blob: a0076e067bb3152fa4d12658c919b63d564c2152
1 | /* |
2 | * Copyright (c) 2014 Vittorio Giovara <vittorio.giovara@gmail.com> |
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 <stdint.h> |
22 | #include <string.h> |
23 | #include <math.h> |
24 | |
25 | #include "display.h" |
26 | #include "mathematics.h" |
27 | |
28 | // fixed point to double |
29 | #define CONV_FP(x) ((double) (x)) / (1 << 16) |
30 | |
31 | // double to fixed point |
32 | #define CONV_DB(x) (int32_t) ((x) * (1 << 16)) |
33 | |
34 | double av_display_rotation_get(const int32_t matrix[9]) |
35 | { |
36 | double rotation, scale[2]; |
37 | |
38 | scale[0] = hypot(CONV_FP(matrix[0]), CONV_FP(matrix[3])); |
39 | scale[1] = hypot(CONV_FP(matrix[1]), CONV_FP(matrix[4])); |
40 | |
41 | if (scale[0] == 0.0 || scale[1] == 0.0) |
42 | return NAN; |
43 | |
44 | rotation = atan2(CONV_FP(matrix[1]) / scale[1], |
45 | CONV_FP(matrix[0]) / scale[0]) * 180 / M_PI; |
46 | |
47 | return -rotation; |
48 | } |
49 | |
50 | void av_display_rotation_set(int32_t matrix[9], double angle) |
51 | { |
52 | double radians = -angle * M_PI / 180.0f; |
53 | double c = cos(radians); |
54 | double s = sin(radians); |
55 | |
56 | memset(matrix, 0, 9 * sizeof(int32_t)); |
57 | |
58 | matrix[0] = CONV_DB(c); |
59 | matrix[1] = CONV_DB(-s); |
60 | matrix[3] = CONV_DB(s); |
61 | matrix[4] = CONV_DB(c); |
62 | matrix[8] = 1 << 30; |
63 | } |
64 | |
65 | void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip) |
66 | { |
67 | int i; |
68 | const int flip[] = { 1 - 2 * (!!hflip), 1 - 2 * (!!vflip), 1 }; |
69 | |
70 | if (hflip || vflip) |
71 | for (i = 0; i < 9; i++) |
72 | matrix[i] *= flip[i % 3]; |
73 | } |
74 |