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Diffstat (limited to 'libavfilter/transform.h')
| -rw-r--r-- | libavfilter/transform.h | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/libavfilter/transform.h b/libavfilter/transform.h new file mode 100644 index 0000000000..07436bfccb --- /dev/null +++ b/libavfilter/transform.h @@ -0,0 +1,127 @@ +/* + * 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 + */ + +#ifndef AVFILTER_TRANSFORM_H +#define AVFILTER_TRANSFORM_H + +#include <stdint.h> + +/** + * @file + * 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 ] + * + * @param x_shift horizontal translation + * @param y_shift vertical translation + * @param angle rotation in radians + * @param zoom scale percent (1.0 = 100%) + * @param 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. + * + * @param m1 9-item transformation matrix + * @param m2 9-item transformation matrix + * @param 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. + * + * @param m1 9-item transformation matrix + * @param m2 9-item transformation matrix + * @param 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. + * + * @param m1 9-item transformation matrix + * @param scalar a number + * @param 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. + * + * @param src source image + * @param dst destination image + * @param src_stride source image line size in bytes + * @param dst_stride destination image line size in bytes + * @param width image width in pixels + * @param height image height in pixels + * @param matrix 9-item affine transformation matrix + * @param interpolate pixel interpolation method + * @param fill edge fill method + * @return negative on error + */ +int 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); + +#endif /* AVFILTER_TRANSFORM_H */ |