FFmpeg
vf_entropy.c
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1 /*
2  * Copyright (c) 2017 Paul B Mahol
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "libavutil/mem.h"
22 #include "libavutil/opt.h"
23 #include "libavutil/pixdesc.h"
24 #include "avfilter.h"
25 #include "drawutils.h"
26 #include "internal.h"
27 #include "video.h"
28 
29 typedef struct EntropyContext {
30  const AVClass *class;
31 
32  int mode;
33 
34  int nb_planes;
35  int planeheight[4];
36  int planewidth[4];
37  int depth;
38  int is_rgb;
39  uint8_t rgba_map[4];
40  char planenames[4];
41  int64_t *histogram;
43 
44 #define OFFSET(x) offsetof(EntropyContext, x)
45 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
46 static const AVOption entropy_options[] = {
47  { "mode", "set kind of histogram entropy measurement", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, .unit = "mode" },
48  { "normal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, .unit = "mode" },
49  { "diff", NULL, 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, .unit = "mode" },
50  { NULL }
51 };
52 
53 AVFILTER_DEFINE_CLASS(entropy);
54 
55 static const enum AVPixelFormat pixfmts[] = {
71 };
72 
74 {
76  AVFilterContext *ctx = inlink->dst;
77  EntropyContext *s = ctx->priv;
78 
79  s->nb_planes = desc->nb_components;
80 
81  s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
82  s->planeheight[0] = s->planeheight[3] = inlink->h;
83  s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
84  s->planewidth[0] = s->planewidth[3] = inlink->w;
85 
86  s->depth = desc->comp[0].depth;
87  s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
88 
89  s->planenames[0] = s->is_rgb ? 'R' : 'Y';
90  s->planenames[1] = s->is_rgb ? 'G' : 'U';
91  s->planenames[2] = s->is_rgb ? 'B' : 'V';
92  s->planenames[3] = 'A';
93 
94  s->histogram = av_malloc_array(1 << s->depth, sizeof(*s->histogram));
95  if (!s->histogram)
96  return AVERROR(ENOMEM);
97 
98  return 0;
99 }
100 
102 {
103  AVFilterContext *ctx = inlink->dst;
104  AVFilterLink *outlink = ctx->outputs[0];
105  EntropyContext *s = ctx->priv;
106  int plane, y, x;
107 
108  for (plane = 0; plane < s->nb_planes; plane++) {
109  int cidx = s->is_rgb ? s->rgba_map[plane] : plane;
110  const uint8_t *src8 = in->data[plane];
111  const uint16_t *src16 = (const uint16_t *)in->data[plane];
112  float total = s->planewidth[plane] * s->planeheight[plane];
113  float entropy = 0;
114  char metabuf[128];
115  char key[128];
116 
117  memset(s->histogram, 0, (1 << s->depth) * sizeof(*s->histogram));
118 
119  if (s->depth <= 8) {
120  for (y = 0; y < s->planeheight[plane]; y++) {
121  for (x = 0; x < s->planewidth[plane]; x++) {
122  s->histogram[src8[x]]++;
123  }
124 
125  src8 += in->linesize[plane];
126  }
127  } else {
128  for (y = 0; y < s->planeheight[plane]; y++) {
129  for (x = 0; x < s->planewidth[plane]; x++) {
130  s->histogram[src16[x]]++;
131  }
132 
133  src16 += in->linesize[plane] / 2;
134  }
135  }
136 
137  for (y = 0; y < 1 << s->depth; y++) {
138  if (s->mode == 0) {
139  if (s->histogram[y]) {
140  float p = s->histogram[y] / total;
141  entropy += -log2(p) * p;
142  }
143  } else if (s->mode == 1) {
144  if (y && (s->histogram[y] - s->histogram[y - 1]) != 0) {
145  float p = FFABS(s->histogram[y] - s->histogram[y - 1]) / total;
146  entropy += -log2(p) * p;
147  }
148  }
149  }
150 
151  snprintf(key, sizeof(key), "lavfi.entropy.entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]);
152  snprintf(metabuf, sizeof(metabuf), "%f", entropy);
153  av_dict_set(&in->metadata, key, metabuf, 0);
154  snprintf(key, sizeof(key), "lavfi.entropy.normalized_entropy.%s.%c", s->mode ? "diff" : "normal", s->planenames[cidx]);
155  snprintf(metabuf, sizeof(metabuf), "%f", entropy / log2(1 << s->depth));
156  av_dict_set(&in->metadata, key, metabuf, 0);
157  }
158 
159  return ff_filter_frame(outlink, in);
160 }
161 
163 {
164  EntropyContext *s = ctx->priv;
165 
166  av_freep(&s->histogram);
167 }
168 
169 static const AVFilterPad inputs[] = {
170  {
171  .name = "default",
172  .type = AVMEDIA_TYPE_VIDEO,
173  .filter_frame = filter_frame,
174  .config_props = config_input,
175  },
176 };
177 
179  .name = "entropy",
180  .description = NULL_IF_CONFIG_SMALL("Measure video frames entropy."),
181  .priv_size = sizeof(EntropyContext),
182  .uninit = uninit,
186  .priv_class = &entropy_class,
188 };
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:71
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1015
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2965
EntropyContext::planenames
char planenames[4]
Definition: vf_entropy.c:40
FILTER_PIXFMTS_ARRAY
#define FILTER_PIXFMTS_ARRAY(array)
Definition: internal.h:162
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
inputs
static const AVFilterPad inputs[]
Definition: vf_entropy.c:169
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
pixdesc.h
AVOption
AVOption.
