Commit 13fabd7a authored by Stefano Sabatini's avatar Stefano Sabatini
Browse files

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
parent b6c06894
......@@ -41,6 +41,7 @@ version <next>:
- make the crop filter accept parametric expressions
- make ffprobe accept AVFormatContext options
- yadif filter
- blackframe filter
version 0.6:
......
......@@ -1401,6 +1401,7 @@ tcp_protocol_deps="network"
udp_protocol_deps="network"
# filters
blackframe_filter_deps="gpl"
ocv_smooth_filter_deps="libopencv"
yadif_filter_deps="gpl"
......
......@@ -71,6 +71,27 @@ build.
Below is a description of the currently available video filters.
@section blackframe
Detect frames that are (almost) completely black. Can be useful to
detect chapter transitions or commercials. Output lines consist of
the frame number of the detected frame, the percentage of blackness,
the position in the file if known or -1 and the timestamp in seconds.
In order to display the output lines, you need to set the loglevel at
least to the AV_LOG_INFO value.
The filter accepts the syntax:
@example
blackframe[=@var{amount}:[@var{threshold}]]
@end example
@var{amount} is the percentage of the pixels that have to be below the
threshold, and defaults to 98.
@var{threshold} is the threshold below which a pixel value is
considered black, and defaults to 32.
@section crop
Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
......
......@@ -21,6 +21,7 @@ OBJS-$(CONFIG_ANULLSRC_FILTER) += asrc_anullsrc.o
OBJS-$(CONFIG_ANULLSINK_FILTER) += asink_anullsink.o
OBJS-$(CONFIG_ASPECT_FILTER) += vf_aspect.o
OBJS-$(CONFIG_BLACKFRAME_FILTER) += vf_blackframe.o
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_FIFO_FILTER) += vf_fifo.o
OBJS-$(CONFIG_FORMAT_FILTER) += vf_format.o
......
......@@ -41,6 +41,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (ANULLSINK, anullsink, asink);
REGISTER_FILTER (ASPECT, aspect, vf);
REGISTER_FILTER (BLACKFRAME, blackframe, vf);
REGISTER_FILTER (CROP, crop, vf);
REGISTER_FILTER (FIFO, fifo, vf);
REGISTER_FILTER (FORMAT, format, vf);
......
......@@ -25,7 +25,7 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 1
#define LIBAVFILTER_VERSION_MINOR 45
#define LIBAVFILTER_VERSION_MINOR 46
#define LIBAVFILTER_VERSION_MICRO 0
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
......
/*
* 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}},
};
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