FFmpeg
vf_blockdetect.c
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1 /*
2  * Copyright (c) 2021 Thilo Borgmann <thilo.borgmann _at_ mail.de>
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 /**
22  * @file
23  * No-reference blockdetect filter
24  *
25  * Implementing:
26  * Remco Muijs and Ihor Kirenko: "A no-reference blocking artifact measure for adaptive video processing." 2005 13th European signal processing conference. IEEE, 2005.
27  * http://www.eurasip.org/Proceedings/Eusipco/Eusipco2005/defevent/papers/cr1042.pdf
28  *
29  * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>
30  */
31 
32 #include "libavutil/mem.h"
33 #include "libavutil/opt.h"
34 #include "libavutil/pixdesc.h"
35 
36 #include "filters.h"
37 #include "video.h"
38 
39 typedef struct BLKContext {
40  const AVClass *class;
41 
42  int hsub, vsub;
43  int nb_planes;
44 
45  int period_min; // minimum period to search for
46  int period_max; // maximum period to search for
47  int planes; // number of planes to filter
48 
49  double block_total;
50  uint64_t nb_frames;
51 
52  float *gradients;
53 } BLKContext;
54 
55 #define OFFSET(x) offsetof(BLKContext, x)
56 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
57 static const AVOption blockdetect_options[] = {
58  { "period_min", "Minimum period to search for", OFFSET(period_min), AV_OPT_TYPE_INT, {.i64=3}, 2, 32, FLAGS},
59  { "period_max", "Maximum period to search for", OFFSET(period_max), AV_OPT_TYPE_INT, {.i64=24}, 2, 64, FLAGS},
60  { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=1}, 0, 15, FLAGS },
61  { NULL }
62 };
63 
64 AVFILTER_DEFINE_CLASS(blockdetect);
65 
67 {
68  AVFilterContext *ctx = inlink->dst;
69  BLKContext *s = ctx->priv;
70  const int bufsize = inlink->w * inlink->h;
71  const AVPixFmtDescriptor *pix_desc;
72 
73  pix_desc = av_pix_fmt_desc_get(inlink->format);
74  s->hsub = pix_desc->log2_chroma_w;
75  s->vsub = pix_desc->log2_chroma_h;
76  s->nb_planes = av_pix_fmt_count_planes(inlink->format);
77 
78  s->gradients = av_calloc(bufsize, sizeof(*s->gradients));
79 
80  if (!s->gradients)
81  return AVERROR(ENOMEM);
82 
83  return 0;
84 }
85 
86 static float calculate_blockiness(BLKContext *s, int w, int h,
87  float *grad, int grad_linesize,
88  uint8_t* src, int src_linesize)
89 {
90  float block = 0.0f;
91  float nonblock = 0.0f;
92  int block_count = 0;
93  int nonblock_count = 0;
94  float ret = 0;
95 
96  // Calculate BS in horizontal and vertical directions according to (1)(2)(3).
97  // Also try to find integer pixel periods (grids) even for scaled images.
98  // In case of fractional periods, FFMAX of current and neighbor pixels
99  // can help improve the correlation with MQS.
100  // Skip linear correction term (4)(5), as it appears only valid for their own test samples.
101 
102  // horizontal blockiness (fixed width)
103  for (int j = 1; j < h; j++) {
104  for (int i = 3; i < w - 4; i++) {
105  float temp = 0.0f;
106  grad[j * grad_linesize + i] =
107  abs(src[j * src_linesize + i + 0] - src[j * src_linesize + i + 1]);
108  temp += abs(src[j * src_linesize + i + 1] - src[j * src_linesize + i + 2]);
109  temp += abs(src[j * src_linesize + i + 2] - src[j * src_linesize + i + 3]);
110  temp += abs(src[j * src_linesize + i + 3] - src[j * src_linesize + i + 4]);
111  temp += abs(src[j * src_linesize + i - 0] - src[j * src_linesize + i - 1]);
112  temp += abs(src[j * src_linesize + i - 1] - src[j * src_linesize + i - 2]);
113  temp += abs(src[j * src_linesize + i - 2] - src[j * src_linesize + i - 3]);
114  temp = FFMAX(1, temp);
115  grad[j * grad_linesize + i] /= temp;
116 
117  // use first row to store acculated results
118  grad[i] += grad[j * grad_linesize + i];
119  }
120  }
121 
122  // find horizontal period
123  for (int period = s->period_min; period < s->period_max + 1; period++) {
124  float temp;
125  block = 0;
126  nonblock = 0;
127  block_count = 0;
128  nonblock_count = 0;
129  for (int i = 3; i < w - 4; i++) {
130  if ((i % period) == (period - 1)) {
131  block += FFMAX(FFMAX(grad[i + 0], grad[i + 1]), grad[i - 1]);
132  block_count++;
133  } else {
134  nonblock += grad[i];
135  nonblock_count++;
136  }
137  }
138  if (block_count && nonblock_count) {
139  temp = (block / block_count) / (nonblock / nonblock_count);
140  ret = FFMAX(ret, temp);
141  }
142  }
143 
144  // vertical blockiness (fixed height)
145  block_count = 0;
146  for (int j = 3; j < h - 4; j++) {
