| /* |
| * 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/timestamp.h" |
| #include "avfilter.h" |
| #include "internal.h" |
| |
| typedef struct { |
| 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 |
| int black_started; |
| |
| double picture_black_ratio_th; |
| double pixel_black_th; |
| unsigned int pixel_black_th_i; |
| |
| unsigned int frame_count; ///< frame number |
| unsigned int nb_black_pixels; ///< number of black pixels counted so far |
| } BlackDetectContext; |
| |
| #define OFFSET(x) offsetof(BlackDetectContext, x) |
| 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}, |
| { "black_min_duration", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time), AV_OPT_TYPE_DOUBLE, {.dbl=2}, 0, DBL_MAX}, |
| { "picture_black_ratio_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1}, |
| { "pic_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th), AV_OPT_TYPE_DOUBLE, {.dbl=.98}, 0, 1}, |
| { "pixel_black_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1}, |
| { "pix_th", "set the pixel black threshold", OFFSET(pixel_black_th), AV_OPT_TYPE_DOUBLE, {.dbl=.10}, 0, 1}, |
| { NULL }, |
| }; |
| |
| static const char *blackdetect_get_name(void *ctx) |
| { |
| return "blackdetect"; |
| } |
| |
| static const AVClass blackdetect_class = { |
| .class_name = "BlackDetectContext", |
| .item_name = blackdetect_get_name, |
| .option = blackdetect_options, |
| }; |
| |
| #define YUVJ_FORMATS \ |
| PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ444P, PIX_FMT_YUVJ440P |
| |
| static enum PixelFormat yuvj_formats[] = { |
| YUVJ_FORMATS, PIX_FMT_NONE |
| }; |
| |
| static int query_formats(AVFilterContext *ctx) |
| { |
| static const enum PixelFormat pix_fmts[] = { |
| PIX_FMT_YUV410P, PIX_FMT_YUV420P, PIX_FMT_GRAY8, PIX_FMT_NV12, |
| PIX_FMT_NV21, PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV411P, |
| YUVJ_FORMATS, |
| PIX_FMT_NONE |
| }; |
| |
| avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts)); |
| return 0; |
| } |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| int ret; |
| BlackDetectContext *blackdetect = ctx->priv; |
| |
| blackdetect->class = &blackdetect_class; |
| av_opt_set_defaults(blackdetect); |
| |
| if ((ret = av_set_options_string(blackdetect, args, "=", ":")) < 0) { |
| av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| static int config_input(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| BlackDetectContext *blackdetect = ctx->priv; |
| |
| blackdetect->black_min_duration = |
| blackdetect->black_min_duration_time / av_q2d(inlink->time_base); |
| |
| blackdetect->pixel_black_th_i = ff_fmt_is_in(inlink->format, yuvj_formats) ? |
| // luminance_minimum_value + pixel_black_th * luminance_range_size |
| blackdetect->pixel_black_th * 255 : |
| 16 + blackdetect->pixel_black_th * (235 - 16); |
| |
| av_log(blackdetect, AV_LOG_INFO, |
| "black_min_duration:%s pixel_black_th:%f pixel_black_th_i:%d picture_black_ratio_th:%f\n", |
| av_ts2timestr(blackdetect->black_min_duration, &inlink->time_base), |
| blackdetect->pixel_black_th, blackdetect->pixel_black_th_i, |
| blackdetect->picture_black_ratio_th); |
| return 0; |
| } |
| |
| static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| BlackDetectContext *blackdetect = ctx->priv; |
| AVFilterBufferRef *picref = inlink->cur_buf; |
| int x, i; |
| const uint8_t *p = picref->data[0] + y * picref->linesize[0]; |
| |
| for (i = 0; i < h; i++) { |
| for (x = 0; x < inlink->w; x++) |
| blackdetect->nb_black_pixels += p[x] <= blackdetect->pixel_black_th_i; |
| p += picref->linesize[0]; |
| } |
| |
| avfilter_draw_slice(ctx->outputs[0], y, h, slice_dir); |
| } |
| |
| static void end_frame(AVFilterLink *inlink) |
| { |
| AVFilterContext *ctx = inlink->dst; |
| BlackDetectContext *blackdetect = ctx->priv; |
| AVFilterBufferRef *picref = inlink->cur_buf; |
| double picture_black_ratio = 0; |
| |
| picture_black_ratio = (double)blackdetect->nb_black_pixels / (inlink->w * inlink->h); |
| |
| av_log(ctx, AV_LOG_DEBUG, |
| "frame:%u picture_black_ratio:%f pos:%"PRId64" pts:%s t:%s type:%c\n", |
| blackdetect->frame_count, picture_black_ratio, |
| picref->pos, av_ts2str(picref->pts), |
| av_ts2timestr(blackdetect->black_start, &inlink->time_base), |
| av_get_picture_type_char(picref->video->pict_type)); |
| |
| if (picture_black_ratio >= blackdetect->picture_black_ratio_th) { |
| if (!blackdetect->black_started) { |
| /* black starts here */ |
| blackdetect->black_started = 1; |
| blackdetect->black_start = picref->pts; |
| } |
| } else if (blackdetect->black_started) { |
| /* black ends here */ |
| blackdetect->black_started = 0; |
| blackdetect->black_end = picref->pts; |
| |
| if ((blackdetect->black_end - blackdetect->black_start) >= blackdetect->black_min_duration) { |
| av_log(blackdetect, AV_LOG_INFO, |
| "black_start:%s black_end:%s black_duration:%s\n", |
| av_ts2timestr(blackdetect->black_start, &inlink->time_base), |
| av_ts2timestr(blackdetect->black_end, &inlink->time_base), |
| av_ts2timestr(blackdetect->black_end - blackdetect->black_start, &inlink->time_base)); |
| } |
| } |
| |
| blackdetect->frame_count++; |
| blackdetect->nb_black_pixels = 0; |
| avfilter_unref_buffer(picref); |
| avfilter_end_frame(inlink->dst->outputs[0]); |
| } |
| |
| AVFilter avfilter_vf_blackdetect = { |
| .name = "blackdetect", |
| .description = NULL_IF_CONFIG_SMALL("Detect video intervals that are (almost) black."), |
| .priv_size = sizeof(BlackDetectContext), |
| .init = init, |
| .query_formats = query_formats, |
| |
| .inputs = (const AVFilterPad[]) { |
| { .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO, |
| .config_props = config_input, |
| .draw_slice = draw_slice, |
| .get_video_buffer = avfilter_null_get_video_buffer, |
| .start_frame = ff_null_start_frame_keep_ref, |
| .end_frame = end_frame, }, |
| { .name = NULL } |
| }, |
| |
| .outputs = (const AVFilterPad[]) { |
| { .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO }, |
| { .name = NULL } |
| }, |
| }; |