[FFmpeg-devel,v2,1/3] avfilter/vf_scenechangedetect: add filter to detect scene change

Submitted by lance.lmwang@gmail.com on Sept. 29, 2019, 1:25 p.m.

Details

Message ID 20190929132515.4093-1-lance.lmwang@gmail.com
State New
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Commit Message

lance.lmwang@gmail.com Sept. 29, 2019, 1:25 p.m.
From: Limin Wang <lance.lmwang@gmail.com>

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
---
Please provide a comment to add a new filter for scene change detection to avoid
multiple calculations of mafd in the filter chain. The filter can avoid duplication
code also for I am writing a new filter to synchronize frames that require scene
change information. If the detect metadata can get, the code will be simple.

In addition, I'm trying  to add a reduced size before scene change detection to improve
the performance. From the initial test, we can only get 10-20% improvement, but some
scene change aren't detected after that. Therefore, I think that should not be done.

This version, I removed the version change for it's easy to cause code conflict, 
please the committer help to update it if review done.

 configure                          |   1 +
 doc/filters.texi                   |  35 +++++
 libavfilter/Makefile               |   1 +
 libavfilter/allfilters.c           |   1 +
 libavfilter/vf_scenechangedetect.c | 220 +++++++++++++++++++++++++++++
 5 files changed, 258 insertions(+)
 create mode 100644 libavfilter/vf_scenechangedetect.c

Comments

lance.lmwang@gmail.com Oct. 7, 2019, 3:10 p.m.
ping, please give comments.

On Sun, Sep 29, 2019 at 09:25:12PM +0800, lance.lmwang@gmail.com wrote:
> From: Limin Wang <lance.lmwang@gmail.com>
> 
> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> ---
> Please provide a comment to add a new filter for scene change detection to avoid
> multiple calculations of mafd in the filter chain. The filter can avoid duplication
> code also for I am writing a new filter to synchronize frames that require scene
> change information. If the detect metadata can get, the code will be simple.
> 
> In addition, I'm trying  to add a reduced size before scene change detection to improve
> the performance. From the initial test, we can only get 10-20% improvement, but some
> scene change aren't detected after that. Therefore, I think that should not be done.
> 
> This version, I removed the version change for it's easy to cause code conflict, 
> please the committer help to update it if review done.
> 
>  configure                          |   1 +
>  doc/filters.texi                   |  35 +++++
>  libavfilter/Makefile               |   1 +
>  libavfilter/allfilters.c           |   1 +
>  libavfilter/vf_scenechangedetect.c | 220 +++++++++++++++++++++++++++++
>  5 files changed, 258 insertions(+)
>  create mode 100644 libavfilter/vf_scenechangedetect.c
> 
> diff --git a/configure b/configure
> index 8413826f9e..909a77b9cf 100755
> --- a/configure
> +++ b/configure
> @@ -3520,6 +3520,7 @@ sab_filter_deps="gpl swscale"
>  scale2ref_filter_deps="swscale"
>  scale_filter_deps="swscale"
>  scale_qsv_filter_deps="libmfx"
> +scenechangedetect_filter_select="scene_sad"
>  select_filter_select="scene_sad"
>  sharpness_vaapi_filter_deps="vaapi"
>  showcqt_filter_deps="avcodec avformat swscale"
> diff --git a/doc/filters.texi b/doc/filters.texi
> index e6f8bf0ee9..f9247643cb 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -15642,6 +15642,41 @@ Scale a logo to 1/10th the height of a video, while preserving its display aspec
>  @end example
>  @end itemize
>  
> +@anchor{scenechangedetect}
> +@section scenechangedetect
> +
> +Detect video scene change.
> +
> +This filter sets frame metadata with mafd between frame, the scene score, and
> +forward the frame to the next filter, so they can use these metadata to detect
> +scene change or others.
> +
> +In addition, this filter logs a message and sets frame metadata when it detects
> +a scene change by @option{threshold}.
> +
> +@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
> +
> +@code{lavfi.scd.score} metadata keys are set with scene change score for every frame
> +to detect scene change.
> +
> +@code{lavfi.scd.time} metadata keys are set with current filtered frame time which
> +detect scene change with @option{threshold}.
> +
> +The filter accepts the following options:
> +
> +@table @option
> +@item threshold, t
> +Set the scene change detection threshold as a percentage of maximum change.  Good
> +values are in the @code{[8.0, 14.0]} range. The range for @option{threshold} is
> +@code{[0., 100.]}.
> +
> +Default value is @code{10.}.
> +
> +@item sc_pass, s
> +Set the scene change pass the frame to the next filter or not. Default value is @code{0}
> +You can enable it if you want to get snapshot of scene change frames.
> +@end table
> +
>  @anchor{selectivecolor}
>  @section selectivecolor
>  
> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> index b99ecc8c26..f6c6ba5d45 100644
> --- a/libavfilter/Makefile
> +++ b/libavfilter/Makefile
> @@ -356,6 +356,7 @@ OBJS-$(CONFIG_SCALE_NPP_FILTER)              += vf_scale_npp.o scale.o
>  OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
>  OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale.o vaapi_vpp.o
>  OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
> +OBJS-$(CONFIG_SCENECHANGEDETECT_FILTER)      += vf_scenechangedetect.o
>  OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
>  OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
>  OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> index 788652ab1e..69a4d5e8e5 100644
> --- a/libavfilter/allfilters.c
> +++ b/libavfilter/allfilters.c
> @@ -338,6 +338,7 @@ extern AVFilter ff_vf_scale_npp;
>  extern AVFilter ff_vf_scale_qsv;
>  extern AVFilter ff_vf_scale_vaapi;
>  extern AVFilter ff_vf_scale2ref;
> +extern AVFilter ff_vf_scenechangedetect;
