| 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 | } |