trivial unrelated changes into
> > separate patches.
> > Removed trivial changes from this patch.
> >
> >  - Can't tables be generated at .init/.config_props time? No point in
> > storing them into binary.
> > Done.
> >
> >  - Adding extra delay is not backward compatible change, it should be
> > implemented properly by adding option for users to select mode: next &
> prev
> > frame or just next or prev frame.
> > Added legacy option to the mode parameter.
> >
> >  - Could split frame clone change into earlier separate patch.
> > Cannot be done. It's either frame clone or 1 frame delay.
> >
> >  - Where are results of improvements with accuracy so it can be
confirmed?
> > Here are my test results with manual labeling of scene changes:
> > 2379	Full length movie
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	7	2357	423	22		0.847841727
0.990752417
> > 0.913742973
> > Cubic	10	2297	200	82		0.919903885
0.965531736
> > 0.94216571
> > Cubic	12	2217	146	162		0.938214135
0.931904161
> > 0.935048503
> > Cubic	15	2049	101	330		0.953023256
0.861286255
> > 0.904835505
> > Linear	2.8	2357	1060	22		0.689786362
> 0.990752417
> > 0.813319531
> > Linear	8	2099	236	280		0.898929336
> 0.882303489
> > 0.890538821
> > Linear	10	1886	173	493		0.91597863
> 0.792770071
> > 0.849932402
> > Legacy	5	2235	1260	144		0.639484979
> 0.939470366
> > 0.760980592
> > Legacy	8	1998	414	381		0.828358209
> 0.839848676
> > 0.83406387
> > Legacy	10	1743	193	636		0.900309917
> 0.732660782
> > 0.80787949
> >
> > 15	HDR10Plus_PB_EAC3JOC
> > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > viDc3zMj8ZHruHcWKyA
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	10	15	0	0		1	1	1
> > Linear	5	13	1	2		0.928571429
> 0.866666667
> > 0.896551724
> > Legacy	5	12	2	3		0.857142857	0.8
> > 0.827586207
> >
> > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> >
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47E
> > hR2o
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	10	21	0	0		1	1	1
> > Linear	4	20	0	1		1	0.952380952
> > 0.975609756
> > Legacy	4	19	0	2		1	0.904761905
> 0.95
> >
> > 94	Bieber Grammys
> > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	15	91	23	3		0.798245614
0.968085106
> > 0.875
> > Cubic	18	85	9	9		0.904255319
0.904255319
> > 0.904255319
> > Linear	7	79	49	15		0.6171875
> 0.840425532
> > 0.711711712
> > Linear	8	74	28	20		0.725490196
> 0.787234043
> > 0.755102041
> > Legacy	7	74	40	20		0.649122807
> 0.787234043
> > 0.711538462
> > Legacy	8	71	26	23		0.731958763
> 0.755319149
> > 0.743455497
> >
> >
> > Improve scene detection accuracy by comparing frame with both previous
> > and next frame (creates one frame delay).
> > Add new mode parameter and new method to compute the frame difference
> > using cubic square to increase the weight of small changes and new
> > mean formula.
> > This improves accuracy significantly. Slightly improve performance by
> > not using frame clone.
> > Add legacy mode for backward compatibility.
> >
> > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > ---
> >  doc/filters.texi            |  16 ++++
> >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> >  libavfilter/scene_sad.h     |   6 ++
> >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> >  tests/fate/filter-video.mak |   3 +
> >  5 files changed, 284 insertions(+), 48 deletions(-)
> >
> > diff --git a/doc/filters.texi b/doc/filters.texi index
> > bfa8ccec8b..53814e003b 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> >  @item sc_pass, s
> >  Set the flag to pass scene change frames to the next filter. Default
> value
> > is @code{0}
> >  You can enable it if you want to get snapshot of scene change frames
> only.
> > +
> > +@item mode
> > +Set the scene change detection method. Default value is @code{-1}
> > +Available values are:
> > +
> > +@table @samp
> > +@item -1
> > +Legacy mode for sum of absolute linear differences. Compare frame
> > +with
> > previous only and no delay.
> > +
> > +@item 0
> > +Sum of absolute linear differences. Compare frame with both previous
> > +and
> > next which introduces a 1 frame delay.
> > +
> > +@item 1
> > +Sum of mean of cubic root differences. Compare frame with both
> > +previous
> > and
> > next which introduces a 1 frame delay.
> > +
> > +@end table
> >  @end table
> >
> >  @anchor{selectivecolor}
> > diff --git a/libavfilter/scene_sad.c b/libavfilter/scene_sad.c index
> > caf911eb5d..9b80d426bc 100644
> > --- a/libavfilter/scene_sad.c
> > +++ b/libavfilter/scene_sad.c
> > @@ -21,6 +21,7 @@
> >   * Scene SAD functions
> >   */
> >
> > +#include "libavutil/thread.h"
> >  #include "scene_sad.h"
> >
> >  void ff_scene_sad16_c(SCENE_SAD_PARAMS)
> > @@ -71,3 +72,153 @@ ff_scene_sad_fn ff_scene_sad_get_fn(int depth)
> >      return sad;
> >  }
> >
> > +static AVMutex cbrt_mutex = AV_MUTEX_INITIALIZER; static uint8_t
> > +*cbrt_table[16] = { NULL }; static int cbrt_table_ref[16] = { 0 };
> > +
> > +int ff_init_cbrt(int bitdepth)
> > +{
> > +    if (bitdepth < 4 || bitdepth > 16)
> > +        return AVERROR(EINVAL);
> > +
> > +    ff_mutex_lock(&cbrt_mutex);
> > +
> > +    uint8_t *table = cbrt_table[bitdepth];
> > +    if (table) {
> > +        cbrt_table_ref[bitdepth]++;
> > +        goto end;
> > +    }
> > +
> > +    table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > +    if (!table)
> > +        goto end;
> > +    cbrt_table[bitdepth] = table;
> > +    cbrt_table_ref[bitdepth] = 1;
> > +
> > +    int size = 1 << bitdepth;
> > +    double factor = pow(size - 1, 2. / 3.);
> > +    if (bitdepth <= 8) {
> > +        for (int i = 0; i < size; i++)
> > +            table[i] = round(factor * pow(i, 1. / 3.));
> > +    } else {
> > +        uint16_t *tablew = (uint16_t*)table;
> > +        for (int i = 0; i < size; i++)
> > +            tablew[i] = round(factor * pow(i, 1. / 3.));
> > +    }
> > +
> > +end:
> > +    ff_mutex_unlock(&cbrt_mutex);
> > +    return table != NULL;
> > +}
> > +
> > +void ff_uninit_cbrt(int bitdepth)
> > +{
> > +    if (bitdepth < 4 || bitdepth > 16)
> > +        return;
> > +    ff_mutex_lock(&cbrt_mutex);
> > +    if (!--cbrt_table_ref[bitdepth]) {
> > +        av_free(cbrt_table[bitdepth]);
> > +        cbrt_table[bitdepth] = NULL;
> > +    }
> > +    ff_mutex_unlock(&cbrt_mutex);
> > +}
> > +
> > +void ff_scene_scrd_c(SCENE_SAD_PARAMS) {
> > +    uint64_t scrdPlus = 0;
> > +    uint64_t scrdMinus = 0;
> > +    int x, y;
> > +
> > +    uint8_t *table = cbrt_table[8];
> > +    if (!table) {
> > +        *sum = 0;
> > +        return;
> > +    }
> > +
> > +    for (y = 0; y < height; y++) {
> > +        for (x = 0; x < width; x++)
> > +            if (src1[x] > src2[x])
> > +                scrdMinus += table[src1[x] - src2[x]];
> > +            else
> > +                scrdPlus += table[src2[x] - src1[x]];
> > +        src1 += stride1;
> > +        src2 += stride2;
> > +    }
> > +
> > +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > +    *sum = 2.0 * mean * mean;
> > +}
> > +
> > +void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth) {
> > +    uint64_t scrdPlus = 0;
> > +    uint64_t scrdMinus = 0;
> > +    const uint16_t *src1w = (const uint16_t*)src1;
> > +    const uint16_t *src2w = (const uint16_t*)src2;
> > +    int x, y;
> > +
> > +    uint16_t *table = (uint16_t*)cbrt_table[bitdepth];
> > +    if (!table) {
> > +        *sum = 0;
> > +        return;
> > +    }
> > +
> > +    stride1 /= 2;
> > +    stride2 /= 2;
> > +
> > +    for (y = 0; y < height; y++) {
> > +        for (x = 0; x < width; x++)
> > +            if (src1w[x] > src2w[x])
> > +                scrdMinus += table[src1w[x] - src2w[x]];
> > +            else
> > +                scrdPlus += table[src2w[x] - src1w[x]];
> > +        src1w += stride1;
> > +        src2w += stride2;
> > +    }
> > +
> > +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > +    *sum = 2.0 * mean * mean;
> > +}
> > +
> > +void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum,
> 9);
> > +}
> > +
> > +void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum,
> > 10);
> > +}
> > +
> > +void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum,
> > 12);
> > +}
> > +
> > +void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum,
> > 14);
> > +}
> > +
> > +void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum,
> > 16);
> > +}
> > +
> > +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth) {
> > +    ff_scene_sad_fn scrd = NULL;
> > +    if (depth == 8)
> > +        scrd = ff_scene_scrd_c;
> > +    else if (depth == 9)
> > +        scrd = ff_scene_scrd9_c;
> > +    else if (depth == 10)
> > +        scrd = ff_scene_scrd10_c;
> > +    else if (depth == 12)
> > +        scrd = ff_scene_scrd12_c;
> > +    else if (depth == 14)
> > +        scrd = ff_scene_scrd14_c;
> > +    else if (depth == 16)
> > +        scrd = ff_scene_scrd16_c;
> > +    return scrd;
> > +}
> > diff --git a/libavfilter/scene_sad.h b/libavfilter/scene_sad.h index
> > 173a051f2b..c294bd90f9 100644
> > --- a/libavfilter/scene_sad.h
> > +++ b/libavfilter/scene_sad.h
> > @@ -41,4 +41,10 @@ ff_scene_sad_fn ff_scene_sad_get_fn_x86(int depth);
> >
> >  ff_scene_sad_fn ff_scene_sad_get_fn(int depth);
> >
> > +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth);
> > +
> > +int ff_init_cbrt(int bitdepth);
> > +
> > +void ff_uninit_cbrt(int bitdepth);
> > +
> >  #endif /* AVFILTER_SCENE_SAD_H */
> > diff --git a/libavfilter/vf_scdet.c b/libavfilter/vf_scdet.c index
> > 15399cfebf..93da5837b3 100644
> > --- a/libavfilter/vf_scdet.c
> > +++ b/libavfilter/vf_scdet.c
> > @@ -31,6 +31,18 @@
> >  #include "scene_sad.h"
> >  #include "video.h"
> >
> > +enum SCDETMode {
> > +    MODE_LEGACY = -1,
> > +    MODE_LINEAR = 0,
> > +    MODE_MEAN_CBRT = 1
> > +};
> > +
> > +typedef struct SCDETFrameInfo {
> > +    AVFrame *picref;
> > +    double mafd;
> > +    double diff;
> > +} SCDETFrameInfo;
> > +
> >  typedef struct SCDetContext {
> >      const AVClass *class;
> >
> > @@ -39,11 +51,12 @@ typedef struct SCDetContext {
> >      int nb_planes;
> >      int bitdepth;
> >      ff_scene_sad_fn sad;
> > -    double prev_mafd;
> > -    double scene_score;
> > -    AVFrame *prev_picref;
> > +    SCDETFrameInfo curr_frame;
> > +    SCDETFrameInfo prev_frame;
> > +
> >      double threshold;
> >      int sc_pass;
> > +    enum SCDETMode mode;
> >  } SCDetContext;
> >
> >  #define OFFSET(x) offsetof(SCDetContext, x) @@ -55,6 +68,7 @@ static
> > const AVOption scdet_options[] = {
> >      { "t",           "set scene change detect threshold",
> > OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100.,
V|F
> },
> >      { "sc_pass",     "Set the flag to pass scene change frames",
> > OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,
V|F
> },
> >      { "s",           "Set the flag to pass scene change frames",
> > OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,
V|F
> },
> > +    { "mode",        "scene change detection method",
> > OFFSET(mode),       AV_OPT_TYPE_INT,      {.i64 = MODE_LEGACY},
> > MODE_LEGACY,
> > MODE_MEAN_CBRT, V|F },
> >      {NULL}
> >  };
> >
> > @@ -91,7 +105,14 @@ static int config_input(AVFilterLink *inlink)
> >          s->height[plane] = inlink->h >> ((plane == 1 || plane == 2) ?
> > desc->log2_chroma_h : 0);
> >      }
> >
> > -    s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> > +    if (s->mode == MODE_LINEAR || s->mode == MODE_LEGACY)
> > +        s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> > +    else if (s->mode == MODE_MEAN_CBRT) {
> > +        int ret = ff_init_cbrt(s->bitdepth);
> > +        if (ret < 0)
> > +            return ret;
> > +        s->sad = ff_scene_scrd_get_fn(s->bitdepth);
> > +    }
> >      if (!s->sad)
> >          return AVERROR(EINVAL);
> >
> > @@ -101,46 +122,97 @@ static int config_input(AVFilterLink *inlink)
> > static av_cold void uninit(AVFilterContext *ctx)  {
> >      SCDetContext *s = ctx->priv;
> > -
> > -    av_frame_free(&s->prev_picref);
> > +    if (s->mode == MODE_LEGACY)
> > +        av_frame_free(&s->prev_frame.picref);
> > +    if (s->mode == MODE_MEAN_CBRT)
> > +        ff_uninit_cbrt(s->bitdepth);
> >  }
> >
> > -static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
> > +static void compute_diff(AVFilterContext *ctx)
> >  {
> > -    double ret = 0;
> >      SCDetContext *s = ctx->priv;
> > -    AVFrame *prev_picref = s->prev_picref;
> > +    AVFrame *prev_picref = s->prev_frame.picref;
> > +    AVFrame *curr_picref = s->curr_frame.picref;
> >
> > -    if (prev_picref && frame->height == prev_picref->height
> > -                    && frame->width  == prev_picref->width) {
> > -        uint64_t sad = 0;
> > -        double mafd, diff;
> > -        uint64_t count = 0;
> > +    if (prev_picref && curr_picref
> > +            && curr_picref->height == prev_picref->height
> > +            && curr_picref->width  == prev_picref->width) {
> >
> > +        uint64_t sum = 0;
> > +        uint64_t count = 0;
> >          for (int plane = 0; plane < s->nb_planes; plane++) {
> > -            uint64_t plane_sad;
> > +            uint64_t plane_sum;
> >              s->sad(prev_picref->data[plane],
> prev_picref->linesize[plane],
> > -                    frame->data[plane], frame->linesize[plane],
> > -                    s->width[plane], s->height[plane], &plane_sad);
> > -            sad += plane_sad;
> > +                    curr_picref->data[plane],
> curr_picref->linesize[plane],
> > +                    s->width[plane], s->height[plane], &plane_sum);
> > +            sum += plane_sum;
> >              count += s->width[plane] * s->height[plane];
> >          }
> >
> > -        mafd = (double)sad * 100. / count / (1ULL << s->bitdepth);
> > -        diff = fabs(mafd - s->prev_mafd);
> > -        ret  = av_clipf(FFMIN(mafd, diff), 0, 100.);
> > -        s->prev_mafd = mafd;
> > -        av_frame_free(&prev_picref);
> > +        s->curr_frame.mafd = (double)sum * 100. / count / (1ULL <<
> > s->bitdepth);
> > +        if (s->mode == MODE_LEGACY)
> > +            s->curr_frame.diff = fabs(s->curr_frame.mafd -
> > s->prev_frame.mafd);
> > +        else
> > +            s->curr_frame.diff = s->curr_frame.mafd -
s->prev_frame.mafd;
> > +    } else {
> > +        s->curr_frame.mafd = 0;
> > +        s->curr_frame.diff = 0;
> >      }
> > -    s->prev_picref = av_frame_clone(frame);
> > -    return ret;
> >  }
> >
> > -static int set_meta(SCDetContext *s, AVFrame *frame, const char *key,
> const
> > char *value)
> > +static int set_meta(AVFrame *frame, const char *key, const char
> > +*value)
> >  {
> >      return av_dict_set(&frame->metadata, key, value, 0);  }
> >
> > +static int filter_frame(AVFilterContext *ctx, AVFrame *frame) {
> > +    AVFilterLink *inlink = ctx->inputs[0];
> > +    AVFilterLink *outlink = ctx->outputs[0];
> > +    SCDetContext *s = ctx->priv;
> > +
> > +    s->prev_frame = s->curr_frame;
> > +    s->curr_frame.picref = frame;
> > +
> > +    if ((s->mode != MODE_LEGACY && s->prev_frame.picref) || (s->mode
> > + ==
> > MODE_LEGACY && frame != NULL)) {
> > +        compute_diff(ctx);
> > +
> > +        if (s->mode == MODE_LEGACY) {
> > +            av_frame_free(&s->prev_frame.picref);
> > +            s->prev_frame = s->curr_frame;
> > +            s->curr_frame.picref =
av_frame_clone(s->curr_frame.picref);
> > +        } else if (s->prev_frame.diff < -s->curr_frame.diff) {
> > +            s->prev_frame.diff = -s->curr_frame.diff;
> > +            s->prev_frame.mafd = s->curr_frame.mafd;
> > +        }
> > +        double scene_score = av_clipf(s->mode == MODE_LEGACY ?
> > FFMIN(s->prev_frame.mafd, s->prev_frame.diff) :
> > FFMAX(s->prev_frame.diff, 0), 0, 100.);
> > +
> > +        char buf[64];
> > +        snprintf(buf, sizeof(buf), "%0.3f", s->prev_frame.mafd);
> > +        set_meta(s->prev_frame.picref, "lavfi.scd.mafd", buf);
> > +        snprintf(buf, sizeof(buf), "%0.3f", scene_score);
> > +        set_meta(s->prev_frame.picref, "lavfi.scd.score", buf);
> > +
> > +        if (scene_score >= s->threshold) {
> > +            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
> lavfi.scd.time:
> > %s\n",
> > +                scene_score, av_ts2timestr(s->prev_frame.picref->pts,
> > &inlink->time_base));
> > +            set_meta(s->prev_frame.picref, "lavfi.scd.time",
> > +                av_ts2timestr(s->prev_frame.picref->pts,
> > &inlink->time_base));
> > +        }
> > +
> > +        if (s->sc_pass) {
> > +            if (scene_score >= s->threshold)
> > +                return ff_filter_frame(outlink, s->prev_frame.picref);
> > +            else
> > +                av_frame_free(&s->prev_frame.picref);
> > +        }
> > +        else
> > +            return ff_filter_frame(outlink, s->prev_frame.picref);
> > +    }
> > +
> > +    return 0;
> > +}
> > +
> >  static int activate(AVFilterContext *ctx)  {
> >      int ret;
> > @@ -148,6 +220,8 @@ static int activate(AVFilterContext *ctx)
> >      AVFilterLink *outlink = ctx->outputs[0];
> >      SCDetContext *s = ctx->priv;
> >      AVFrame *frame;
> > +    int64_t pts;
> > +    int status;
> >
> >      FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
> >
> > @@ -155,31 +229,17 @@ static int activate(AVFilterContext *ctx)
> >      if (ret < 0)
> >          return ret;
> >
> > -    if (frame) {
> > -        char buf[64];
> > -        s->scene_score = get_scene_score(ctx, frame);
> > -        snprintf(buf, sizeof(buf), "%0.3f", s->prev_mafd);
> > -        set_meta(s, frame, "lavfi.scd.mafd", buf);
> > -        snprintf(buf, sizeof(buf), "%0.3f", s->scene_score);
> > -        set_meta(s, frame, "lavfi.scd.score", buf);
> > +    if (ret > 0)
> > +        return filter_frame(ctx, frame);
> >
> > -        if (s->scene_score >= s->threshold) {
> > -            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
> lavfi.scd.time:
> > %s\n",
> > -                    s->scene_score, av_ts2timestr(frame->pts,
> > &inlink->time_base));
> > -            set_meta(s, frame, "lavfi.scd.time",
> > -                    av_ts2timestr(frame->pts, &inlink->time_base));
> > -        }
> > -        if (s->sc_pass) {
> > -            if (s->scene_score >= s->threshold)
> > -                return ff_filter_frame(outlink, frame);
> > -            else {
> > -                av_frame_free(&frame);
> > -            }
> > -        } else
> > -            return ff_filter_frame(outlink, frame);
> > +    if (ff_inlink_acknowledge_status(inlink, &status, &pts)) {
> > +        if (status == AVERROR_EOF)
> > +            ret = filter_frame(ctx, NULL);
> > +
> > +        ff_outlink_set_status(outlink, status, pts);
> > +        return ret;
> >      }
> >
> > -    FF_FILTER_FORWARD_STATUS(inlink, outlink);
> >      FF_FILTER_FORWARD_WANTED(outlink, inlink);
> >
> >      return FFERROR_NOT_READY;
> > diff --git a/tests/fate/filter-video.mak b/tests/fate/filter-video.mak
> > index ee9f0f5e40..cff48e33d9 100644
> > --- a/tests/fate/filter-video.mak
> > +++ b/tests/fate/filter-video.mak
> > @@ -672,6 +672,9 @@ SCDET_DEPS = LAVFI_INDEV FILE_PROTOCOL
> > MOVIE_FILTER SCDET_FILTER SCALE_FILTER \  FATE_METADATA_FILTER-$(call
> > ALLYES, $(SCDET_DEPS)) += fate-filter-metadata-scdet
> >  fate-filter-metadata-scdet: SRC =
> > $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
> >  fate-filter-metadata-scdet: CMD = run $(FILTER_METADATA_COMMAND)
> > "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1"
> > +FATE_METADATA_FILTER-$(call ALLYES, $(SCDET_DEPS)) +=
> > fate-filter-metadata-scdet1
> > +fate-filter-metadata-scdet1: SRC =
> > $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
> > +fate-filter-metadata-scdet1: CMD = run $(FILTER_METADATA_COMMAND)
> > "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1:t=6.5:mode=1"
> >
> >  CROPDETECT_DEPS = LAVFI_INDEV FILE_PROTOCOL MOVIE_FILTER
> MOVIE_FILTER
> > MESTIMATE_FILTER CROPDETECT_FILTER \
> >                    SCALE_FILTER MOV_DEMUXER H264_DECODER
> > --
> > 2.43.0.windows.1
> >
> 
> So what's next? Is there anything else I should do?
> 
Anybody?

