| /* |
| * 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 "avfilter.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 PixelFormat pix_fmts[] = { |
| PIX_FMT_YUV410P, PIX_FMT_YUV420P, PIX_FMT_GRAY8, PIX_FMT_NV12, |
| PIX_FMT_NV21, PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV411P, |
| PIX_FMT_NONE |
| }; |
| |
| avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts)); |
| return 0; |
| } |
| |
| static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) |
| { |
| 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_INFO, "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 void 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]; |
| } |
| |
| avfilter_draw_slice(ctx->outputs[0], y, h, slice_dir); |
| } |
| |
| static void 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; |
| avfilter_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 = avfilter_null_get_video_buffer, |
| .start_frame = avfilter_null_start_frame, |
| .end_frame = end_frame, }, |
| { .name = NULL}}, |
| |
| .outputs = (const AVFilterPad[]) {{ .name = "default", |
| .type = AVMEDIA_TYPE_VIDEO }, |
| { .name = NULL}}, |
| }; |