/*
* 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/imgutils.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timestamp.h"
#include "avfilter.h"
#include "filters.h"
#include "scene_sad.h"
#include "video.h"
typedef struct SCDetContext {
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;
} SCDetContext;
#define OFFSET(x) offsetof(SCDetContext, x)
#define V AV_OPT_FLAG_VIDEO_PARAM
#define F AV_OPT_FLAG_FILTERING_PARAM
static const AVOption scdet_options[] = {
{ "threshold", "set scene change detect threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl = 10.}, 0, 100., V|F },
{ "t", "set scene change detect threshold", OFFSET(threshold), AV_OPT_TYPE_DOUBLE, {.dbl = 10.}, 0, 100., V|F },
{ "sc_pass", "Set the flag to pass scene change frames", OFFSET(sc_pass), AV_OPT_TYPE_BOOL, {.dbl = 0 }, 0, 1, V|F },
{ "s", "Set the flag to pass scene change frames", OFFSET(sc_pass), AV_OPT_TYPE_BOOL, {.dbl = 0 }, 0, 1, V|F },
{NULL}
};
AVFILTER_DEFINE_CLASS(scdet);
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_YUV440P, AV_PIX_FMT_YUVJ440P,
AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV420P12,
AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV422P12,
AV_PIX_FMT_YUV444P9, AV_PIX_FMT_YUV444P10, AV_PIX_FMT_YUV444P12,
AV_PIX_FMT_NONE
};
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
SCDetContext *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)
{
SCDetContext *s = ctx->priv;
av_frame_free(&s->prev_picref);
}
static double get_scene_score(AVFilterContext *ctx, AVFrame *frame)
{
double ret = 0;
SCDetContext *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];
}
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(SCDetContext *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];
SCDetContext *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 scdet_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
},
};
const AVFilter ff_vf_scdet = {
.name = "scdet",
.description = NULL_IF_CONFIG_SMALL("Detect video scene change"),
.priv_size = sizeof(SCDetContext),
.priv_class = &scdet_class,
.uninit = uninit,
.flags = AVFILTER_FLAG_METADATA_ONLY,
FILTER_INPUTS(scdet_inputs),
FILTER_OUTPUTS(ff_video_default_filterpad),
FILTER_PIXFMTS_ARRAY(pix_fmts),
.activate = activate,
};