On Tue, May 28, 2024 at 9:51 AM <radu.taraibuta@gmail.com> wrote:

> > -----Original Message-----
> > From: radu.taraibuta@gmail.com <radu.taraibuta@gmail.com>
> > Sent: duminică, 19 mai 2024 19:05
> > To: ffmpeg-devel@ffmpeg.org
> > Subject: RE: [PATCH] area changed: scdet filter
> >
> >
> > > -----Original Message-----
> > > From: radu.taraibuta@gmail.com <radu.taraibuta@gmail.com>
> > > Sent: luni, 13 mai 2024 18:52
> > > To: ffmpeg-devel@ffmpeg.org
> > > Subject: [PATCH] area changed: scdet filter
> > >
> > > Previous observations:
> > >
> > >  - Inconsistent code style with other filters. (Mostly using
> > > AVFilterLink* link instead of AVFilterLink *link).
> > > I hope it's fine now.
> > >
> > >  - Unrelated changes, please split trivial unrelated changes into
> > > separate patches.
> > > Removed trivial changes from this patch.
> > >
> > >  - Can't tables be generated at .init/.config_props time? No point in
> > > storing them into binary.
> > > Done.
> > >
> > >  - Adding extra delay is not backward compatible change, it should be
> > > implemented properly by adding option for users to select mode: next &
> > prev
> > > frame or just next or prev frame.
> > > Added legacy option to the mode parameter.
> > >
> > >  - Could split frame clone change into earlier separate patch.
> > > Cannot be done. It's either frame clone or 1 frame delay.
> > >
> > >  - Where are results of improvements with accuracy so it can be
> confirmed?
> > > Here are my test results with manual labeling of scene changes:
> > > 2379        Full length movie
> > >
> > > Method      Threshold       TP      FP      FN              Precision
> > > Recall      F
> > > Cubic       7       2357    423     22              0.847841727
> 0.990752417
> > > 0.913742973
> > > Cubic       10      2297    200     82              0.919903885
> 0.965531736
> > > 0.94216571
> > > Cubic       12      2217    146     162             0.938214135
> 0.931904161
> > > 0.935048503
> > > Cubic       15      2049    101     330             0.953023256
> 0.861286255
> > > 0.904835505
> > > Linear      2.8     2357    1060    22              0.689786362
> > 0.990752417
> > > 0.813319531
> > > Linear      8       2099    236     280             0.898929336
> > 0.882303489
> > > 0.890538821
> > > Linear      10      1886    173     493             0.91597863
> > 0.792770071
> > > 0.849932402
> > > Legacy      5       2235    1260    144             0.639484979
> > 0.939470366
> > > 0.760980592
> > > Legacy      8       1998    414     381             0.828358209
> > 0.839848676
> > > 0.83406387
> > > Legacy      10      1743    193     636             0.900309917
> > 0.732660782
> > > 0.80787949
> > >
> > > 15  HDR10Plus_PB_EAC3JOC
> > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > > viDc3zMj8ZHruHcWKyA
> > >
> > > Method      Threshold       TP      FP      FN              Precision
> > > Recall      F
> > > Cubic       10      15      0       0               1       1       1
> > > Linear      5       13      1       2               0.928571429
> > 0.866666667
> > > 0.896551724
> > > Legacy      5       12      2       3               0.857142857     0.8
> > > 0.827586207
> > >
> > > 21  (HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > >
> > https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47E
> > > hR2o
> > >
> > > Method      Threshold       TP      FP      FN              Precision
> > > Recall      F
> > > Cubic       10      21      0       0               1       1       1
> > > Linear      4       20      0       1               1       0.952380952
> > > 0.975609756
> > > Legacy      4       19      0       2               1       0.904761905
> > 0.95
> > >
> > > 94  Bieber Grammys
> > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > >
> > > Method      Threshold       TP      FP      FN              Precision
> > > Recall      F
> > > Cubic       15      91      23      3               0.798245614
> 0.968085106
> > > 0.875
> > > Cubic       18      85      9       9               0.904255319
> 0.904255319
> > > 0.904255319
> > > Linear      7       79      49      15              0.6171875
> > 0.840425532
> > > 0.711711712
> > > Linear      8       74      28      20              0.725490196
> > 0.787234043
> > > 0.755102041
> > > Legacy      7       74      40      20              0.649122807
> > 0.787234043
> > > 0.711538462
> > > Legacy      8       71      26      23              0.731958763
> > 0.755319149
> > > 0.743455497
> > >
> > >
> > > Improve scene detection accuracy by comparing frame with both previous
> > > and next frame (creates one frame delay).
> > > Add new mode parameter and new method to compute the frame difference
> > > using cubic square to increase the weight of small changes and new
> > > mean formula.
> > > This improves accuracy significantly. Slightly improve performance by
> > > not using frame clone.
> > > Add legacy mode for backward compatibility.
> > >
> > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > ---
> > >  doc/filters.texi            |  16 ++++
> > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > >  libavfilter/scene_sad.h     |   6 ++
> > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > >  tests/fate/filter-video.mak |   3 +
> > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > >
> > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > bfa8ccec8b..53814e003b 100644
> > > --- a/doc/filters.texi
> > > +++ b/doc/filters.texi
> > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > >  @item sc_pass, s
> > >  Set the flag to pass scene change frames to the next filter. Default
> > value
> > > is @code{0}
> > >  You can enable it if you want to get snapshot of scene change frames
> > only.
> > > +
> > > +@item mode
> > > +Set the scene change detection method. Default value is @code{-1}
> > > +Available values are:
> > > +
> > > +@table @samp
> > > +@item -1
> > > +Legacy mode for sum of absolute linear differences. Compare frame
> > > +with
> > > previous only and no delay.
> > > +
> > > +@item 0
> > > +Sum of absolute linear differences. Compare frame with both previous
> > > +and
> > > next which introduces a 1 frame delay.
> > > +
> > > +@item 1
> > > +Sum of mean of cubic root differences. Compare frame with both
> > > +previous
> > > and
> > > next which introduces a 1 frame delay.
> > > +
> > > +@end table
> > >  @end table
> > >
> > >  @anchor{selectivecolor}
> > > diff --git a/libavfilter/scene_sad.c b/libavfilter/scene_sad.c index
> > > caf911eb5d..9b80d426bc 100644
> > > --- a/libavfilter/scene_sad.c
> > > +++ b/libavfilter/scene_sad.c
> > > @@ -21,6 +21,7 @@
> > >   * Scene SAD functions
> > >   */
> > >
> > > +#include "libavutil/thread.h"
> > >  #include "scene_sad.h"
> > >
> > >  void ff_scene_sad16_c(SCENE_SAD_PARAMS)
> > > @@ -71,3 +72,153 @@ ff_scene_sad_fn ff_scene_sad_get_fn(int depth)
> > >      return sad;
> > >  }
> > >
> > > +static AVMutex cbrt_mutex = AV_MUTEX_INITIALIZER; static uint8_t
> > > +*cbrt_table[16] = { NULL }; static int cbrt_table_ref[16] = { 0 };
> > > +
> > > +int ff_init_cbrt(int bitdepth)
> > > +{
> > > +    if (bitdepth < 4 || bitdepth > 16)
> > > +        return AVERROR(EINVAL);
> > > +
> > > +    ff_mutex_lock(&cbrt_mutex);
> > > +
> > > +    uint8_t *table = cbrt_table[bitdepth];
> > > +    if (table) {
> > > +        cbrt_table_ref[bitdepth]++;
> > > +        goto end;
> > > +    }
> > > +
> > > +    table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > > +    if (!table)
> > > +        goto end;
> > > +    cbrt_table[bitdepth] = table;
> > > +    cbrt_table_ref[bitdepth] = 1;
> > > +
> > > +    int size = 1 << bitdepth;
> > > +    double factor = pow(size - 1, 2. / 3.);
> > > +    if (bitdepth <= 8) {
> > > +        for (int i = 0; i < size; i++)
> > > +            table[i] = round(factor * pow(i, 1. / 3.));
> > > +    } else {
> > > +        uint16_t *tablew = (uint16_t*)table;
> > > +        for (int i = 0; i < size; i++)
> > > +            tablew[i] = round(factor * pow(i, 1. / 3.));
> > > +    }
> > > +
> > > +end:
> > > +    ff_mutex_unlock(&cbrt_mutex);
> > > +    return table != NULL;
> > > +}
> > > +
> > > +void ff_uninit_cbrt(int bitdepth)
> > > +{
> > > +    if (bitdepth < 4 || bitdepth > 16)
> > > +        return;
> > > +    ff_mutex_lock(&cbrt_mutex);
> > > +    if (!--cbrt_table_ref[bitdepth]) {
> > > +        av_free(cbrt_table[bitdepth]);
> > > +        cbrt_table[bitdepth] = NULL;
> > > +    }
> > > +    ff_mutex_unlock(&cbrt_mutex);
> > > +}
> > > +
> > > +void ff_scene_scrd_c(SCENE_SAD_PARAMS) {
> > > +    uint64_t scrdPlus = 0;
> > > +    uint64_t scrdMinus = 0;
> > > +    int x, y;
> > > +
> > > +    uint8_t *table = cbrt_table[8];
> > > +    if (!table) {
> > > +        *sum = 0;
> > > +        return;
> > > +    }
> > > +
> > > +    for (y = 0; y < height; y++) {
> > > +        for (x = 0; x < width; x++)
> > > +            if (src1[x] > src2[x])
> > > +                scrdMinus += table[src1[x] - src2[x]];
> > > +            else
> > > +                scrdPlus += table[src2[x] - src1[x]];
> > > +        src1 += stride1;
> > > +        src2 += stride2;
> > > +    }
> > > +
> > > +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > > +    *sum = 2.0 * mean * mean;
> > > +}
> > > +
> > > +void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth) {
> > > +    uint64_t scrdPlus = 0;
> > > +    uint64_t scrdMinus = 0;
> > > +    const uint16_t *src1w = (const uint16_t*)src1;
> > > +    const uint16_t *src2w = (const uint16_t*)src2;
> > > +    int x, y;
> > > +
> > > +    uint16_t *table = (uint16_t*)cbrt_table[bitdepth];
> > > +    if (!table) {
> > > +        *sum = 0;
> > > +        return;
> > > +    }
> > > +
> > > +    stride1 /= 2;
> > > +    stride2 /= 2;
> > > +
> > > +    for (y = 0; y < height; y++) {
> > > +        for (x = 0; x < width; x++)
> > > +            if (src1w[x] > src2w[x])
> > > +                scrdMinus += table[src1w[x] - src2w[x]];
> > > +            else
> > > +                scrdPlus += table[src2w[x] - src1w[x]];
> > > +        src1w += stride1;
> > > +        src2w += stride2;
> > > +    }
> > > +
> > > +    double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > > +    *sum = 2.0 * mean * mean;
> > > +}
> > > +
> > > +void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> > > +{
> > > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > > +sum,
> > 9);
> > > +}
> > > +
> > > +void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> > > +{
> > > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > > +sum,
> > > 10);
> > > +}
> > > +
> > > +void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> > > +{
> > > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > > +sum,
> > > 12);
> > > +}
> > > +
> > > +void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> > > +{
> > > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > > +sum,
> > > 14);
> > > +}
> > > +
> > > +void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> > > +{
> > > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > > +sum,
> > > 16);
> > > +}
> > > +
> > > +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth) {
> > > +    ff_scene_sad_fn scrd = NULL;
> > > +    if (depth == 8)
> > > +        scrd = ff_scene_scrd_c;
> > > +    else if (depth == 9)
> > > +        scrd = ff_scene_scrd9_c;
> > > +    else if (depth == 10)
> > > +        scrd = ff_scene_scrd10_c;
> > > +    else if (depth == 12)
> > > +        scrd = ff_scene_scrd12_c;
> > > +    else if (depth == 14)
> > > +        scrd = ff_scene_scrd14_c;
> > > +    else if (depth == 16)
> > > +        scrd = ff_scene_scrd16_c;
> > > +    return scrd;
> > > +}
> > > diff --git a/libavfilter/scene_sad.h b/libavfilter/scene_sad.h index
> > > 173a051f2b..c294bd90f9 100644
> > > --- a/libavfilter/scene_sad.h
> > > +++ b/libavfilter/scene_sad.h
> > > @@ -41,4 +41,10 @@ ff_scene_sad_fn ff_scene_sad_get_fn_x86(int depth);
> > >
> > >  ff_scene_sad_fn ff_scene_sad_get_fn(int depth);
> > >
> > > +ff_scene_sad_fn ff_scene_scrd_get_fn(int depth);
> > > +
> > > +int ff_init_cbrt(int bitdepth);
> > > +
> > > +void ff_uninit_cbrt(int bitdepth);
> > > +
> > >  #endif /* AVFILTER_SCENE_SAD_H */
> > > diff --git a/libavfilter/vf_scdet.c b/libavfilter/vf_scdet.c index
> > > 15399cfebf..93da5837b3 100644
> > > --- a/libavfilter/vf_scdet.c
> > > +++ b/libavfilter/vf_scdet.c
> > > @@ -31,6 +31,18 @@
> > >  #include "scene_sad.h"
> > >  #include "video.h"
> > >
> > > +enum SCDETMode {
> > > +    MODE_LEGACY = -1,
> > > +    MODE_LINEAR = 0,
> > > +    MODE_MEAN_CBRT = 1
> > > +};
> > > +
> > > +typedef struct SCDETFrameInfo {
> > > +    AVFrame *picref;
> > > +    double mafd;
> > > +    double diff;
> > > +} SCDETFrameInfo;
> > > +
> > >  typedef struct SCDetContext {
> > >      const AVClass *class;
> > >
> > > @@ -39,11 +51,12 @@ typedef struct SCDetContext {
> > >      int nb_planes;
> > >      int bitdepth;
> > >      ff_scene_sad_fn sad;
> > > -    double prev_mafd;
> > > -    double scene_score;
> > > -    AVFrame *prev_picref;
> > > +    SCDETFrameInfo curr_frame;
> > > +    SCDETFrameInfo prev_frame;
> > > +
> > >      double threshold;
> > >      int sc_pass;
> > > +    enum SCDETMode mode;
> > >  } SCDetContext;
> > >
> > >  #define OFFSET(x) offsetof(SCDetContext, x) @@ -55,6 +68,7 @@ static
> > > const AVOption scdet_options[] = {
> > >      { "t",           "set scene change detect threshold",
> > > OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100.,
> V|F
> > },
> > >      { "sc_pass",     "Set the flag to pass scene change frames",
> > > OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,
> V|F
> > },
> > >      { "s",           "Set the flag to pass scene change frames",