>  extern AVFilter ff_vf_select;
>  extern AVFilter ff_vf_selectivecolor;
>  extern AVFilter ff_vf_sendcmd;
> diff --git a/libavfilter/vf_scenechangedetect.c b/libavfilter/vf_scenechangedetect.c
> new file mode 100644
> index 0000000000..269fa399d0
> --- /dev/null
> +++ b/libavfilter/vf_scenechangedetect.c
> @@ -0,0 +1,220 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +
> +/**
> + * @file
> + * video scene change detection filter
> + */
> +
> +#include "libavutil/avassert.h"
> +#include "libavutil/imgutils.h"
> +#include "libavutil/opt.h"
> +#include "libavutil/pixdesc.h"
> +#include "libavutil/timestamp.h"
> +
> +#include "avfilter.h"
> +#include "filters.h"
> +#include "scene_sad.h"
> +
> +typedef struct SceneChangeDetectContext {
> +    const AVClass *class;
> +
> +    ptrdiff_t width[4];
> +    ptrdiff_t height[4];
> +    int nb_planes;
> +    int bitdepth;
> +    ff_scene_sad_fn sad;
> +    double prev_mafd;
> +    double scene_score;
> +    AVFrame *prev_picref;
> +    double threshold;
> +    int sc_pass;
> +} SceneChangeDetectContext;
> +
> +#define OFFSET(x) offsetof(SceneChangeDetectContext, x)
> +#define V AV_OPT_FLAG_VIDEO_PARAM
> +#define F AV_OPT_FLAG_FILTERING_PARAM
> +
> +static const AVOption scenechangedetect_options[] = {
> +    { "threshold",   "set scene change detect level",   OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F },
> +    { "t",           "set scene change detect level",   OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F },
> +    { "sc_pass",     "set scene change frame pass",     OFFSET(sc_pass),  AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
> +    { "s",           "set scene change frame pass",     OFFSET(sc_pass),  AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
> +    {NULL}
> +};
> +
> +AVFILTER_DEFINE_CLASS(scenechangedetect);
> +
> +static int query_formats(AVFilterContext *ctx)
> +{
> +    static const enum AVPixelFormat pix_fmts[] = {
> +            AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, AV_PIX_FMT_RGBA,
> +            AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8,
> +            AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
> +            AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
> +            AV_PIX_FMT_YUV420P10,
> +            AV_PIX_FMT_NONE
> +    };
> +
> +    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
> +    if (!fmts_list)
> +        return AVERROR(ENOMEM);
> +    return ff_set_common_formats(ctx, fmts_list);
> +}
> +
> +static int config_input(AVFilterLink *inlink)
> +{
> +    AVFilterContext *ctx = inlink->dst;
> +    SceneChangeDetectContext *s = ctx->priv;
> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> +    int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
> +        (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
> +        desc->nb_components >= 3;
> +
> +    s->bitdepth = desc->comp[0].depth;
> +    s->nb_planes = is_yuv ? 1 : av_pix_fmt_count_planes(inlink->format);
> +
> +    for (int plane = 0; plane < 4; plane++) {
> +        ptrdiff_t line_size = av_image_get_linesize(inlink->format, inlink->w, plane);
> +        s->width[plane] = line_size >> (s->bitdepth > 8);
> +        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->sad)
> +        return AVERROR(EINVAL);
> +
> +    return 0;
> +}
> +
> +static av_cold void uninit(AVFilterContext *ctx)
> +{
> +    SceneChangeDetectContext *s = ctx->priv;
> +
> +    av_frame_free(&s->prev_picref);
> +}
> +
> +static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
> +{
> +    double ret = 0;
> +    SceneChangeDetectContext *s = ctx->priv;
> +    AVFrame *prev_picref = s->prev_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;
> +
> +        for (int plane = 0; plane < s->nb_planes; plane++) {
> +            uint64_t plane_sad;
> +            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;
> +            count += s->width[plane] * s->height[plane];
> +        }
> +
> +        emms_c();
> +        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->prev_picref = av_frame_clone(frame);
> +    return ret;
> +}
> +
> +static int set_meta(SceneChangeDetectContext *s, AVFrame *frame, const char *key, const char *value)
> +{
> +    return av_dict_set(&frame->metadata, key, value, 0);
> +}
> +
> +static int activate(AVFilterContext *ctx)
> +{
> +    int ret;
> +    AVFilterLink *inlink = ctx->inputs[0];
> +    AVFilterLink *outlink = ctx->outputs[0];
> +    SceneChangeDetectContext *s = ctx->priv;
> +    AVFrame *frame;
> +
> +    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
> +
> +    ret = ff_inlink_consume_frame(inlink, &frame);
> +    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 (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);
> +    }
> +
> +    FF_FILTER_FORWARD_STATUS(inlink, outlink);
> +    FF_FILTER_FORWARD_WANTED(outlink, inlink);
> +
> +    return FFERROR_NOT_READY;
> +}
> +
> +static const AVFilterPad scenechangedetect_inputs[] = {
> +    {
> +        .name         = "default",
> +        .type         = AVMEDIA_TYPE_VIDEO,
> +        .config_props = config_input,
> +    },
> +    { NULL }
> +};
> +
> +static const AVFilterPad scenechangedetect_outputs[] = {
> +    {
> +        .name          = "default",
> +        .type          = AVMEDIA_TYPE_VIDEO,
> +    },
> +    { NULL }
> +};
> +
> +AVFilter ff_vf_scenechangedetect = {
> +    .name          = "scenechangedetect",
> +    .description   = NULL_IF_CONFIG_SMALL("Detect video scene change"),
> +    .priv_size     = sizeof(SceneChangeDetectContext),
> +    .priv_class    = &scenechangedetect_class,
> +    .uninit        = uninit,
> +    .query_formats = query_formats,
> +    .inputs        = scenechangedetect_inputs,
> +    .outputs       = scenechangedetect_outputs,
> +    .activate      = activate,
> +};
> -- 
> 2.21.0
>
Paul B Mahol Oct. 7, 2019, 7 p.m.
Too long filter name.

