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"
28 #include "libavutil/avassert.h"
30 #include "transform.h"
32 #define INTERPOLATE_METHOD(name) \
33 static uint8_t name(float x, float y, const uint8_t *src, \
34 int width, int height, int stride, uint8_t def)
36 #define PIXEL(img, x, y, w, h, stride, def) \
37 ((x) < 0 || (y) < 0) ? (def) : \
38 (((x) >= (w) || (y) >= (h)) ? (def) : \
39 img[(x) + (y) * (stride)])
42 * Nearest neighbor interpolation
44 INTERPOLATE_METHOD(interpolate_nearest)
46 return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def);
50 * Bilinear interpolation
52 INTERPOLATE_METHOD(interpolate_bilinear)
54 int x_c, x_f, y_c, y_f;
57 if (x < -1 || x > width || y < -1 || y > height) {
66 v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
67 v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
68 v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
69 v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
71 return (v1*(x - x_f)*(y - y_f) + v2*((x - x_f)*(y_c - y)) +
72 v3*(x_c - x)*(y - y_f) + v4*((x_c - x)*(y_c - y)));
77 * Biquadratic interpolation
79 INTERPOLATE_METHOD(interpolate_biquadratic)
81 int x_c, x_f, y_c, y_f;
82 uint8_t v1, v2, v3, v4;
85 if (x < - 1 || x > width || y < -1 || y > height)
93 v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
94 v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
95 v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
96 v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
98 f1 = 1 - sqrt((x_c - x) * (y_c - y));
99 f2 = 1 - sqrt((x_c - x) * (y - y_f));
100 f3 = 1 - sqrt((x - x_f) * (y_c - y));
101 f4 = 1 - sqrt((x - x_f) * (y - y_f));
102 return (v1 * f1 + v2 * f2 + v3 * f3 + v4 * f4) / (f1 + f2 + f3 + f4);
106 void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix) {
107 matrix[0] = zoom * cos(angle);
108 matrix[1] = -sin(angle);
110 matrix[3] = -matrix[1];
111 matrix[4] = matrix[0];
118 void avfilter_add_matrix(const float *m1, const float *m2, float *result)
121 for (i = 0; i < 9; i++)
122 result[i] = m1[i] + m2[i];
125 void avfilter_sub_matrix(const float *m1, const float *m2, float *result)
128 for (i = 0; i < 9; i++)
129 result[i] = m1[i] - m2[i];
132 void avfilter_mul_matrix(const float *m1, float scalar, float *result)
135 for (i = 0; i < 9; i++)
136 result[i] = m1[i] * scalar;
139 static inline int mirror(int v, int m)
141 while ((unsigned)v > (unsigned)m) {
149 int avfilter_transform(const uint8_t *src, uint8_t *dst,
150 int src_stride, int dst_stride,
151 int width, int height, const float *matrix,
152 enum InterpolateMethod interpolate,
153 enum FillMethod fill)
158 uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
160 switch(interpolate) {
161 case INTERPOLATE_NEAREST:
162 func = interpolate_nearest;
164 case INTERPOLATE_BILINEAR:
165 func = interpolate_bilinear;
167 case INTERPOLATE_BIQUADRATIC:
168 func = interpolate_biquadratic;
171 return AVERROR(EINVAL);
174 for (y = 0; y < height; y++) {
175 for(x = 0; x < width; x++) {
176 x_s = x * matrix[0] + y * matrix[1] + matrix[2];
177 y_s = x * matrix[3] + y * matrix[4] + matrix[5];
181 def = src[y * src_stride + x];
184 y_s = av_clipf(y_s, 0, height - 1);
185 x_s = av_clipf(x_s, 0, width - 1);
186 def = src[(int)y_s * src_stride + (int)x_s];
189 x_s = mirror(x_s, width-1);
190 y_s = mirror(y_s, height-1);
192 av_assert2(x_s >= 0 && y_s >= 0);
193 av_assert2(x_s < width && y_s < height);
194 def = src[(int)y_s * src_stride + (int)x_s];
197 dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);