> > > OFFSET(sc_pass),    AV_OPT_TYPE_BOOL,     {.dbl =  0  },    0,    1,
> V|F
> > },
> > > +    { "mode",        "scene change detection method",
> > > OFFSET(mode),       AV_OPT_TYPE_INT,      {.i64 = MODE_LEGACY},
> > > MODE_LEGACY,
> > > MODE_MEAN_CBRT, V|F },
> > >      {NULL}
> > >  };
> > >
> > > @@ -91,7 +105,14 @@ static int config_input(AVFilterLink *inlink)
> > >          s->height[plane] = inlink->h >> ((plane == 1 || plane == 2) ?
> > > desc->log2_chroma_h : 0);
> > >      }
> > >
> > > -    s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> > > +    if (s->mode == MODE_LINEAR || s->mode == MODE_LEGACY)
> > > +        s->sad = ff_scene_sad_get_fn(s->bitdepth == 8 ? 8 : 16);
> > > +    else if (s->mode == MODE_MEAN_CBRT) {
> > > +        int ret = ff_init_cbrt(s->bitdepth);
> > > +        if (ret < 0)
> > > +            return ret;
> > > +        s->sad = ff_scene_scrd_get_fn(s->bitdepth);
> > > +    }
> > >      if (!s->sad)
> > >          return AVERROR(EINVAL);
> > >
> > > @@ -101,46 +122,97 @@ static int config_input(AVFilterLink *inlink)
> > > static av_cold void uninit(AVFilterContext *ctx)  {
> > >      SCDetContext *s = ctx->priv;
> > > -
> > > -    av_frame_free(&s->prev_picref);
> > > +    if (s->mode == MODE_LEGACY)
> > > +        av_frame_free(&s->prev_frame.picref);
> > > +    if (s->mode == MODE_MEAN_CBRT)
> > > +        ff_uninit_cbrt(s->bitdepth);
> > >  }
> > >
> > > -static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
> > > +static void compute_diff(AVFilterContext *ctx)
> > >  {
> > > -    double ret = 0;
> > >      SCDetContext *s = ctx->priv;
> > > -    AVFrame *prev_picref = s->prev_picref;
> > > +    AVFrame *prev_picref = s->prev_frame.picref;
> > > +    AVFrame *curr_picref = s->curr_frame.picref;
> > >
> > > -    if (prev_picref && frame->height == prev_picref->height
> > > -                    && frame->width  == prev_picref->width) {
> > > -        uint64_t sad = 0;
> > > -        double mafd, diff;
> > > -        uint64_t count = 0;
> > > +    if (prev_picref && curr_picref
> > > +            && curr_picref->height == prev_picref->height
> > > +            && curr_picref->width  == prev_picref->width) {
> > >
> > > +        uint64_t sum = 0;
> > > +        uint64_t count = 0;
> > >          for (int plane = 0; plane < s->nb_planes; plane++) {
> > > -            uint64_t plane_sad;
> > > +            uint64_t plane_sum;
> > >              s->sad(prev_picref->data[plane],
> > prev_picref->linesize[plane],
> > > -                    frame->data[plane], frame->linesize[plane],
> > > -                    s->width[plane], s->height[plane], &plane_sad);
> > > -            sad += plane_sad;
> > > +                    curr_picref->data[plane],
> > curr_picref->linesize[plane],
> > > +                    s->width[plane], s->height[plane], &plane_sum);
> > > +            sum += plane_sum;
> > >              count += s->width[plane] * s->height[plane];
> > >          }
> > >
> > > -        mafd = (double)sad * 100. / count / (1ULL << s->bitdepth);
> > > -        diff = fabs(mafd - s->prev_mafd);
> > > -        ret  = av_clipf(FFMIN(mafd, diff), 0, 100.);
> > > -        s->prev_mafd = mafd;
> > > -        av_frame_free(&prev_picref);
> > > +        s->curr_frame.mafd = (double)sum * 100. / count / (1ULL <<
> > > s->bitdepth);
> > > +        if (s->mode == MODE_LEGACY)
> > > +            s->curr_frame.diff = fabs(s->curr_frame.mafd -
> > > s->prev_frame.mafd);
> > > +        else
> > > +            s->curr_frame.diff = s->curr_frame.mafd -
> s->prev_frame.mafd;
> > > +    } else {
> > > +        s->curr_frame.mafd = 0;
> > > +        s->curr_frame.diff = 0;
> > >      }
> > > -    s->prev_picref = av_frame_clone(frame);
> > > -    return ret;
> > >  }
> > >
> > > -static int set_meta(SCDetContext *s, AVFrame *frame, const char *key,
> > const
> > > char *value)
> > > +static int set_meta(AVFrame *frame, const char *key, const char
> > > +*value)
> > >  {
> > >      return av_dict_set(&frame->metadata, key, value, 0);  }
> > >
> > > +static int filter_frame(AVFilterContext *ctx, AVFrame *frame) {
> > > +    AVFilterLink *inlink = ctx->inputs[0];
> > > +    AVFilterLink *outlink = ctx->outputs[0];
> > > +    SCDetContext *s = ctx->priv;
> > > +
> > > +    s->prev_frame = s->curr_frame;
> > > +    s->curr_frame.picref = frame;
> > > +
> > > +    if ((s->mode != MODE_LEGACY && s->prev_frame.picref) || (s->mode
> > > + ==
> > > MODE_LEGACY && frame != NULL)) {
> > > +        compute_diff(ctx);
> > > +
> > > +        if (s->mode == MODE_LEGACY) {
> > > +            av_frame_free(&s->prev_frame.picref);
> > > +            s->prev_frame = s->curr_frame;
> > > +            s->curr_frame.picref =
> av_frame_clone(s->curr_frame.picref);
> > > +        } else if (s->prev_frame.diff < -s->curr_frame.diff) {
> > > +            s->prev_frame.diff = -s->curr_frame.diff;
> > > +            s->prev_frame.mafd = s->curr_frame.mafd;
> > > +        }
> > > +        double scene_score = av_clipf(s->mode == MODE_LEGACY ?
> > > FFMIN(s->prev_frame.mafd, s->prev_frame.diff) :
> > > FFMAX(s->prev_frame.diff, 0), 0, 100.);
> > > +
> > > +        char buf[64];
> > > +        snprintf(buf, sizeof(buf), "%0.3f", s->prev_frame.mafd);
> > > +        set_meta(s->prev_frame.picref, "lavfi.scd.mafd", buf);
> > > +        snprintf(buf, sizeof(buf), "%0.3f", scene_score);
> > > +        set_meta(s->prev_frame.picref, "lavfi.scd.score", buf);
> > > +
> > > +        if (scene_score >= s->threshold) {
> > > +            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
> > lavfi.scd.time:
> > > %s\n",
> > > +                scene_score, av_ts2timestr(s->prev_frame.picref->pts,
> > > &inlink->time_base));
> > > +            set_meta(s->prev_frame.picref, "lavfi.scd.time",
> > > +                av_ts2timestr(s->prev_frame.picref->pts,
> > > &inlink->time_base));
> > > +        }
> > > +
> > > +        if (s->sc_pass) {
> > > +            if (scene_score >= s->threshold)
> > > +                return ff_filter_frame(outlink, s->prev_frame.picref);
> > > +            else
> > > +                av_frame_free(&s->prev_frame.picref);
> > > +        }
> > > +        else
> > > +            return ff_filter_frame(outlink, s->prev_frame.picref);
> > > +    }
> > > +
> > > +    return 0;
> > > +}
> > > +
> > >  static int activate(AVFilterContext *ctx)  {
> > >      int ret;
> > > @@ -148,6 +220,8 @@ static int activate(AVFilterContext *ctx)
> > >      AVFilterLink *outlink = ctx->outputs[0];
> > >      SCDetContext *s = ctx->priv;
> > >      AVFrame *frame;
> > > +    int64_t pts;
> > > +    int status;
> > >
> > >      FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
> > >
> > > @@ -155,31 +229,17 @@ static int activate(AVFilterContext *ctx)
> > >      if (ret < 0)
> > >          return ret;
> > >
> > > -    if (frame) {
> > > -        char buf[64];
> > > -        s->scene_score = get_scene_score(ctx, frame);
> > > -        snprintf(buf, sizeof(buf), "%0.3f", s->prev_mafd);
> > > -        set_meta(s, frame, "lavfi.scd.mafd", buf);
> > > -        snprintf(buf, sizeof(buf), "%0.3f", s->scene_score);
> > > -        set_meta(s, frame, "lavfi.scd.score", buf);
> > > +    if (ret > 0)
> > > +        return filter_frame(ctx, frame);
> > >
> > > -        if (s->scene_score >= s->threshold) {
> > > -            av_log(s, AV_LOG_INFO, "lavfi.scd.score: %.3f,
> > lavfi.scd.time:
> > > %s\n",
> > > -                    s->scene_score, av_ts2timestr(frame->pts,
> > > &inlink->time_base));
> > > -            set_meta(s, frame, "lavfi.scd.time",
> > > -                    av_ts2timestr(frame->pts, &inlink->time_base));
> > > -        }
> > > -        if (s->sc_pass) {
> > > -            if (s->scene_score >= s->threshold)
> > > -                return ff_filter_frame(outlink, frame);
> > > -            else {
> > > -                av_frame_free(&frame);
> > > -            }
> > > -        } else
> > > -            return ff_filter_frame(outlink, frame);
> > > +    if (ff_inlink_acknowledge_status(inlink, &status, &pts)) {
> > > +        if (status == AVERROR_EOF)
> > > +            ret = filter_frame(ctx, NULL);
> > > +
> > > +        ff_outlink_set_status(outlink, status, pts);
> > > +        return ret;
> > >      }
> > >
> > > -    FF_FILTER_FORWARD_STATUS(inlink, outlink);
> > >      FF_FILTER_FORWARD_WANTED(outlink, inlink);
> > >
> > >      return FFERROR_NOT_READY;
> > > diff --git a/tests/fate/filter-video.mak b/tests/fate/filter-video.mak
> > > index ee9f0f5e40..cff48e33d9 100644
> > > --- a/tests/fate/filter-video.mak
> > > +++ b/tests/fate/filter-video.mak
> > > @@ -672,6 +672,9 @@ SCDET_DEPS = LAVFI_INDEV FILE_PROTOCOL
> > > MOVIE_FILTER SCDET_FILTER SCALE_FILTER \  FATE_METADATA_FILTER-$(call
> > > ALLYES, $(SCDET_DEPS)) += fate-filter-metadata-scdet
> > >  fate-filter-metadata-scdet: SRC =
> > > $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
> > >  fate-filter-metadata-scdet: CMD = run $(FILTER_METADATA_COMMAND)
> > > "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1"
> > > +FATE_METADATA_FILTER-$(call ALLYES, $(SCDET_DEPS)) +=
> > > fate-filter-metadata-scdet1
> > > +fate-filter-metadata-scdet1: SRC =
> > > $(TARGET_SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
> > > +fate-filter-metadata-scdet1: CMD = run $(FILTER_METADATA_COMMAND)
> > >
> "sws_flags=+accurate_rnd+bitexact;movie='$(SRC)',scdet=s=1:t=6.5:mode=1"
> > >
> > >  CROPDETECT_DEPS = LAVFI_INDEV FILE_PROTOCOL MOVIE_FILTER
> > MOVIE_FILTER
> > > MESTIMATE_FILTER CROPDETECT_FILTER \
> > >                    SCALE_FILTER MOV_DEMUXER H264_DECODER
> > > --
> > > 2.43.0.windows.1
> > >
> >
> > So what's next? Is there anything else I should do?
> >
> Anybody?
>

I Plan to push it to another fork.


>
> _______________________________________________
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> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
>

On Mon, May 13, 2024 at 06:52:19PM +0300, radu.taraibuta@gmail.com wrote:
> Previous observations:
> 
>  - Inconsistent code style with other filters. (Mostly using AVFilterLink*
> link instead of AVFilterLink *link).
> I hope it's fine now.	
> 
>  - Unrelated changes, please split trivial unrelated changes into separate
> patches.
> Removed trivial changes from this patch.
> 
>  - Can't tables be generated at .init/.config_props time? No point in
> storing them into binary.
> Done.
> 
>  - Adding extra delay is not backward compatible change, it should be
> implemented properly by adding option for users to select mode: next & prev
> frame or just next or prev frame.
> Added legacy option to the mode parameter.
> 
>  - Could split frame clone change into earlier separate patch.
> Cannot be done. It's either frame clone or 1 frame delay.
> 
>  - Where are results of improvements with accuracy so it can be confirmed?
> Here are my test results with manual labeling of scene changes:
> 2379	Full length movie
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	7	2357	423	22		0.847841727	0.990752417
> 0.913742973
> Cubic	10	2297	200	82		0.919903885	0.965531736
> 0.94216571
> Cubic	12	2217	146	162		0.938214135	0.931904161
> 0.935048503
> Cubic	15	2049	101	330		0.953023256	0.861286255
> 0.904835505
> Linear	2.8	2357	1060	22		0.689786362	0.990752417
> 0.813319531
> Linear	8	2099	236	280		0.898929336	0.882303489
> 0.890538821
> Linear	10	1886	173	493		0.91597863	0.792770071
> 0.849932402
> Legacy	5	2235	1260	144		0.639484979	0.939470366
> 0.760980592
> Legacy	8	1998	414	381		0.828358209	0.839848676
> 0.83406387
> Legacy	10	1743	193	636		0.900309917	0.732660782
> 0.80787949
> 								
> 15	HDR10Plus_PB_EAC3JOC
> https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-viDc3zMj8ZHruHcWKyA
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	10	15	0	0		1	1	1
> Linear	5	13	1	2		0.928571429	0.866666667
> 0.896551724
> Legacy	5	12	2	3		0.857142857	0.8
> 0.827586207
> 								
> 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47EhR2o
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	10	21	0	0		1	1	1
> Linear	4	20	0	1		1	0.952380952
> 0.975609756
> Legacy	4	19	0	2		1	0.904761905	0.95
> 								
> 94	Bieber Grammys
> https://mega.nz/#!c9dhAaKA!MG5Yi-MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> 
> Method	Threshold	TP	FP	FN		Precision
> Recall	F
> Cubic	15	91	23	3		0.798245614	0.968085106
> 0.875
> Cubic	18	85	9	9		0.904255319	0.904255319
> 0.904255319
> Linear	7	79	49	15		0.6171875	0.840425532
> 0.711711712
> Linear	8	74	28	20		0.725490196	0.787234043
> 0.755102041
> Legacy	7	74	40	20		0.649122807	0.787234043
> 0.711538462
> Legacy	8	71	26	23		0.731958763	0.755319149
> 0.743455497
> 
> 
> Improve scene detection accuracy by comparing frame with both previous and
> next frame (creates one frame delay).
> Add new mode parameter and new method to compute the frame difference using
> cubic square to increase the weight of small changes and new mean formula.
> This improves accuracy significantly. Slightly improve performance by not
> using frame clone.
> Add legacy mode for backward compatibility.
> 
> Signed-off-by: raduct <radu.taraibuta@gmail.com>
> ---
>  doc/filters.texi            |  16 ++++
>  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
>  libavfilter/scene_sad.h     |   6 ++
>  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
>  tests/fate/filter-video.mak |   3 +
>  5 files changed, 284 insertions(+), 48 deletions(-)
> 
> diff --git a/doc/filters.texi b/doc/filters.texi
> index bfa8ccec8b..53814e003b 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
>  @item sc_pass, s
>  Set the flag to pass scene change frames to the next filter. Default value
> is @code{0}

The patch is corrupted by linebreaks:

Applying: area changed: scdet filter
error: corrupt patch at line 16
Patch failed at 0001 area changed: scdet filter

please check the linebreak settings or attach the patch or use git send-email

thx

[...]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> Michael Niedermayer
> Sent: vineri, 31 mai 2024 00:32
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> 
> On Mon, May 13, 2024 at 06:52:19PM +0300, radu.taraibuta@gmail.com
> wrote:
> > Previous observations:
> >
> >  - Inconsistent code style with other filters. (Mostly using
> > AVFilterLink* link instead of AVFilterLink *link).
> > I hope it's fine now.
> >
> >  - Unrelated changes, please split trivial unrelated changes into
> > separate patches.
> > Removed trivial changes from this patch.
> >
> >  - Can't tables be generated at .init/.config_props time? No point in
> > storing them into binary.
> > Done.
> >
> >  - Adding extra delay is not backward compatible change, it should be
> > implemented properly by adding option for users to select mode: next &
> > prev frame or just next or prev frame.
> > Added legacy option to the mode parameter.
> >
> >  - Could split frame clone change into earlier separate patch.
> > Cannot be done. It's either frame clone or 1 frame delay.
> >
> >  - Where are results of improvements with accuracy so it can be
confirmed?
> > Here are my test results with manual labeling of scene changes:
> > 2379	Full length movie
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	7	2357	423	22		0.847841727
0.990752417
> > 0.913742973
> > Cubic	10	2297	200	82		0.919903885
0.965531736
> > 0.94216571
> > Cubic	12	2217	146	162		0.938214135
0.931904161
> > 0.935048503
> > Cubic	15	2049	101	330		0.953023256
0.861286255
> > 0.904835505
> > Linear	2.8	2357	1060	22		0.689786362
0.990752417
> > 0.813319531
> > Linear	8	2099	236	280		0.898929336
0.882303489
> > 0.890538821
> > Linear	10	1886	173	493		0.91597863
0.792770071
> > 0.849932402
> > Legacy	5	2235	1260	144		0.639484979
> 	0.939470366
> > 0.760980592
> > Legacy	8	1998	414	381		0.828358209
> 	0.839848676
> > 0.83406387
> > Legacy	10	1743	193	636		0.900309917
> 	0.732660782
> > 0.80787949
> >
> > 15	HDR10Plus_PB_EAC3JOC
> > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> viDc3zMj8ZHruHcW
> > KyA
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	10	15	0	0		1	1	1
> > Linear	5	13	1	2		0.928571429
0.866666667
> > 0.896551724
> > Legacy	5	12	2	3		0.857142857	0.8
> > 0.827586207
> >
> > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> >
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47E
> h
> > R2o
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	10	21	0	0		1	1	1
> > Linear	4	20	0	1		1	0.952380952
> > 0.975609756
> > Legacy	4	19	0	2		1	0.904761905
> 	0.95
> >
> > 94	Bieber Grammys
> > https://mega.nz/#!c9dhAaKA!MG5Yi-
> MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> >
> > Method	Threshold	TP	FP	FN		Precision
> > Recall	F
> > Cubic	15	91	23	3		0.798245614
0.968085106
> > 0.875
> > Cubic	18	85	9	9		0.904255319
0.904255319
> > 0.904255319
> > Linear	7	79	49	15		0.6171875
0.840425532
> > 0.711711712
> > Linear	8	74	28	20		0.725490196
0.787234043
> > 0.755102041
> > Legacy	7	74	40	20		0.649122807
> 	0.787234043
> > 0.711538462
> > Legacy	8	71	26	23		0.731958763
> 	0.755319149
> > 0.743455497
> >
> >
> > Improve scene detection accuracy by comparing frame with both previous
> > and next frame (creates one frame delay).
> > Add new mode parameter and new method to compute the frame difference
> > using cubic square to increase the weight of small changes and new mean
> formula.
> > This improves accuracy significantly. Slightly improve performance by
> > not using frame clone.
> > Add legacy mode for backward compatibility.
> >
> > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > ---
> >  doc/filters.texi            |  16 ++++
> >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> >  libavfilter/scene_sad.h     |   6 ++
> >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> >  tests/fate/filter-video.mak |   3 +
> >  5 files changed, 284 insertions(+), 48 deletions(-)
> >
> > diff --git a/doc/filters.texi b/doc/filters.texi index
> > bfa8ccec8b..53814e003b 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> >  @item sc_pass, s
> >  Set the flag to pass scene change frames to the next filter. Default
> > value is @code{0}
> 
> The patch is corrupted by linebreaks:
> 
> Applying: area changed: scdet filter
> error: corrupt patch at line 16
> Patch failed at 0001 area changed: scdet filter
> 
> please check the linebreak settings or attach the patch or use git
send-email
> 
> thx
> 
> [...]
> --
> Michael     GnuPG fingerprint:
> 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> Homeopathy is like voting while filling the ballot out with transparent
ink.
> Sometimes the outcome one wanted occurs. Rarely its worse than filling out
a
> ballot properly.

Please find attached the patch.

On Sun, Jun 02, 2024 at 11:17:29PM +0300, radu.taraibuta@gmail.com wrote:
> 
> 
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > Michael Niedermayer
> > Sent: vineri, 31 mai 2024 00:32
> > To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > 
> > On Mon, May 13, 2024 at 06:52:19PM +0300, radu.taraibuta@gmail.com
> > wrote:
> > > Previous observations:
> > >
> > >  - Inconsistent code style with other filters. (Mostly using
> > > AVFilterLink* link instead of AVFilterLink *link).
> > > I hope it's fine now.
> > >
> > >  - Unrelated changes, please split trivial unrelated changes into
> > > separate patches.
> > > Removed trivial changes from this patch.
> > >
> > >  - Can't tables be generated at .init/.config_props time? No point in
> > > storing them into binary.
> > > Done.
> > >
> > >  - Adding extra delay is not backward compatible change, it should be
> > > implemented properly by adding option for users to select mode: next &
> > > prev frame or just next or prev frame.
> > > Added legacy option to the mode parameter.
> > >
> > >  - Could split frame clone change into earlier separate patch.
> > > Cannot be done. It's either frame clone or 1 frame delay.
> > >
> > >  - Where are results of improvements with accuracy so it can be
> confirmed?
> > > Here are my test results with manual labeling of scene changes:
> > > 2379	Full length movie
> > >
> > > Method	Threshold	TP	FP	FN		Precision
> > > Recall	F
> > > Cubic	7	2357	423	22		0.847841727
> 0.990752417
> > > 0.913742973
> > > Cubic	10	2297	200	82		0.919903885
> 0.965531736
> > > 0.94216571
> > > Cubic	12	2217	146	162		0.938214135
> 0.931904161
> > > 0.935048503
> > > Cubic	15	2049	101	330		0.953023256
> 0.861286255
> > > 0.904835505
> > > Linear	2.8	2357	1060	22		0.689786362
> 0.990752417
> > > 0.813319531
> > > Linear	8	2099	236	280		0.898929336
> 0.882303489
> > > 0.890538821
> > > Linear	10	1886	173	493		0.91597863
> 0.792770071
> > > 0.849932402
> > > Legacy	5	2235	1260	144		0.639484979
> > 	0.939470366
> > > 0.760980592
> > > Legacy	8	1998	414	381		0.828358209
> > 	0.839848676
> > > 0.83406387
> > > Legacy	10	1743	193	636		0.900309917
> > 	0.732660782
> > > 0.80787949
> > >
> > > 15	HDR10Plus_PB_EAC3JOC
> > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > viDc3zMj8ZHruHcW
> > > KyA
> > >
> > > Method	Threshold	TP	FP	FN		Precision
> > > Recall	F
> > > Cubic	10	15	0	0		1	1	1
> > > Linear	5	13	1	2		0.928571429
> 0.866666667
> > > 0.896551724
> > > Legacy	5	12	2	3		0.857142857	0.8
> > > 0.827586207
> > >
> > > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > >
> > https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47E
> > h
> > > R2o
> > >
> > > Method	Threshold	TP	FP	FN		Precision
> > > Recall	F
> > > Cubic	10	21	0	0		1	1	1
> > > Linear	4	20	0	1		1	0.952380952
> > > 0.975609756
> > > Legacy	4	19	0	2		1	0.904761905
> > 	0.95
> > >
> > > 94	Bieber Grammys
> > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > >
> > > Method	Threshold	TP	FP	FN		Precision
> > > Recall	F
> > > Cubic	15	91	23	3		0.798245614
> 0.968085106
> > > 0.875
> > > Cubic	18	85	9	9		0.904255319
> 0.904255319
> > > 0.904255319
> > > Linear	7	79	49	15		0.6171875
> 0.840425532
> > > 0.711711712
> > > Linear	8	74	28	20		0.725490196
> 0.787234043
> > > 0.755102041
> > > Legacy	7	74	40	20		0.649122807
> > 	0.787234043
> > > 0.711538462
> > > Legacy	8	71	26	23		0.731958763
> > 	0.755319149
> > > 0.743455497
> > >
> > >
> > > Improve scene detection accuracy by comparing frame with both previous
> > > and next frame (creates one frame delay).
> > > Add new mode parameter and new method to compute the frame difference
> > > using cubic square to increase the weight of small changes and new mean
> > formula.
> > > This improves accuracy significantly. Slightly improve performance by
> > > not using frame clone.
> > > Add legacy mode for backward compatibility.
> > >
> > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > ---
> > >  doc/filters.texi            |  16 ++++
> > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > >  libavfilter/scene_sad.h     |   6 ++
> > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > >  tests/fate/filter-video.mak |   3 +
> > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > >
> > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > bfa8ccec8b..53814e003b 100644
> > > --- a/doc/filters.texi
> > > +++ b/doc/filters.texi
> > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > >  @item sc_pass, s
> > >  Set the flag to pass scene change frames to the next filter. Default
> > > value is @code{0}
> > 
> > The patch is corrupted by linebreaks:
> > 
> > Applying: area changed: scdet filter
> > error: corrupt patch at line 16
> > Patch failed at 0001 area changed: scdet filter
> > 
> > please check the linebreak settings or attach the patch or use git
> send-email
> > 
> > thx
> > 
> > [...]
> > --
> > Michael     GnuPG fingerprint:
> > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > 
> > Homeopathy is like voting while filling the ballot out with transparent
> ink.
> > Sometimes the outcome one wanted occurs. Rarely its worse than filling out
> a
> > ballot properly.
> 
> Please find attached the patch.
> 

>  doc/filters.texi            |   16 ++++
>  libavfilter/scene_sad.c     |  151 ++++++++++++++++++++++++++++++++++++++++++
>  libavfilter/scene_sad.h     |    6 +
>  libavfilter/vf_scdet.c      |  156 ++++++++++++++++++++++++++++++--------------
>  tests/fate/filter-video.mak |    3 
>  5 files changed, 284 insertions(+), 48 deletions(-)
> 8f29f2e1c202ab283a9ca0f5d9599de6ab534d7a  0001-area-changed-scdet-filter.patch
> From 6d55c65d92376b0ab6e3bb2439af30fbcc430d0b Mon Sep 17 00:00:00 2001
> From: raduct <radu.taraibuta@gmail.com>
> Date: Wed, 8 May 2024 08:24:46 +0300
> Subject: [PATCH] area changed: scdet filter
> 
> Improve scene detection accuracy by comparing frame with both previous and next frame (creates one frame delay).
> Add new mode parameter and new method to compute the frame difference using cubic square to increase the weight of small changes and new mean formula. This improves accuracy significantly. Slightly improve performance by not using frame clone.
> Add legacy mode for backward compatibility.
> 
> Signed-off-by: raduct <radu.taraibuta@gmail.com>
> ---
>  doc/filters.texi            |  16 ++++
>  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
>  libavfilter/scene_sad.h     |   6 ++
>  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
>  tests/fate/filter-video.mak |   3 +
>  5 files changed, 284 insertions(+), 48 deletions(-)

fails to build

libavfilter/scene_sad.c: In function ‘ff_init_cbrt’:
libavfilter/scene_sad.c:86:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   86 |     uint8_t *table = cbrt_table[bitdepth];
      |     ^~~~~~~
libavfilter/scene_sad.c:92:13: error: implicit declaration of function ‘av_malloc’; did you mean ‘malloc’? [-Werror=implicit-function-declaration]
   92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
      |             ^~~~~~~~~
      |             malloc
libavfilter/scene_sad.c:92:11: warning: assignment to ‘uint8_t *’ {aka ‘unsigned char *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
   92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
      |           ^
libavfilter/scene_sad.c:98:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
   98 |     int size = 1 << bitdepth;
      |     ^~~
libavfilter/scene_sad.c: In function ‘ff_uninit_cbrt’:
libavfilter/scene_sad.c:120:9: error: implicit declaration of function ‘av_free’; did you mean ‘free’? [-Werror=implicit-function-declaration]
  120 |         av_free(cbrt_table[bitdepth]);
      |         ^~~~~~~
      |         free
libavfilter/scene_sad.c: At top level:
libavfilter/scene_sad.c:126:6: error: no previous prototype for ‘ff_scene_scrd_c’ [-Werror=missing-prototypes]
  126 | void ff_scene_scrd_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~
libavfilter/scene_sad.c: In function ‘ff_scene_scrd_c’:
libavfilter/scene_sad.c:148:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  148 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
      |     ^~~~~~
libavfilter/scene_sad.c: At top level:
libavfilter/scene_sad.c:152:6: error: no previous prototype for ‘ff_scene_scrd2B_c’ [-Werror=missing-prototypes]
  152 | void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
      |      ^~~~~~~~~~~~~~~~~
libavfilter/scene_sad.c: In function ‘ff_scene_scrd2B_c’:
libavfilter/scene_sad.c:179:5: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
  179 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
      |     ^~~~~~
libavfilter/scene_sad.c: At top level:
libavfilter/scene_sad.c:183:6: error: no previous prototype for ‘ff_scene_scrd9_c’ [-Werror=missing-prototypes]
  183 | void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~~
libavfilter/scene_sad.c:188:6: error: no previous prototype for ‘ff_scene_scrd10_c’ [-Werror=missing-prototypes]
  188 | void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~~~
libavfilter/scene_sad.c:193:6: error: no previous prototype for ‘ff_scene_scrd12_c’ [-Werror=missing-prototypes]
  193 | void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~~~
libavfilter/scene_sad.c:198:6: error: no previous prototype for ‘ff_scene_scrd14_c’ [-Werror=missing-prototypes]
  198 | void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~~~
libavfilter/scene_sad.c:203:6: error: no previous prototype for ‘ff_scene_scrd16_c’ [-Werror=missing-prototypes]
  203 | void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
      |      ^~~~~~~~~~~~~~~~~
cc1: some warnings being treated as errors
make: *** [ffbuild/common.mak:81: libavfilter/scene_sad.o] Error 1
make: *** Waiting for unfinished jobs....