147  for (int i = 1; i < w; i++) {
148  float temp = 0.0f;
149  grad[j * grad_linesize + i] =
150  abs(src[(j + 0) * src_linesize + i] - src[(j + 1) * src_linesize + i]);
151  temp += abs(src[(j + 1) * src_linesize + i] - src[(j + 2) * src_linesize + i]);
152  temp += abs(src[(j + 2) * src_linesize + i] - src[(j + 3) * src_linesize + i]);
153  temp += abs(src[(j + 3) * src_linesize + i] - src[(j + 4) * src_linesize + i]);
154  temp += abs(src[(j - 0) * src_linesize + i] - src[(j - 1) * src_linesize + i]);
155  temp += abs(src[(j - 1) * src_linesize + i] - src[(j - 2) * src_linesize + i]);
156  temp += abs(src[(j - 2) * src_linesize + i] - src[(j - 3) * src_linesize + i]);
157  temp = FFMAX(1, temp);
158  grad[j * grad_linesize + i] /= temp;
159 
160  // use first column to store accumulated results
161  grad[j * grad_linesize] += grad[j * grad_linesize + i];
162  }
163  }
164 
165  // find vertical period
166  for (int period = s->period_min; period < s->period_max + 1; period++) {
167  float temp;
168  block = 0;
169  nonblock = 0;
170  block_count = 0;
171  nonblock_count = 0;
172  for (int j = 3; j < h - 4; j++) {
173  if ((j % period) == (period - 1)) {
174  block += FFMAX(FFMAX(grad[(j + 0) * grad_linesize],
175  grad[(j + 1) * grad_linesize]),
176  grad[(j - 1) * grad_linesize]);
177  block_count++;
178  } else {
179  nonblock += grad[j * grad_linesize];
180  nonblock_count++;
181  }
182  }
183  if (block_count && nonblock_count) {
184  temp = (block / block_count) / (nonblock / nonblock_count);
185  ret = FFMAX(ret, temp);
186  }
187  }
188 
189  // return highest value of horz||vert
190  return ret;
191 }
192 
193 static void set_meta(AVDictionary **metadata, const char *key, float d)
194 {
195  char value[128];
196  snprintf(value, sizeof(value), "%f", d);
197  av_dict_set(metadata, key, value, 0);
198 }
199 
201 {
203  AVFilterContext *ctx = inlink->dst;
204  BLKContext *s = ctx->priv;
205  AVFilterLink *outlink = ctx->outputs[0];
206 
207  const int inw = inlink->w;
208  const int inh = inlink->h;
209 
210  float *gradients = s->gradients;
211 
212  float block = 0.0f;
213  int nplanes = 0;
214  AVDictionary **metadata;
215  metadata = &in->metadata;
216 
217  for (int plane = 0; plane < s->nb_planes; plane++) {
218  int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
219  int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
220  int w = AV_CEIL_RSHIFT(inw, hsub);
221  int h = AV_CEIL_RSHIFT(inh, vsub);
222 
223  if (!((1 << plane) & s->planes))
224  continue;
225 
226  nplanes++;
227 
228  block += calculate_blockiness(s, w, h, gradients, w, in->data[plane], in->linesize[plane]);
229  }
230 
231  if (nplanes)
232  block /= nplanes;
233 
234  s->block_total += block;
235 
236  // write stats
237  av_log(ctx, AV_LOG_VERBOSE, "block: %.7f\n", block);
238 
239  set_meta(metadata, "lavfi.block", block);
240 
241  s->nb_frames = inl->frame_count_in;
242 
243  return ff_filter_frame(outlink, in);
244 }
245 
247 {
248  BLKContext *s = ctx->priv;
249 
250  if (s->nb_frames > 0) {
251  av_log(ctx, AV_LOG_INFO, "block mean: %.7f\n",
252  s->block_total / s->nb_frames);
253  }
254 
255  av_freep(&s->gradients);
256 }
257 
258 static const enum AVPixelFormat pix_fmts[] = {
268 };
269 
270 static const AVFilterPad blockdetect_inputs[] = {
271  {
272  .name = "default",
273  .type = AVMEDIA_TYPE_VIDEO,
274  .config_props = blockdetect_config_input,
275  .filter_frame = blockdetect_filter_frame,
276  },
277 };
278 
280  .name = "blockdetect",
281  .description = NULL_IF_CONFIG_SMALL("Blockdetect filter."),
282  .priv_size = sizeof(BLKContext),
287  .priv_class = &blockdetect_class,
289 };
BLKContext::gradients
float * gradients
Definition: vf_blockdetect.c:52
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
FILTER_PIXFMTS_ARRAY
#define FILTER_PIXFMTS_ARRAY(array)
Definition: filters.h:242
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1062
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:3025
BLKContext::period_max
int period_max
Definition: vf_blockdetect.c:46
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
BLKContext::period_min
int period_min
Definition: vf_blockdetect.c:45
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: filters.h:262
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
pixdesc.h
w
uint8_t w
Definition: llviddspenc.c:38
pix_fmts
static enum AVPixelFormat pix_fmts[]
Definition: vf_blockdetect.c:258
AVOption
AVOption.
