Blame view

ffmpeg-4.2.2/libavfilter/bbox.c 2.09 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
  /*
   * Copyright (c) 2005 Robert Edele <yartrebo@earthlink.net>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "bbox.h"
  
  int ff_calculate_bounding_box(FFBoundingBox *bbox,
                                const uint8_t *data, int linesize, int w, int h,
                                int min_val)
  {
      int x, y;
      int start_x;
      int start_y;
      int end_x;
      int end_y;
      const uint8_t *line;
  
      /* left bound */
      for (start_x = 0; start_x < w; start_x++)
          for (y = 0; y < h; y++)
              if ((data[y * linesize + start_x] > min_val))
                  goto outl;
  outl:
      if (start_x == w) /* no points found */
          return 0;
  
      /* right bound */
      for (end_x = w - 1; end_x >= start_x; end_x--)
          for (y = 0; y < h; y++)
              if ((data[y * linesize + end_x] > min_val))
                  goto outr;
  outr:
  
      /* top bound */
      line = data;
      for (start_y = 0; start_y < h; start_y++) {
          for (x = 0; x < w; x++)
              if (line[x] > min_val)
                  goto outt;
          line += linesize;
      }
  outt:
  
      /* bottom bound */
      line = data + (h-1)*linesize;
      for (end_y = h - 1; end_y >= start_y; end_y--) {
          for (x = 0; x < w; x++)
              if (line[x] > min_val)
                  goto outb;
          line -= linesize;
      }
  outb:
  
      bbox->x1 = start_x;
      bbox->y1 = start_y;
      bbox->x2 = end_x;
      bbox->y2 = end_y;
      return 1;
  }