[...]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> Michael Niedermayer
> Sent: marți, 4 iunie 2024 01:42
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> 
> On Sun, Jun 02, 2024 at 11:17:29PM +0300, radu.taraibuta@gmail.com wrote:
> >
> >
> > > -----Original Message-----
> > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > > Michael Niedermayer
> > > Sent: vineri, 31 mai 2024 00:32
> > > To: FFmpeg development discussions and patches
> > > <ffmpeg-devel@ffmpeg.org>
> > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > >
> > > On Mon, May 13, 2024 at 06:52:19PM +0300, radu.taraibuta@gmail.com
> > > wrote:
> > > > Previous observations:
> > > >
> > > >  - Inconsistent code style with other filters. (Mostly using
> > > > AVFilterLink* link instead of AVFilterLink *link).
> > > > I hope it's fine now.
> > > >
> > > >  - Unrelated changes, please split trivial unrelated changes into
> > > > separate patches.
> > > > Removed trivial changes from this patch.
> > > >
> > > >  - Can't tables be generated at .init/.config_props time? No point
> > > > in storing them into binary.
> > > > Done.
> > > >
> > > >  - Adding extra delay is not backward compatible change, it should
> > > > be implemented properly by adding option for users to select mode:
> > > > next & prev frame or just next or prev frame.
> > > > Added legacy option to the mode parameter.
> > > >
> > > >  - Could split frame clone change into earlier separate patch.
> > > > Cannot be done. It's either frame clone or 1 frame delay.
> > > >
> > > >  - Where are results of improvements with accuracy so it can be
> > confirmed?
> > > > Here are my test results with manual labeling of scene changes:
> > > > 2379	Full length movie
> > > >
> > > > Method	Threshold	TP	FP	FN		Precision
> > > > Recall	F
> > > > Cubic	7	2357	423	22		0.847841727
> > 0.990752417
> > > > 0.913742973
> > > > Cubic	10	2297	200	82		0.919903885
> > 0.965531736
> > > > 0.94216571
> > > > Cubic	12	2217	146	162		0.938214135
> > 0.931904161
> > > > 0.935048503
> > > > Cubic	15	2049	101	330		0.953023256
> > 0.861286255
> > > > 0.904835505
> > > > Linear	2.8	2357	1060	22		0.689786362
> > 0.990752417
> > > > 0.813319531
> > > > Linear	8	2099	236	280		0.898929336
> > 0.882303489
> > > > 0.890538821
> > > > Linear	10	1886	173	493		0.91597863
> > 0.792770071
> > > > 0.849932402
> > > > Legacy	5	2235	1260	144		0.639484979
> > > 	0.939470366
> > > > 0.760980592
> > > > Legacy	8	1998	414	381		0.828358209
> > > 	0.839848676
> > > > 0.83406387
> > > > Legacy	10	1743	193	636		0.900309917
> > > 	0.732660782
> > > > 0.80787949
> > > >
> > > > 15	HDR10Plus_PB_EAC3JOC
> > > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > > viDc3zMj8ZHruHcW
> > > > KyA
> > > >
> > > > Method	Threshold	TP	FP	FN		Precision
> > > > Recall	F
> > > > Cubic	10	15	0	0		1	1	1
> > > > Linear	5	13	1	2		0.928571429
> > 0.866666667
> > > > 0.896551724
> > > > Legacy	5	12	2	3		0.857142857	0.8
> > > > 0.827586207
> > > >
> > > > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > > >
> > >
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47
> > > E
> > > h
> > > > R2o
> > > >
> > > > Method	Threshold	TP	FP	FN		Precision
> > > > Recall	F
> > > > Cubic	10	21	0	0		1	1	1
> > > > Linear	4	20	0	1		1	0.952380952
> > > > 0.975609756
> > > > Legacy	4	19	0	2		1	0.904761905
> > > 	0.95
> > > >
> > > > 94	Bieber Grammys
> > > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > > >
> > > > Method	Threshold	TP	FP	FN		Precision
> > > > Recall	F
> > > > Cubic	15	91	23	3		0.798245614
> > 0.968085106
> > > > 0.875
> > > > Cubic	18	85	9	9		0.904255319
> > 0.904255319
> > > > 0.904255319
> > > > Linear	7	79	49	15		0.6171875
> > 0.840425532
> > > > 0.711711712
> > > > Linear	8	74	28	20		0.725490196
> > 0.787234043
> > > > 0.755102041
> > > > Legacy	7	74	40	20		0.649122807
> > > 	0.787234043
> > > > 0.711538462
> > > > Legacy	8	71	26	23		0.731958763
> > > 	0.755319149
> > > > 0.743455497
> > > >
> > > >
> > > > Improve scene detection accuracy by comparing frame with both
> > > > previous and next frame (creates one frame delay).
> > > > Add new mode parameter and new method to compute the frame
> > > > difference using cubic square to increase the weight of small
> > > > changes and new mean
> > > formula.
> > > > This improves accuracy significantly. Slightly improve performance
> > > > by not using frame clone.
> > > > Add legacy mode for backward compatibility.
> > > >
> > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > ---
> > > >  doc/filters.texi            |  16 ++++
> > > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > > >  libavfilter/scene_sad.h     |   6 ++
> > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > >  tests/fate/filter-video.mak |   3 +
> > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > >
> > > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > > bfa8ccec8b..53814e003b 100644
> > > > --- a/doc/filters.texi
> > > > +++ b/doc/filters.texi
> > > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > > >  @item sc_pass, s
> > > >  Set the flag to pass scene change frames to the next filter.
> > > > Default value is @code{0}
> > >
> > > The patch is corrupted by linebreaks:
> > >
> > > Applying: area changed: scdet filter
> > > error: corrupt patch at line 16
> > > Patch failed at 0001 area changed: scdet filter
> > >
> > > please check the linebreak settings or attach the patch or use git
> > send-email
> > >
> > > thx
> > >
> > > [...]
> > > --
> > > Michael     GnuPG fingerprint:
> > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > >
> > > Homeopathy is like voting while filling the ballot out with
> > > transparent
> > ink.
> > > Sometimes the outcome one wanted occurs. Rarely its worse than
> > > filling out
> > a
> > > ballot properly.
> >
> > Please find attached the patch.
> >
> 
> >  doc/filters.texi            |   16 ++++
> >  libavfilter/scene_sad.c     |  151
> ++++++++++++++++++++++++++++++++++++++++++
> >  libavfilter/scene_sad.h     |    6 +
> >  libavfilter/vf_scdet.c      |  156 ++++++++++++++++++++++++++++++--------------
> >  tests/fate/filter-video.mak |    3
> >  5 files changed, 284 insertions(+), 48 deletions(-)
> > 8f29f2e1c202ab283a9ca0f5d9599de6ab534d7a
> > 0001-area-changed-scdet-filter.patch
> > From 6d55c65d92376b0ab6e3bb2439af30fbcc430d0b Mon Sep 17 00:00:00
> 2001
> > From: raduct <radu.taraibuta@gmail.com>
> > Date: Wed, 8 May 2024 08:24:46 +0300
> > Subject: [PATCH] area changed: scdet filter
> >
> > Improve scene detection accuracy by comparing frame with both previous
> and next frame (creates one frame delay).
> > Add new mode parameter and new method to compute the frame difference
> using cubic square to increase the weight of small changes and new mean
> formula. This improves accuracy significantly. Slightly improve performance by
> not using frame clone.
> > Add legacy mode for backward compatibility.
> >
> > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > ---
> >  doc/filters.texi            |  16 ++++
> >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> >  libavfilter/scene_sad.h     |   6 ++
> >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> >  tests/fate/filter-video.mak |   3 +
> >  5 files changed, 284 insertions(+), 48 deletions(-)
> 
> fails to build
> 
> libavfilter/scene_sad.c: In function ‘ff_init_cbrt’:
> libavfilter/scene_sad.c:86:5: warning: ISO C90 forbids mixed declarations and
> code [-Wdeclaration-after-statement]
>    86 |     uint8_t *table = cbrt_table[bitdepth];
>       |     ^~~~~~~
> libavfilter/scene_sad.c:92:13: error: implicit declaration of function ‘av_malloc’;
> did you mean ‘malloc’? [-Werror=implicit-function-declaration]
>    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
>       |             ^~~~~~~~~
>       |             malloc
> libavfilter/scene_sad.c:92:11: warning: assignment to ‘uint8_t *’ {aka ‘unsigned
> char *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
>    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
>       |           ^
> libavfilter/scene_sad.c:98:5: warning: ISO C90 forbids mixed declarations and
> code [-Wdeclaration-after-statement]
>    98 |     int size = 1 << bitdepth;
>       |     ^~~
> libavfilter/scene_sad.c: In function ‘ff_uninit_cbrt’:
> libavfilter/scene_sad.c:120:9: error: implicit declaration of function ‘av_free’;
> did you mean ‘free’? [-Werror=implicit-function-declaration]
>   120 |         av_free(cbrt_table[bitdepth]);
>       |         ^~~~~~~
>       |         free
> libavfilter/scene_sad.c: At top level:
> libavfilter/scene_sad.c:126:6: error: no previous prototype for
> ‘ff_scene_scrd_c’ [-Werror=missing-prototypes]
>   126 | void ff_scene_scrd_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~
> libavfilter/scene_sad.c: In function ‘ff_scene_scrd_c’:
> libavfilter/scene_sad.c:148:5: warning: ISO C90 forbids mixed declarations and
> code [-Wdeclaration-after-statement]
>   148 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
>       |     ^~~~~~
> libavfilter/scene_sad.c: At top level:
> libavfilter/scene_sad.c:152:6: error: no previous prototype for
> ‘ff_scene_scrd2B_c’ [-Werror=missing-prototypes]
>   152 | void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
>       |      ^~~~~~~~~~~~~~~~~
> libavfilter/scene_sad.c: In function ‘ff_scene_scrd2B_c’:
> libavfilter/scene_sad.c:179:5: warning: ISO C90 forbids mixed declarations and
> code [-Wdeclaration-after-statement]
>   179 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
>       |     ^~~~~~
> libavfilter/scene_sad.c: At top level:
> libavfilter/scene_sad.c:183:6: error: no previous prototype for
> ‘ff_scene_scrd9_c’ [-Werror=missing-prototypes]
>   183 | void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~~
> libavfilter/scene_sad.c:188:6: error: no previous prototype for
> ‘ff_scene_scrd10_c’ [-Werror=missing-prototypes]
>   188 | void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~~~
> libavfilter/scene_sad.c:193:6: error: no previous prototype for
> ‘ff_scene_scrd12_c’ [-Werror=missing-prototypes]
>   193 | void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~~~
> libavfilter/scene_sad.c:198:6: error: no previous prototype for
> ‘ff_scene_scrd14_c’ [-Werror=missing-prototypes]
>   198 | void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~~~
> libavfilter/scene_sad.c:203:6: error: no previous prototype for
> ‘ff_scene_scrd16_c’ [-Werror=missing-prototypes]
>   203 | void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
>       |      ^~~~~~~~~~~~~~~~~
> cc1: some warnings being treated as errors
> make: *** [ffbuild/common.mak:81: libavfilter/scene_sad.o] Error 1
> make: *** Waiting for unfinished jobs....
> 
> 
> [...]
> 
> --
> Michael     GnuPG fingerprint:
> 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker.
> User questions about the command line tools should be sent to the ffmpeg-
> user ML.
> And questions about how to use libav* should be sent to the libav-user ML.

Please find attached a new version of the patch.
I'm building using msvc and I don't get these warnings.

On Tue, Jun 11, 2024 at 10:07:32AM +0300, radu.taraibuta@gmail.com wrote:
> 
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > Michael Niedermayer
> > Sent: marți, 4 iunie 2024 01:42
> > To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > 
> > On Sun, Jun 02, 2024 at 11:17:29PM +0300, radu.taraibuta@gmail.com wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > > > Michael Niedermayer
> > > > Sent: vineri, 31 mai 2024 00:32
> > > > To: FFmpeg development discussions and patches
> > > > <ffmpeg-devel@ffmpeg.org>
> > > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > > >
> > > > On Mon, May 13, 2024 at 06:52:19PM +0300, radu.taraibuta@gmail.com
> > > > wrote:
> > > > > Previous observations:
> > > > >
> > > > >  - Inconsistent code style with other filters. (Mostly using
> > > > > AVFilterLink* link instead of AVFilterLink *link).
> > > > > I hope it's fine now.
> > > > >
> > > > >  - Unrelated changes, please split trivial unrelated changes into
> > > > > separate patches.
> > > > > Removed trivial changes from this patch.
> > > > >
> > > > >  - Can't tables be generated at .init/.config_props time? No point
> > > > > in storing them into binary.
> > > > > Done.
> > > > >
> > > > >  - Adding extra delay is not backward compatible change, it should
> > > > > be implemented properly by adding option for users to select mode:
> > > > > next & prev frame or just next or prev frame.
> > > > > Added legacy option to the mode parameter.
> > > > >
> > > > >  - Could split frame clone change into earlier separate patch.
> > > > > Cannot be done. It's either frame clone or 1 frame delay.
> > > > >
> > > > >  - Where are results of improvements with accuracy so it can be
> > > confirmed?
> > > > > Here are my test results with manual labeling of scene changes:
> > > > > 2379	Full length movie
> > > > >
> > > > > Method	Threshold	TP	FP	FN		Precision
> > > > > Recall	F
> > > > > Cubic	7	2357	423	22		0.847841727
> > > 0.990752417
> > > > > 0.913742973
> > > > > Cubic	10	2297	200	82		0.919903885
> > > 0.965531736
> > > > > 0.94216571
> > > > > Cubic	12	2217	146	162		0.938214135
> > > 0.931904161
> > > > > 0.935048503
> > > > > Cubic	15	2049	101	330		0.953023256
> > > 0.861286255
> > > > > 0.904835505
> > > > > Linear	2.8	2357	1060	22		0.689786362
> > > 0.990752417
> > > > > 0.813319531
> > > > > Linear	8	2099	236	280		0.898929336
> > > 0.882303489
> > > > > 0.890538821
> > > > > Linear	10	1886	173	493		0.91597863
> > > 0.792770071
> > > > > 0.849932402
> > > > > Legacy	5	2235	1260	144		0.639484979
> > > > 	0.939470366
> > > > > 0.760980592
> > > > > Legacy	8	1998	414	381		0.828358209
> > > > 	0.839848676
> > > > > 0.83406387
> > > > > Legacy	10	1743	193	636		0.900309917
> > > > 	0.732660782
> > > > > 0.80787949
> > > > >
> > > > > 15	HDR10Plus_PB_EAC3JOC
> > > > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > > > viDc3zMj8ZHruHcW
> > > > > KyA
> > > > >
> > > > > Method	Threshold	TP	FP	FN		Precision
> > > > > Recall	F
> > > > > Cubic	10	15	0	0		1	1	1
> > > > > Linear	5	13	1	2		0.928571429
> > > 0.866666667
> > > > > 0.896551724
> > > > > Legacy	5	12	2	3		0.857142857	0.8
> > > > > 0.827586207
> > > > >
> > > > > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > > > >
> > > >
> > https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47
> > > > E
> > > > h
> > > > > R2o
> > > > >
> > > > > Method	Threshold	TP	FP	FN		Precision
> > > > > Recall	F
> > > > > Cubic	10	21	0	0		1	1	1
> > > > > Linear	4	20	0	1		1	0.952380952
> > > > > 0.975609756
> > > > > Legacy	4	19	0	2		1	0.904761905
> > > > 	0.95
> > > > >
> > > > > 94	Bieber Grammys
> > > > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > > > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > > > >
> > > > > Method	Threshold	TP	FP	FN		Precision
> > > > > Recall	F
> > > > > Cubic	15	91	23	3		0.798245614
> > > 0.968085106
> > > > > 0.875
> > > > > Cubic	18	85	9	9		0.904255319
> > > 0.904255319
> > > > > 0.904255319
> > > > > Linear	7	79	49	15		0.6171875
> > > 0.840425532
> > > > > 0.711711712
> > > > > Linear	8	74	28	20		0.725490196
> > > 0.787234043
> > > > > 0.755102041
> > > > > Legacy	7	74	40	20		0.649122807
> > > > 	0.787234043
> > > > > 0.711538462
> > > > > Legacy	8	71	26	23		0.731958763
> > > > 	0.755319149
> > > > > 0.743455497
> > > > >
> > > > >
> > > > > Improve scene detection accuracy by comparing frame with both
> > > > > previous and next frame (creates one frame delay).
> > > > > Add new mode parameter and new method to compute the frame
> > > > > difference using cubic square to increase the weight of small
> > > > > changes and new mean
> > > > formula.
> > > > > This improves accuracy significantly. Slightly improve performance
> > > > > by not using frame clone.
> > > > > Add legacy mode for backward compatibility.
> > > > >
> > > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > > ---
> > > > >  doc/filters.texi            |  16 ++++
> > > > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > > > >  libavfilter/scene_sad.h     |   6 ++
> > > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > > >  tests/fate/filter-video.mak |   3 +
> > > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > > >
> > > > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > > > bfa8ccec8b..53814e003b 100644
> > > > > --- a/doc/filters.texi
> > > > > +++ b/doc/filters.texi
> > > > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > > > >  @item sc_pass, s
> > > > >  Set the flag to pass scene change frames to the next filter.
> > > > > Default value is @code{0}
> > > >
> > > > The patch is corrupted by linebreaks:
> > > >
> > > > Applying: area changed: scdet filter
> > > > error: corrupt patch at line 16
> > > > Patch failed at 0001 area changed: scdet filter
> > > >
> > > > please check the linebreak settings or attach the patch or use git
> > > send-email
> > > >
> > > > thx
> > > >
> > > > [...]
> > > > --
> > > > Michael     GnuPG fingerprint:
> > > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > > >
> > > > Homeopathy is like voting while filling the ballot out with
> > > > transparent
> > > ink.
> > > > Sometimes the outcome one wanted occurs. Rarely its worse than
> > > > filling out
> > > a
> > > > ballot properly.
> > >
> > > Please find attached the patch.
> > >
> > 
> > >  doc/filters.texi            |   16 ++++
> > >  libavfilter/scene_sad.c     |  151
> > ++++++++++++++++++++++++++++++++++++++++++
> > >  libavfilter/scene_sad.h     |    6 +
> > >  libavfilter/vf_scdet.c      |  156 ++++++++++++++++++++++++++++++--------------
> > >  tests/fate/filter-video.mak |    3
> > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > 8f29f2e1c202ab283a9ca0f5d9599de6ab534d7a
> > > 0001-area-changed-scdet-filter.patch
> > > From 6d55c65d92376b0ab6e3bb2439af30fbcc430d0b Mon Sep 17 00:00:00
> > 2001
> > > From: raduct <radu.taraibuta@gmail.com>
> > > Date: Wed, 8 May 2024 08:24:46 +0300
> > > Subject: [PATCH] area changed: scdet filter
> > >
> > > Improve scene detection accuracy by comparing frame with both previous
> > and next frame (creates one frame delay).
> > > Add new mode parameter and new method to compute the frame difference
> > using cubic square to increase the weight of small changes and new mean
> > formula. This improves accuracy significantly. Slightly improve performance by
> > not using frame clone.
> > > Add legacy mode for backward compatibility.
> > >
> > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > ---
> > >  doc/filters.texi            |  16 ++++
> > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > >  libavfilter/scene_sad.h     |   6 ++
> > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > >  tests/fate/filter-video.mak |   3 +
> > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > 
> > fails to build
> > 
> > libavfilter/scene_sad.c: In function ‘ff_init_cbrt’:
> > libavfilter/scene_sad.c:86:5: warning: ISO C90 forbids mixed declarations and
> > code [-Wdeclaration-after-statement]
> >    86 |     uint8_t *table = cbrt_table[bitdepth];
> >       |     ^~~~~~~
> > libavfilter/scene_sad.c:92:13: error: implicit declaration of function ‘av_malloc’;
> > did you mean ‘malloc’? [-Werror=implicit-function-declaration]
> >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> >       |             ^~~~~~~~~
> >       |             malloc
> > libavfilter/scene_sad.c:92:11: warning: assignment to ‘uint8_t *’ {aka ‘unsigned
> > char *’} from ‘int’ makes pointer from integer without a cast [-Wint-conversion]
> >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> >       |           ^
> > libavfilter/scene_sad.c:98:5: warning: ISO C90 forbids mixed declarations and
> > code [-Wdeclaration-after-statement]
> >    98 |     int size = 1 << bitdepth;
> >       |     ^~~
> > libavfilter/scene_sad.c: In function ‘ff_uninit_cbrt’:
> > libavfilter/scene_sad.c:120:9: error: implicit declaration of function ‘av_free’;
> > did you mean ‘free’? [-Werror=implicit-function-declaration]
> >   120 |         av_free(cbrt_table[bitdepth]);
> >       |         ^~~~~~~
> >       |         free
> > libavfilter/scene_sad.c: At top level:
> > libavfilter/scene_sad.c:126:6: error: no previous prototype for
> > ‘ff_scene_scrd_c’ [-Werror=missing-prototypes]
> >   126 | void ff_scene_scrd_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c: In function ‘ff_scene_scrd_c’:
> > libavfilter/scene_sad.c:148:5: warning: ISO C90 forbids mixed declarations and
> > code [-Wdeclaration-after-statement]
> >   148 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> >       |     ^~~~~~
> > libavfilter/scene_sad.c: At top level:
> > libavfilter/scene_sad.c:152:6: error: no previous prototype for
> > ‘ff_scene_scrd2B_c’ [-Werror=missing-prototypes]
> >   152 | void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
> >       |      ^~~~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c: In function ‘ff_scene_scrd2B_c’:
> > libavfilter/scene_sad.c:179:5: warning: ISO C90 forbids mixed declarations and
> > code [-Wdeclaration-after-statement]
> >   179 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> >       |     ^~~~~~
> > libavfilter/scene_sad.c: At top level:
> > libavfilter/scene_sad.c:183:6: error: no previous prototype for
> > ‘ff_scene_scrd9_c’ [-Werror=missing-prototypes]
> >   183 | void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c:188:6: error: no previous prototype for
> > ‘ff_scene_scrd10_c’ [-Werror=missing-prototypes]
> >   188 | void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c:193:6: error: no previous prototype for
> > ‘ff_scene_scrd12_c’ [-Werror=missing-prototypes]
> >   193 | void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c:198:6: error: no previous prototype for
> > ‘ff_scene_scrd14_c’ [-Werror=missing-prototypes]
> >   198 | void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~~~
> > libavfilter/scene_sad.c:203:6: error: no previous prototype for
> > ‘ff_scene_scrd16_c’ [-Werror=missing-prototypes]
> >   203 | void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> >       |      ^~~~~~~~~~~~~~~~~
> > cc1: some warnings being treated as errors
> > make: *** [ffbuild/common.mak:81: libavfilter/scene_sad.o] Error 1
> > make: *** Waiting for unfinished jobs....
> > 
> > 
> > [...]
> > 
> > --
> > Michael     GnuPG fingerprint:
> > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > 
> > Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker.
> > User questions about the command line tools should be sent to the ffmpeg-
> > user ML.
> > And questions about how to use libav* should be sent to the libav-user ML.
> 
> Please find attached a new version of the patch.
> I'm building using msvc and I don't get these warnings.