Definition: opt.h:429
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:225
blockdetect_inputs
static const AVFilterPad blockdetect_inputs[]
Definition: vf_blockdetect.c:270
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
AVDictionary
Definition: dict.c:34
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:205
blockdetect_uninit
static av_cold void blockdetect_uninit(AVFilterContext *ctx)
Definition: vf_blockdetect.c:246
video.h
BLKContext::planes
int planes
Definition: vf_blockdetect.c:47
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:410
hsub
static void hsub(htype *dst, const htype *src, int bins)
Definition: vf_median.c:74
av_pix_fmt_count_planes
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:3065
ff_vf_blockdetect
const AVFilter ff_vf_blockdetect
Definition: vf_blockdetect.c:279
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:212
BLKContext
Definition: vf_blockdetect.c:39
set_meta
static void set_meta(AVDictionary **metadata, const char *key, float d)
Definition: vf_blockdetect.c:193
AVFilterPad
A filter pad used for either input or output.
Definition: filters.h:38
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
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_YUVA420P
@ AV_PIX_FMT_YUVA420P
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:108
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:60
filters.h
ctx
AVFormatContext * ctx
Definition: movenc.c:49
AVPixFmtDescriptor::log2_chroma_w
uint8_t log2_chroma_w
Amount to shift the luma width right to find the chroma width.
Definition: pixdesc.h:80
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_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:263
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
OFFSET
#define OFFSET(x)
Definition: vf_blockdetect.c:55
BLKContext::nb_planes
int nb_planes
Definition: vf_blockdetect.c:43
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
NULL
#define NULL
Definition: coverity.c:32
grad
static double grad(int hash, double x, double y, double z)
Definition: perlin.c:42
FLAGS
#define FLAGS
Definition: vf_blockdetect.c:56
period
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option keep it simple and lowercase description are in without period
Definition: writing_filters.txt:89
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
abs
#define abs(x)
Definition: cuda_runtime.h:35
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:81
ff_filter_link
static FilterLink * ff_filter_link(AVFilterLink *link)
Definition: filters.h:197
calculate_blockiness
static float calculate_blockiness(BLKContext *s, int w, int h, float *grad, int grad_linesize, uint8_t *src, int src_linesize)
Definition: vf_blockdetect.c:86
BLKContext::hsub
int hsub
Definition: vf_blockdetect.c:42
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
AV_PIX_FMT_YUVA444P
@ AV_PIX_FMT_YUVA444P
planar YUV 4:4:4 32bpp, (1 Cr & Cb sample per 1x1 Y & A samples)
Definition: pixfmt.h:174
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:220
uninit
static void uninit(AVBSFContext *ctx)
Definition: pcm_rechunk.c:68
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
BLKContext::block_total
double block_total
Definition: vf_blockdetect.c:49
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
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
blockdetect_filter_frame
static int blockdetect_filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_blockdetect.c:200
AVFilterPad::name
const char * name
Pad name.
Definition: filters.h:44
BLKContext::vsub
int vsub
Definition: vf_blockdetect.c:42
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:264
AVFilter
Filter definition.
Definition: avfilter.h:201
ret
ret
Definition: filter_design.txt:187
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:72
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:707
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:168
temp
else temp
Definition: vf_mcdeint.c:263
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:457
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:165
blockdetect_options
static const AVOption blockdetect_options[]
Definition: vf_blockdetect.c:57
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
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(blockdetect)
AVPixFmtDescriptor
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:69
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
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:434
AV_PIX_FMT_YUV410P
@ AV_PIX_FMT_YUV410P
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:79
block
The exact code depends on how similar the blocks are and how related they are to the block
Definition: filter_design.txt:207
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
h
h
Definition: vp9dsp_template.c:2070
BLKContext::nb_frames
uint64_t nb_frames
Definition: vf_blockdetect.c:50
snprintf
#define snprintf
Definition: snprintf.h:34
AVPixFmtDescriptor::log2_chroma_h
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:89
src
#define src
Definition: vp8dsp.c:248
AV_PIX_FMT_YUVA422P
@ AV_PIX_FMT_YUVA422P
planar YUV 4:2:2 24bpp, (1 Cr & Cb sample per 2x1 Y & A samples)
Definition: pixfmt.h:173
planes
static const struct @458 planes[]
blockdetect_config_input
static int blockdetect_config_input(AVFilterLink *inlink)
Definition: vf_blockdetect.c:66