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
);