From 7985381e236a95c711a5315a83c891eef0c56d3b Mon Sep 17 00:00:00 2001 From: danielgtaylor Date: Tue, 4 Oct 2011 02:10:18 +0200 Subject: libavfilter: image transform code Signed-off-by: Michael Niedermayer --- libavfilter/transform.h | 125 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) create mode 100644 libavfilter/transform.h (limited to 'libavfilter/transform.h') diff --git a/libavfilter/transform.h b/libavfilter/transform.h new file mode 100644 index 0000000000..2d5cf37aa1 --- /dev/null +++ b/libavfilter/transform.h @@ -0,0 +1,125 @@ +/* + * Copyright (C) 2010 Georg Martius + * Copyright (C) 2010 Daniel G. Taylor + * + * 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); + -- cgit v1.2.3