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
23 #define BBOX(type, name) \
24 static int bbox_##name(FFBoundingBox *bbox, \
25 const type *data, int linesize, int w, int h, \
26 int min_val) \
27 { \
28 int x, y; \
29 int start_x; \
30 int start_y; \
31 int end_x; \
32 int end_y; \
33 const type *line; \
34 \
35 /* left bound */ \
36 for (start_x = 0; start_x < w; start_x++) \
37 for (y = 0; y < h; y++) \
38 if ((data[y * linesize + start_x] > min_val)) \
39 goto outl; \
40 outl: \
41 if (start_x == w) /* no points found */ \
42 return 0; \
43 \
44 /* right bound */ \
45 for (end_x = w - 1; end_x >= start_x; end_x--) \
46 for (y = 0; y < h; y++) \
47 if ((data[y * linesize + end_x] > min_val)) \
48 goto outr; \
49 outr: \
50 \
51 /* top bound */ \
52 line = data; \
53 for (start_y = 0; start_y < h; start_y++) { \
54 for (x = 0; x < w; x++) \
55 if (line[x] > min_val) \
56 goto outt; \
57 line += linesize; \
58 } \
59 outt: \
60 \
61 /* bottom bound */ \
62 line = data + (h-1)*linesize; \
63 for (end_y = h - 1; end_y >= start_y; end_y--) { \
64 for (x = 0; x < w; x++) \
65 if (line[x] > min_val) \
66 goto outb; \
67 line -= linesize; \
68 } \
69 outb: \
70 \
71 bbox->x1 = start_x; \
72 bbox->y1 = start_y; \
73 bbox->x2 = end_x; \
74 bbox->y2 = end_y; \
75 return 1; \
76 }
77
78 BBOX(uint8_t, 8)
79 BBOX(uint16_t, 16)
80
ff_calculate_bounding_box(FFBoundingBox * bbox,const uint8_t * data,int linesize,int w,int h,int min_val,int depth)81 int ff_calculate_bounding_box(FFBoundingBox *bbox,
82 const uint8_t *data, int linesize,
83 int w, int h,
84 int min_val, int depth)
85 {
86 if (depth <= 8)
87 return bbox_8(bbox, data, linesize, w, h, min_val);
88 else
89 return bbox_16(bbox, (const uint16_t *)data, linesize / 2, w, h, min_val);
90 }
91