2 * Copyright (C) 2010 Georg Martius <georg.martius@web.de>
3 * Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * transform input video
27 #include "libavutil/common.h"
29 #include "transform.h"
31 #define INTERPOLATE_METHOD(name) \
32 static uint8_t name(float x, float y, const uint8_t *src, \
33 int width, int height, int stride, uint8_t def)
35 #define PIXEL(img, x, y, w, h, stride, def) \
36 ((x) < 0 || (y) < 0) ? (def) : \
37 (((x) >= (w) || (y) >= (h)) ? (def) : \
38 img[(x) + (y) * (stride)])
41 * Nearest neighbor interpolation
43 INTERPOLATE_METHOD(interpolate_nearest)
45 return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def);
49 * Bilinear interpolation
51 INTERPOLATE_METHOD(interpolate_bilinear)
53 int x_c, x_f, y_c, y_f;
56 if (x < -1 || x > width || y < -1 || y > height) {
65 v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
66 v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
67 v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
68 v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
70 return (v1*(x - x_f)*(y - y_f) + v2*((x - x_f)*(y_c - y)) +
71 v3*(x_c - x)*(y - y_f) + v4*((x_c - x)*(y_c - y)));
76 * Biquadratic interpolation
78 INTERPOLATE_METHOD(interpolate_biquadratic)
80 int x_c, x_f, y_c, y_f;
81 uint8_t v1, v2, v3, v4;
84 if (x < - 1 || x > width || y < -1 || y > height)
92 v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
93 v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
94 v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
95 v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
97 f1 = 1 - sqrt((x_c - x) * (y_c - y));
98 f2 = 1 - sqrt((x_c - x) * (y - y_f));
99 f3 = 1 - sqrt((x - x_f) * (y_c - y));
100 f4 = 1 - sqrt((x - x_f) * (y - y_f));
101 return (v1 * f1 + v2 * f2 + v3 * f3 + v4 * f4) / (f1 + f2 + f3 + f4);
105 void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix) {
106 matrix[0] = zoom * cos(angle);
107 matrix[1] = -sin(angle);
109 matrix[3] = -matrix[1];
110 matrix[4] = matrix[0];
117 void avfilter_add_matrix(const float *m1, const float *m2, float *result)
120 for (i = 0; i < 9; i++)
121 result[i] = m1[i] + m2[i];
124 void avfilter_sub_matrix(const float *m1, const float *m2, float *result)
127 for (i = 0; i < 9; i++)
128 result[i] = m1[i] - m2[i];
131 void avfilter_mul_matrix(const float *m1, float scalar, float *result)
134 for (i = 0; i < 9; i++)
135 result[i] = m1[i] * scalar;
138 void avfilter_transform(const uint8_t *src, uint8_t *dst,
139 int src_stride, int dst_stride,
140 int width, int height, const float *matrix,
141 enum InterpolateMethod interpolate,
142 enum FillMethod fill)
147 uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
149 switch(interpolate) {
150 case INTERPOLATE_NEAREST:
151 func = interpolate_nearest;
153 case INTERPOLATE_BILINEAR:
154 func = interpolate_bilinear;
156 case INTERPOLATE_BIQUADRATIC:
157 func = interpolate_biquadratic;
161 for (y = 0; y < height; y++) {
162 for(x = 0; x < width; x++) {
163 x_s = x * matrix[0] + y * matrix[1] + matrix[2];
164 y_s = x * matrix[3] + y * matrix[4] + matrix[5];
168 def = src[y * src_stride + x];
171 y_s = av_clipf(y_s, 0, height - 1);
172 x_s = av_clipf(x_s, 0, width - 1);
173 def = src[(int)y_s * src_stride + (int)x_s];
176 y_s = (y_s < 0) ? -y_s : (y_s >= height) ? (height + height - y_s) : y_s;
177 x_s = (x_s < 0) ? -x_s : (x_s >= width) ? (width + width - x_s) : x_s;
178 def = src[(int)y_s * src_stride + (int)x_s];
181 dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);