| 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 | }; |