FFmpeg  4.0
display.c
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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 "libavutil/display.c"
22 
23 static void print_matrix(int32_t matrix[9])
24 {
25  int i, j;
26 
27  for (i = 0; i < 3; ++i) {
28  for (j = 0; j < 3 - 1; ++j)
29  printf("%d ", matrix[i*3 + j]);
30 
31  printf("%d\n", matrix[i*3 + j]);
32  }
33 }
34 
35 int main(void)
36 {
37  int32_t matrix[9];
38 
39  // Set the matrix to 90 degrees
40  av_display_rotation_set(matrix, 90);
41  print_matrix(matrix);
42  printf("degrees: %f\n", av_display_rotation_get(matrix));
43 
44  // Set the matrix to -45 degrees
45  av_display_rotation_set(matrix, -45);
46  print_matrix(matrix);
47  printf("degrees: %f\n", av_display_rotation_get(matrix));
48 
49  // flip horizontal
50  av_display_matrix_flip(matrix, 1, 0);
51  print_matrix(matrix);
52  printf("degrees: %f\n", av_display_rotation_get(matrix));
53 
54  // flip vertical
55  av_display_matrix_flip(matrix, 0, 1);
56  print_matrix(matrix);
57  printf("degrees: %f\n", av_display_rotation_get(matrix));
58 
59  return 0;
60 
61 }
void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip)
Flip the input matrix horizontally and/or vertically.
Definition: display.c:65
void av_display_rotation_set(int32_t matrix[9], double angle)
Initialize a transformation matrix describing a pure counterclockwise rotation by the specified angle...
Definition: display.c:50
int32_t
int main(void)
Definition: display.c:35
static void print_matrix(int32_t matrix[9])
Definition: display.c:23
double av_display_rotation_get(const int32_t matrix[9])
Extract the rotation component of the transformation matrix.
Definition: display.c:34