Definition: opt.h:357
AV_PIX_FMT_YUV420P10
#define AV_PIX_FMT_YUV420P10
Definition: pixfmt.h:478
EntropyContext::nb_planes
int nb_planes
Definition: vf_entropy.c:34
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_entropy.c:73
AV_PIX_FMT_YUV440P
@ AV_PIX_FMT_YUV440P
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
Definition: pixfmt.h:106
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:170
video.h
AV_PIX_FMT_GRAY9
#define AV_PIX_FMT_GRAY9
Definition: pixfmt.h:458
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:395
AV_PIX_FMT_GBRP14
#define AV_PIX_FMT_GBRP14
Definition: pixfmt.h:496
AV_PIX_FMT_GBRP10
#define AV_PIX_FMT_GBRP10
Definition: pixfmt.h:494
AV_PIX_FMT_YUV422P9
#define AV_PIX_FMT_YUV422P9
Definition: pixfmt.h:476
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_entropy.c:101
AV_PIX_FMT_GRAY16
#define AV_PIX_FMT_GRAY16
Definition: pixfmt.h:462
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:33
AV_PIX_FMT_YUV444P10
#define AV_PIX_FMT_YUV444P10
Definition: pixfmt.h:481
AV_PIX_FMT_YUVJ411P
@ AV_PIX_FMT_YUVJ411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples) full scale (JPEG), deprecated in favor ...
Definition: pixfmt.h:283
av_cold
#define av_cold
Definition: attributes.h:90
AV_PIX_FMT_YUV422P16
#define AV_PIX_FMT_YUV422P16
Definition: pixfmt.h:490
OFFSET
#define OFFSET(x)
Definition: vf_entropy.c:44
ff_video_default_filterpad
const AVFilterPad ff_video_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_VIDEO.
Definition: video.c:37
AV_PIX_FMT_YUVJ422P
@ AV_PIX_FMT_YUVJ422P
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
Definition: pixfmt.h:86
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_PIX_FMT_YUV444P16
#define AV_PIX_FMT_YUV444P16
Definition: pixfmt.h:491
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:59
AV_PIX_FMT_YUV420P9
#define AV_PIX_FMT_YUV420P9
Definition: pixfmt.h:475
AV_PIX_FMT_YUV420P16
#define AV_PIX_FMT_YUV420P16
Definition: pixfmt.h:489
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AV_PIX_FMT_GRAY14
#define AV_PIX_FMT_GRAY14
Definition: pixfmt.h:461
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:73
key
const char * key
Definition: hwcontext_opencl.c:189
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:182
AV_PIX_FMT_YUVJ444P
@ AV_PIX_FMT_YUVJ444P
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
Definition: pixfmt.h:87
FFABS
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:73
AV_PIX_FMT_GRAY10
#define AV_PIX_FMT_GRAY10
Definition: pixfmt.h:459
AV_PIX_FMT_GBRP16
#define AV_PIX_FMT_GBRP16
Definition: pixfmt.h:497
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
ff_vf_entropy
const AVFilter ff_vf_entropy
Definition: vf_entropy.c:178
pixfmts
static enum AVPixelFormat pixfmts[]
Definition: vf_entropy.c:55
AV_PIX_FMT_YUVJ420P
@ AV_PIX_FMT_YUVJ420P
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:85
AV_PIX_FMT_YUV440P10
#define AV_PIX_FMT_YUV440P10
Definition: pixfmt.h:480
EntropyContext::planewidth
int planewidth[4]
Definition: vf_entropy.c:36
FLAGS
#define FLAGS
Definition: vf_entropy.c:45
AV_PIX_FMT_YUV422P10
#define AV_PIX_FMT_YUV422P10
Definition: pixfmt.h:479
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:81
AV_PIX_FMT_GBRP9
#define AV_PIX_FMT_GBRP9
Definition: pixfmt.h:493
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_entropy.c:162
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
EntropyContext::histogram
int64_t * histogram
Definition: vf_entropy.c:41
AV_PIX_FMT_YUV422P12
#define AV_PIX_FMT_YUV422P12
Definition: pixfmt.h:483
AV_PIX_FMT_YUV444P12
#define AV_PIX_FMT_YUV444P12
Definition: pixfmt.h:485
internal.h
AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC
Some filters support a generic "enable" expression option that can be used to enable or disable a fil...
