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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavfilter/vf_blackdetect.c
Anton Khirnov b9c928a486 avfilter: add AVFILTER_FLAG_METADATA_ONLY
This flag allows distinguishing between filters that actually modify the
data and those that only modify metadata or gather some stream
information.
2021-12-04 14:07:19 +01:00

262 lines
9.5 KiB
C

/*
* Copyright (c) 2012 Stefano Sabatini
*
* 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 black detector, loosely based on blackframe with extended
* syntax and features
*/
#include <float.h>
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/timestamp.h"
#include "avfilter.h"
#include "internal.h"
typedef struct BlackDetectContext {
const AVClass *class;
double black_min_duration_time; ///< minimum duration of detected black, in seconds
int64_t black_min_duration; ///< minimum duration of detected black, expressed in timebase units
int64_t black_start; ///< pts start time of the first black picture
int64_t black_end; ///< pts end time of the last black picture
int64_t last_picref_pts; ///< pts of the last input picture
int black_started;
double picture_black_ratio_th;
double pixel_black_th;
unsigned int pixel_black_th_i;
unsigned int nb_black_pixels; ///< number of black pixels counted so far
AVRational time_base;
int depth;
int nb_threads;
unsigned int *counter;
} BlackDetectContext;
#define OFFSET(x) offsetof(BlackDetectContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption blackdetect_options[] = {
{ "d", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX, FLAGS },
{ "black_min_duration", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX, FLAGS },
{ "picture_black_ratio_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1, FLAGS },
{ "pic_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1, FLAGS },
{ "pixel_black_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1, FLAGS },
{ "pix_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(blackdetect);
#define YUVJ_FORMATS \
AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P
static const enum AVPixelFormat yuvj_formats[] = {
YUVJ_FORMATS, AV_PIX_FMT_NONE
};
static const enum AVPixelFormat pix_fmts[] = {
AV_PIX_FMT_GRAY8,
AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
AV_PIX_FMT_NV12, AV_PIX_FMT_NV21,
YUVJ_FORMATS,
AV_PIX_FMT_GRAY10, AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14,
AV_PIX_FMT_GRAY16,
AV_PIX_FMT_YUV420P9, AV_PIX_FMT_YUV422P9, AV_PIX_FMT_YUV444P9,
AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
AV_PIX_FMT_YUV440P10,
AV_PIX_FMT_YUV444P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV420P12,
AV_PIX_FMT_YUV440P12,
AV_PIX_FMT_YUV444P14, AV_PIX_FMT_YUV422P14, AV_PIX_FMT_YUV420P14,
AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
AV_PIX_FMT_YUVA444P9, AV_PIX_FMT_YUVA444P10, AV_PIX_FMT_YUVA444P12, AV_PIX_FMT_YUVA444P16,
AV_PIX_FMT_YUVA422P9, AV_PIX_FMT_YUVA422P10, AV_PIX_FMT_YUVA422P12, AV_PIX_FMT_YUVA422P16,
AV_PIX_FMT_YUVA420P9, AV_PIX_FMT_YUVA420P10, AV_PIX_FMT_YUVA420P16,
AV_PIX_FMT_NONE
};
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
BlackDetectContext *s = ctx->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
const int depth = desc->comp[0].depth;
const int max = (1 << depth) - 1;
const int factor = (1 << (depth - 8));
s->depth = depth;
s->nb_threads = ff_filter_get_nb_threads(ctx);
s->time_base = inlink->time_base;
s->black_min_duration = s->black_min_duration_time / av_q2d(s->time_base);
s->counter = av_calloc(s->nb_threads, sizeof(*s->counter));
if (!s->counter)
return AVERROR(ENOMEM);
s->pixel_black_th_i = ff_fmt_is_in(inlink->format, yuvj_formats) ?
