Libav
vf_blackframe.c
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1 /*
2  * Copyright (c) 2010 Stefano Sabatini
3  * Copyright (c) 2006 Ivo van Poorten
4  * Copyright (c) 2006 Julian Hall
5  * Copyright (c) 2002-2003 Brian J. Murrell
6  *
7  * This file is part of Libav.
8  *
9  * Libav is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * Libav is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with Libav; if not, write to the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
30 #include <stdio.h>
31 #include <inttypes.h>
32 
33 #include "libavutil/internal.h"
34 #include "libavutil/opt.h"
35 
36 #include "avfilter.h"
37 #include "formats.h"
38 #include "internal.h"
39 #include "video.h"
40 
41 typedef struct BlackFrameContext {
42  const AVClass *class;
43  int bamount;
44  int bthresh;
45  unsigned int frame;
46  unsigned int nblack;
48 
50 {
51  static const enum AVPixelFormat pix_fmts[] = {
55  };
56 
58  return 0;
59 }
60 
61 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
62 {
63  AVFilterContext *ctx = inlink->dst;
64  BlackFrameContext *s = ctx->priv;
65  int x, i;
66  int pblack = 0;
67  uint8_t *p = frame->data[0];
68 
69  for (i = 0; i < frame->height; i++) {
70  for (x = 0; x < inlink->w; x++)
71  s->nblack += p[x] < s->bthresh;
72  p += frame->linesize[0];
73  }
74 
75  pblack = s->nblack * 100 / (inlink->w * inlink->h);
76  if (pblack >= s->bamount)
77  av_log(ctx, AV_LOG_INFO, "frame:%u pblack:%u pts:%"PRId64" t:%f\n",
78  s->frame, pblack, frame->pts,
79  frame->pts == AV_NOPTS_VALUE ? -1 : frame->pts * av_q2d(inlink->time_base));
80 
81  s->frame++;
82  s->nblack = 0;
83  return ff_filter_frame(inlink->dst->outputs[0], frame);
84 }
85 
86 #define OFFSET(x) offsetof(BlackFrameContext, x)
87 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM
88 static const AVOption options[] = {
89  { "amount", "Percentage of the pixels that have to be below the threshold "
90  "for the frame to be considered black.", OFFSET(bamount), AV_OPT_TYPE_INT, { .i64 = 98 }, 0, 100, FLAGS },
91  { "threshold", "threshold below which a pixel value is considered black",
92  OFFSET(bthresh), AV_OPT_TYPE_INT, { .i64 = 32 }, 0, INT_MAX, FLAGS },
93  { NULL },
94 };
95 
96 static const AVClass blackframe_class = {
97  .class_name = "blackframe",
98  .item_name = av_default_item_name,
99  .option = options,
100  .version = LIBAVUTIL_VERSION_INT,
101 };
102 
104  {
105  .name = "default",
106  .type = AVMEDIA_TYPE_VIDEO,
107  .get_video_buffer = ff_null_get_video_buffer,
108  .filter_frame = filter_frame,
109  },
110  { NULL }
111 };
112 
114  {
115  .name = "default",
116  .type = AVMEDIA_TYPE_VIDEO
117  },
118  { NULL }
119 };
120 
122  .name = "blackframe",
123  .description = NULL_IF_CONFIG_SMALL("Detect frames that are (almost) black."),
124 
125  .priv_size = sizeof(BlackFrameContext),
126  .priv_class = &blackframe_class,
127 
129 
131 
133 };
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
static const AVClass blackframe_class
Definition: vf_blackframe.c:96
AVOption.
Definition: opt.h:234
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:70
static const AVFilterPad outputs[]
Definition: af_ashowinfo.c:232
Main libavfilter public API header.
static const AVFilterPad avfilter_vf_blackframe_inputs[]
AVFrame * ff_null_get_video_buffer(AVFilterLink *link, int w, int h)
Definition: video.c:30
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:165
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:38
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:733
uint8_t
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:211
static double av_q2d(AVRational a)
Convert rational to double.
Definition: rational.h:69
void ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:379
int bamount
black amount
Definition: vf_blackframe.c:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void * priv
private data for use by the filter
Definition: avfilter.h:584
planar YUV 4:2:0, 12bpp, 1 plane for Y and 1 plane for the UV components, which are interleaved (firs...
Definition: pixfmt.h:92
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:69
common internal API header
as above, but U and V bytes are swapped
Definition: pixfmt.h:93
#define FLAGS
Definition: vf_blackframe.c:87
AVFilter ff_vf_blackframe
unsigned int frame
frame number
Definition: vf_blackframe.c:45
#define OFFSET(x)
Definition: vf_blackframe.c:86
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
NULL
Definition: eval.c:55
unsigned int nblack
number of black pixels counted so far
Definition: vf_blackframe.c:46
#define AV_LOG_INFO
Standard information.
Definition: log.h:134
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
av_default_item_name
Definition: dnxhdenc.c:52
int bthresh
black threshold
Definition: vf_blackframe.c:44
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
Definition: vf_blackframe.c:61
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:71
Describe the class of an AVClass context structure.
Definition: log.h:33
Filter definition.
Definition: avfilter.h:421
static const AVFilterPad inputs[]
Definition: af_ashowinfo.c:221
const char * name
Filter name.
Definition: avfilter.h:425
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:578
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
static const AVFilterPad avfilter_vf_blackframe_outputs[]
static const AVOption options[]
Definition: vf_blackframe.c:88
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:65
Y , 8bpp.
Definition: pixfmt.h:73
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:72
struct AVFilterPad AVFilterPad
Definition: avfilter.h:67
An instance of a filter.
Definition: avfilter.h:563
int height
Definition: frame.h:174
internal API functions
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:228
static int query_formats(AVFilterContext *ctx)
Definition: vf_blackframe.c:49