diff options
author | Stefano Sabatini <stefano.sabatini-lala@poste.it> | 2010-09-26 21:36:05 +0000 |
---|---|---|
committer | Stefano Sabatini <stefano.sabatini-lala@poste.it> | 2010-09-26 21:36:05 +0000 |
commit | 13fabd7a8d6b01587cfc5049549d2e389b568182 (patch) | |
tree | d5ec71628686c25550c495c23e1e499ca579d946 /libavfilter/vf_blackframe.c | |
parent | b6c06894560b9ed11bb6bf6d3036e7c278e1becf (diff) |
Port MPlayer blackframe filter.
See thread:
Subject: [FFmpeg-devel] [PATCH] Port MPlayer blackframe filter.
Date: Sun, 26 Sep 2010 01:10:40 +0200
Originally committed as revision 25214 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavfilter/vf_blackframe.c')
-rw-r--r-- | libavfilter/vf_blackframe.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/libavfilter/vf_blackframe.c b/libavfilter/vf_blackframe.c new file mode 100644 index 0000000000..0645ffa219 --- /dev/null +++ b/libavfilter/vf_blackframe.c @@ -0,0 +1,129 @@ +/* + * 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 +} 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_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; + + 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; + + 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:%f\n", + blackframe->frame, pblack, picref->pos, + picref->pts == AV_NOPTS_VALUE ? -1 : (double)picref->pts / AV_TIME_BASE); + + 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 = (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 = (AVFilterPad[]) {{ .name = "default", + .type = AVMEDIA_TYPE_VIDEO }, + { .name = NULL}}, +}; |