// luminance_minimum_value + pixel_black_th * luminance_range_size
s->pixel_black_th * max :
16 * factor + s->pixel_black_th * (235 - 16) * factor;
av_log(s, AV_LOG_VERBOSE,
"black_min_duration:%s pixel_black_th:%f pixel_black_th_i:%d picture_black_ratio_th:%f\n",
av_ts2timestr(s->black_min_duration, &s->time_base),
s->pixel_black_th, s->pixel_black_th_i,
s->picture_black_ratio_th);
return 0;
}
static void check_black_end(AVFilterContext *ctx)
{
BlackDetectContext *s = ctx->priv;
if ((s->black_end - s->black_start) >= s->black_min_duration) {
av_log(s, AV_LOG_INFO,
"black_start:%s black_end:%s black_duration:%s\n",
av_ts2timestr(s->black_start, &s->time_base),
av_ts2timestr(s->black_end, &s->time_base),
av_ts2timestr(s->black_end - s->black_start, &s->time_base));
}
}
static int black_counter(AVFilterContext *ctx, void *arg,
int jobnr, int nb_jobs)
{
BlackDetectContext *s = ctx->priv;
const unsigned int threshold = s->pixel_black_th_i;
unsigned int *counterp = &s->counter[jobnr];
AVFrame *in = arg;
const int linesize = in->linesize[0];
const int w = in->width;
const int h = in->height;
const int start = (h * jobnr) / nb_jobs;
const int end = (h * (jobnr+1)) / nb_jobs;
const int size = end - start;
unsigned int counter = 0;
if (s->depth == 8) {
const uint8_t *p = in->data[0] + start * linesize;
for (int i = 0; i < size; i++) {
for (int x = 0; x < w; x++)
counter += p[x] <= threshold;
p += linesize;
}
} else {
const uint16_t *p = (const uint16_t *)(in->data[0] + start * linesize);
for (int i = 0; i < size; i++) {
for (int x = 0; x < w; x++)
counter += p[x] <= threshold;
p += linesize / 2;
}
}
*counterp = counter;
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *picref)
{
AVFilterContext *ctx = inlink->dst;
BlackDetectContext *s = ctx->priv;
double picture_black_ratio = 0;
ff_filter_execute(ctx, black_counter, picref, NULL,
FFMIN(inlink->h, s->nb_threads));
for (int i = 0; i < s->nb_threads; i++)
s->nb_black_pixels += s->counter[i];
picture_black_ratio = (double)s->nb_black_pixels / (inlink->w * inlink->h);
av_log(ctx, AV_LOG_DEBUG,
"frame:%"PRId64" picture_black_ratio:%f pts:%s t:%s type:%c\n",
inlink->frame_count_out, picture_black_ratio,
av_ts2str(picref->pts), av_ts2timestr(picref->pts, &s->time_base),
av_get_picture_type_char(picref->pict_type));
if (picture_black_ratio >= s->picture_black_ratio_th) {
if (!s->black_started) {
/* black starts here */
s->black_started = 1;
s->black_start = picref->pts;
av_dict_set(&picref->metadata, "lavfi.black_start",
av_ts2timestr(s->black_start, &s->time_base), 0);
}
} else if (s->black_started) {
/* black ends here */
s->black_started = 0;
s->black_end = picref->pts;
check_black_end(ctx);
av_dict_set(&picref->metadata, "lavfi.black_end",
av_ts2timestr(s->black_end, &s->time_base), 0);
}
s->last_picref_pts = picref->pts;
s->nb_black_pixels = 0;
return ff_filter_frame(inlink->dst->outputs[0], picref);
}
static av_cold void uninit(AVFilterContext *ctx)
{
BlackDetectContext *s = ctx->priv;
av_freep(&s->counter);
if (s->black_started) {
// FIXME: black_end should be set to last_picref_pts + last_picref_duration
s->black_end = s->last_picref_pts;
check_black_end(ctx);
}
}
static const AVFilterPad blackdetect_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_input,
.filter_frame = filter_frame,
},
};
static const AVFilterPad blackdetect_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
};
const AVFilter ff_vf_blackdetect = {
.name = "blackdetect",
.description = NULL_IF_CONFIG_SMALL("Detect video intervals that are (almost) black."),
.priv_size = sizeof(BlackDetectContext),
FILTER_INPUTS(blackdetect_inputs),
FILTER_OUTPUTS(blackdetect_outputs),
FILTER_PIXFMTS_ARRAY(pix_fmts),
.uninit = uninit,
.priv_class = &blackdetect_class,
.flags = AVFILTER_FLAG_SLICE_THREADS | AVFILTER_FLAG_METADATA_ONLY,
};