On 10/7/19, Limin Wang <lance.lmwang@gmail.com> wrote:
>
> ping, please give comments.
>
> On Sun, Sep 29, 2019 at 09:25:12PM +0800, lance.lmwang@gmail.com wrote:
>> From: Limin Wang <lance.lmwang@gmail.com>
>>
>> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
>> ---
>> Please provide a comment to add a new filter for scene change detection to
>> avoid
>> multiple calculations of mafd in the filter chain. The filter can avoid
>> duplication
>> code also for I am writing a new filter to synchronize frames that require
>> scene
>> change information. If the detect metadata can get, the code will be
>> simple.
>>
>> In addition, I'm trying  to add a reduced size before scene change
>> detection to improve
>> the performance. From the initial test, we can only get 10-20%
>> improvement, but some
>> scene change aren't detected after that. Therefore, I think that should
>> not be done.
>>
>> This version, I removed the version change for it's easy to cause code
>> conflict,
>> please the committer help to update it if review done.
>>
>>  configure                          |   1 +
>>  doc/filters.texi                   |  35 +++++
>>  libavfilter/Makefile               |   1 +
>>  libavfilter/allfilters.c           |   1 +
>>  libavfilter/vf_scenechangedetect.c | 220 +++++++++++++++++++++++++++++
>>  5 files changed, 258 insertions(+)
>>  create mode 100644 libavfilter/vf_scenechangedetect.c
>>
>> diff --git a/configure b/configure
>> index 8413826f9e..909a77b9cf 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3520,6 +3520,7 @@ sab_filter_deps="gpl swscale"
>>  scale2ref_filter_deps="swscale"
>>  scale_filter_deps="swscale"
>>  scale_qsv_filter_deps="libmfx"
>> +scenechangedetect_filter_select="scene_sad"
>>  select_filter_select="scene_sad"
>>  sharpness_vaapi_filter_deps="vaapi"
>>  showcqt_filter_deps="avcodec avformat swscale"
>> diff --git a/doc/filters.texi b/doc/filters.texi
>> index e6f8bf0ee9..f9247643cb 100644
>> --- a/doc/filters.texi
>> +++ b/doc/filters.texi
>> @@ -15642,6 +15642,41 @@ Scale a logo to 1/10th the height of a video,
>> while preserving its display aspec
>>  @end example
>>  @end itemize
>>
>> +@anchor{scenechangedetect}
>> +@section scenechangedetect
>> +
>> +Detect video scene change.
>> +
>> +This filter sets frame metadata with mafd between frame, the scene score,
>> and
>> +forward the frame to the next filter, so they can use these metadata to
>> detect
>> +scene change or others.
>> +
>> +In addition, this filter logs a message and sets frame metadata when it
>> detects
>> +a scene change by @option{threshold}.
>> +
>> +@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
>> +
>> +@code{lavfi.scd.score} metadata keys are set with scene change score for
>> every frame
>> +to detect scene change.
>> +
>> +@code{lavfi.scd.time} metadata keys are set with current filtered frame
>> time which
>> +detect scene change with @option{threshold}.
>> +
>> +The filter accepts the following options:
>> +
>> +@table @option
>> +@item threshold, t
>> +Set the scene change detection threshold as a percentage of maximum
>> change.  Good
>> +values are in the @code{[8.0, 14.0]} range. The range for
>> @option{threshold} is
>> +@code{[0., 100.]}.
>> +
>> +Default value is @code{10.}.
>> +
>> +@item sc_pass, s
>> +Set the scene change pass the frame to the next filter or not. Default
>> value is @code{0}
>> +You can enable it if you want to get snapshot of scene change frames.
>> +@end table
>> +
>>  @anchor{selectivecolor}
>>  @section selectivecolor
>>
>> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
>> index b99ecc8c26..f6c6ba5d45 100644
>> --- a/libavfilter/Makefile
>> +++ b/libavfilter/Makefile
>> @@ -356,6 +356,7 @@ OBJS-$(CONFIG_SCALE_NPP_FILTER)              +=
>> vf_scale_npp.o scale.o
>>  OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
>>  OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale.o
>> vaapi_vpp.o
>>  OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
>> +OBJS-$(CONFIG_SCENECHANGEDETECT_FILTER)      += vf_scenechangedetect.o
>>  OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
>>  OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
>>  OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
>> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
>> index 788652ab1e..69a4d5e8e5 100644
>> --- a/libavfilter/allfilters.c
>> +++ b/libavfilter/allfilters.c
>> @@ -338,6 +338,7 @@ extern AVFilter ff_vf_scale_npp;
>>  extern AVFilter ff_vf_scale_qsv;
>>  extern AVFilter ff_vf_scale_vaapi;
>>  extern AVFilter ff_vf_scale2ref;
>> +extern AVFilter ff_vf_scenechangedetect;
>>  extern AVFilter ff_vf_select;
>>  extern AVFilter ff_vf_selectivecolor;
>>  extern AVFilter ff_vf_sendcmd;
>> diff --git a/libavfilter/vf_scenechangedetect.c
>> b/libavfilter/vf_scenechangedetect.c
>> new file mode 100644
>> index 0000000000..269fa399d0
>> --- /dev/null
>> +++ b/libavfilter/vf_scenechangedetect.c
>> @@ -0,0 +1,220 @@
>> +/*
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> 02110-1301 USA
>> + */
>> +
>> +/**
>> + * @file
>> + * video scene change detection filter
>> + */
>> +
>> +#include "libavutil/avassert.h"
>> +#include "libavutil/imgutils.h"
>> +#include "libavutil/opt.h"
>> +#include "libavutil/pixdesc.h"
>> +#include "libavutil/timestamp.h"
>> +
>> +#include "avfilter.h"
>> +#include "filters.h"
>> +#include "scene_sad.h"
>> +
>> +typedef struct SceneChangeDetectContext {
>> +    const AVClass *class;
>> +
>> +    ptrdiff_t width[4];
>> +    ptrdiff_t height[4];
>> +    int nb_planes;
>> +    int bitdepth;
>> +    ff_scene_sad_fn sad;
>> +    double prev_mafd;
>> +    double scene_score;
>> +    AVFrame *prev_picref;
>> +    double threshold;
>> +    int sc_pass;
>> +} SceneChangeDetectContext;
>> +
>> +#define OFFSET(x) offsetof(SceneChangeDetectContext, x)
>> +#define V AV_OPT_FLAG_VIDEO_PARAM
>> +#define F AV_OPT_FLAG_FILTERING_PARAM
>> +
>> +static const AVOption scenechangedetect_options[] = {
>> +    { "threshold",   "set scene change detect level",
>> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F
>> },
>> +    { "t",           "set scene change detect level",
>> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F
>> },
>> +    { "sc_pass",     "set scene change frame pass",     OFFSET(sc_pass),
>> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
>> +    { "s",           "set scene change frame pass",     OFFSET(sc_pass),
>> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
>> +    {NULL}
>> +};
>> +
>> +AVFILTER_DEFINE_CLASS(scenechangedetect);
>> +
>> +static int query_formats(AVFilterContext *ctx)
>> +{
>> +    static const enum AVPixelFormat pix_fmts[] = {
>> +            AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, AV_PIX_FMT_RGBA,
>> +            AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8,
>> +            AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
>> +            AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
>> +            AV_PIX_FMT_YUV420P10,
>> +            AV_PIX_FMT_NONE
>> +    };
>> +
>> +    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
>> +    if (!fmts_list)
>> +        return AVERROR(ENOMEM);
>> +    return ff_set_common_formats(ctx, fmts_list);
>> +}
>> +
>> +static int config_input(AVFilterLink *inlink)
>> +{
>> +    AVFilterContext *ctx = inlink->dst;
>> +    SceneChangeDetectContext *s = ctx->priv;
>> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
>> +    int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
>> +        (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
>> +        desc->nb_components >= 3;
>> +
>> +    s->bitdepth = desc->comp[0].depth;
>> +    s->nb_planes = is_yuv ? 1 : av_pix_fmt_count_planes(inlink->format);
>> +
>> +    for (int plane = 0; plane < 4; plane++) {
>> +        ptrdiff_t line_size = av_image_get_linesize(inlink->format,
>> inlink->w, plane);
>> +        s->width[plane] = line_size >> (s->bitdepth > 8);
>> +        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->sad)
>> +        return AVERROR(EINVAL);
>> +
>> +    return 0;
>> +}
>> +
>> +static av_cold void uninit(AVFilterContext *ctx)
>> +{
>> +    SceneChangeDetectContext *s = ctx->priv;
>> +
>> +    av_frame_free(&s->prev_picref);
>> +}
>> +
>> +static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
>> +{
>> +    double ret = 0;
>> +    SceneChangeDetectContext *s = ctx->priv;
>> +    AVFrame *prev_picref = s->prev_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;
>> +
>> +        for (int plane = 0; plane < s->nb_planes; plane++) {
>> +            uint64_t plane_sad;
>> +            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;
>> +            count += s->width[plane] * s->height[plane];
>> +        }
>> +
>> +        emms_c();
>> +        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->prev_picref = av_frame_clone(frame);
>> +    return ret;
>> +}
>> +
>> +static int set_meta(SceneChangeDetectContext *s, AVFrame *frame, const
>> char *key, const char *value)
>> +{
>> +    return av_dict_set(&frame->metadata, key, value, 0);
>> +}
>> +
>> +static int activate(AVFilterContext *ctx)
>> +{
>> +    int ret;
>> +    AVFilterLink *inlink = ctx->inputs[0];
>> +    AVFilterLink *outlink = ctx->outputs[0];
>> +    SceneChangeDetectContext *s = ctx->priv;
>> +    AVFrame *frame;
>> +
>> +    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
>> +
>> +    ret = ff_inlink_consume_frame(inlink, &frame);
>> +    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 (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);
>> +    }
>> +
>> +    FF_FILTER_FORWARD_STATUS(inlink, outlink);
>> +    FF_FILTER_FORWARD_WANTED(outlink, inlink);
>> +
>> +    return FFERROR_NOT_READY;
>> +}
>> +
>> +static const AVFilterPad scenechangedetect_inputs[] = {
>> +    {
>> +        .name         = "default",
>> +        .type         = AVMEDIA_TYPE_VIDEO,
>> +        .config_props = config_input,
>> +    },
>> +    { NULL }
>> +};
>> +
>> +static const AVFilterPad scenechangedetect_outputs[] = {
>> +    {
>> +        .name          = "default",
>> +        .type          = AVMEDIA_TYPE_VIDEO,
>> +    },
>> +    { NULL }
>> +};
>> +
>> +AVFilter ff_vf_scenechangedetect = {
>> +    .name          = "scenechangedetect",
>> +    .description   = NULL_IF_CONFIG_SMALL("Detect video scene change"),
>> +    .priv_size     = sizeof(SceneChangeDetectContext),
>> +    .priv_class    = &scenechangedetect_class,
>> +    .uninit        = uninit,
>> +    .query_formats = query_formats,
>> +    .inputs        = scenechangedetect_inputs,
>> +    .outputs       = scenechangedetect_outputs,
>> +    .activate      = activate,
>> +};
>> --
>> 2.21.0
>>
> _______________________________________________
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> ffmpeg-devel@ffmpeg.org
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> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
lance.lmwang@gmail.com Oct. 8, 2019, 12:50 a.m.
On Mon, Oct 07, 2019 at 09:00:10PM +0200, Paul B Mahol wrote:

