path: root/libavfilter/transform.c (plain)
blob: f92fc4d42fb87f66a0f970966b4989453d21ab36

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	*/
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	*/
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	*/
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
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);
109	matrix[2] = x_shift;
110	matrix[3] = -matrix[1];
111	matrix[4] = matrix[0];
112	matrix[5] = y_shift;
113	matrix[6] = 0;
114	matrix[7] = 0;
115	matrix[8] = 1;
116	}
117
118	void avfilter_add_matrix(const float *m1, const float *m2, float *result)
119	{
120	int i;
121	for (i = 0; i < 9; i++)
122	result[i] = m1[i] + m2[i];
123	}
124
125	void avfilter_sub_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
132	void avfilter_mul_matrix(const float *m1, float scalar, float *result)
133	{
134	int i;
135	for (i = 0; i < 9; i++)
136	result[i] = m1[i] * scalar;
137	}
138
139	int avfilter_transform(const uint8_t *src, uint8_t *dst,
140	int src_stride, int dst_stride,
141	int width, int height, const float *matrix,
142	enum InterpolateMethod interpolate,
143	enum FillMethod fill)
144	{
145	int x, y;
146	float x_s, y_s;
147	uint8_t def = 0;
148	uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
149
150	switch(interpolate) {
151	case INTERPOLATE_NEAREST:
152	func = interpolate_nearest;
153	break;
154	case INTERPOLATE_BILINEAR:
155	func = interpolate_bilinear;
156	break;
157	case INTERPOLATE_BIQUADRATIC:
158	func = interpolate_biquadratic;
159	break;
160	default:
161	return AVERROR(EINVAL);
162	}
163
164	for (y = 0; y < height; y++) {
165	for(x = 0; x < width; x++) {
166	x_s = x * matrix[0] + y * matrix[1] + matrix[2];
167	y_s = x * matrix[3] + y * matrix[4] + matrix[5];
168
169	switch(fill) {
170	case FILL_ORIGINAL:
171	def = src[y * src_stride + x];
172	break;
173	case FILL_CLAMP:
174	y_s = av_clipf(y_s, 0, height - 1);
175	x_s = av_clipf(x_s, 0, width - 1);
176	def = src[(int)y_s * src_stride + (int)x_s];
177	break;
178	case FILL_MIRROR:
179	x_s = avpriv_mirror(x_s, width-1);
180	y_s = avpriv_mirror(y_s, height-1);
181
182	av_assert2(x_s >= 0 && y_s >= 0);
183	av_assert2(x_s < width && y_s < height);
184	def = src[(int)y_s * src_stride + (int)x_s];
185	}
186
187	dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);
188	}
189	}
190	return 0;
191	}
192