Definition: avfilter.h:147
av_malloc_array
#define av_malloc_array(a, b)
Definition: tableprint_vlc.h:31
AV_PIX_FMT_GBRP12
#define AV_PIX_FMT_GBRP12
Definition: pixfmt.h:495
EntropyContext::planeheight
int planeheight[4]
Definition: vf_entropy.c:35
AV_PIX_FMT_YUVJ440P
@ AV_PIX_FMT_YUVJ440P
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV440P and setting color_range
Definition: pixfmt.h:107
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(entropy)
EntropyContext
Definition: vf_entropy.c:29
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:39
EntropyContext::mode
int mode
Definition: vf_entropy.c:32
AV_PIX_FMT_YUV444P9
#define AV_PIX_FMT_YUV444P9
Definition: pixfmt.h:477
log2
#define log2(x)
Definition: libm.h:404
AVFilter
Filter definition.
Definition: avfilter.h:166
EntropyContext::is_rgb
int is_rgb
Definition: vf_entropy.c:38
AV_PIX_FMT_YUV420P12
#define AV_PIX_FMT_YUV420P12
Definition: pixfmt.h:482
AV_PIX_FMT_YUV422P14
#define AV_PIX_FMT_YUV422P14
Definition: pixfmt.h:487
EntropyContext::rgba_map
uint8_t rgba_map[4]
Definition: vf_entropy.c:39
mode
mode
Definition: ebur128.h:83
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:72
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:245
avfilter.h
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:692
EntropyContext::depth
int depth
Definition: vf_entropy.c:37
AVFILTER_FLAG_METADATA_ONLY
#define AVFILTER_FLAG_METADATA_ONLY
The filter is a "metadata" filter - it does not modify the frame data in any way.
Definition: avfilter.h:133
AV_PIX_FMT_YUV444P
@ AV_PIX_FMT_YUV444P
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:78
AVFilterContext
An instance of a filter.
Definition: avfilter.h:407
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:165
desc
const char * desc
Definition: libsvtav1.c:79
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_PIX_FMT_YUV422P
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:77
mem.h
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:183
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:88
AV_PIX_FMT_YUV411P
@ AV_PIX_FMT_YUV411P
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:80
ff_fill_rgba_map
int ff_fill_rgba_map(uint8_t *rgba_map, enum AVPixelFormat pix_fmt)
Definition: drawutils.c:35
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:419
AV_PIX_FMT_YUV440P12
#define AV_PIX_FMT_YUV440P12
Definition: pixfmt.h:484
AV_PIX_FMT_YUV444P14
#define AV_PIX_FMT_YUV444P14
Definition: pixfmt.h:488
entropy_options
static const AVOption entropy_options[]
Definition: vf_entropy.c:46
AV_PIX_FMT_GRAY12
#define AV_PIX_FMT_GRAY12
Definition: pixfmt.h:460
drawutils.h
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:254
snprintf
#define snprintf
Definition: snprintf.h:34
AV_PIX_FMT_YUV420P14
#define AV_PIX_FMT_YUV420P14
Definition: pixfmt.h:486