> Too long filter name.
Yes, the name is too long, how about to use scdetect?  If it's OK, I'll
update the patch.

> 
> On 10/7/19, Limin Wang <lance.lmwang@gmail.com> wrote:
> >
> > ping, please give comments.
> >
> > On Sun, Sep 29, 2019 at 09:25:12PM +0800, lance.lmwang@gmail.com wrote:
> >> From: Limin Wang <lance.lmwang@gmail.com>
> >>
> >> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
> >> ---
> >> Please provide a comment to add a new filter for scene change detection to
> >> avoid
> >> multiple calculations of mafd in the filter chain. The filter can avoid
> >> duplication
> >> code also for I am writing a new filter to synchronize frames that require
> >> scene
> >> change information. If the detect metadata can get, the code will be
> >> simple.
> >>
> >> In addition, I'm trying  to add a reduced size before scene change
> >> detection to improve
> >> the performance. From the initial test, we can only get 10-20%
> >> improvement, but some
> >> scene change aren't detected after that. Therefore, I think that should
> >> not be done.
> >>
> >> This version, I removed the version change for it's easy to cause code
> >> conflict,
> >> please the committer help to update it if review done.
> >>
> >>  configure                          |   1 +
> >>  doc/filters.texi                   |  35 +++++
> >>  libavfilter/Makefile               |   1 +
> >>  libavfilter/allfilters.c           |   1 +
> >>  libavfilter/vf_scenechangedetect.c | 220 +++++++++++++++++++++++++++++
> >>  5 files changed, 258 insertions(+)
> >>  create mode 100644 libavfilter/vf_scenechangedetect.c
> >>
> >> diff --git a/configure b/configure
> >> index 8413826f9e..909a77b9cf 100755
> >> --- a/configure
> >> +++ b/configure
> >> @@ -3520,6 +3520,7 @@ sab_filter_deps="gpl swscale"
> >>  scale2ref_filter_deps="swscale"
> >>  scale_filter_deps="swscale"
> >>  scale_qsv_filter_deps="libmfx"
> >> +scenechangedetect_filter_select="scene_sad"
> >>  select_filter_select="scene_sad"
> >>  sharpness_vaapi_filter_deps="vaapi"
> >>  showcqt_filter_deps="avcodec avformat swscale"
> >> diff --git a/doc/filters.texi b/doc/filters.texi
> >> index e6f8bf0ee9..f9247643cb 100644
> >> --- a/doc/filters.texi
> >> +++ b/doc/filters.texi
> >> @@ -15642,6 +15642,41 @@ Scale a logo to 1/10th the height of a video,
> >> while preserving its display aspec
> >>  @end example
> >>  @end itemize
> >>
> >> +@anchor{scenechangedetect}
> >> +@section scenechangedetect
> >> +
> >> +Detect video scene change.
> >> +
> >> +This filter sets frame metadata with mafd between frame, the scene score,
> >> and
> >> +forward the frame to the next filter, so they can use these metadata to
> >> detect
> >> +scene change or others.
> >> +
> >> +In addition, this filter logs a message and sets frame metadata when it
> >> detects
> >> +a scene change by @option{threshold}.
> >> +
> >> +@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
> >> +
> >> +@code{lavfi.scd.score} metadata keys are set with scene change score for
> >> every frame
> >> +to detect scene change.
> >> +
> >> +@code{lavfi.scd.time} metadata keys are set with current filtered frame
> >> time which
> >> +detect scene change with @option{threshold}.
> >> +
> >> +The filter accepts the following options:
> >> +
> >> +@table @option
> >> +@item threshold, t
> >> +Set the scene change detection threshold as a percentage of maximum
> >> change.  Good
> >> +values are in the @code{[8.0, 14.0]} range. The range for
> >> @option{threshold} is
> >> +@code{[0., 100.]}.
> >> +
> >> +Default value is @code{10.}.
> >> +
> >> +@item sc_pass, s
> >> +Set the scene change pass the frame to the next filter or not. Default
> >> value is @code{0}
> >> +You can enable it if you want to get snapshot of scene change frames.
> >> +@end table
> >> +
> >>  @anchor{selectivecolor}
> >>  @section selectivecolor
> >>
> >> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
> >> index b99ecc8c26..f6c6ba5d45 100644
> >> --- a/libavfilter/Makefile
> >> +++ b/libavfilter/Makefile
> >> @@ -356,6 +356,7 @@ OBJS-$(CONFIG_SCALE_NPP_FILTER)              +=
> >> vf_scale_npp.o scale.o
> >>  OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
> >>  OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale.o
> >> vaapi_vpp.o
> >>  OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
> >> +OBJS-$(CONFIG_SCENECHANGEDETECT_FILTER)      += vf_scenechangedetect.o
> >>  OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
> >>  OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
> >>  OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
> >> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
> >> index 788652ab1e..69a4d5e8e5 100644
> >> --- a/libavfilter/allfilters.c
> >> +++ b/libavfilter/allfilters.c
> >> @@ -338,6 +338,7 @@ extern AVFilter ff_vf_scale_npp;
> >>  extern AVFilter ff_vf_scale_qsv;
> >>  extern AVFilter ff_vf_scale_vaapi;
> >>  extern AVFilter ff_vf_scale2ref;
> >> +extern AVFilter ff_vf_scenechangedetect;
> >>  extern AVFilter ff_vf_select;
> >>  extern AVFilter ff_vf_selectivecolor;
> >>  extern AVFilter ff_vf_sendcmd;
> >> diff --git a/libavfilter/vf_scenechangedetect.c
> >> b/libavfilter/vf_scenechangedetect.c
> >> new file mode 100644
> >> index 0000000000..269fa399d0
> >> --- /dev/null
> >> +++ b/libavfilter/vf_scenechangedetect.c
> >> @@ -0,0 +1,220 @@
> >> +/*
> >> + * This file is part of FFmpeg.
> >> + *
> >> + * FFmpeg is free software; you can redistribute it and/or
> >> + * modify it under the terms of the GNU Lesser General Public
> >> + * License as published by the Free Software Foundation; either
> >> + * version 2.1 of the License, or (at your option) any later version.
> >> + *
> >> + * FFmpeg is distributed in the hope that it will be useful,
> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> >> + * Lesser General Public License for more details.
> >> + *
> >> + * You should have received a copy of the GNU Lesser General Public
> >> + * License along with FFmpeg; if not, write to the Free Software
> >> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
> >> 02110-1301 USA
> >> + */
> >> +
> >> +/**
> >> + * @file
> >> + * video scene change detection filter
> >> + */
> >> +
> >> +#include "libavutil/avassert.h"
> >> +#include "libavutil/imgutils.h"
> >> +#include "libavutil/opt.h"
> >> +#include "libavutil/pixdesc.h"
