[FFmpeg-devel] [PATCH v2 1/3] avfilter/vf_scenechangedetect: add filter to detect scene change
Limin Wang
lance.lmwang at gmail.com
Tue Oct 8 03:50:00 EEST 2019
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 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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