FFmpeg
bbox.c
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1 /*
2  * Copyright (c) 2005 Robert Edele <yartrebo@earthlink.net>
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 "bbox.h"
22 
24  const uint8_t *data, int linesize, int w, int h,
25  int min_val)
26 {
27  int x, y;
28  int start_x;
29  int start_y;
30  int end_x;
31  int end_y;
32  const uint8_t *line;
33 
34  /* left bound */
35  for (start_x = 0; start_x < w; start_x++)
36  for (y = 0; y < h; y++)
37  if ((data[y * linesize + start_x] > min_val))
38  goto outl;
39 outl:
40  if (start_x == w) /* no points found */
41  return 0;
42 
43  /* right bound */
44  for (end_x = w - 1; end_x >= start_x; end_x--)
45  for (y = 0; y < h; y++)
46  if ((data[y * linesize + end_x] > min_val))
47  goto outr;
48 outr:
49 
50  /* top bound */
51  line = data;
52  for (start_y = 0; start_y < h; start_y++) {
53  for (x = 0; x < w; x++)
54  if (line[x] > min_val)
55  goto outt;
56  line += linesize;
57  }
58 outt:
59 
60  /* bottom bound */
61  line = data + (h-1)*linesize;
62  for (end_y = h - 1; end_y >= start_y; end_y--) {
63  for (x = 0; x < w; x++)
64  if (line[x] > min_val)
65  goto outb;
66  line -= linesize;
67  }
68 outb:
69 
70  bbox->x1 = start_x;
71  bbox->y1 = start_y;
72  bbox->x2 = end_x;
73  bbox->y2 = end_y;
74  return 1;
75 }
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
uint8_t
int x2
Definition: bbox.h:27
uint8_t w
Definition: llviddspenc.c:38
int y1
Definition: bbox.h:27
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted line
Definition: swscale.txt:33
int ff_calculate_bounding_box(FFBoundingBox *bbox, const uint8_t *data, int linesize, int w, int h, int min_val)
Calculate the smallest rectangle that will encompass the region with values > min_val.
Definition: bbox.c:23
int y2
Definition: bbox.h:27
int x1
Definition: bbox.h:27