> >> +#include "libavutil/timestamp.h"
> >> +
> >> +#include "avfilter.h"
> >> +#include "filters.h"
> >> +#include "scene_sad.h"
> >> +
> >> +typedef struct SceneChangeDetectContext {
> >> +    const AVClass *class;
> >> +
> >> +    ptrdiff_t width[4];
> >> +    ptrdiff_t height[4];
> >> +    int nb_planes;
> >> +    int bitdepth;
> >> +    ff_scene_sad_fn sad;
> >> +    double prev_mafd;
> >> +    double scene_score;
> >> +    AVFrame *prev_picref;
> >> +    double threshold;
> >> +    int sc_pass;
> >> +} SceneChangeDetectContext;
> >> +
> >> +#define OFFSET(x) offsetof(SceneChangeDetectContext, x)
> >> +#define V AV_OPT_FLAG_VIDEO_PARAM
> >> +#define F AV_OPT_FLAG_FILTERING_PARAM
> >> +
> >> +static const AVOption scenechangedetect_options[] = {
> >> +    { "threshold",   "set scene change detect level",
> >> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F
> >> },
> >> +    { "t",           "set scene change detect level",
> >> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F
> >> },
> >> +    { "sc_pass",     "set scene change frame pass",     OFFSET(sc_pass),
> >> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
> >> +    { "s",           "set scene change frame pass",     OFFSET(sc_pass),
> >> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
> >> +    {NULL}
> >> +};
> >> +
> >> +AVFILTER_DEFINE_CLASS(scenechangedetect);
> >> +
> >> +static int query_formats(AVFilterContext *ctx)
> >> +{
> >> +    static const enum AVPixelFormat pix_fmts[] = {
> >> +            AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, AV_PIX_FMT_RGBA,
> >> +            AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8,
> >> +            AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
> >> +            AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
> >> +            AV_PIX_FMT_YUV420P10,
> >> +            AV_PIX_FMT_NONE
> >> +    };
> >> +
> >> +    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
> >> +    if (!fmts_list)
> >> +        return AVERROR(ENOMEM);
> >> +    return ff_set_common_formats(ctx, fmts_list);
> >> +}
> >> +
> >> +static int config_input(AVFilterLink *inlink)
> >> +{
> >> +    AVFilterContext *ctx = inlink->dst;
> >> +    SceneChangeDetectContext *s = ctx->priv;
> >> +    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
> >> +    int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
> >> +        (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
> >> +        desc->nb_components >= 3;
> >> +
> >> +    s->bitdepth = desc->comp[0].depth;
> >> +    s->nb_planes = is_yuv ? 1 : av_pix_fmt_count_planes(inlink->format);
> >> +
> >> +    for (int plane = 0; plane < 4; plane++) {
> >> +        ptrdiff_t line_size = av_image_get_linesize(inlink->format,
> >> inlink->w, plane);
> >> +        s->width[plane] = line_size >> (s->bitdepth > 8);
> >> +        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->sad)
> >> +        return AVERROR(EINVAL);
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static av_cold void uninit(AVFilterContext *ctx)
> >> +{
> >> +    SceneChangeDetectContext *s = ctx->priv;
> >> +
> >> +    av_frame_free(&s->prev_picref);
> >> +}
> >> +
> >> +static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
> >> +{
> >> +    double ret = 0;
> >> +    SceneChangeDetectContext *s = ctx->priv;
> >> +    AVFrame *prev_picref = s->prev_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;
> >> +
> >> +        for (int plane = 0; plane < s->nb_planes; plane++) {
> >> +            uint64_t plane_sad;
> >> +            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;
> >> +            count += s->width[plane] * s->height[plane];
> >> +        }
> >> +
> >> +        emms_c();
> >> +        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->prev_picref = av_frame_clone(frame);
> >> +    return ret;
> >> +}
> >> +
> >> +static int set_meta(SceneChangeDetectContext *s, AVFrame *frame, const
> >> char *key, const char *value)
> >> +{
> >> +    return av_dict_set(&frame->metadata, key, value, 0);
> >> +}
> >> +
> >> +static int activate(AVFilterContext *ctx)
> >> +{
> >> +    int ret;
> >> +    AVFilterLink *inlink = ctx->inputs[0];
> >> +    AVFilterLink *outlink = ctx->outputs[0];
> >> +    SceneChangeDetectContext *s = ctx->priv;
> >> +    AVFrame *frame;
> >> +
> >> +    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
> >> +
> >> +    ret = ff_inlink_consume_frame(inlink, &frame);
> >> +    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 (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);
> >> +    }
> >> +
> >> +    FF_FILTER_FORWARD_STATUS(inlink, outlink);
> >> +    FF_FILTER_FORWARD_WANTED(outlink, inlink);
> >> +
> >> +    return FFERROR_NOT_READY;
> >> +}
> >> +
> >> +static const AVFilterPad scenechangedetect_inputs[] = {
> >> +    {
> >> +        .name         = "default",
> >> +        .type         = AVMEDIA_TYPE_VIDEO,
> >> +        .config_props = config_input,
> >> +    },
> >> +    { NULL }
> >> +};
> >> +
> >> +static const AVFilterPad scenechangedetect_outputs[] = {
> >> +    {
> >> +        .name          = "default",
> >> +        .type          = AVMEDIA_TYPE_VIDEO,
> >> +    },
> >> +    { NULL }
> >> +};
> >> +
> >> +AVFilter ff_vf_scenechangedetect = {
> >> +    .name          = "scenechangedetect",
> >> +    .description   = NULL_IF_CONFIG_SMALL("Detect video scene change"),
> >> +    .priv_size     = sizeof(SceneChangeDetectContext),
> >> +    .priv_class    = &scenechangedetect_class,
> >> +    .uninit        = uninit,
> >> +    .query_formats = query_formats,
> >> +    .inputs        = scenechangedetect_inputs,
> >> +    .outputs       = scenechangedetect_outputs,
> >> +    .activate      = activate,
> >> +};
> >> --
> >> 2.21.0
> >>
> > _______________________________________________
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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".
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> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
Paul B Mahol Oct. 8, 2019, 7:30 a.m.
On 10/8/19, Limin Wang <lance.lmwang@gmail.com> wrote:
> On Mon, Oct 07, 2019 at 09:00:10PM +0200, Paul B Mahol wrote:
>
>> Too long filter name.
> Yes, the name is too long, how about to use scdetect?  If it's OK, I'll
> update the patch.

