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/imgutils.h"
33 #include "libavutil/opt.h"
34 #include "internal.h"
35 
36 typedef struct BLKContext {
37  const AVClass *class;
38 
39  int hsub, vsub;
40  int nb_planes;
41 
42  int period_min; // minimum period to search for
43  int period_max; // maximum period to search for
44  int planes; // number of planes to filter
45 
46  double block_total;
47  uint64_t nb_frames;
48 
49  float *gradients;
50 } BLKContext;
51 
52 #define OFFSET(x) offsetof(BLKContext, x)
53 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
54 static const AVOption blockdetect_options[] = {
55  { "period_min", "Minimum period to search for", OFFSET(period_min), AV_OPT_TYPE_INT, {.i64=3}, 2, 32, FLAGS},
56  { "period_max", "Maximum period to search for", OFFSET(period_max), AV_OPT_TYPE_INT, {.i64=24}, 2, 64, FLAGS},
57  { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT, {.i64=1}, 0, 15, FLAGS },
58  { NULL }
59 };
60 
61 AVFILTER_DEFINE_CLASS(blockdetect);
62 
64 {
65  AVFilterContext *ctx = inlink->dst;
66  BLKContext *s = ctx->priv;
67  const int bufsize = inlink->w * inlink->h;
68  const AVPixFmtDescriptor *pix_desc;
69 
70  pix_desc = av_pix_fmt_desc_get(inlink->format);
71  s->hsub = pix_desc->log2_chroma_w;
72  s->vsub = pix_desc->log2_chroma_h;
73  s->nb_planes = av_pix_fmt_count_planes(inlink->format);
74 
75  s->gradients = av_calloc(bufsize, sizeof(*s->gradients));
76 
77  if (!s->gradients)
78  return AVERROR(ENOMEM);
79 
80  return 0;
81 }
82 
83 static float calculate_blockiness(BLKContext *s, int w, int h,
84  float *grad, int grad_linesize,
85  uint8_t* src, int src_linesize)
86 {
87  float block = 0.0f;
88  float nonblock = 0.0f;
89  int block_count = 0;
90  int nonblock_count = 0;
91  float ret = 0;
92 
93  // Calculate BS in horizontal and vertical directions according to (1)(2)(3).
94  // Also try to find integer pixel periods (grids) even for scaled images.
95  // In case of fractional periods, FFMAX of current and neighbor pixels
96  // can help improve the correlation with MQS.
97  // Skip linear correction term (4)(5), as it appears only valid for their own test samples.
98 
99  // horizontal blockiness (fixed width)
100  for (int j = 1; j < h; j++) {
101  for (int i = 3; i < w - 4; i++) {
102  float temp = 0.0f;
103  grad[j * grad_linesize + i] =
104  abs(src[j * src_linesize + i + 0] - src[j * src_linesize + i + 1]);
105  temp += abs(src[j * src_linesize + i + 1] - src[j * src_linesize + i + 2]);
106  temp += abs(src[j * src_linesize + i + 2] - src[j * src_linesize + i + 3]);
107  temp += abs(src[j * src_linesize + i + 3] - src[j * src_linesize + i + 4]);
108  temp += abs(src[j * src_linesize + i - 0] - src[j * src_linesize + i - 1]);
109  temp += abs(src[j * src_linesize + i - 1] - src[j * src_linesize + i - 2]);
110  temp += abs(src[j * src_linesize + i - 2] - src[j * src_linesize + i - 3]);
111  temp = FFMAX(1, temp);
112  grad[j * grad_linesize + i] /= temp;
113 
114  // use first row to store acculated results
115  grad[i] += grad[j * grad_linesize + i];
116  }
117  }
118 
119  // find horizontal period
120  for (int period = s->period_min; period < s->period_max + 1; period++) {
121  float temp;
122  block = 0;
123  nonblock = 0;
124  block_count = 0;
125  nonblock_count = 0;
126  for (int i = 3; i < w - 4; i++) {
127  if ((i % period) == (period - 1)) {
128  block += FFMAX(FFMAX(grad[i + 0], grad[i + 1]), grad[i - 1]);
129  block_count++;
130  } else {
131  nonblock += grad[i];
132  nonblock_count++;
133  }
134  }
135  if (block_count && nonblock_count) {
136  temp = (block / block_count) / (nonblock / nonblock_count);
137  ret = FFMAX(ret, temp);
138  }
139  }
140 
141  // vertical blockiness (fixed height)
142  block_count = 0;
143  for (int j = 3; j < h - 4; j++) {
144  for (int i = 1; i < w; i++) {
145  float temp = 0.0f;
146  grad[j * grad_linesize + i] =
147  abs(src[(j + 0) * src_linesize + i] - src[(j + 1) * src_linesize + i]);
148  temp += abs(src[(j + 1) * src_linesize + i] - src[(j + 2) * src_linesize + i]);
149  temp += abs(src[(j + 2) * src_linesize + i] - src[(j + 3) * src_linesize + i]);
