/* * Copyright (c) 2010 Stefano Sabatini * Copyright (c) 2006 Ivo van Poorten * Copyright (c) 2006 Julian Hall * Copyright (c) 2002-2003 Brian J. Murrell * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License for more details. * * You should have received a copy of the GNU 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 * Search for black frames to detect scene transitions. * Ported from MPlayer libmpcodecs/vf_blackframe.c. */ #include <stdio.h> #include <inttypes.h> #include "libavutil/internal.h" #include "libavutil/opt.h" #include "avfilter.h" #include "formats.h" #include "internal.h" #include "video.h" typedef struct BlackFrameContext { const AVClass *class; int bamount; ///< black amount int bthresh; ///< black threshold unsigned int frame; ///< frame number unsigned int nblack; ///< number of black pixels counted so far unsigned int last_keyframe; ///< frame number of the last received key-frame } BlackFrameContext; static int query_formats(AVFilterContext *ctx) { static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NV12, AV_PIX_FMT_NV21, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_NONE }; ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); return 0; } #define SET_META(key, format, value) \ snprintf(buf, sizeof(buf), format, value); \ av_dict_set(metadata, key, buf, 0) static int filter_frame(AVFilterLink *inlink, AVFrame *frame) { AVFilterContext *ctx = inlink->dst; BlackFrameContext *s = ctx->priv; int x, i; int pblack = 0; uint8_t *p = frame->data[0]; AVDictionary **metadata; char buf[32]; for (i = 0; i < frame->height; i++) { for (x = 0; x < inlink->w; x++) s->nblack += p[x] < s->bthresh; p += frame->linesize[0]; } if (frame->key_frame) s->last_keyframe = s->frame; pblack = s->nblack * 100 / (inlink->w * inlink->h); if (pblack >= s->bamount) { metadata = avpriv_frame_get_metadatap(frame); av_log(ctx, AV_LOG_INFO, "frame:%u pblack:%u pts:%"PRId64" t:%f " "type:%c last_keyframe:%d\n", s->frame, pblack, frame->pts, frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base), av_get_picture_type_char(frame->pict_type), s->last_keyframe); SET_META("lavfi.blackframe.pblack", "%u", pblack); } s->frame++; s->nblack = 0; return ff_filter_frame(inlink->dst->outputs[0], frame); } #define OFFSET(x) offsetof(BlackFrameContext, x) #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption blackframe_options[] = { { "amount", "Percentage of the pixels that have to be below the threshold " "for the frame to be considered black.", OFFSET(bamount), AV_OPT_TYPE_INT, { .i64 = 98 }, 0, 100, FLAGS }, { "threshold", "threshold below which a pixel value is considered black", OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, { "thresh", "threshold below which a pixel value is considered black", OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, 255, FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(blackframe); static const AVFilterPad avfilter_vf_blackframe_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad avfilter_vf_blackframe_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO }, { NULL } }; AVFilter ff_vf_blackframe = { .name = "blackframe", .description = NULL_IF_CONFIG_SMALL("Detect frames that are (almost) black."), .priv_size = sizeof(BlackFrameContext), .priv_class = &blackframe_class, .query_formats = query_formats, .inputs = avfilter_vf_blackframe_inputs, .outputs = avfilter_vf_blackframe_outputs, };