Blame view

ffmpeg-4.2.2/libavutil/display.c 2.06 KB
aac5773f   hucm   功能基本完成,接口待打磨
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
  /*
   * Copyright (c) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
   *
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include <stdint.h>
  #include <string.h>
  #include <math.h>
  
  #include "display.h"
  #include "mathematics.h"
  
  // fixed point to double
  #define CONV_FP(x) ((double) (x)) / (1 << 16)
  
  // double to fixed point
  #define CONV_DB(x) (int32_t) ((x) * (1 << 16))
  
  double av_display_rotation_get(const int32_t matrix[9])
  {
      double rotation, scale[2];
  
      scale[0] = hypot(CONV_FP(matrix[0]), CONV_FP(matrix[3]));
      scale[1] = hypot(CONV_FP(matrix[1]), CONV_FP(matrix[4]));
  
      if (scale[0] == 0.0 || scale[1] == 0.0)
          return NAN;
  
      rotation = atan2(CONV_FP(matrix[1]) / scale[1],
                       CONV_FP(matrix[0]) / scale[0]) * 180 / M_PI;
  
      return -rotation;
  }
  
  void av_display_rotation_set(int32_t matrix[9], double angle)
  {
      double radians = -angle * M_PI / 180.0f;
      double c = cos(radians);
      double s = sin(radians);
  
      memset(matrix, 0, 9 * sizeof(int32_t));
  
      matrix[0] = CONV_DB(c);
      matrix[1] = CONV_DB(-s);
      matrix[3] = CONV_DB(s);
      matrix[4] = CONV_DB(c);
      matrix[8] = 1 << 30;
  }
  
  void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip)
  {
      int i;
      const int flip[] = { 1 - 2 * (!!hflip), 1 - 2 * (!!vflip), 1 };
  
      if (hflip || vflip)
          for (i = 0; i < 9; i++)
              matrix[i] *= flip[i % 3];
  }