150  temp += abs(src[(j + 3) * src_linesize + i] - src[(j + 4) * src_linesize + i]);
151  temp += abs(src[(j - 0) * src_linesize + i] - src[(j - 1) * src_linesize + i]);
152  temp += abs(src[(j - 1) * src_linesize + i] - src[(j - 2) * src_linesize + i]);
153  temp += abs(src[(j - 2) * src_linesize + i] - src[(j - 3) * src_linesize + i]);
154  temp = FFMAX(1, temp);
155  grad[j * grad_linesize + i] /= temp;
156 
157  // use first column to store accumulated results
158  grad[j * grad_linesize] += grad[j * grad_linesize + i];
159  }
160  }
161 
162  // find vertical period
163  for (int period = s->period_min; period < s->period_max + 1; period++) {
164  float temp;
165  block = 0;
166  nonblock = 0;
167  block_count = 0;
168  nonblock_count = 0;
169  for (int j = 3; j < h - 4; j++) {
170  if ((j % period) == (period - 1)) {
171  block += FFMAX(FFMAX(grad[(j + 0) * grad_linesize],
172  grad[(j + 1) * grad_linesize]),
173  grad[(j - 1) * grad_linesize]);
174  block_count++;
175  } else {
176  nonblock += grad[j * grad_linesize];
177  nonblock_count++;
178  }
179  }
180  if (block_count && nonblock_count) {
181  temp = (block / block_count) / (nonblock / nonblock_count);
182  ret = FFMAX(ret, temp);
183  }
184  }
185 
186  // return highest value of horz||vert
187  return ret;
188 }
189 
190 static void set_meta(AVDictionary **metadata, const char *key, float d)
191 {
192  char value[128];
193  snprintf(value, sizeof(value), "%f", d);
194  av_dict_set(metadata, key, value, 0);
195 }
196 
198 {
199  AVFilterContext *ctx = inlink->dst;
200  BLKContext *s = ctx->priv;
201  AVFilterLink *outlink = ctx->outputs[0];
202 
203  const int inw = inlink->w;
204  const int inh = inlink->h;
205 
206  float *gradients = s->gradients;
207 
208  float block = 0.0f;
209  int nplanes = 0;
210  AVDictionary **metadata;
211  metadata = &in->metadata;
212 
213  for (int plane = 0; plane < s->nb_planes; plane++) {
214  int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
215  int vsub = plane == 1 || plane == 2 ? s->vsub : 0;
216  int w = AV_CEIL_RSHIFT(inw, hsub);
217  int h = AV_CEIL_RSHIFT(inh, vsub);
218 
219  if (!((1 << plane) & s->planes))
220  continue;
221 
222  nplanes++;
223 
224  block += calculate_blockiness(s, w, h, gradients, w, in->data[plane], in->linesize[plane]);
225  }
226 
227  if (nplanes)
228  block /= nplanes;
229 
230  s->block_total += block;
231 
232  // write stats
233  av_log(ctx, AV_LOG_VERBOSE, "block: %.7f\n", block);
234 
235  set_meta(metadata, "lavfi.block", block);
236 
237  s->nb_frames = inlink->frame_count_in;
238 
239  return ff_filter_frame(outlink, in);
240 }
241 
243 {
244  BLKContext *s = ctx->priv;
245 
246  if (s->nb_frames > 0) {
247  av_log(ctx, AV_LOG_INFO, "block mean: %.7f\n",
248  s->block_total / s->nb_frames);
249  }
250 
251  av_freep(&s->gradients);
252 }
253 
254 static const enum AVPixelFormat pix_fmts[] = {
264 };
265 
266 static const AVFilterPad blockdetect_inputs[] = {
267  {
268  .name = "default",
269  .type = AVMEDIA_TYPE_VIDEO,
270  .config_props = blockdetect_config_input,
271  .filter_frame = blockdetect_filter_frame,
272  },
273 };
274 
276  {
277  .name = "default",
278  .type = AVMEDIA_TYPE_VIDEO,
279  },
280 };
281 
283  .name = "blockdetect",
284  .description = NULL_IF_CONFIG_SMALL("Blockdetect filter."),
285  .priv_size = sizeof(BLKContext),
290  .priv_class = &blockdetect_class,
292 };
BLKContext::gradients
float * gradients
Definition: vf_blockdetect.c:49
AVPixelFormat
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
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:1009
av_pix_fmt_desc_get
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2807
BLKContext::period_max
int period_max
Definition: vf_blockdetect.c:43
FILTER_PIXFMTS_ARRAY
#define FILTER_PIXFMTS_ARRAY(array)
Definition: internal.h:170
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:42
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
w
uint8_t w
Definition: llviddspenc.c:38
blockdetect_outputs
static const AVFilterPad blockdetect_outputs[]
Definition: vf_blockdetect.c:275
pix_fmts
static enum AVPixelFormat pix_fmts[]
Definition: vf_blockdetect.c:254
AVOption
AVOption.