>  doc/filters.texi            |   16 ++++
>  libavfilter/scene_sad.c     |  157 ++++++++++++++++++++++++++++++++++++++++++
>  libavfilter/scene_sad.h     |   20 +++++
>  libavfilter/vf_scdet.c      |  161 ++++++++++++++++++++++++++++++--------------
>  tests/fate/filter-video.mak |    3 
>  5 files changed, 309 insertions(+), 48 deletions(-)
> 20737181fba9670a258cd6345edf36eae954bfa2  0001-area-changed-scdet-filter.patch
> From 0a6963360076213d30b70f8297eae3d44a638dab Mon Sep 17 00:00:00 2001
> From: raduct <radu.taraibuta@gmail.com>
> Date: Wed, 8 May 2024 08:24:46 +0300
> Subject: [PATCH] area changed: scdet filter

breaks fate (infinite loops here on ubuntu)
TEST    filter-metadata-scdet
^Cmake: *** [tests/Makefile:311: fate-filter-metadata-scdet] Interrupt

it seems to never exit avformat_find_stream_info()

thx

[...]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> Michael Niedermayer
> Sent: marți, 11 iunie 2024 20:18
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH v2] area changed: scdet filter
> 
> On Tue, Jun 11, 2024 at 10:07:32AM +0300, radu.taraibuta@gmail.com wrote:
> >
> > > -----Original Message-----
> > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > > Michael Niedermayer
> > > Sent: marți, 4 iunie 2024 01:42
> > > To: FFmpeg development discussions and patches
> > > <ffmpeg-devel@ffmpeg.org>
> > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > >
> > > On Sun, Jun 02, 2024 at 11:17:29PM +0300, radu.taraibuta@gmail.com
> wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf
> > > > > Of Michael Niedermayer
> > > > > Sent: vineri, 31 mai 2024 00:32
> > > > > To: FFmpeg development discussions and patches
> > > > > <ffmpeg-devel@ffmpeg.org>
> > > > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > > > >
> > > > > On Mon, May 13, 2024 at 06:52:19PM +0300,
> > > > > radu.taraibuta@gmail.com
> > > > > wrote:
> > > > > > Previous observations:
> > > > > >
> > > > > >  - Inconsistent code style with other filters. (Mostly using
> > > > > > AVFilterLink* link instead of AVFilterLink *link).
> > > > > > I hope it's fine now.
> > > > > >
> > > > > >  - Unrelated changes, please split trivial unrelated changes
> > > > > > into separate patches.
> > > > > > Removed trivial changes from this patch.
> > > > > >
> > > > > >  - Can't tables be generated at .init/.config_props time? No
> > > > > > point in storing them into binary.
> > > > > > Done.
> > > > > >
> > > > > >  - Adding extra delay is not backward compatible change, it
> > > > > > should be implemented properly by adding option for users to select
> mode:
> > > > > > next & prev frame or just next or prev frame.
> > > > > > Added legacy option to the mode parameter.
> > > > > >
> > > > > >  - Could split frame clone change into earlier separate patch.
> > > > > > Cannot be done. It's either frame clone or 1 frame delay.
> > > > > >
> > > > > >  - Where are results of improvements with accuracy so it can
> > > > > > be
> > > > confirmed?
> > > > > > Here are my test results with manual labeling of scene changes:
> > > > > > 2379	Full length movie
> > > > > >
> > > > > > Method	Threshold	TP	FP	FN
> 	Precision
> > > > > > Recall	F
> > > > > > Cubic	7	2357	423	22		0.847841727
> > > > 0.990752417
> > > > > > 0.913742973
> > > > > > Cubic	10	2297	200	82		0.919903885
> > > > 0.965531736
> > > > > > 0.94216571
> > > > > > Cubic	12	2217	146	162		0.938214135
> > > > 0.931904161
> > > > > > 0.935048503
> > > > > > Cubic	15	2049	101	330		0.953023256
> > > > 0.861286255
> > > > > > 0.904835505
> > > > > > Linear	2.8	2357	1060	22		0.689786362
> > > > 0.990752417
> > > > > > 0.813319531
> > > > > > Linear	8	2099	236	280		0.898929336
> > > > 0.882303489
> > > > > > 0.890538821
> > > > > > Linear	10	1886	173	493		0.91597863
> > > > 0.792770071
> > > > > > 0.849932402
> > > > > > Legacy	5	2235	1260	144		0.639484979
> > > > > 	0.939470366
> > > > > > 0.760980592
> > > > > > Legacy	8	1998	414	381		0.828358209
> > > > > 	0.839848676
> > > > > > 0.83406387
> > > > > > Legacy	10	1743	193	636		0.900309917
> > > > > 	0.732660782
> > > > > > 0.80787949
> > > > > >
> > > > > > 15	HDR10Plus_PB_EAC3JOC
> > > > > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > > > > viDc3zMj8ZHruHcW
> > > > > > KyA
> > > > > >
> > > > > > Method	Threshold	TP	FP	FN
> 	Precision
> > > > > > Recall	F
> > > > > > Cubic	10	15	0	0		1	1	1
> > > > > > Linear	5	13	1	2		0.928571429
> > > > 0.866666667
> > > > > > 0.896551724
> > > > > > Legacy	5	12	2	3		0.857142857	0.8
> > > > > > 0.827586207
> > > > > >
> > > > > > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > > > > >
> > > > >
> > >
> https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47
> > > > > E
> > > > > h
> > > > > > R2o
> > > > > >
> > > > > > Method	Threshold	TP	FP	FN
> 	Precision
> > > > > > Recall	F
> > > > > > Cubic	10	21	0	0		1	1	1
> > > > > > Linear	4	20	0	1		1	0.952380952
> > > > > > 0.975609756
> > > > > > Legacy	4	19	0	2		1	0.904761905
> > > > > 	0.95
> > > > > >
> > > > > > 94	Bieber Grammys
> > > > > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > > > > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > > > > >
> > > > > > Method	Threshold	TP	FP	FN
> 	Precision
> > > > > > Recall	F
> > > > > > Cubic	15	91	23	3		0.798245614
> > > > 0.968085106
> > > > > > 0.875
> > > > > > Cubic	18	85	9	9		0.904255319
> > > > 0.904255319
> > > > > > 0.904255319
> > > > > > Linear	7	79	49	15		0.6171875
> > > > 0.840425532
> > > > > > 0.711711712
> > > > > > Linear	8	74	28	20		0.725490196
> > > > 0.787234043
> > > > > > 0.755102041
> > > > > > Legacy	7	74	40	20		0.649122807
> > > > > 	0.787234043
> > > > > > 0.711538462
> > > > > > Legacy	8	71	26	23		0.731958763
> > > > > 	0.755319149
> > > > > > 0.743455497
> > > > > >
> > > > > >
> > > > > > Improve scene detection accuracy by comparing frame with both
> > > > > > previous and next frame (creates one frame delay).
> > > > > > Add new mode parameter and new method to compute the frame
> > > > > > difference using cubic square to increase the weight of small
> > > > > > changes and new mean
> > > > > formula.
> > > > > > This improves accuracy significantly. Slightly improve
> > > > > > performance by not using frame clone.
> > > > > > Add legacy mode for backward compatibility.
> > > > > >
> > > > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > > > ---
> > > > > >  doc/filters.texi            |  16 ++++
> > > > > >  libavfilter/scene_sad.c     | 151
> ++++++++++++++++++++++++++++++++++
> > > > > >  libavfilter/scene_sad.h     |   6 ++
> > > > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > > > >  tests/fate/filter-video.mak |   3 +
> > > > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > > > >
> > > > > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > > > > bfa8ccec8b..53814e003b 100644
> > > > > > --- a/doc/filters.texi
> > > > > > +++ b/doc/filters.texi
> > > > > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > > > > >  @item sc_pass, s
> > > > > >  Set the flag to pass scene change frames to the next filter.
> > > > > > Default value is @code{0}
> > > > >
> > > > > The patch is corrupted by linebreaks:
> > > > >
> > > > > Applying: area changed: scdet filter
> > > > > error: corrupt patch at line 16
> > > > > Patch failed at 0001 area changed: scdet filter
> > > > >
> > > > > please check the linebreak settings or attach the patch or use
> > > > > git
> > > > send-email
> > > > >
> > > > > thx
> > > > >
> > > > > [...]
> > > > > --
> > > > > Michael     GnuPG fingerprint:
> > > > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > > > >
> > > > > Homeopathy is like voting while filling the ballot out with
> > > > > transparent
> > > > ink.
> > > > > Sometimes the outcome one wanted occurs. Rarely its worse than
> > > > > filling out
> > > > a
> > > > > ballot properly.
> > > >
> > > > Please find attached the patch.
> > > >
> > >
> > > >  doc/filters.texi            |   16 ++++
> > > >  libavfilter/scene_sad.c     |  151
> > > ++++++++++++++++++++++++++++++++++++++++++
> > > >  libavfilter/scene_sad.h     |    6 +
> > > >  libavfilter/vf_scdet.c      |  156 ++++++++++++++++++++++++++++++---------
> -----
> > > >  tests/fate/filter-video.mak |    3
> > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > > 8f29f2e1c202ab283a9ca0f5d9599de6ab534d7a
> > > > 0001-area-changed-scdet-filter.patch
> > > > From 6d55c65d92376b0ab6e3bb2439af30fbcc430d0b Mon Sep 17
> 00:00:00
> > > 2001
> > > > From: raduct <radu.taraibuta@gmail.com>
> > > > Date: Wed, 8 May 2024 08:24:46 +0300
> > > > Subject: [PATCH] area changed: scdet filter
> > > >
> > > > Improve scene detection accuracy by comparing frame with both
> > > > previous
> > > and next frame (creates one frame delay).
> > > > Add new mode parameter and new method to compute the frame
> > > > difference
> > > using cubic square to increase the weight of small changes and new
> > > mean formula. This improves accuracy significantly. Slightly improve
> > > performance by not using frame clone.
> > > > Add legacy mode for backward compatibility.
> > > >
> > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > ---
> > > >  doc/filters.texi            |  16 ++++
> > > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > > >  libavfilter/scene_sad.h     |   6 ++
> > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > >  tests/fate/filter-video.mak |   3 +
> > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > >
> > > fails to build
> > >
> > > libavfilter/scene_sad.c: In function ‘ff_init_cbrt’:
> > > libavfilter/scene_sad.c:86:5: warning: ISO C90 forbids mixed
> > > declarations and code [-Wdeclaration-after-statement]
> > >    86 |     uint8_t *table = cbrt_table[bitdepth];
> > >       |     ^~~~~~~
> > > libavfilter/scene_sad.c:92:13: error: implicit declaration of
> > > function ‘av_malloc’; did you mean ‘malloc’? [-Werror=implicit-function-
> declaration]
> > >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > >       |             ^~~~~~~~~
> > >       |             malloc
> > > libavfilter/scene_sad.c:92:11: warning: assignment to ‘uint8_t *’
> > > {aka ‘unsigned char *’} from ‘int’ makes pointer from integer without a cast
> [-Wint-conversion]
> > >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > >       |           ^
> > > libavfilter/scene_sad.c:98:5: warning: ISO C90 forbids mixed
> > > declarations and code [-Wdeclaration-after-statement]
> > >    98 |     int size = 1 << bitdepth;
> > >       |     ^~~
> > > libavfilter/scene_sad.c: In function ‘ff_uninit_cbrt’:
> > > libavfilter/scene_sad.c:120:9: error: implicit declaration of
> > > function ‘av_free’; did you mean ‘free’? [-Werror=implicit-function-
> declaration]
> > >   120 |         av_free(cbrt_table[bitdepth]);
> > >       |         ^~~~~~~
> > >       |         free
> > > libavfilter/scene_sad.c: At top level:
> > > libavfilter/scene_sad.c:126:6: error: no previous prototype for
> > > ‘ff_scene_scrd_c’ [-Werror=missing-prototypes]
> > >   126 | void ff_scene_scrd_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c: In function ‘ff_scene_scrd_c’:
> > > libavfilter/scene_sad.c:148:5: warning: ISO C90 forbids mixed
> > > declarations and code [-Wdeclaration-after-statement]
> > >   148 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > >       |     ^~~~~~
> > > libavfilter/scene_sad.c: At top level:
> > > libavfilter/scene_sad.c:152:6: error: no previous prototype for
> > > ‘ff_scene_scrd2B_c’ [-Werror=missing-prototypes]
> > >   152 | void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
> > >       |      ^~~~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c: In function ‘ff_scene_scrd2B_c’:
> > > libavfilter/scene_sad.c:179:5: warning: ISO C90 forbids mixed
> > > declarations and code [-Wdeclaration-after-statement]
> > >   179 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > >       |     ^~~~~~
> > > libavfilter/scene_sad.c: At top level:
> > > libavfilter/scene_sad.c:183:6: error: no previous prototype for
> > > ‘ff_scene_scrd9_c’ [-Werror=missing-prototypes]
> > >   183 | void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c:188:6: error: no previous prototype for
> > > ‘ff_scene_scrd10_c’ [-Werror=missing-prototypes]
> > >   188 | void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c:193:6: error: no previous prototype for
> > > ‘ff_scene_scrd12_c’ [-Werror=missing-prototypes]
> > >   193 | void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c:198:6: error: no previous prototype for
> > > ‘ff_scene_scrd14_c’ [-Werror=missing-prototypes]
> > >   198 | void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~~~
> > > libavfilter/scene_sad.c:203:6: error: no previous prototype for
> > > ‘ff_scene_scrd16_c’ [-Werror=missing-prototypes]
> > >   203 | void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> > >       |      ^~~~~~~~~~~~~~~~~
> > > cc1: some warnings being treated as errors
> > > make: *** [ffbuild/common.mak:81: libavfilter/scene_sad.o] Error 1
> > > make: *** Waiting for unfinished jobs....
> > >
> > >
> > > [...]
> > >
> > > --
> > > Michael     GnuPG fingerprint:
> > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > >
> > > Frequently ignored answer#1 FFmpeg bugs should be sent to our
> bugtracker.
> > > User questions about the command line tools should be sent to the
> > > ffmpeg- user ML.
> > > And questions about how to use libav* should be sent to the libav-user ML.
> >
> > Please find attached a new version of the patch.
> > I'm building using msvc and I don't get these warnings.
> 
> >  doc/filters.texi            |   16 ++++
> >  libavfilter/scene_sad.c     |  157
> ++++++++++++++++++++++++++++++++++++++++++
> >  libavfilter/scene_sad.h     |   20 +++++
> >  libavfilter/vf_scdet.c      |  161 ++++++++++++++++++++++++++++++--------------
> >  tests/fate/filter-video.mak |    3
> >  5 files changed, 309 insertions(+), 48 deletions(-)
> > 20737181fba9670a258cd6345edf36eae954bfa2
> > 0001-area-changed-scdet-filter.patch
> > From 0a6963360076213d30b70f8297eae3d44a638dab Mon Sep 17 00:00:00
> 2001
> > From: raduct <radu.taraibuta@gmail.com>
> > Date: Wed, 8 May 2024 08:24:46 +0300
> > Subject: [PATCH] area changed: scdet filter
> 
> breaks fate (infinite loops here on ubuntu)
> TEST    filter-metadata-scdet
> ^Cmake: *** [tests/Makefile:311: fate-filter-metadata-scdet] Interrupt
> 
> it seems to never exit avformat_find_stream_info()
> 
> thx
> 
> [...]
> 
> --
> Michael     GnuPG fingerprint:
> 9FF2128B147EF6730BADF133611EC787040B0FAB
> 
> He who knows, does not speak. He who speaks, does not know. -- Lao Tsu

V3 - fate should work now.

