1 /*
2 * Copyright (C) 2010 Georg Martius <georg.martius@web.de>
3 * Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * transform input video
25 */
26
27 #include "libavutil/common.h"
28 #include "libavutil/avassert.h"
29
30 #include "transform.h"
31
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)
35
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)])
40
41 /**
42 * Nearest neighbor interpolation
43 */
INTERPOLATE_METHOD(interpolate_nearest)44 INTERPOLATE_METHOD(interpolate_nearest)
45 {
46 return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def);
47 }
48
49 /**
50 * Bilinear interpolation
51 */
INTERPOLATE_METHOD(interpolate_bilinear)52 INTERPOLATE_METHOD(interpolate_bilinear)
53 {
54 int x_c, x_f, y_c, y_f;
55 int v1, v2, v3, v4;
56
57 if (x < -1 || x > width || y < -1 || y > height) {
58 return def;
59 } else {
60 x_f = (int)x;
61 x_c = x_f + 1;
62
63 y_f = (int)y;
64 y_c = y_f + 1;
65
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);
70
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)));
73 }
74 }
75
76 /**
77 * Biquadratic interpolation
78 */
INTERPOLATE_METHOD(interpolate_biquadratic)79 INTERPOLATE_METHOD(interpolate_biquadratic)
80 {
81 int x_c, x_f, y_c, y_f;
82 uint8_t v1, v2, v3, v4;
83 float f1, f2, f3, f4;
84
85 if (x < - 1 || x > width || y < -1 || y > height)
86 return def;
87 else {
88 x_f = (int)x;
89 x_c = x_f + 1;
90 y_f = (int)y;
91 y_c = y_f + 1;
92
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);
97
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);
103 }
104 }
105
ff_get_matrix(float x_shift,float y_shift,float angle,float scale_x,float scale_y,float * matrix)106 void ff_get_matrix(
107 float x_shift,
108 float y_shift,
109 float angle,
110 float scale_x,
111 float scale_y,
112 float *matrix
113 ) {
114 matrix[0] = scale_x * cos(angle);
115 matrix[1] = -sin(angle);
116 matrix[2] = x_shift;
117 matrix[3] = -matrix[1];
118 matrix[4] = scale_y * cos(angle);
119 matrix[5] = y_shift;
120 matrix[6] = 0;
121 matrix[7] = 0;
122 matrix[8] = 1;
123 }
124
avfilter_add_matrix(const float * m1,const float * m2,float * result)125 void avfilter_add_matrix(const float *m1, const float *m2, float *result)
126 {
127 int i;
128 for (i = 0; i < 9; i++)
129 result[i] = m1[i] + m2[i];
130 }
131
avfilter_sub_matrix(const float * m1,const float * m2,float * result)132 void avfilter_sub_matrix(const float *m1, const float *m2, float *result)
133 {
134 int i;
135 for (i = 0; i < 9; i++)
136 result[i] = m1[i] - m2[i];
137 }
138
avfilter_mul_matrix(const float * m1,float scalar,float * result)139 void avfilter_mul_matrix(const float *m1, float scalar, float *result)
140 {
141 int i;
142 for (i = 0; i < 9; i++)
143 result[i] = m1[i] * scalar;
144 }
145
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)146 int avfilter_transform(const uint8_t *src, uint8_t *dst,
147 int src_stride, int dst_stride,
148 int width, int height, const float *matrix,
149 enum InterpolateMethod interpolate,
150 enum FillMethod fill)
151 {
152 int x, y;
153 float x_s, y_s;
154 uint8_t def = 0;
155 uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
156
157 switch(interpolate) {
158 case INTERPOLATE_NEAREST:
159 func = interpolate_nearest;
160 break;
161 case INTERPOLATE_BILINEAR:
162 func = interpolate_bilinear;
163 break;
164 case INTERPOLATE_BIQUADRATIC:
165 func = interpolate_biquadratic;
166 break;
167 default:
168 return AVERROR(EINVAL);
169 }
170
171 for (y = 0; y < height; y++) {
172 for(x = 0; x < width; x++) {
173 x_s = x * matrix[0] + y * matrix[1] + matrix[2];
174 y_s = x * matrix[3] + y * matrix[4] + matrix[5];
175
176 switch(fill) {
177 case FILL_ORIGINAL:
178 def = src[y * src_stride + x];
179 break;
180 case FILL_CLAMP:
181 y_s = av_clipf(y_s, 0, height - 1);
182 x_s = av_clipf(x_s, 0, width - 1);
183 def = src[(int)y_s * src_stride + (int)x_s];
184 break;
185 case FILL_MIRROR:
186 x_s = avpriv_mirror(x_s, width-1);
187 y_s = avpriv_mirror(y_s, height-1);
188
189 av_assert2(x_s >= 0 && y_s >= 0);
190 av_assert2(x_s < width && y_s < height);
191 def = src[(int)y_s * src_stride + (int)x_s];
192 }
193
194 dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);
195 }
196 }
197 return 0;
198 }
199