2 * Copyright (c) 2012 Stefano Sabatini
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 * Video black detector, loosely based on blackframe with extended
28 #include "libavutil/opt.h"
29 #include "libavutil/timestamp.h"
35 double black_min_duration_time
; ///< minimum duration of detected black, in seconds
36 int64_t black_min_duration
; ///< minimum duration of detected black, expressed in timebase units
37 int64_t black_start
; ///< pts start time of the first black picture
38 int64_t black_end
; ///< pts end time of the last black picture
39 int64_t last_picref_pts
; ///< pts of the last input picture
42 double picture_black_ratio_th
;
43 double pixel_black_th
;
44 unsigned int pixel_black_th_i
;
46 unsigned int nb_black_pixels
; ///< number of black pixels counted so far
49 #define OFFSET(x) offsetof(BlackDetectContext, x)
50 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
52 static const AVOption blackdetect_options
[] = {
53 { "d", "set minimum detected black duration in seconds", OFFSET(black_min_duration_time
), AV_OPT_TYPE_DOUBLE
, {.dbl
=2}, 0, DBL_MAX
, FLAGS
},
54 { "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
},
55 { "picture_black_ratio_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th
), AV_OPT_TYPE_DOUBLE
, {.dbl
=.98}, 0, 1, FLAGS
},
56 { "pic_th", "set the picture black ratio threshold", OFFSET(picture_black_ratio_th
), AV_OPT_TYPE_DOUBLE
, {.dbl
=.98}, 0, 1, FLAGS
},
57 { "pixel_black_th", "set the pixel black threshold", OFFSET(pixel_black_th
), AV_OPT_TYPE_DOUBLE
, {.dbl
=.10}, 0, 1, FLAGS
},
58 { "pix_th", "set the pixel black threshold", OFFSET(pixel_black_th
), AV_OPT_TYPE_DOUBLE
, {.dbl
=.10}, 0, 1, FLAGS
},
62 AVFILTER_DEFINE_CLASS(blackdetect
);
64 #define YUVJ_FORMATS \
65 AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P
67 static const enum AVPixelFormat yuvj_formats
[] = {
68 YUVJ_FORMATS
, AV_PIX_FMT_NONE
71 static int query_formats(AVFilterContext
*ctx
)
73 static const enum AVPixelFormat pix_fmts
[] = {
75 AV_PIX_FMT_YUV410P
, AV_PIX_FMT_YUV411P
,
76 AV_PIX_FMT_YUV420P
, AV_PIX_FMT_YUV422P
,
77 AV_PIX_FMT_YUV440P
, AV_PIX_FMT_YUV444P
,
78 AV_PIX_FMT_NV12
, AV_PIX_FMT_NV21
,
83 ff_set_common_formats(ctx
, ff_make_format_list(pix_fmts
));
87 static int config_input(AVFilterLink
*inlink
)
89 AVFilterContext
*ctx
= inlink
->dst
;
90 BlackDetectContext
*blackdetect
= ctx
->priv
;
92 blackdetect
->black_min_duration
=
93 blackdetect
->black_min_duration_time
/ av_q2d(inlink
->time_base
);
95 blackdetect
->pixel_black_th_i
= ff_fmt_is_in(inlink
->format
, yuvj_formats
) ?
