FFmpeg
vf_find_rect.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2014-2015 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (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
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19  */
20 
21 /**
22  * @todo switch to dualinput
23  */
24 
25 #include "libavutil/imgutils.h"
26 #include "libavutil/opt.h"
27 #include "internal.h"
28 
29 #include "lavfutils.h"
30 
31 #define MAX_MIPMAPS 5
32 
33 typedef struct FOCContext {
34  AVClass *class;
35  float threshold;
36  int mipmaps;
37  int xmin, ymin, xmax, ymax;
38  char *obj_filename;
39  int last_x, last_y;
40  AVFrame *obj_frame;
41  AVFrame *needle_frame[MAX_MIPMAPS];
42  AVFrame *haystack_frame[MAX_MIPMAPS];
43  int discard;
44 } FOCContext;
45 
46 #define OFFSET(x) offsetof(FOCContext, x)
47 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
48 static const AVOption find_rect_options[] = {
49  { "object", "object bitmap filename", OFFSET(obj_filename), AV_OPT_TYPE_STRING, {.str = NULL}, .flags = FLAGS },
50  { "threshold", "set threshold", OFFSET(threshold), AV_OPT_TYPE_FLOAT, {.dbl = 0.5}, 0, 1.0, FLAGS },
51  { "mipmaps", "set mipmaps", OFFSET(mipmaps), AV_OPT_TYPE_INT, {.i64 = 3}, 1, MAX_MIPMAPS, FLAGS },
52  { "xmin", "", OFFSET(xmin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
53  { "ymin", "", OFFSET(ymin), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
54  { "xmax", "", OFFSET(xmax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
55  { "ymax", "", OFFSET(ymax), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, FLAGS },
56  { "discard", "", OFFSET(discard), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS },
57  { NULL }
58 };
59 
60 AVFILTER_DEFINE_CLASS(find_rect);
61 
62 static AVFrame *downscale(AVFrame *in)
63 {
64  int x, y;
65  AVFrame *frame = av_frame_alloc();
66  uint8_t *src, *dst;
67  if (!frame)
68  return NULL;
69 
70  frame->format = in->format;
71  frame->width = (in->width + 1) / 2;
72  frame->height = (in->height+ 1) / 2;
73 
74  if (av_frame_get_buffer(frame, 0) < 0) {
75  av_frame_free(&frame);
76  return NULL;
77  }
78  src = in ->data[0];
79  dst = frame->data[0];
80 
81  for(y = 0; y < frame->height; y++) {
82  for(x = 0; x < frame->width; x++) {
83  dst[x] = ( src[2*x+0]
84  + src[2*x+1]
85  + src[2*x+0 + in->linesize[0]]
86  + src[2*x+1 + in->linesize[0]]
87  + 2) >> 2;
88  }
89  src += 2*in->linesize[0];
90  dst += frame->linesize[0];
91  }
92  return frame;
93 }
94 
95 static float compare(const AVFrame *haystack, const AVFrame *obj, int offx, int offy)
96 {
97  int x,y;
98  int o_sum_v = 0;
99  int h_sum_v = 0;
100  int64_t oo_sum_v = 0;
101  int64_t hh_sum_v = 0;
102  int64_t oh_sum_v = 0;
103  float c;
104  int n = obj->height * obj->width;
105  const uint8_t *odat = obj ->data[0];
106  const uint8_t *hdat = haystack->data[0] + offx + offy * haystack->linesize[0];
107  int64_t o_sigma, h_sigma;
108 
109  for(y = 0; y < obj->height; y++) {
110  for(x = 0; x < obj->width; x++) {
111  int o_v = odat[x];
112  int h_v = hdat[x];
113  o_sum_v += o_v;
114  h_sum_v += h_v;
115  oo_sum_v += o_v * o_v;
