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 "libm.h"
27 #include "mathematics.h"
28
29 // fixed point to double
30 #define CONV_FP(x) ((double) (x)) / (1 << 16)
31
32 // double to fixed point
33 #define CONV_DB(x) (int32_t) ((x) * (1 << 16))
34
av_display_rotation_get(const int32_t matrix[9])35 double av_display_rotation_get(const int32_t matrix[9])
36 {
37 double rotation, scale[2];
38
39 scale[0] = hypot(CONV_FP(matrix[0]), CONV_FP(matrix[3]));
40 scale[1] = hypot(CONV_FP(matrix[1]), CONV_FP(matrix[4]));
41
42 if (scale[0] == 0.0 || scale[1] == 0.0)
43 return NAN;
44
45 rotation = atan2(CONV_FP(matrix[1]) / scale[1],
46 CONV_FP(matrix[0]) / scale[0]) * 180 / M_PI;
47
48 return -rotation;
49 }
50
av_display_rotation_set(int32_t matrix[9],double angle)51 void av_display_rotation_set(int32_t matrix[9], double angle)
52 {
53 double radians = -angle * M_PI / 180.0f;
54 double c = cos(radians);
55 double s = sin(radians);
56
57 memset(matrix, 0, 9 * sizeof(int32_t));
58
59 matrix[0] = CONV_DB(c);
60 matrix[1] = CONV_DB(-s);
61 matrix[3] = CONV_DB(s);
62 matrix[4] = CONV_DB(c);
63 matrix[8] = 1 << 30;
64 }
65
av_display_matrix_flip(int32_t matrix[9],int hflip,int vflip)66 void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip)
67 {
68 int i;
69 const int flip[] = { 1 - 2 * (!!hflip), 1 - 2 * (!!vflip), 1 };
70
71 if (hflip || vflip)
72 for (i = 0; i < 9; i++)
73 matrix[i] *= flip[i % 3];
74 }
75