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/*
* Copyright (C) 2010 Georg Martius <georg.martius@web.de>
* Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
*
* 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 libavfilter/transform.h
* transform input video
*
* All matrices are defined as a single 9-item block of contiguous memory. For
* example, the identity matrix would be:
*
* float *matrix = {1, 0, 0,
* 0, 1, 0,
* 0, 0, 1};
*/
enum InterpolateMethod {
INTERPOLATE_NEAREST, //< Nearest-neighbor (fast)
INTERPOLATE_BILINEAR, //< Bilinear
INTERPOLATE_BIQUADRATIC, //< Biquadratic (best)
INTERPOLATE_COUNT, //< Number of interpolation methods
};
// Shortcuts for the fastest and best interpolation methods
#define INTERPOLATE_DEFAULT INTERPOLATE_BILINEAR
#define INTERPOLATE_FAST INTERPOLATE_NEAREST
#define INTERPOLATE_BEST INTERPOLATE_BIQUADRATIC
enum FillMethod {
FILL_BLANK, //< Fill zeroes at blank locations
FILL_ORIGINAL, //< Original image at blank locations
FILL_CLAMP, //< Extruded edge value at blank locations
FILL_MIRROR, //< Mirrored edge at blank locations
FILL_COUNT, //< Number of edge fill methods
};
// Shortcuts for fill methods
#define FILL_DEFAULT FILL_ORIGINAL
/**
* Get an affine transformation matrix from a given translation, rotation, and
* zoom factor. The matrix will look like:
*
* [ zoom * cos(angle), -sin(angle), x_shift,
* sin(angle), zoom * cos(angle), y_shift,
0, 0, 1 ]
*
* Paramters:
* x_shift: Horizontal translation
* y_shift: Vertical translation
* angle: Rotation in radians
* zoom: Scale percent (1.0 = 100%)
* matrix: 9-item affine transformation matrix
*/
void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix);
/**
* Add two matrices together. result = m1 + m2.
*
* Parameters:
* m1: 9-item transformation matrix
* m2: 9-item transformation matrix
* result: 9-item transformation matrix
*/
void avfilter_add_matrix(const float *m1, const float *m2, float *result);
/**
* Subtract one matrix from another. result = m1 - m2.
*
* Parameters:
* m1: 9-item transformation matrix
* m2: 9-item transformation matrix
* result: 9-item transformation matrix
*/
void avfilter_sub_matrix(const float *m1, const float *m2, float *result);
/**
* Multiply a matrix by a scalar value. result = m1 * scalar.
*
* Parameters:
* m1: 9-item transformation matrix
* scalar: A number
* result: 9-item transformation matrix
*/
void avfilter_mul_matrix(const float *m1, float scalar, float *result);
/**
* Do an affine transformation with the given interpolation method. This
* multiplies each vector [x,y,1] by the matrix and then interpolates to
* get the final value.
*
* Parameters:
* src: Source image
* dst: Destination image
* src_stride: Source image line size in bytes
* dst_stride: Destination image line size in bytes
* width: Image width in pixels
* height: Image height in pixels
* matrix: 9-item affine transformation matrix
* interpolate: Pixel interpolation method
* fill: Edge fill method
*/
void avfilter_transform(const uint8_t *src, uint8_t *dst,
int src_stride, int dst_stride,
int width, int height, const float *matrix,
enum InterpolateMethod interpolate,
enum FillMethod fill);
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