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1 | /* |
2 | * Copyright (c) 2010 Stefano Sabatini | |
3 | * Copyright (c) 2006 Ivo van Poorten | |
4 | * Copyright (c) 2006 Julian Hall | |
5 | * Copyright (c) 2002-2003 Brian J. Murrell | |
6 | * | |
7 | * This file is part of FFmpeg. | |
8 | * | |
9 | * FFmpeg is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * FFmpeg is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with FFmpeg; if not, write to the Free Software Foundation, Inc., | |
21 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
22 | */ | |
23 | ||
24 | /** | |
25 | * @file | |
26 | * Search for black frames to detect scene transitions. | |
27 | * Ported from MPlayer libmpcodecs/vf_blackframe.c. | |
28 | */ | |
29 | ||
30 | #include <stdio.h> | |
31 | #include <inttypes.h> | |
32 | ||
33 | #include "libavutil/internal.h" | |
34 | #include "libavutil/opt.h" | |
35 | #include "avfilter.h" | |
36 | #include "formats.h" | |
37 | #include "internal.h" | |
38 | #include "video.h" | |
39 | ||
40 | typedef struct BlackFrameContext { | |
41 | const AVClass *class; | |
42 | int bamount; ///< black amount | |
43 | int bthresh; ///< black threshold | |
44 | unsigned int frame; ///< frame number | |
45 | unsigned int nblack; ///< number of black pixels counted so far | |
46 | unsigned int last_keyframe; ///< frame number of the last received key-frame | |
47 | } BlackFrameContext; | |
48 | ||
49 | static int query_formats(AVFilterContext *ctx) | |
50 | { | |
51 | static const enum AVPixelFormat pix_fmts[] = { | |
52 | AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NV12, | |
53 | AV_PIX_FMT_NV21, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P, | |
54 | AV_PIX_FMT_NONE | |
55 | }; | |
56 | ||
57 | ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); | |
58 | return 0; | |
59 | } | |
60 | ||
61 | #define SET_META(key, format, value) \ | |
62 | snprintf(buf, sizeof(buf), format, value); \ | |
63 | av_dict_set(metadata, key, buf, 0) | |
64 | ||
65 | static int filter_frame(AVFilterLink *inlink, AVFrame *frame) | |
66 | { | |
67 | AVFilterContext *ctx = inlink->dst; | |
68 | BlackFrameContext *s = ctx->priv; | |
69 | int x, i; | |
70 | int pblack = 0; | |
71 | uint8_t *p = frame->data[0]; | |
72 | AVDictionary **metadata; | |
73 | char buf[32]; | |
74 | ||
75 | for (i = 0; i < frame->height; i++) { | |
76 | for (x = 0; x < inlink->w; x++) | |
77 | s->nblack += p[x] < s->bthresh; | |
78 | p += frame->linesize[0]; | |
79 | } | |
80 | ||
81 | if (frame->key_frame) | |
82 | s->last_keyframe = s->frame; | |
83 | ||
84 | pblack = s->nblack * 100 / (inlink->w * inlink->h); | |
85 | if (pblack >= s->bamount) { | |
86 | metadata = avpriv_frame_get_metadatap(frame); | |
87 | ||
88 | av_log(ctx, AV_LOG_INFO, "frame:%u pblack:%u pts:%"PRId64" t:%f " | |
89 | "type:%c last_keyframe:%d\n", | |
90 | s->frame, pblack, frame->pts, | |
91 | frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base), | |
92 | av_get_picture_type_char(frame->pict_type), s->last_keyframe); | |
93 | ||
94 | SET_META("lavfi.blackframe.pblack", "%u", pblack); | |
95 | } | |
96 | ||
97 | s->frame++; | |
98 | s->nblack = 0; | |
99 | return ff_filter_frame(inlink->dst->outputs[0], frame); | |
100 | } | |
101 | ||
102 | #define OFFSET(x) offsetof(BlackFrameContext, x) | |
103 | #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM | |
104 | static const AVOption blackframe_options[] = { | |
105 | { "amount", "Percentage of the pixels that have to be below the threshold " | |
106 | "for the frame to be considered black.", OFFSET(bamount), AV_OPT_TYPE_INT, { .i64 = 98 }, 0, 100, FLAGS }, | |
107 | { "threshold", "threshold below which a pixel value is considered black", | |
108 | OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, | |
109 | { "thresh", "threshold below which a pixel value is considered black", | |
110 | OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, | |
111 | { NULL } | |
112 | }; | |
113 | ||
114 | AVFILTER_DEFINE_CLASS(blackframe); | |
115 | ||
116 | static const AVFilterPad avfilter_vf_blackframe_inputs[] = { | |
117 | { | |
118 | .name = "default", | |
119 | .type = AVMEDIA_TYPE_VIDEO, | |
120 | .filter_frame = filter_frame, | |
121 | }, | |
122 | { NULL } | |
123 | }; | |
124 | ||
125 | static const AVFilterPad avfilter_vf_blackframe_outputs[] = { | |
126 | { | |
127 | .name = "default", | |
128 | .type = AVMEDIA_TYPE_VIDEO | |
129 | }, | |
130 | { NULL } | |
131 | }; | |
132 | ||
133 | AVFilter ff_vf_blackframe = { | |
134 | .name = "blackframe", | |
135 | .description = NULL_IF_CONFIG_SMALL("Detect frames that are (almost) black."), | |
136 | .priv_size = sizeof(BlackFrameContext), | |
137 | .priv_class = &blackframe_class, | |
138 | .query_formats = query_formats, | |
139 | .inputs = avfilter_vf_blackframe_inputs, | |
140 | .outputs = avfilter_vf_blackframe_outputs, | |
141 | }; |