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Diffstat (limited to 'libavfilter/transform.c')
| -rw-r--r-- | libavfilter/transform.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/libavfilter/transform.c b/libavfilter/transform.c new file mode 100644 index 0000000000..1db8c0836d --- /dev/null +++ b/libavfilter/transform.c @@ -0,0 +1,202 @@ +/* + * 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 + * transform input video + */ + +#include "libavutil/common.h" +#include "libavutil/avassert.h" + +#include "transform.h" + +#define INTERPOLATE_METHOD(name) \ + static uint8_t name(float x, float y, const uint8_t *src, \ + int width, int height, int stride, uint8_t def) + +#define PIXEL(img, x, y, w, h, stride, def) \ + ((x) < 0 || (y) < 0) ? (def) : \ + (((x) >= (w) || (y) >= (h)) ? (def) : \ + img[(x) + (y) * (stride)]) + +/** + * Nearest neighbor interpolation + */ +INTERPOLATE_METHOD(interpolate_nearest) +{ + return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def); +} + +/** + * Bilinear interpolation + */ +INTERPOLATE_METHOD(interpolate_bilinear) +{ + int x_c, x_f, y_c, y_f; + int v1, v2, v3, v4; + + if (x < -1 || x > width || y < -1 || y > height) { + return def; + } else { + x_f = (int)x; + x_c = x_f + 1; + + y_f = (int)y; + y_c = y_f + 1; + + v1 = PIXEL(src, x_c, y_c, width, height, stride, def); + v2 = PIXEL(src, x_c, y_f, width, height, stride, def); + v3 = PIXEL(src, x_f, y_c, width, height, stride, def); + v4 = PIXEL(src, x_f, y_f, width, height, stride, def); + + return (v1*(x - x_f)*(y - y_f) + v2*((x - x_f)*(y_c - y)) + + v3*(x_c - x)*(y - y_f) + v4*((x_c - x)*(y_c - y))); + } +} + +/** + * Biquadratic interpolation + */ +INTERPOLATE_METHOD(interpolate_biquadratic) +{ + int x_c, x_f, y_c, y_f; + uint8_t v1, v2, v3, v4; + float f1, f2, f3, f4; + + if (x < - 1 || x > width || y < -1 || y > height) + return def; + else { + x_f = (int)x; + x_c = x_f + 1; + y_f = (int)y; + y_c = y_f + 1; + + v1 = PIXEL(src, x_c, y_c, width, height, stride, def); + v2 = PIXEL(src, x_c, y_f, width, height, stride, def); + v3 = PIXEL(src, x_f, y_c, width, height, stride, def); + v4 = PIXEL(src, x_f, y_f, width, height, stride, def); + + f1 = 1 - sqrt((x_c - x) * (y_c - y)); + f2 = 1 - sqrt((x_c - x) * (y - y_f)); + f3 = 1 - sqrt((x - x_f) * (y_c - y)); + f4 = 1 - sqrt((x - x_f) * (y - y_f)); + return (v1 * f1 + v2 * f2 + v3 * f3 + v4 * f4) / (f1 + f2 + f3 + f4); + } +} + +void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix) { + matrix[0] = zoom * cos(angle); + matrix[1] = -sin(angle); + matrix[2] = x_shift; + matrix[3] = -matrix[1]; + matrix[4] = matrix[0]; + matrix[5] = y_shift; + matrix[6] = 0; + matrix[7] = 0; + matrix[8] = 1; +} + +void avfilter_add_matrix(const float *m1, const float *m2, float *result) +{ + int i; + for (i = 0; i < 9; i++) + result[i] = m1[i] + m2[i]; +} + +void avfilter_sub_matrix(const float *m1, const float *m2, float *result) +{ + int i; + for (i = 0; i < 9; i++) + result[i] = m1[i] - m2[i]; +} + +void avfilter_mul_matrix(const float *m1, float scalar, float *result) +{ + int i; + for (i = 0; i < 9; i++) + result[i] = m1[i] * scalar; +} + +static inline int mirror(int v, int m) +{ + while ((unsigned)v > (unsigned)m) { + v = -v; + if (v < 0) + v += 2 * m; + } + return v; +} + +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) +{ + int x, y; + float x_s, y_s; + uint8_t def = 0; + uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL; + + switch(interpolate) { + case INTERPOLATE_NEAREST: + func = interpolate_nearest; + break; + case INTERPOLATE_BILINEAR: + func = interpolate_bilinear; + break; + case INTERPOLATE_BIQUADRATIC: + func = interpolate_biquadratic; + break; + default: + return AVERROR(EINVAL); + } + + for (y = 0; y < height; y++) { + for(x = 0; x < width; x++) { + x_s = x * matrix[0] + y * matrix[1] + matrix[2]; + y_s = x * matrix[3] + y * matrix[4] + matrix[5]; + + switch(fill) { + case FILL_ORIGINAL: + def = src[y * src_stride + x]; + break; + case FILL_CLAMP: + y_s = av_clipf(y_s, 0, height - 1); + x_s = av_clipf(x_s, 0, width - 1); + def = src[(int)y_s * src_stride + (int)x_s]; + break; + case FILL_MIRROR: + x_s = mirror(x_s, width-1); + y_s = mirror(y_s, height-1); + + av_assert2(x_s >= 0 && y_s >= 0); + av_assert2(x_s < width && y_s < height); + def = src[(int)y_s * src_stride + (int)x_s]; + } + + dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def); + } + } + return 0; +} + |