On Wed, Jun 12, 2024 at 10:51:47PM +0300, radu.taraibuta@gmail.com wrote:
> > -----Original Message-----
> > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > Michael Niedermayer
> > Sent: marți, 11 iunie 2024 20:18
> > To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH v2] area changed: scdet filter
> > 
> > On Tue, Jun 11, 2024 at 10:07:32AM +0300, radu.taraibuta@gmail.com wrote:
> > >
> > > > -----Original Message-----
> > > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> > > > Michael Niedermayer
> > > > Sent: marți, 4 iunie 2024 01:42
> > > > To: FFmpeg development discussions and patches
> > > > <ffmpeg-devel@ffmpeg.org>
> > > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > > >
> > > > On Sun, Jun 02, 2024 at 11:17:29PM +0300, radu.taraibuta@gmail.com
> > wrote:
> > > > >
> > > > >
> > > > > > -----Original Message-----
> > > > > > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf
> > > > > > Of Michael Niedermayer
> > > > > > Sent: vineri, 31 mai 2024 00:32
> > > > > > To: FFmpeg development discussions and patches
> > > > > > <ffmpeg-devel@ffmpeg.org>
> > > > > > Subject: Re: [FFmpeg-devel] [PATCH] area changed: scdet filter
> > > > > >
> > > > > > On Mon, May 13, 2024 at 06:52:19PM +0300,
> > > > > > radu.taraibuta@gmail.com
> > > > > > wrote:
> > > > > > > Previous observations:
> > > > > > >
> > > > > > >  - Inconsistent code style with other filters. (Mostly using
> > > > > > > AVFilterLink* link instead of AVFilterLink *link).
> > > > > > > I hope it's fine now.
> > > > > > >
> > > > > > >  - Unrelated changes, please split trivial unrelated changes
> > > > > > > into separate patches.
> > > > > > > Removed trivial changes from this patch.
> > > > > > >
> > > > > > >  - Can't tables be generated at .init/.config_props time? No
> > > > > > > point in storing them into binary.
> > > > > > > Done.
> > > > > > >
> > > > > > >  - Adding extra delay is not backward compatible change, it
> > > > > > > should be implemented properly by adding option for users to select
> > mode:
> > > > > > > next & prev frame or just next or prev frame.
> > > > > > > Added legacy option to the mode parameter.
> > > > > > >
> > > > > > >  - Could split frame clone change into earlier separate patch.
> > > > > > > Cannot be done. It's either frame clone or 1 frame delay.
> > > > > > >
> > > > > > >  - Where are results of improvements with accuracy so it can
> > > > > > > be
> > > > > confirmed?
> > > > > > > Here are my test results with manual labeling of scene changes:
> > > > > > > 2379	Full length movie
> > > > > > >
> > > > > > > Method	Threshold	TP	FP	FN
> > 	Precision
> > > > > > > Recall	F
> > > > > > > Cubic	7	2357	423	22		0.847841727
> > > > > 0.990752417
> > > > > > > 0.913742973
> > > > > > > Cubic	10	2297	200	82		0.919903885
> > > > > 0.965531736
> > > > > > > 0.94216571
> > > > > > > Cubic	12	2217	146	162		0.938214135
> > > > > 0.931904161
> > > > > > > 0.935048503
> > > > > > > Cubic	15	2049	101	330		0.953023256
> > > > > 0.861286255
> > > > > > > 0.904835505
> > > > > > > Linear	2.8	2357	1060	22		0.689786362
> > > > > 0.990752417
> > > > > > > 0.813319531
> > > > > > > Linear	8	2099	236	280		0.898929336
> > > > > 0.882303489
> > > > > > > 0.890538821
> > > > > > > Linear	10	1886	173	493		0.91597863
> > > > > 0.792770071
> > > > > > > 0.849932402
> > > > > > > Legacy	5	2235	1260	144		0.639484979
> > > > > > 	0.939470366
> > > > > > > 0.760980592
> > > > > > > Legacy	8	1998	414	381		0.828358209
> > > > > > 	0.839848676
> > > > > > > 0.83406387
> > > > > > > Legacy	10	1743	193	636		0.900309917
> > > > > > 	0.732660782
> > > > > > > 0.80787949
> > > > > > >
> > > > > > > 15	HDR10Plus_PB_EAC3JOC
> > > > > > > https://mega.nz/file/nehDka6Z#C5_OPbSZkONdOp1jRmc09C9-
> > > > > > viDc3zMj8ZHruHcW
> > > > > > > KyA
> > > > > > >
> > > > > > > Method	Threshold	TP	FP	FN
> > 	Precision
> > > > > > > Recall	F
> > > > > > > Cubic	10	15	0	0		1	1	1
> > > > > > > Linear	5	13	1	2		0.928571429
> > > > > 0.866666667
> > > > > > > 0.896551724
> > > > > > > Legacy	5	12	2	3		0.857142857	0.8
> > > > > > > 0.827586207
> > > > > > >
> > > > > > > 21	(HDR HEVC 10-bit BT.2020 24fps) Exodus Sample
> > > > > > >
> > > > > >
> > > >
> > https://mega.nz/file/Sfw1hDpK#ErxCOpQDVjcI1gq6ZbX3vIfdtXZompkFe0jq47
> > > > > > E
> > > > > > h
> > > > > > > R2o
> > > > > > >
> > > > > > > Method	Threshold	TP	FP	FN
> > 	Precision
> > > > > > > Recall	F
> > > > > > > Cubic	10	21	0	0		1	1	1
> > > > > > > Linear	4	20	0	1		1	0.952380952
> > > > > > > 0.975609756
> > > > > > > Legacy	4	19	0	2		1	0.904761905
> > > > > > 	0.95
> > > > > > >
> > > > > > > 94	Bieber Grammys
> > > > > > > https://mega.nz/#!c9dhAaKA!MG5Yi-
> > > > > > MJNATE2_KqcnNJZCRKtTWvdjJP1NwG8Ggdw3E
> > > > > > >
> > > > > > > Method	Threshold	TP	FP	FN
> > 	Precision
> > > > > > > Recall	F
> > > > > > > Cubic	15	91	23	3		0.798245614
> > > > > 0.968085106
> > > > > > > 0.875
> > > > > > > Cubic	18	85	9	9		0.904255319
> > > > > 0.904255319
> > > > > > > 0.904255319
> > > > > > > Linear	7	79	49	15		0.6171875
> > > > > 0.840425532
> > > > > > > 0.711711712
> > > > > > > Linear	8	74	28	20		0.725490196
> > > > > 0.787234043
> > > > > > > 0.755102041
> > > > > > > Legacy	7	74	40	20		0.649122807
> > > > > > 	0.787234043
> > > > > > > 0.711538462
> > > > > > > Legacy	8	71	26	23		0.731958763
> > > > > > 	0.755319149
> > > > > > > 0.743455497
> > > > > > >
> > > > > > >
> > > > > > > Improve scene detection accuracy by comparing frame with both
> > > > > > > previous and next frame (creates one frame delay).
> > > > > > > Add new mode parameter and new method to compute the frame
> > > > > > > difference using cubic square to increase the weight of small
> > > > > > > changes and new mean
> > > > > > formula.
> > > > > > > This improves accuracy significantly. Slightly improve
> > > > > > > performance by not using frame clone.
> > > > > > > Add legacy mode for backward compatibility.
> > > > > > >
> > > > > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > > > > ---
> > > > > > >  doc/filters.texi            |  16 ++++
> > > > > > >  libavfilter/scene_sad.c     | 151
> > ++++++++++++++++++++++++++++++++++
> > > > > > >  libavfilter/scene_sad.h     |   6 ++
> > > > > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > > > > >  tests/fate/filter-video.mak |   3 +
> > > > > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > > > > >
> > > > > > > diff --git a/doc/filters.texi b/doc/filters.texi index
> > > > > > > bfa8ccec8b..53814e003b 100644
> > > > > > > --- a/doc/filters.texi
> > > > > > > +++ b/doc/filters.texi
> > > > > > > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> > > > > > >  @item sc_pass, s
> > > > > > >  Set the flag to pass scene change frames to the next filter.
> > > > > > > Default value is @code{0}
> > > > > >
> > > > > > The patch is corrupted by linebreaks:
> > > > > >
> > > > > > Applying: area changed: scdet filter
> > > > > > error: corrupt patch at line 16
> > > > > > Patch failed at 0001 area changed: scdet filter
> > > > > >
> > > > > > please check the linebreak settings or attach the patch or use
> > > > > > git
> > > > > send-email
> > > > > >
> > > > > > thx
> > > > > >
> > > > > > [...]
> > > > > > --
> > > > > > Michael     GnuPG fingerprint:
> > > > > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > > > > >
> > > > > > Homeopathy is like voting while filling the ballot out with
> > > > > > transparent
> > > > > ink.
> > > > > > Sometimes the outcome one wanted occurs. Rarely its worse than
> > > > > > filling out
> > > > > a
> > > > > > ballot properly.
> > > > >
> > > > > Please find attached the patch.
> > > > >
> > > >
> > > > >  doc/filters.texi            |   16 ++++
> > > > >  libavfilter/scene_sad.c     |  151
> > > > ++++++++++++++++++++++++++++++++++++++++++
> > > > >  libavfilter/scene_sad.h     |    6 +
> > > > >  libavfilter/vf_scdet.c      |  156 ++++++++++++++++++++++++++++++---------
> > -----
> > > > >  tests/fate/filter-video.mak |    3
> > > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > > > 8f29f2e1c202ab283a9ca0f5d9599de6ab534d7a
> > > > > 0001-area-changed-scdet-filter.patch
> > > > > From 6d55c65d92376b0ab6e3bb2439af30fbcc430d0b Mon Sep 17
> > 00:00:00
> > > > 2001
> > > > > From: raduct <radu.taraibuta@gmail.com>
> > > > > Date: Wed, 8 May 2024 08:24:46 +0300
> > > > > Subject: [PATCH] area changed: scdet filter
> > > > >
> > > > > Improve scene detection accuracy by comparing frame with both
> > > > > previous
> > > > and next frame (creates one frame delay).
> > > > > Add new mode parameter and new method to compute the frame
> > > > > difference
> > > > using cubic square to increase the weight of small changes and new
> > > > mean formula. This improves accuracy significantly. Slightly improve
> > > > performance by not using frame clone.
> > > > > Add legacy mode for backward compatibility.
> > > > >
> > > > > Signed-off-by: raduct <radu.taraibuta@gmail.com>
> > > > > ---
> > > > >  doc/filters.texi            |  16 ++++
> > > > >  libavfilter/scene_sad.c     | 151 ++++++++++++++++++++++++++++++++++
> > > > >  libavfilter/scene_sad.h     |   6 ++
> > > > >  libavfilter/vf_scdet.c      | 156 +++++++++++++++++++++++++-----------
> > > > >  tests/fate/filter-video.mak |   3 +
> > > > >  5 files changed, 284 insertions(+), 48 deletions(-)
> > > >
> > > > fails to build
> > > >
> > > > libavfilter/scene_sad.c: In function ‘ff_init_cbrt’:
> > > > libavfilter/scene_sad.c:86:5: warning: ISO C90 forbids mixed
> > > > declarations and code [-Wdeclaration-after-statement]
> > > >    86 |     uint8_t *table = cbrt_table[bitdepth];
> > > >       |     ^~~~~~~
> > > > libavfilter/scene_sad.c:92:13: error: implicit declaration of
> > > > function ‘av_malloc’; did you mean ‘malloc’? [-Werror=implicit-function-
> > declaration]
> > > >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > > >       |             ^~~~~~~~~
> > > >       |             malloc
> > > > libavfilter/scene_sad.c:92:11: warning: assignment to ‘uint8_t *’
> > > > {aka ‘unsigned char *’} from ‘int’ makes pointer from integer without a cast
> > [-Wint-conversion]
> > > >    92 |     table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> > > >       |           ^
> > > > libavfilter/scene_sad.c:98:5: warning: ISO C90 forbids mixed
> > > > declarations and code [-Wdeclaration-after-statement]
> > > >    98 |     int size = 1 << bitdepth;
> > > >       |     ^~~
> > > > libavfilter/scene_sad.c: In function ‘ff_uninit_cbrt’:
> > > > libavfilter/scene_sad.c:120:9: error: implicit declaration of
> > > > function ‘av_free’; did you mean ‘free’? [-Werror=implicit-function-
> > declaration]
> > > >   120 |         av_free(cbrt_table[bitdepth]);
> > > >       |         ^~~~~~~
> > > >       |         free
> > > > libavfilter/scene_sad.c: At top level:
> > > > libavfilter/scene_sad.c:126:6: error: no previous prototype for
> > > > ‘ff_scene_scrd_c’ [-Werror=missing-prototypes]
> > > >   126 | void ff_scene_scrd_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c: In function ‘ff_scene_scrd_c’:
> > > > libavfilter/scene_sad.c:148:5: warning: ISO C90 forbids mixed
> > > > declarations and code [-Wdeclaration-after-statement]
> > > >   148 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > > >       |     ^~~~~~
> > > > libavfilter/scene_sad.c: At top level:
> > > > libavfilter/scene_sad.c:152:6: error: no previous prototype for
> > > > ‘ff_scene_scrd2B_c’ [-Werror=missing-prototypes]
> > > >   152 | void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
> > > >       |      ^~~~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c: In function ‘ff_scene_scrd2B_c’:
> > > > libavfilter/scene_sad.c:179:5: warning: ISO C90 forbids mixed
> > > > declarations and code [-Wdeclaration-after-statement]
> > > >   179 |     double mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > > >       |     ^~~~~~
> > > > libavfilter/scene_sad.c: At top level:
> > > > libavfilter/scene_sad.c:183:6: error: no previous prototype for
> > > > ‘ff_scene_scrd9_c’ [-Werror=missing-prototypes]
> > > >   183 | void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c:188:6: error: no previous prototype for
> > > > ‘ff_scene_scrd10_c’ [-Werror=missing-prototypes]
> > > >   188 | void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c:193:6: error: no previous prototype for
> > > > ‘ff_scene_scrd12_c’ [-Werror=missing-prototypes]
> > > >   193 | void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c:198:6: error: no previous prototype for
> > > > ‘ff_scene_scrd14_c’ [-Werror=missing-prototypes]
> > > >   198 | void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~~~
> > > > libavfilter/scene_sad.c:203:6: error: no previous prototype for
> > > > ‘ff_scene_scrd16_c’ [-Werror=missing-prototypes]
> > > >   203 | void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> > > >       |      ^~~~~~~~~~~~~~~~~
> > > > cc1: some warnings being treated as errors
> > > > make: *** [ffbuild/common.mak:81: libavfilter/scene_sad.o] Error 1
> > > > make: *** Waiting for unfinished jobs....
> > > >
> > > >
> > > > [...]
> > > >
> > > > --
> > > > Michael     GnuPG fingerprint:
> > > > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > > >
> > > > Frequently ignored answer#1 FFmpeg bugs should be sent to our
> > bugtracker.
> > > > User questions about the command line tools should be sent to the
> > > > ffmpeg- user ML.
> > > > And questions about how to use libav* should be sent to the libav-user ML.
> > >
> > > Please find attached a new version of the patch.
> > > I'm building using msvc and I don't get these warnings.
> > 
> > >  doc/filters.texi            |   16 ++++
> > >  libavfilter/scene_sad.c     |  157
> > ++++++++++++++++++++++++++++++++++++++++++
> > >  libavfilter/scene_sad.h     |   20 +++++
> > >  libavfilter/vf_scdet.c      |  161 ++++++++++++++++++++++++++++++--------------
> > >  tests/fate/filter-video.mak |    3
> > >  5 files changed, 309 insertions(+), 48 deletions(-)
> > > 20737181fba9670a258cd6345edf36eae954bfa2
> > > 0001-area-changed-scdet-filter.patch
> > > From 0a6963360076213d30b70f8297eae3d44a638dab Mon Sep 17 00:00:00
> > 2001
> > > From: raduct <radu.taraibuta@gmail.com>
> > > Date: Wed, 8 May 2024 08:24:46 +0300
> > > Subject: [PATCH] area changed: scdet filter
> > 
> > breaks fate (infinite loops here on ubuntu)
> > TEST    filter-metadata-scdet
> > ^Cmake: *** [tests/Makefile:311: fate-filter-metadata-scdet] Interrupt
> > 
> > it seems to never exit avformat_find_stream_info()
> > 
> > thx
> > 
> > [...]
> > 
> > --
> > Michael     GnuPG fingerprint:
> > 9FF2128B147EF6730BADF133611EC787040B0FAB
> > 
> > He who knows, does not speak. He who speaks, does not know. -- Lao Tsu
> 
> V3 - fate should work now.

yes


[...]
> @@ -71,3 +73,158 @@ ff_scene_sad_fn ff_scene_sad_get_fn(int depth)
>      return sad;
>  }
>  
> +static AVMutex cbrt_mutex = AV_MUTEX_INITIALIZER;
> +static uint8_t *cbrt_table[16] = { NULL };
> +static int cbrt_table_ref[16] = { 0 };



> +
> +int ff_init_cbrt(int bitdepth)
> +{
> +    uint8_t *table;
> +    int size;
> +
> +    if (bitdepth < 4 || bitdepth > 16)
> +        return AVERROR(EINVAL);
> +
> +    ff_mutex_lock(&cbrt_mutex);
> +
> +    table = cbrt_table[bitdepth];
> +    if (table) {
> +        cbrt_table_ref[bitdepth]++;
> +        goto end;
> +    }
> +
> +    table = av_malloc((1 << bitdepth) * (bitdepth > 8 ? 2 : 1));
> +    if (!table)
> +        goto end;
> +    cbrt_table[bitdepth] = table;
> +    cbrt_table_ref[bitdepth] = 1;
> +
> +    size = 1 << bitdepth;
> +    double factor = pow(size - 1, 2. / 3.);
> +    if (bitdepth <= 8) {
> +        for (int i = 0; i < size; i++)
> +            table[i] = round(factor * pow(i, 1. / 3.));
> +    } else {
> +        uint16_t *tablew = (uint16_t*)table;
> +        for (int i = 0; i < size; i++)
> +            tablew[i] = round(factor * pow(i, 1. / 3.));
> +    }
> +
> +end:
> +    ff_mutex_unlock(&cbrt_mutex);
> +    return table != NULL;
> +}
> +
> +void ff_uninit_cbrt(int bitdepth)
> +{
> +    if (bitdepth < 4 || bitdepth > 16)
> +        return;
> +    ff_mutex_lock(&cbrt_mutex);
> +    if (!--cbrt_table_ref[bitdepth]) {
> +        av_free(cbrt_table[bitdepth]);
> +        cbrt_table[bitdepth] = NULL;
> +    }
> +    ff_mutex_unlock(&cbrt_mutex);
> +}

I honestly dont see the value of refcounting the global cbrt tables

either they can be static and initialized by a single AV_ONCE_INIT or
just allocate and reinint for each filter.