96 // luminance_minimum_value + pixel_black_th * luminance_range_size
97 blackdetect
->pixel_black_th
* 255 :
98 16 + blackdetect
->pixel_black_th
* (235 - 16);
100 av_log(blackdetect
, AV_LOG_VERBOSE
,
101 "black_min_duration:%s pixel_black_th:%f pixel_black_th_i:%d picture_black_ratio_th:%f\n",
102 av_ts2timestr(blackdetect
->black_min_duration
, &inlink
->time_base
),
103 blackdetect
->pixel_black_th
, blackdetect
->pixel_black_th_i
,
104 blackdetect
->picture_black_ratio_th
);
108 static void check_black_end(AVFilterContext
*ctx
)
110 BlackDetectContext
*blackdetect
= ctx
->priv
;
111 AVFilterLink
*inlink
= ctx
->inputs
[0];
113 if ((blackdetect
->black_end
- blackdetect
->black_start
) >= blackdetect
->black_min_duration
) {
114 av_log(blackdetect
, AV_LOG_INFO
,
115 "black_start:%s black_end:%s black_duration:%s\n",
116 av_ts2timestr(blackdetect
->black_start
, &inlink
->time_base
),
117 av_ts2timestr(blackdetect
->black_end
, &inlink
->time_base
),
118 av_ts2timestr(blackdetect
->black_end
- blackdetect
->black_start
, &inlink
->time_base
));
122 static int request_frame(AVFilterLink
*outlink
)
124 AVFilterContext
*ctx
= outlink
->src
;
125 BlackDetectContext
*blackdetect
= ctx
->priv
;
126 AVFilterLink
*inlink
= ctx
->inputs
[0];
127 int ret
= ff_request_frame(inlink
);
129 if (ret
== AVERROR_EOF
&& blackdetect
->black_started
) {
130 // FIXME: black_end should be set to last_picref_pts + last_picref_duration
131 blackdetect
->black_end
= blackdetect
->last_picref_pts
;
132 check_black_end(ctx
);
137 // TODO: document metadata
138 static int filter_frame(AVFilterLink
*inlink
, AVFrame
*picref
)
140 AVFilterContext
*ctx
= inlink
->dst
;
141 BlackDetectContext
*blackdetect
= ctx
->priv
;
142 double picture_black_ratio
= 0;
143 const uint8_t *p
= picref
->data
[0];
146 for (i
= 0; i
< inlink
->h
; i
++) {
147 for (x
= 0; x
< inlink
->w
; x
++)
148 blackdetect
->nb_black_pixels
+= p
[x
] <= blackdetect
->pixel_black_th_i
;
149 p
+= picref
->linesize
[0];
152 picture_black_ratio
= (double)blackdetect
->nb_black_pixels
/ (inlink
->w
* inlink
->h
);
154 av_log(ctx
, AV_LOG_DEBUG
,
155 "frame:%"PRId64
" picture_black_ratio:%f pts:%s t:%s type:%c\n",
156 inlink
->frame_count
, picture_black_ratio
,
157 av_ts2str(picref
->pts
), av_ts2timestr(picref
->pts
, &inlink
->time_base
),
158 av_get_picture_type_char(picref
->pict_type
));
160 if (picture_black_ratio
>= blackdetect
->picture_black_ratio_th
) {
161 if (!blackdetect
->black_started
) {
162 /* black starts here */
163 blackdetect
->black_started
= 1;
164 blackdetect
->black_start
= picref
->pts
;
165 av_dict_set(avpriv_frame_get_metadatap(picref
), "lavfi.black_start",
166 av_ts2timestr(blackdetect
->black_start
, &inlink
->time_base
), 0);
168 } else if (blackdetect
->black_started
) {
169 /* black ends here */
170 blackdetect
->black_started
= 0;
171 blackdetect
->black_end
= picref
->pts
;
172 check_black_end(ctx
);
173 av_dict_set(avpriv_frame_get_metadatap(picref
), "lavfi.black_end",
174 av_ts2timestr(blackdetect
->black_end
, &inlink
->time_base
), 0);
177 blackdetect
->last_picref_pts
= picref
->pts
;
178 blackdetect
->nb_black_pixels
= 0;
179 return ff_filter_frame(inlink
->dst
->outputs
[0], picref
);
182 static const AVFilterPad blackdetect_inputs
[] = {
185 .type
= AVMEDIA_TYPE_VIDEO
,
186 .config_props
= config_input
,
187 .filter_frame
= filter_frame
,
192 static const AVFilterPad blackdetect_outputs
[] = {
195 .type
= AVMEDIA_TYPE_VIDEO
,
196 .request_frame
= request_frame
,
201 AVFilter ff_vf_blackdetect
= {
202 .name
= "blackdetect",
203 .description
= NULL_IF_CONFIG_SMALL("Detect video intervals that are (almost) black."),
204 .priv_size
= sizeof(BlackDetectContext
),
205 .query_formats
= query_formats
,
206 .inputs
= blackdetect_inputs
,
207 .outputs
= blackdetect_outputs
,
208 .priv_class
= &blackdetect_class
,