/* * 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 "avfilter.h" #include "internal.h" #include "formats.h" #include "internal.h" #include "video.h" typedef struct { unsigned int bamount; ///< black amount unsigned 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; } static av_cold int init(AVFilterContext *ctx, const char *args) { BlackFrameContext *blackframe = ctx->priv; blackframe->bamount = 98; blackframe->bthresh = 32; blackframe->nblack = 0; blackframe->frame = 0; blackframe->last_keyframe = 0; if (args) sscanf(args, "%u:%u", &blackframe->bamount, &blackframe->bthresh); av_log(ctx, AV_LOG_VERBOSE, "bamount:%u bthresh:%u\n", blackframe->bamount, blackframe->bthresh); if (blackframe->bamount > 100 || blackframe->bthresh > 255) { av_log(ctx, AV_LOG_ERROR, "Too big value for bamount (max is 100) or bthresh (max is 255)\n"); return AVERROR(EINVAL); } return 0; } static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { AVFilterContext *ctx = inlink->dst; BlackFrameContext *blackframe = ctx->priv; AVFilterBufferRef *picref = inlink->cur_buf; int x, i; uint8_t *p = picref->data[0] + y * picref->linesize[0]; for (i = 0; i < h; i++) { for (x = 0; x < inlink->w; x++) blackframe->nblack += p[x] < blackframe->bthresh; p += picref->linesize[0]; } return ff_draw_slice(ctx->outputs[0], y, h, slice_dir); } static int end_frame(AVFilterLink *inlink) { AVFilterContext *ctx = inlink->dst; BlackFrameContext *blackframe = ctx->priv; AVFilterBufferRef *picref = inlink->cur_buf; int pblack = 0; if (picref->video->key_frame) blackframe->last_keyframe = blackframe->frame; pblack = blackframe->nblack * 100 / (inlink->w * inlink->h); if (pblack >= blackframe->bamount) av_log(ctx, AV_LOG_INFO, "frame:%u pblack:%u pos:%"PRId64" pts:%"PRId64" t:%f " "type:%c last_keyframe:%d\n", blackframe->frame, pblack, picref->pos, picref->pts, picref->pts == AV_NOPTS_VALUE ? -1 : picref->pts * av_q2d(inlink->time_base), av_get_picture_type_char(picref->video->pict_type), blackframe->last_keyframe); blackframe->frame++; blackframe->nblack = 0; return ff_end_frame(inlink->dst->outputs[0]); } AVFilter avfilter_vf_blackframe = { .name = "blackframe", .description = NULL_IF_CONFIG_SMALL("Detect frames that are (almost) black."), .priv_size = sizeof(BlackFrameContext), .init = init, .query_formats = query_formats, .inputs = (const AVFilterPad[]) {{ .name = "default", .type = AVMEDIA_TYPE_VIDEO, .draw_slice = draw_slice, .get_video_buffer = ff_null_get_video_buffer, .start_frame = ff_null_start_frame, .end_frame = end_frame, }, { .name = NULL}}, .outputs = (const AVFilterPad[]) {{ .name = "default", .type = AVMEDIA_TYPE_VIDEO }, { .name = NULL}}, };