ef1d4ee2f8
* commit 'bddd8cbf68551f6405b2bf77cc3e212af9fbe834': Add transformation matrix API. Conflicts: libavcodec/avcodec.h libavcodec/utils.c libavutil/version.h Merged-by: Michael Niedermayer <michaelni@gmx.at>
78 lines
2.8 KiB
C
78 lines
2.8 KiB
C
/*
|
|
* 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
|
|
*/
|
|
|
|
#ifndef AVUTIL_DISPLAY_H
|
|
#define AVUTIL_DISPLAY_H
|
|
|
|
#include <stdint.h>
|
|
|
|
/**
|
|
* 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:
|
|
*
|
|
* | a b u |
|
|
* (a, b, u, c, d, v, x, y, w) -> | c d v |
|
|
* | x y w |
|
|
*
|
|
* 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:
|
|
* | a b u |
|
|
* (p, q, 1) . | c d v | = z * (p', q', 1)
|
|
* | x y w |
|
|
*
|
|
* The transformation can also be more explicitly written in components as
|
|
* follows:
|
|
* p' = (a * p + c * q + x) / z;
|
|
* q' = (b * p + d * q + y) / z;
|
|
* z = u * p + v * q + w
|
|
*/
|
|
|
|
/**
|
|
* 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.
|
|
* 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 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);
|
|
|
|
#endif /* AVUTIL_DISPLAY_H */
|