116  hh_sum_v += h_v * h_v;
117  oh_sum_v += o_v * h_v;
118  }
119  odat += obj->linesize[0];
120  hdat += haystack->linesize[0];
121  }
122  o_sigma = n*oo_sum_v - o_sum_v*(int64_t)o_sum_v;
123  h_sigma = n*hh_sum_v - h_sum_v*(int64_t)h_sum_v;
124 
125  if (o_sigma == 0 || h_sigma == 0)
126  return 1.0;
127 
128  c = (n*oh_sum_v - o_sum_v*(int64_t)h_sum_v) / (sqrt(o_sigma)*sqrt(h_sigma));
129 
130  return 1 - fabs(c);
131 }
132 
133 static int config_input(AVFilterLink *inlink)
134 {
135  AVFilterContext *ctx = inlink->dst;
136  FOCContext *foc = ctx->priv;
137 
138  if (foc->xmax <= 0)
139  foc->xmax = inlink->w - foc->obj_frame->width;
140  if (foc->ymax <= 0)
141  foc->ymax = inlink->h - foc->obj_frame->height;
142 
143  return 0;
144 }
145 
146 static float search(FOCContext *foc, int pass, int maxpass, int xmin, int xmax, int ymin, int ymax, int *best_x, int *best_y, float best_score)
147 {
148  int x, y;
149 
150  if (pass + 1 <= maxpass) {
151  int sub_x, sub_y;
152  search(foc, pass+1, maxpass, xmin>>1, (xmax+1)>>1, ymin>>1, (ymax+1)>>1, &sub_x, &sub_y, 2.0);
153  xmin = FFMAX(xmin, 2*sub_x - 4);
154  xmax = FFMIN(xmax, 2*sub_x + 4);
155  ymin = FFMAX(ymin, 2*sub_y - 4);
156  ymax = FFMIN(ymax, 2*sub_y + 4);
157  }
158 
159  for (y = ymin; y <= ymax; y++) {
160  for (x = xmin; x <= xmax; x++) {
161  float score = compare(foc->haystack_frame[pass], foc->needle_frame[pass], x, y);
162  if (score < best_score) {
163  best_score = score;
164  *best_x = x;
165  *best_y = y;
166  }
167  }
168  }
169  return best_score;
170 }
171 
172 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
173 {
174  AVFilterContext *ctx = inlink->dst;
175  FOCContext *foc = ctx->priv;
176  float best_score;
177  int best_x, best_y;
178  int i;
179  char buf[32];
180 
181  foc->haystack_frame[0] = av_frame_clone(in);
182  for (i=1; i<foc->mipmaps; i++) {
183  foc->haystack_frame[i] = downscale(foc->haystack_frame[i-1]);
184  }
185 
186  best_score = search(foc, 0, 0,
187  FFMAX(foc->xmin, foc->last_x - 8),
188  FFMIN(foc->xmax, foc->last_x + 8),
189  FFMAX(foc->ymin, foc->last_y - 8),
190  FFMIN(foc->ymax, foc->last_y + 8),
191  &best_x, &best_y, 2.0);
192 
193  best_score = search(foc, 0, foc->mipmaps - 1, foc->xmin, foc->xmax, foc->ymin, foc->ymax,
194  &best_x, &best_y, best_score);
195 
196  for (i=0; i<MAX_MIPMAPS; i++) {
197  av_frame_free(&foc->haystack_frame[i]);
198  }
199 
200  if (best_score > foc->threshold) {
201  if (foc->discard) {
202  av_frame_free(&in);
203  return 0;
204  } else {
205  return ff_filter_frame(ctx->outputs[0], in);
206  }
207  }
208 
209  av_log(ctx, AV_LOG_INFO, "Found at n=%"PRId64" pts_time=%f x=%d y=%d with score=%f\n",
210  inlink->frame_count_out, TS2D(in->pts) * av_q2d(inlink->time_base),
211  best_x, best_y, best_score);
212  foc->last_x = best_x;
213  foc->last_y = best_y;
214 
215  snprintf(buf, sizeof(buf), "%f", best_score);
216 
217  av_dict_set_int(&in->metadata, "lavfi.rect.w", foc->obj_frame->width, 0);
218  av_dict_set_int(&in->metadata, "lavfi.rect.h", foc->obj_frame->height, 0);
219  av_dict_set_int(&in->metadata, "lavfi.rect.x", best_x, 0);