Just scdet.

>
>>
>> On 10/7/19, Limin Wang <lance.lmwang@gmail.com> wrote:
>> >
>> > ping, please give comments.
>> >
>> > On Sun, Sep 29, 2019 at 09:25:12PM +0800, lance.lmwang@gmail.com wrote:
>> >> From: Limin Wang <lance.lmwang@gmail.com>
>> >>
>> >> Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
>> >> ---
>> >> Please provide a comment to add a new filter for scene change detection
>> >> to
>> >> avoid
>> >> multiple calculations of mafd in the filter chain. The filter can avoid
>> >> duplication
>> >> code also for I am writing a new filter to synchronize frames that
>> >> require
>> >> scene
>> >> change information. If the detect metadata can get, the code will be
>> >> simple.
>> >>
>> >> In addition, I'm trying  to add a reduced size before scene change
>> >> detection to improve
>> >> the performance. From the initial test, we can only get 10-20%
>> >> improvement, but some
>> >> scene change aren't detected after that. Therefore, I think that should
>> >> not be done.
>> >>
>> >> This version, I removed the version change for it's easy to cause code
>> >> conflict,
>> >> please the committer help to update it if review done.
>> >>
>> >>  configure                          |   1 +
>> >>  doc/filters.texi                   |  35 +++++
>> >>  libavfilter/Makefile               |   1 +
>> >>  libavfilter/allfilters.c           |   1 +
>> >>  libavfilter/vf_scenechangedetect.c | 220 +++++++++++++++++++++++++++++
>> >>  5 files changed, 258 insertions(+)
>> >>  create mode 100644 libavfilter/vf_scenechangedetect.c
>> >>
>> >> diff --git a/configure b/configure
>> >> index 8413826f9e..909a77b9cf 100755
>> >> --- a/configure
>> >> +++ b/configure
>> >> @@ -3520,6 +3520,7 @@ sab_filter_deps="gpl swscale"
>> >>  scale2ref_filter_deps="swscale"
>> >>  scale_filter_deps="swscale"
>> >>  scale_qsv_filter_deps="libmfx"
>> >> +scenechangedetect_filter_select="scene_sad"
>> >>  select_filter_select="scene_sad"
>> >>  sharpness_vaapi_filter_deps="vaapi"
>> >>  showcqt_filter_deps="avcodec avformat swscale"
>> >> diff --git a/doc/filters.texi b/doc/filters.texi
>> >> index e6f8bf0ee9..f9247643cb 100644
>> >> --- a/doc/filters.texi
>> >> +++ b/doc/filters.texi
>> >> @@ -15642,6 +15642,41 @@ Scale a logo to 1/10th the height of a video,
>> >> while preserving its display aspec
>> >>  @end example
>> >>  @end itemize
>> >>
>> >> +@anchor{scenechangedetect}
>> >> +@section scenechangedetect
>> >> +
>> >> +Detect video scene change.
>> >> +
>> >> +This filter sets frame metadata with mafd between frame, the scene
>> >> score,
>> >> and
>> >> +forward the frame to the next filter, so they can use these metadata
>> >> to
>> >> detect
>> >> +scene change or others.
>> >> +
>> >> +In addition, this filter logs a message and sets frame metadata when
>> >> it
>> >> detects
>> >> +a scene change by @option{threshold}.
>> >> +
>> >> +@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
>> >> +
>> >> +@code{lavfi.scd.score} metadata keys are set with scene change score
>> >> for
>> >> every frame
>> >> +to detect scene change.
>> >> +
>> >> +@code{lavfi.scd.time} metadata keys are set with current filtered
>> >> frame
>> >> time which
>> >> +detect scene change with @option{threshold}.
>> >> +
>> >> +The filter accepts the following options:
>> >> +
>> >> +@table @option
>> >> +@item threshold, t
>> >> +Set the scene change detection threshold as a percentage of maximum
>> >> change.  Good
>> >> +values are in the @code{[8.0, 14.0]} range. The range for
>> >> @option{threshold} is
>> >> +@code{[0., 100.]}.
>> >> +
>> >> +Default value is @code{10.}.
>> >> +
>> >> +@item sc_pass, s
>> >> +Set the scene change pass the frame to the next filter or not. Default
>> >> value is @code{0}
>> >> +You can enable it if you want to get snapshot of scene change frames.
>> >> +@end table
>> >> +
>> >>  @anchor{selectivecolor}
>> >>  @section selectivecolor
>> >>
>> >> diff --git a/libavfilter/Makefile b/libavfilter/Makefile
>> >> index b99ecc8c26..f6c6ba5d45 100644
>> >> --- a/libavfilter/Makefile
>> >> +++ b/libavfilter/Makefile
>> >> @@ -356,6 +356,7 @@ OBJS-$(CONFIG_SCALE_NPP_FILTER)              +=
>> >> vf_scale_npp.o scale.o
>> >>  OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
>> >>  OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o
>> >> scale.o
>> >> vaapi_vpp.o
>> >>  OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
>> >> +OBJS-$(CONFIG_SCENECHANGEDETECT_FILTER)      += vf_scenechangedetect.o
>> >>  OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
>> >>  OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
>> >>  OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
>> >> diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
>> >> index 788652ab1e..69a4d5e8e5 100644
>> >> --- a/libavfilter/allfilters.c
>> >> +++ b/libavfilter/allfilters.c
>> >> @@ -338,6 +338,7 @@ extern AVFilter ff_vf_scale_npp;
>> >>  extern AVFilter ff_vf_scale_qsv;
>> >>  extern AVFilter ff_vf_scale_vaapi;
>> >>  extern AVFilter ff_vf_scale2ref;
>> >> +extern AVFilter ff_vf_scenechangedetect;
>> >>  extern AVFilter ff_vf_select;
>> >>  extern AVFilter ff_vf_selectivecolor;
>> >>  extern AVFilter ff_vf_sendcmd;
>> >> diff --git a/libavfilter/vf_scenechangedetect.c
>> >> b/libavfilter/vf_scenechangedetect.c
>> >> new file mode 100644
>> >> index 0000000000..269fa399d0
>> >> --- /dev/null
>> >> +++ b/libavfilter/vf_scenechangedetect.c
>> >> @@ -0,0 +1,220 @@
>> >> +/*
>> >> + * This file is part of FFmpeg.
>> >> + *
>> >> + * FFmpeg is free software; you can redistribute it and/or
>> >> + * modify it under the terms of the GNU Lesser General Public
>> >> + * License as published by the Free Software Foundation; either
>> >> + * version 2.1 of the License, or (at your option) any later version.
>> >> + *
>> >> + * FFmpeg is distributed in the hope that it will be useful,
>> >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> >> + * Lesser General Public License for more details.
>> >> + *
>> >> + * You should have received a copy of the GNU Lesser General Public
>> >> + * License along with FFmpeg; if not, write to the Free Software
>> >> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
>> >> 02110-1301 USA
>> >> + */
>> >> +
>> >> +/**
>> >> + * @file
>> >> + * video scene change detection filter
>> >> + */
>> >> +
>> >> +#include "libavutil/avassert.h"
>> >> +#include "libavutil/imgutils.h"
>> >> +#include "libavutil/opt.h"