> +
> +void ff_scene_scrd_c(SCENE_SAD_PARAMS)
> +{
> +    uint64_t scrdPlus = 0;
> +    uint64_t scrdMinus = 0;
> +    int x, y;
> +    double mean;
> +    uint8_t *table = cbrt_table[8];
> +
> +    if (!table) {
> +        *sum = 0;
> +        return;
> +    }
> +
> +    for (y = 0; y < height; y++) {
> +        for (x = 0; x < width; x++)
> +            if (src1[x] > src2[x])
> +                scrdMinus += table[src1[x] - src2[x]];
> +            else
> +                scrdPlus += table[src2[x] - src1[x]];
> +        src1 += stride1;
> +        src2 += stride2;
> +    }
> +

> +    mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> +    *sum = 2.0 * mean * mean;

one sqrt less:
0.5*(scrdPlus + scrdMinus) + sqrt(scrdPlus * (double)scrdMinus)



> +}
> +
> +void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth)
> +{
> +    uint64_t scrdPlus = 0;
> +    uint64_t scrdMinus = 0;
> +    const uint16_t *src1w = (const uint16_t*)src1;
> +    const uint16_t *src2w = (const uint16_t*)src2;
> +    int x, y;
> +    double mean;
> +    uint16_t *table = (uint16_t*)cbrt_table[bitdepth];
> +
> +    if (!table) {
> +        *sum = 0;
> +        return;
> +    }
> +
> +    stride1 /= 2;
> +    stride2 /= 2;
> +
> +    for (y = 0; y < height; y++) {
> +        for (x = 0; x < width; x++)
> +            if (src1w[x] > src2w[x])
> +                scrdMinus += table[src1w[x] - src2w[x]];
> +            else
> +                scrdPlus += table[src2w[x] - src1w[x]];
> +        src1w += stride1;
> +        src2w += stride2;
> +    }
> +
> +    mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> +    *sum = 2.0 * mean * mean;
> +}
> +
> +void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum, 9);
> +}
> +
> +void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum, 10);
> +}
> +
> +void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum, 12);
> +}
> +
> +void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum, 14);
> +}
> +
> +void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> +{
> +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height, sum, 16);
> +}

duplicating this 5 times just for a different LUT pointer is ugly


thx

[...]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of
> Michael Niedermayer
> Sent: joi, 13 iunie 2024 02:52
> To: FFmpeg development discussions and patches <ffmpeg-devel@ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter
> 
> 
> I honestly dont see the value of refcounting the global cbrt tables
> 
> either they can be static and initialized by a single AV_ONCE_INIT or just
> allocate and reinint for each filter.
> 

There is one cbrt_table for each bitdepth. Initializing all of them before knowing which one is used, would be a waste.
To allocate and initialize one table for each filter/client would be a waste too in a multiple clients scenario.

> > +
> > +void ff_scene_scrd_c(SCENE_SAD_PARAMS) {
> > +    uint64_t scrdPlus = 0;
> > +    uint64_t scrdMinus = 0;
> > +    int x, y;
> > +    double mean;
> > +    uint8_t *table = cbrt_table[8];
> > +
> > +    if (!table) {
> > +        *sum = 0;
> > +        return;
> > +    }
> > +
> > +    for (y = 0; y < height; y++) {
> > +        for (x = 0; x < width; x++)
> > +            if (src1[x] > src2[x])
> > +                scrdMinus += table[src1[x] - src2[x]];
> > +            else
> > +                scrdPlus += table[src2[x] - src1[x]];
> > +        src1 += stride1;
> > +        src2 += stride2;
> > +    }
> > +
> 
> > +    mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > +    *sum = 2.0 * mean * mean;
> 
> one sqrt less:
> 0.5*(scrdPlus + scrdMinus) + sqrt(scrdPlus * (double)scrdMinus)
> 

OK, will do in the next version.

> > +}
> > +
> > +void ff_scene_scrd2B_c(SCENE_SAD_PARAMS, int bitdepth) {
> > +    uint64_t scrdPlus = 0;
> > +    uint64_t scrdMinus = 0;
> > +    const uint16_t *src1w = (const uint16_t*)src1;
> > +    const uint16_t *src2w = (const uint16_t*)src2;
> > +    int x, y;
> > +    double mean;
> > +    uint16_t *table = (uint16_t*)cbrt_table[bitdepth];
> > +
> > +    if (!table) {
> > +        *sum = 0;
> > +        return;
> > +    }
> > +
> > +    stride1 /= 2;
> > +    stride2 /= 2;
> > +
> > +    for (y = 0; y < height; y++) {
> > +        for (x = 0; x < width; x++)
> > +            if (src1w[x] > src2w[x])
> > +                scrdMinus += table[src1w[x] - src2w[x]];
> > +            else
> > +                scrdPlus += table[src2w[x] - src1w[x]];
> > +        src1w += stride1;
> > +        src2w += stride2;
> > +    }
> > +
> > +    mean = (sqrt(scrdPlus) + sqrt(scrdMinus)) / 2.0;
> > +    *sum = 2.0 * mean * mean;
> > +}
> > +
> > +void ff_scene_scrd9_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum, 9); }
> > +
> > +void ff_scene_scrd10_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum, 10); }
> > +
> > +void ff_scene_scrd12_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum, 12); }
> > +
> > +void ff_scene_scrd14_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum, 14); }
> > +
> > +void ff_scene_scrd16_c(SCENE_SAD_PARAMS)
> > +{
> > +    ff_scene_scrd2B_c(src1, stride1, src2, stride2, width, height,
> > +sum, 16); }
> 
> duplicating this 5 times just for a different LUT pointer is ugly
> 
> 

It's not pretty, but I did it to preserve the existing interface and keep logic together.
Any suggestion how else to do it?

On 12/06/2024 21:51, radu.taraibuta@gmail.com wrote:

[...]

> diff --git a/doc/filters.texi b/doc/filters.texi
> index bfa8ccec8b..53814e003b 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
>  @item sc_pass, s
>  Set the flag to pass scene change frames to the next filter. Default 
> value is @code{0}
>  You can enable it if you want to get snapshot of scene change frames 
> only.
> +
> +@item mode
> +Set the scene change detection method. Default value is @code{-1}
> +Available values are:
> +
> +@table @samp
> +@item -1
> +Legacy mode for sum of absolute linear differences. Compare frame 
> with previous only and no delay.
> +
> +@item 0
> +Sum of absolute linear differences. Compare frame with both previous 
> and next which introduces a 1 frame delay.
> +
> +@item 1
> +Sum of mean of cubic root differences. Compare frame with both 
> previous and next which introduces a 1 frame delay.
> +
> +@end table
>  @end table
>
>  @anchor{selectivecolor}

Out of curiosity: How do these three modes roughly compare (CPU) 
performance wise?

I'd prefer if mode "-1" could be used for the default case, and the 
three modes get explicit values 0/1/2. Regarding naming I think that the 
"Legacy" mode still has its usecases in the future. Naming it something 
like "simple" would not imply that it is deprecated in general, but 
rather that it has lower precision (and is possibly faster).

Best regards,
Tobias

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Tobias
> Rapp
> Sent: joi, 13 iunie 2024 12:52
> To: ffmpeg-devel@ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter
> 
> On 12/06/2024 21:51, radu.taraibuta@gmail.com wrote:
> 
> [...]
> 
> > diff --git a/doc/filters.texi b/doc/filters.texi index
> > bfa8ccec8b..53814e003b 100644
> > --- a/doc/filters.texi
> > +++ b/doc/filters.texi
> > @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> >  @item sc_pass, s
> >  Set the flag to pass scene change frames to the next filter. Default
> > value is @code{0}
> >  You can enable it if you want to get snapshot of scene change frames
> > only.
> > +
> > +@item mode
> > +Set the scene change detection method. Default value is @code{-1}
> > +Available values are:
> > +
> > +@table @samp
> > +@item -1
> > +Legacy mode for sum of absolute linear differences. Compare frame
> > with previous only and no delay.
> > +
> > +@item 0
> > +Sum of absolute linear differences. Compare frame with both previous
> > and next which introduces a 1 frame delay.
> > +
> > +@item 1
> > +Sum of mean of cubic root differences. Compare frame with both
> > previous and next which introduces a 1 frame delay.
> > +
> > +@end table
> >  @end table
> >
> >  @anchor{selectivecolor}
> 
> Out of curiosity: How do these three modes roughly compare (CPU)
> performance wise?

Mode -1 is virtually equal with mode 0 (no frame clone speedup of mode 0 is mostly theoretical). Mode 1 is roughly 40% slower, depending on input, it could benefit from ASM.

> I'd prefer if mode "-1" could be used for the default case, and the three modes
> get explicit values 0/1/2. 

So you want four possible values for mode where the default -1 is the same as one of the others?

>Regarding naming I think that the "Legacy" mode still
> has its usecases in the future. Naming it something like "simple" would not
> imply that it is deprecated in general, but rather that it has lower precision
> (and is possibly faster).
> 
OK, I will rename "Legacy" mode so it doesn't look deprecated to somebody that can't allow 1 frame delay. Otherwise it shouldn't be used.

On 13/06/2024 13:21, radu.taraibuta@gmail.com wrote:

>> -----Original Message-----
>> From: ffmpeg-devel<ffmpeg-devel-bounces@ffmpeg.org>  On Behalf Of Tobias
>> Rapp
>> Sent: joi, 13 iunie 2024 12:52
>> To:ffmpeg-devel@ffmpeg.org
>> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter
>>
>> On 12/06/2024 21:51,radu.taraibuta@gmail.com  wrote:
>>
>> [...]
>>
>>> diff --git a/doc/filters.texi b/doc/filters.texi index
>>> bfa8ccec8b..53814e003b 100644
>>> --- a/doc/filters.texi
>>> +++ b/doc/filters.texi
>>> @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
>>>   @item sc_pass, s
>>>   Set the flag to pass scene change frames to the next filter. Default
>>> value is @code{0}
>>>   You can enable it if you want to get snapshot of scene change frames
>>> only.
>>> +
>>> +@item mode
>>> +Set the scene change detection method. Default value is @code{-1}
>>> +Available values are:
>>> +
>>> +@table @samp
>>> +@item -1
>>> +Legacy mode for sum of absolute linear differences. Compare frame
>>> with previous only and no delay.
>>> +
>>> +@item 0
>>> +Sum of absolute linear differences. Compare frame with both previous
>>> and next which introduces a 1 frame delay.
>>> +
>>> +@item 1
>>> +Sum of mean of cubic root differences. Compare frame with both
>>> previous and next which introduces a 1 frame delay.
>>> +
>>> +@end table
>>>   @end table
>>>
>>>   @anchor{selectivecolor}
>> Out of curiosity: How do these three modes roughly compare (CPU)
>> performance wise?
> Mode -1 is virtually equal with mode 0 (no frame clone speedup of mode 0 is mostly theoretical). Mode 1 is roughly 40% slower, depending on input, it could benefit from ASM.
>
>> I'd prefer if mode "-1" could be used for the default case, and the three modes
>> get explicit values 0/1/2.
> So you want four possible values for mode where the default -1 is the same as one of the others?

Yes. This pattern is also used for the "shaping" option of the ass 
filter, for example.It allows users to make it explicit that the filter 
should choose a default (which may vary between versions).

>> Regarding naming I think that the "Legacy" mode still
>> has its usecases in the future. Naming it something like "simple" would not
>> imply that it is deprecated in general, but rather that it has lower precision
>> (and is possibly faster).
>>
> OK, I will rename "Legacy" mode so it doesn't look deprecated to somebody that can't allow 1 frame delay. Otherwise it shouldn't be used.

Thanks.

Regards, Tobias

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Tobias
> Rapp
> Sent: joi, 13 iunie 2024 16:18
> To: ffmpeg-devel@ffmpeg.org
> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter
> 
> On 13/06/2024 13:21, radu.taraibuta@gmail.com wrote:
> 
> >> -----Original Message-----
> >> From: ffmpeg-devel<ffmpeg-devel-bounces@ffmpeg.org>  On Behalf Of
> >> Tobias Rapp
> >> Sent: joi, 13 iunie 2024 12:52
> >> To:ffmpeg-devel@ffmpeg.org
> >> Subject: Re: [FFmpeg-devel] [PATCH v3] area changed: scdet filter
> >>
> >> On 12/06/2024 21:51,radu.taraibuta@gmail.com  wrote:
> >>
> >> [...]
> >>
> >>> diff --git a/doc/filters.texi b/doc/filters.texi index
> >>> bfa8ccec8b..53814e003b 100644
> >>> --- a/doc/filters.texi
> >>> +++ b/doc/filters.texi
> >>> @@ -21797,6 +21797,22 @@ Default value is @code{10.}.
> >>>   @item sc_pass, s
> >>>   Set the flag to pass scene change frames to the next filter.
> >>> Default value is @code{0}
> >>>   You can enable it if you want to get snapshot of scene change
> >>> frames only.
> >>> +
> >>> +@item mode
> >>> +Set the scene change detection method. Default value is @code{-1}
> >>> +Available values are:
> >>> +
> >>> +@table @samp
> >>> +@item -1
> >>> +Legacy mode for sum of absolute linear differences. Compare frame
> >>> with previous only and no delay.
> >>> +
> >>> +@item 0
> >>> +Sum of absolute linear differences. Compare frame with both
> >>> +previous
> >>> and next which introduces a 1 frame delay.
> >>> +
> >>> +@item 1
> >>> +Sum of mean of cubic root differences. Compare frame with both
> >>> previous and next which introduces a 1 frame delay.
> >>> +
> >>> +@end table
> >>>   @end table
> >>>
> >>>   @anchor{selectivecolor}
> >> Out of curiosity: How do these three modes roughly compare (CPU)
> >> performance wise?
> > Mode -1 is virtually equal with mode 0 (no frame clone speedup of mode 0
is
> mostly theoretical). Mode 1 is roughly 40% slower, depending on input, it
> could benefit from ASM.
> >
> >> I'd prefer if mode "-1" could be used for the default case, and the
> >> three modes get explicit values 0/1/2.
> > So you want four possible values for mode where the default -1 is the
same as
> one of the others?
> 
> Yes. This pattern is also used for the "shaping" option of the ass filter,
for
> example.It allows users to make it explicit that the filter should choose
a
> default (which may vary between versions).

Scdet filter doesn't choose a mode. The default has to be current "Legacy"
for backward compatibility.
I will renumber modes to 0/1/2 to avoid confusion with an "auto" (-1)
option.

> >> Regarding naming I think that the "Legacy" mode still has its
> >> usecases in the future. Naming it something like "simple" would not
> >> imply that it is deprecated in general, but rather that it has lower
> >> precision (and is possibly faster).
> >>
> > OK, I will rename "Legacy" mode so it doesn't look deprecated to
somebody
> that can't allow 1 frame delay. Otherwise it shouldn't be used.
> 
> Thanks.
> 
> Regards, Tobias
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Update as discussed

On 13/06/2024 20:16, radu.taraibuta@gmail.com wrote:

> Update as discussed

The mode options are fine to me, will leave the implementation check and 
final push to Michael.

(Only if you update the patch anyway I'd suggest rewording the commit 
message to rephrase the "legacy" mode there, too, and maybe a more 
common patch title line like "avfilter/scdet: add improved detection 
modes". But no need to resend the patch for such cosmetics only.)

Regards, Tobias