220  av_dict_set_int(&in->metadata, "lavfi.rect.y", best_y, 0);
221  av_dict_set(&in->metadata, "lavfi.rect.score", buf, 0);
222 
223  return ff_filter_frame(ctx->outputs[0], in);
224 }
225 
226 static av_cold void uninit(AVFilterContext *ctx)
227 {
228  FOCContext *foc = ctx->priv;
229  int i;
230 
231  for (i = 0; i < MAX_MIPMAPS; i++) {
232  av_frame_free(&foc->needle_frame[i]);
233  av_frame_free(&foc->haystack_frame[i]);
234  }
235 
236  if (foc->obj_frame)
237  av_freep(&foc->obj_frame->data[0]);
238  av_frame_free(&foc->obj_frame);
239 }
240 
241 static av_cold int init(AVFilterContext *ctx)
242 {
243  FOCContext *foc = ctx->priv;
244  int ret, i;
245 
246  if (!foc->obj_filename) {
247  av_log(ctx, AV_LOG_ERROR, "object filename not set\n");
248  return AVERROR(EINVAL);
249  }
250 
251  foc->obj_frame = av_frame_alloc();
252  if (!foc->obj_frame)
253  return AVERROR(ENOMEM);
254 
255  if ((ret = ff_load_image(foc->obj_frame->data, foc->obj_frame->linesize,
256  &foc->obj_frame->width, &foc->obj_frame->height,
257  &foc->obj_frame->format, foc->obj_filename, ctx)) < 0)
258  return ret;
259 
260  if (foc->obj_frame->format != AV_PIX_FMT_GRAY8) {
261  av_log(ctx, AV_LOG_ERROR, "object image is not a grayscale image\n");
262  return AVERROR(EINVAL);
263  }
264 
265  foc->needle_frame[0] = av_frame_clone(foc->obj_frame);
266  for (i = 1; i < foc->mipmaps; i++) {
267  foc->needle_frame[i] = downscale(foc->needle_frame[i-1]);
268  if (!foc->needle_frame[i])
269  return AVERROR(ENOMEM);
270  }
271 
272  return 0;
273 }
274 
275 static const AVFilterPad foc_inputs[] = {
276  {
277  .name = "default",
278  .type = AVMEDIA_TYPE_VIDEO,
279  .config_props = config_input,
280  .filter_frame = filter_frame,
281  },
282 };
283 
284 static const AVFilterPad foc_outputs[] = {
285  {
286  .name = "default",
287  .type = AVMEDIA_TYPE_VIDEO,
288  },
289 };
290 
291 const AVFilter ff_vf_find_rect = {
292  .name = "find_rect",
293  .description = NULL_IF_CONFIG_SMALL("Find a user specified object."),
294  .priv_size = sizeof(FOCContext),
295  .init = init,
296  .uninit = uninit,
297  .flags = AVFILTER_FLAG_METADATA_ONLY,
298  FILTER_INPUTS(foc_inputs),
299  FILTER_OUTPUTS(foc_outputs),
300  FILTER_PIXFMTS(AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVJ420P),
301  .priv_class = &find_rect_class,
302 };
FOCContext::threshold
float threshold
Definition: vf_find_rect.c:35
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
FLAGS
#define FLAGS
Definition: vf_find_rect.c:47
av_frame_get_buffer
int av_frame_get_buffer(AVFrame *frame, int align)
Allocate new buffer(s) for audio or video data.
Definition: frame.c:244
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:971
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
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:101
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:330
AVFrame::pts
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:437
AVFrame::width
int width
Definition: frame.h:402
downscale
static AVFrame * downscale(AVFrame *in)
Definition: vf_find_rect.c:62
AVOption
AVOption.
