[FFmpeg-devel] [PATCH v2 1/3] avfilter/vf_scenechangedetect: add filter to detect scene change
Paul B Mahol
onemda at gmail.com
Tue Oct 8 10:30:08 EEST 2019
On 10/8/19, Limin Wang <lance.lmwang at 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 at gmail.com> wrote:
>> >
>> > ping, please give comments.
>> >
>> > On Sun, Sep 29, 2019 at 09:25:12PM +0800, lance.lmwang at gmail.com wrote:
>> >> From: Limin Wang <lance.lmwang at gmail.com>
>> >>
>> >> Signed-off-by: Limin Wang <lance.lmwang at 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
>> >>
>> >> + at anchor{scenechangedetect}
>> >> + at 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}.
>> >> +
>> >> + at code{lavfi.scd.mafd} metadata keys are set with mafd for every frame.
>> >> +
>> >> + at code{lavfi.scd.score} metadata keys are set with scene change score
>> >> for
>> >> every frame
>> >> +to detect scene change.
>> >> +
>> >> + at 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:
>> >> +
>> >> + at table @option
>> >> + at 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
>> >> + at code{[0., 100.]}.
>> >> +
>> >> +Default value is @code{10.}.
>> >> +
>> >> + at 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.
>> >> + at 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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