>> >> +#include "libavutil/pixdesc.h"
>> >> +#include "libavutil/timestamp.h"
>> >> +
>> >> +#include "avfilter.h"
>> >> +#include "filters.h"
>> >> +#include "scene_sad.h"
>> >> +
>> >> +typedef struct SceneChangeDetectContext {
>> >> +    const AVClass *class;
>> >> +
>> >> +    ptrdiff_t width[4];
>> >> +    ptrdiff_t height[4];
>> >> +    int nb_planes;
>> >> +    int bitdepth;
>> >> +    ff_scene_sad_fn sad;
>> >> +    double prev_mafd;
>> >> +    double scene_score;
>> >> +    AVFrame *prev_picref;
>> >> +    double threshold;
>> >> +    int sc_pass;
>> >> +} SceneChangeDetectContext;
>> >> +
>> >> +#define OFFSET(x) offsetof(SceneChangeDetectContext, x)
>> >> +#define V AV_OPT_FLAG_VIDEO_PARAM
>> >> +#define F AV_OPT_FLAG_FILTERING_PARAM
>> >> +
>> >> +static const AVOption scenechangedetect_options[] = {
>> >> +    { "threshold",   "set scene change detect level",
>> >> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100.,
>> >> V|F
>> >> },
>> >> +    { "t",           "set scene change detect level",
>> >> OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100.,
>> >> V|F
>> >> },
>> >> +    { "sc_pass",     "set scene change frame pass",
>> >> OFFSET(sc_pass),
>> >> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
>> >> +    { "s",           "set scene change frame pass",
>> >> OFFSET(sc_pass),
>> >> AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
>> >> +    {NULL}
>> >> +};
>> >> +
>> >> +AVFILTER_DEFINE_CLASS(scenechangedetect);
>> >> +
>> >> +static int query_formats(AVFilterContext *ctx)
>> >> +{
>> >> +    static const enum AVPixelFormat pix_fmts[] = {
>> >> +            AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, AV_PIX_FMT_RGBA,
>> >> +            AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8,
>> >> +            AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
>> >> +            AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
>> >> +            AV_PIX_FMT_YUV420P10,
>> >> +            AV_PIX_FMT_NONE
>> >> +    };
>> >> +
>> >> +    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
>> >> +    if (!fmts_list)
>> >> +        return AVERROR(ENOMEM);
>> >> +    return ff_set_common_formats(ctx, fmts_list);
>> >> +}
>> >> +
>> >> +static int config_input(AVFilterLink *inlink)
>> >> +{
>> >> +    AVFilterContext *ctx = inlink->dst;
>> >> +    SceneChangeDetectContext *s = ctx->priv;
>> >> +    const AVPixFmtDescriptor *desc =
>> >> av_pix_fmt_desc_get(inlink->format);
>> >> +    int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
>> >> +        (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
>> >> +        desc->nb_components >= 3;
>> >> +
>> >> +    s->bitdepth = desc->comp[0].depth;
>> >> +    s->nb_planes = is_yuv ? 1 :
>> >> av_pix_fmt_count_planes(inlink->format);
>> >> +
>> >> +    for (int plane = 0; plane < 4; plane++) {
>> >> +        ptrdiff_t line_size = av_image_get_linesize(inlink->format,
>> >> inlink->w, plane);
>> >> +        s->width[plane] = line_size >> (s->bitdepth > 8);
>> >> +        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->sad)
>> >> +        return AVERROR(EINVAL);
>> >> +
>> >> +    return 0;
>> >> +}
>> >> +
>> >> +static av_cold void uninit(AVFilterContext *ctx)
>> >> +{
>> >> +    SceneChangeDetectContext *s = ctx->priv;
>> >> +
>> >> +    av_frame_free(&s->prev_picref);
>> >> +}
>> >> +
>> >> +static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
>> >> +{
>> >> +    double ret = 0;
>> >> +    SceneChangeDetectContext *s = ctx->priv;
>> >> +    AVFrame *prev_picref = s->prev_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;
>> >> +
>> >> +        for (int plane = 0; plane < s->nb_planes; plane++) {
>> >> +            uint64_t plane_sad;
>> >> +            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;
>> >> +            count += s->width[plane] * s->height[plane];
>> >> +        }
>> >> +
>> >> +        emms_c();
>> >> +        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->prev_picref = av_frame_clone(frame);
>> >> +    return ret;
>> >> +}
>> >> +
>> >> +static int set_meta(SceneChangeDetectContext *s, AVFrame *frame, const
>> >> char *key, const char *value)
>> >> +{
>> >> +    return av_dict_set(&frame->metadata, key, value, 0);
>> >> +}
>> >> +
>> >> +static int activate(AVFilterContext *ctx)
>> >> +{
>> >> +    int ret;
>> >> +    AVFilterLink *inlink = ctx->inputs[0];
>> >> +    AVFilterLink *outlink = ctx->outputs[0];
>> >> +    SceneChangeDetectContext *s = ctx->priv;
>> >> +    AVFrame *frame;
>> >> +
>> >> +    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
>> >> +
>> >> +    ret = ff_inlink_consume_frame(inlink, &frame);
>> >> +    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 (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);
>> >> +    }
>> >> +
>> >> +    FF_FILTER_FORWARD_STATUS(inlink, outlink);
>> >> +    FF_FILTER_FORWARD_WANTED(outlink, inlink);
>> >> +
>> >> +    return FFERROR_NOT_READY;
>> >> +}
>> >> +
>> >> +static const AVFilterPad scenechangedetect_inputs[] = {
>> >> +    {
>> >> +        .name         = "default",
>> >> +        .type         = AVMEDIA_TYPE_VIDEO,
>> >> +        .config_props = config_input,
>> >> +    },
>> >> +    { NULL }
>> >> +};
>> >> +
>> >> +static const AVFilterPad scenechangedetect_outputs[] = {
>> >> +    {
>> >> +        .name          = "default",
>> >> +        .type          = AVMEDIA_TYPE_VIDEO,
>> >> +    },
>> >> +    { NULL }
>> >> +};
>> >> +
>> >> +AVFilter ff_vf_scenechangedetect = {
>> >> +    .name          = "scenechangedetect",
>> >> +    .description   = NULL_IF_CONFIG_SMALL("Detect video scene
>> >> change"),
>> >> +    .priv_size     = sizeof(SceneChangeDetectContext),
>> >> +    .priv_class    = &scenechangedetect_class,
>> >> +    .uninit        = uninit,
>> >> +    .query_formats = query_formats,
>> >> +    .inputs        = scenechangedetect_inputs,
>> >> +    .outputs       = scenechangedetect_outputs,
>> >> +    .activate      = activate,
>> >> +};
>> >> --
>> >> 2.21.0
>> >>
>> > _______________________________________________
>> > ffmpeg-devel mailing list
>> > 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".
>> _______________________________________________
>> ffmpeg-devel mailing list
>> 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".
> _______________________________________________
> ffmpeg-devel mailing list
> 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".