Definition: opt.h:251
FOCContext::obj_filename
char * obj_filename
Definition: vf_find_rect.c:38
FFMAX
#define FFMAX(a, b)
Definition: macros.h:47
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:170
FOCContext::last_x
int last_x
Definition: vf_find_rect.c:39
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:351
FOCContext::xmin
int xmin
Definition: vf_find_rect.c:37
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:49
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:89
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_find_rect.c:172
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
FOCContext::discard
int discard
Definition: vf_find_rect.c:43
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_frame_clone
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:471
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
FOCContext::ymax
int ymax
Definition: vf_find_rect.c:37
pass
#define pass
Definition: fft_template.c:608
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:194
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
fabs
static __device__ float fabs(float a)
Definition: cuda_runtime.h:182
TS2D
#define TS2D(ts)
Definition: internal.h:264
NULL
#define NULL
Definition: coverity.c:32
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
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(find_rect)
AV_PIX_FMT_GRAY8
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
init
static av_cold int init(AVFilterContext *ctx)
Definition: vf_find_rect.c:241
FOCContext::mipmaps
int mipmaps
Definition: vf_find_rect.c:36
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
foc_inputs
static const AVFilterPad foc_inputs[]
Definition: vf_find_rect.c:275
FOCContext
Definition: vf_find_rect.c:33
FILTER_PIXFMTS
#define FILTER_PIXFMTS(...)
Definition: internal.h:180
ff_load_image
int ff_load_image(uint8_t *data[4], int linesize[4], int *w, int *h, enum AVPixelFormat *pix_fmt, const char *filename, void *log_ctx)
Load image from filename and put the resulting image in data.
Definition: lavfutils.c:34
AVFrame::format
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:417
FOCContext::haystack_frame
AVFrame * haystack_frame[MAX_MIPMAPS]
Definition: vf_find_rect.c:42
OFFSET
#define OFFSET(x)
Definition: vf_find_rect.c:46
ff_vf_find_rect
const AVFilter ff_vf_find_rect
Definition: vf_find_rect.c:291
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
internal.h
AV_OPT_TYPE_FLOAT
@ AV_OPT_TYPE_FLOAT
Definition: opt.h:228
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_find_rect.c:133
FOCContext::last_y
int last_y
Definition: vf_find_rect.c:39
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:55
FOCContext::xmax
int xmax
Definition: vf_find_rect.c:37
AVFilter
Filter definition.
Definition: avfilter.h:166
ret
ret
Definition: filter_design.txt:187
search
static float search(FOCContext *foc, int pass, int maxpass, int xmin, int xmax, int ymin, int ymax, int *best_x, int *best_y, float best_score)
Definition: vf_find_rect.c:146
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
FOCContext::needle_frame
AVFrame * needle_frame[MAX_MIPMAPS]
Definition: vf_find_rect.c:41
FOCContext::ymin
int ymin
Definition: vf_find_rect.c:37
AVFrame::height
int height
Definition: frame.h:402
compare
static float compare(const AVFrame *haystack, const AVFrame *obj, int offx, int offy)
Definition: vf_find_rect.c:95
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:655
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_find_rect.c:226
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
find_rect_options
static const AVOption find_rect_options[]
Definition: vf_find_rect.c:48
foc_outputs
static const AVFilterPad foc_outputs[]
Definition: vf_find_rect.c:284
lavfutils.h
MAX_MIPMAPS
#define MAX_MIPMAPS
Definition: vf_find_rect.c:31
AVFilterContext
An instance of a filter.
Definition: avfilter.h:397
av_dict_set_int
int av_dict_set_int(AVDictionary **pm, const char *key, int64_t value, int flags)
Convenience wrapper for av_dict_set() that converts the value to a string and stores it.
Definition: dict.c:167
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_OPT_TYPE_BOOL
@ AV_OPT_TYPE_BOOL
Definition: opt.h:244
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:195
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:86
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
FOCContext::obj_frame
AVFrame * obj_frame
Definition: vf_find_rect.c:40
imgutils.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
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:375
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:229
snprintf
#define snprintf
Definition: snprintf.h:34
Generated on Tue Mar 28 2023 19:22:04 for FFmpeg by   doxygen 1.8.17