/* * 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; }