cobalt / cobalt / cc19caab3101a025a2ae4db11601ed3496c7d730 / . / third_party / ffmpeg_includes / ffmpeg.58.35.100 / libavutil / display.h

/* | |

* 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 | |

*/ | |

/** | |

* @file | |

* Display matrix | |

*/ | |

#ifndef AVUTIL_DISPLAY_H | |

#define AVUTIL_DISPLAY_H | |

#include <stdint.h> | |

#include "common.h" | |

/** | |

* @addtogroup lavu_video | |

* @{ | |

* | |

* @defgroup lavu_video_display Display transformation matrix functions | |

* @{ | |

*/ | |

/** | |

* @addtogroup lavu_video_display | |

* The display transformation matrix specifies an affine transformation that | |

* should be applied to video frames for correct presentation. It is compatible | |

* with the matrices stored in the ISO/IEC 14496-12 container format. | |

* | |

* The data is a 3x3 matrix represented as a 9-element array: | |

* | |

* @code{.unparsed} | |

* | a b u | | |

* (a, b, u, c, d, v, x, y, w) -> | c d v | | |

* | x y w | | |

* @endcode | |

* | |

* All numbers are stored in native endianness, as 16.16 fixed-point values, | |

* except for u, v and w, which are stored as 2.30 fixed-point values. | |

* | |

* The transformation maps a point (p, q) in the source (pre-transformation) | |

* frame to the point (p', q') in the destination (post-transformation) frame as | |

* follows: | |

* | |

* @code{.unparsed} | |

* | a b u | | |

* (p, q, 1) . | c d v | = z * (p', q', 1) | |

* | x y w | | |

* @endcode | |

* | |

* The transformation can also be more explicitly written in components as | |

* follows: | |

* | |

* @code{.unparsed} | |

* p' = (a * p + c * q + x) / z; | |

* q' = (b * p + d * q + y) / z; | |

* z = u * p + v * q + w | |

* @endcode | |

*/ | |

/** | |

* Extract the rotation component of the transformation matrix. | |

* | |

* @param matrix the transformation matrix | |

* @return the angle (in degrees) by which the transformation rotates the frame | |

* counterclockwise. The angle will be in range [-180.0, 180.0], | |

* or NaN if the matrix is singular. | |

* | |

* @note floating point numbers are inherently inexact, so callers are | |

* recommended to round the return value to nearest integer before use. | |

*/ | |

double av_display_rotation_get(const int32_t matrix[9]); | |

/** | |

* Initialize a transformation matrix describing a pure counterclockwise | |

* rotation by the specified angle (in degrees). | |

* | |

* @param matrix an allocated transformation matrix (will be fully overwritten | |

* by this function) | |

* @param angle rotation angle in degrees. | |

*/ | |

void av_display_rotation_set(int32_t matrix[9], double angle); | |

/** | |

* Flip the input matrix horizontally and/or vertically. | |

* | |

* @param matrix an allocated transformation matrix | |

* @param hflip whether the matrix should be flipped horizontally | |

* @param vflip whether the matrix should be flipped vertically | |

*/ | |

void av_display_matrix_flip(int32_t matrix[9], int hflip, int vflip); | |

/** | |

* @} | |

* @} | |

*/ | |

#endif /* AVUTIL_DISPLAY_H */ |