Patch hide | download patch | download mbox

diff --git a/configure b/configure
index 8413826f9e..909a77b9cf 100755
--- a/configure
+++ b/configure
@@ -3520,6 +3520,7 @@  sab_filter_deps="gpl swscale"
 scale2ref_filter_deps="swscale"
 scale_filter_deps="swscale"
 scale_qsv_filter_deps="libmfx"
+scenechangedetect_filter_select="scene_sad"
 select_filter_select="scene_sad"
 sharpness_vaapi_filter_deps="vaapi"
 showcqt_filter_deps="avcodec avformat swscale"
diff --git a/doc/filters.texi b/doc/filters.texi
index e6f8bf0ee9..f9247643cb 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -15642,6 +15642,41 @@  Scale a logo to 1/10th the height of a video, while preserving its display aspec
 @end example
 @end itemize
 
+@anchor{scenechangedetect}
+@section scenechangedetect
+
+Detect video scene change.
+
+This filter sets frame metadata with mafd between frame, the scene score, and
+forward the frame to the next filter, so they can use these metadata to detect
+scene change or others.
+
+In addition, this filter logs a message and sets frame metadata when it detects
+a scene change by @option{threshold}.
+
+@code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
+
+@code{lavfi.scd.score} metadata keys are set with scene change score for every frame
+to detect scene change.
+
+@code{lavfi.scd.time} metadata keys are set with current filtered frame time which
+detect scene change with @option{threshold}.
+
+The filter accepts the following options:
+
+@table @option
+@item threshold, t
+Set the scene change detection threshold as a percentage of maximum change.  Good
+values are in the @code{[8.0, 14.0]} range. The range for @option{threshold} is
+@code{[0., 100.]}.
+
+Default value is @code{10.}.
+
+@item sc_pass, s
+Set the scene change pass the frame to the next filter or not. Default value is @code{0}
+You can enable it if you want to get snapshot of scene change frames.
+@end table
+
 @anchor{selectivecolor}
 @section selectivecolor
 
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index b99ecc8c26..f6c6ba5d45 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -356,6 +356,7 @@  OBJS-$(CONFIG_SCALE_NPP_FILTER)              += vf_scale_npp.o scale.o
 OBJS-$(CONFIG_SCALE_QSV_FILTER)              += vf_scale_qsv.o
 OBJS-$(CONFIG_SCALE_VAAPI_FILTER)            += vf_scale_vaapi.o scale.o vaapi_vpp.o
 OBJS-$(CONFIG_SCALE2REF_FILTER)              += vf_scale.o scale.o
+OBJS-$(CONFIG_SCENECHANGEDETECT_FILTER)      += vf_scenechangedetect.o
 OBJS-$(CONFIG_SELECT_FILTER)                 += f_select.o
 OBJS-$(CONFIG_SELECTIVECOLOR_FILTER)         += vf_selectivecolor.o
 OBJS-$(CONFIG_SENDCMD_FILTER)                += f_sendcmd.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 788652ab1e..69a4d5e8e5 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -338,6 +338,7 @@  extern AVFilter ff_vf_scale_npp;
 extern AVFilter ff_vf_scale_qsv;
 extern AVFilter ff_vf_scale_vaapi;
 extern AVFilter ff_vf_scale2ref;
+extern AVFilter ff_vf_scenechangedetect;
 extern AVFilter ff_vf_select;
 extern AVFilter ff_vf_selectivecolor;
 extern AVFilter ff_vf_sendcmd;
diff --git a/libavfilter/vf_scenechangedetect.c b/libavfilter/vf_scenechangedetect.c
new file mode 100644
index 0000000000..269fa399d0
--- /dev/null
+++ b/libavfilter/vf_scenechangedetect.c
@@ -0,0 +1,220 @@ 
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * video scene change detection filter
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/timestamp.h"
+
+#include "avfilter.h"
+#include "filters.h"
+#include "scene_sad.h"
+
+typedef struct SceneChangeDetectContext {
+    const AVClass *class;
+
+    ptrdiff_t width[4];
+    ptrdiff_t height[4];
+    int nb_planes;
+    int bitdepth;
+    ff_scene_sad_fn sad;
+    double prev_mafd;
+    double scene_score;
+    AVFrame *prev_picref;
+    double threshold;
+    int sc_pass;
+} SceneChangeDetectContext;
+
+#define OFFSET(x) offsetof(SceneChangeDetectContext, x)
+#define V AV_OPT_FLAG_VIDEO_PARAM
+#define F AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption scenechangedetect_options[] = {
+    { "threshold",   "set scene change detect level",   OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F },
+    { "t",           "set scene change detect level",   OFFSET(threshold),  AV_OPT_TYPE_DOUBLE,   {.dbl = 10.},     0,  100., V|F },
+    { "sc_pass",     "set scene change frame pass",     OFFSET(sc_pass),  AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
+    { "s",           "set scene change frame pass",     OFFSET(sc_pass),  AV_OPT_TYPE_BOOL,       {.dbl = 0  },     0,    1., V|F },
+    {NULL}
+};
+
+AVFILTER_DEFINE_CLASS(scenechangedetect);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat pix_fmts[] = {
+            AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24, AV_PIX_FMT_RGBA,
+            AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA, AV_PIX_FMT_GRAY8,
+            AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P,
+            AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUVJ422P,
+            AV_PIX_FMT_YUV420P10,
+            AV_PIX_FMT_NONE
+    };
+
+    AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
+    if (!fmts_list)
+        return AVERROR(ENOMEM);
+    return ff_set_common_formats(ctx, fmts_list);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    SceneChangeDetectContext *s = ctx->priv;
+    const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
+    int is_yuv = !(desc->flags & AV_PIX_FMT_FLAG_RGB) &&
+        (desc->flags & AV_PIX_FMT_FLAG_PLANAR) &&
+        desc->nb_components >= 3;
+
+    s->bitdepth = desc->comp[0].depth;
+    s->nb_planes = is_yuv ? 1 : av_pix_fmt_count_planes(inlink->format);
+
+    for (int plane = 0; plane < 4; plane++) {
+        ptrdiff_t line_size = av_image_get_linesize(inlink->format, inlink->w, plane);
+        s->width[plane] = line_size >> (s->bitdepth > 8);
+        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->sad)
+        return AVERROR(EINVAL);
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    SceneChangeDetectContext *s = ctx->priv;
+
+    av_frame_free(&s->prev_picref);
+}
+
+static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
+{
+    double ret = 0;
+    SceneChangeDetectContext *s = ctx->priv;
+    AVFrame *prev_picref = s->prev_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;
+
+        for (int plane = 0; plane < s->nb_planes; plane++) {
+            uint64_t plane_sad;
+            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;
+            count += s->width[plane] * s->height[plane];
+        }
+
+        emms_c();
+        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->prev_picref = av_frame_clone(frame);
+    return ret;
+}
+
+static int set_meta(SceneChangeDetectContext *s, AVFrame *frame, const char *key, const char *value)
+{
+    return av_dict_set(&frame->metadata, key, value, 0);
+}
+
+static int activate(AVFilterContext *ctx)
+{
+    int ret;
+    AVFilterLink *inlink = ctx->inputs[0];
+    AVFilterLink *outlink = ctx->outputs[0];
+    SceneChangeDetectContext *s = ctx->priv;
+    AVFrame *frame;
+
+    FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
+
+    ret = ff_inlink_consume_frame(inlink, &frame);
+    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 (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);
+    }
+
+    FF_FILTER_FORWARD_STATUS(inlink, outlink);
+    FF_FILTER_FORWARD_WANTED(outlink, inlink);
+
+    return FFERROR_NOT_READY;
+}
+
+static const AVFilterPad scenechangedetect_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad scenechangedetect_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_scenechangedetect = {
+    .name          = "scenechangedetect",
+    .description   = NULL_IF_CONFIG_SMALL("Detect video scene change"),
+    .priv_size     = sizeof(SceneChangeDetectContext),
+    .priv_class    = &scenechangedetect_class,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = scenechangedetect_inputs,
+    .outputs       = scenechangedetect_outputs,
+    .activate      = activate,
+};