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63 lines
1.8 KiB
63 lines
1.8 KiB
/* |
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* Copyright (c) 2014 Vittorio Giovara <vittorio.giovara@gmail.com> |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include <stdint.h> |
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#include <string.h> |
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#include <math.h> |
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#include "display.h" |
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#include "mathematics.h" |
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// fixed point to double |
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#define CONV_FP(x) ((double) (x)) / (1 << 16) |
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// double to fixed point |
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#define CONV_DB(x) (int32_t) ((x) * (1 << 16)) |
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double av_display_rotation_get(const int32_t matrix[9]) |
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{ |
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double rotation, scale[2]; |
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scale[0] = hypot(CONV_FP(matrix[0]), CONV_FP(matrix[3])); |
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scale[1] = hypot(CONV_FP(matrix[1]), CONV_FP(matrix[4])); |
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if (scale[0] == 0.0 || scale[1] == 0.0) |
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return NAN; |
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rotation = atan2(CONV_FP(matrix[1]) / scale[1], |
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CONV_FP(matrix[0]) / scale[0]) * 180 / M_PI; |
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return rotation; |
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} |
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void av_display_rotation_set(int32_t matrix[9], double angle) |
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{ |
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double radians = angle * M_PI / 180.0f; |
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double c = cos(radians); |
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double s = sin(radians); |
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memset(matrix, 0, 9 * sizeof(int32_t)); |
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matrix[0] = CONV_DB(c); |
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matrix[1] = CONV_DB(-s); |
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matrix[3] = CONV_DB(s); |
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matrix[4] = CONV_DB(c); |
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matrix[8] = 1 << 30; |
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}
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