Definition: opt.h:251
AV_LOG_VERBOSE
#define AV_LOG_VERBOSE
Detailed information.
Definition: log.h:196
blockdetect_inputs
static const AVFilterPad blockdetect_inputs[]
Definition: vf_blockdetect.c:266
AV_PIX_FMT_YUV440P
@ AV_PIX_FMT_YUV440P
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
Definition: pixfmt.h:99
AVDictionary
Definition: dict.c:31
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:175
blockdetect_uninit
static av_cold void blockdetect_uninit(AVFilterContext *ctx)
Definition: vf_blockdetect.c:242
BLKContext::planes
int planes
Definition: vf_blockdetect.c:44
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:346
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:2847
ff_vf_blockdetect
const AVFilter ff_vf_blockdetect
Definition: vf_blockdetect.c:282
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:205
BLKContext
Definition: vf_blockdetect.c:36
set_meta
static void set_meta(AVDictionary **metadata, const char *key, float d)
Definition: vf_blockdetect.c:190
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
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:248
av_cold
#define av_cold
Definition: attributes.h:90
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:79
s
#define s(width, name)
Definition: cbs_vp9.c:256
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:101
AV_CEIL_RSHIFT
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:50
ctx
AVFormatContext * ctx
Definition: movenc.c:48
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:66
key
const char * key
Definition: hwcontext_opencl.c:174
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:190
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:80
OFFSET
#define OFFSET(x)
Definition: vf_blockdetect.c:52
BLKContext::nb_planes
int nb_planes
Definition: vf_blockdetect.c:40
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
FLAGS
#define FLAGS
Definition: vf_blockdetect.c:53
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:78
abs
#define abs(x)
Definition: cuda_runtime.h:35
planes
static const struct @336 planes[]
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
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:83
BLKContext::hsub
int hsub
Definition: vf_blockdetect.c:39
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:115
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:167
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
internal.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
BLKContext::block_total
double block_total
Definition: vf_blockdetect.c:46
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:100
blockdetect_filter_frame
static int blockdetect_filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_blockdetect.c:197
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
BLKContext::vsub
int vsub
Definition: vf_blockdetect.c:39
av_calloc
void * av_calloc(size_t nmemb, size_t size)
Definition: mem.c:272
AVFilter
Filter definition.
Definition: avfilter.h:171
ret
ret
Definition: filter_design.txt:187
AV_PIX_FMT_NONE
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:625
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:143
temp
else temp
Definition: vf_mcdeint.c:248
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:71
AVFilterContext
An instance of a filter.
Definition: avfilter.h:408
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:158
blockdetect_options
static const AVOption blockdetect_options[]
Definition: vf_blockdetect.c:54
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:70
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
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:191
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:71
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
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:73
d
d
Definition: ffmpeg_filter.c:156
imgutils.h
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:370
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:72
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
uninit
static av_cold int uninit(AVCodecContext *avctx)
Definition: crystalhd.c:285
h
h
Definition: vp9dsp_template.c:2038
BLKContext::nb_frames
uint64_t nb_frames
Definition: vf_blockdetect.c:47
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
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:166
blockdetect_config_input
static int blockdetect_config_input(AVFilterLink *inlink)
Definition: vf_blockdetect.c:63