/* * 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" #include "video.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; 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); av_log(s, AV_LOG_VERBOSE, "black_min_duration:%s pixel_black_th:%f picture_black_ratio_th:%f\n", av_ts2timestr(s->black_min_duration, &s->time_base), s->pixel_black_th, 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; const int max = (1 << s->depth) - 1; const int factor = (1 << (s->depth - 8)); const int full = picref->color_range == AVCOL_RANGE_JPEG || ff_fmt_is_in(picref->format, yuvj_formats); s->pixel_black_th_i = full ? s->pixel_black_th * max : // luminance_minimum_value + pixel_black_th * luminance_range_size 16 * factor + s->pixel_black_th * (235 - 16) * factor; 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, }, }; 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(ff_video_default_filterpad), FILTER_PIXFMTS_ARRAY(pix_fmts), .uninit = uninit, .priv_class = &blackdetect_class, .flags = AVFILTER_FLAG_SLICE_THREADS | AVFILTER_FLAG_METADATA_ONLY, };