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
av_display_rotation_get(const int32_t matrix[9])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
av_display_rotation_set(int32_t matrix[9],double angle)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
av_display_matrix_flip(int32_t matrix[9],int hflip,int vflip)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