/*
* Copyright (C) 2010 Georg Martius <georg.martius@web.de>
* Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* transform input video
*/
#include "libavutil/common.h"
#include "libavutil/avassert.h"
#include "transform.h"
#define INTERPOLATE_METHOD(name) \
static uint8_t name(float x, float y, const uint8_t *src, \
int width, int height, int stride, uint8_t def)
#define PIXEL(img, x, y, w, h, stride, def) \
((x) < 0 || (y) < 0) ? (def) : \
(((x) >= (w) || (y) >= (h)) ? (def) : \
img[(x) + (y) * (stride)])
/**
* Nearest neighbor interpolation
*/
INTERPOLATE_METHOD(interpolate_nearest)
{
return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def);
}
/**
* Bilinear interpolation
*/
INTERPOLATE_METHOD(interpolate_bilinear)
{
int x_c, x_f, y_c, y_f;
int v1, v2, v3, v4;
if (x < -1 || x > width || y < -1 || y > height) {
return def;
} else {
x_f = (int)x;
x_c = x_f + 1;
y_f = (int)y;
y_c = y_f + 1;
v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
return (v1*(x - x_f)*(y - y_f) + v2*((x - x_f)*(y_c - y)) +
v3*(x_c - x)*(y - y_f) + v4*((x_c - x)*(y_c - y)));
}
}
/**
* Biquadratic interpolation
*/
INTERPOLATE_METHOD(interpolate_biquadratic)
{
int x_c, x_f, y_c, y_f;
uint8_t v1, v2, v3, v4;
float f1, f2, f3, f4;
if (x < - 1 || x > width || y < -1 || y > height)
return def;
else {
x_f = (int)x;
x_c = x_f + 1;
y_f = (int)y;
y_c = y_f + 1;
v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
f1
= 1 - sqrt((x_c
- x
) * (y_c
- y
)); f2
= 1 - sqrt((x_c
- x
) * (y
- y_f
)); f3
= 1 - sqrt((x
- x_f
) * (y_c
- y
)); f4
= 1 - sqrt((x
- x_f
) * (y
- y_f
)); return (v1 * f1 + v2 * f2 + v3 * f3 + v4 * f4) / (f1 + f2 + f3 + f4);
}
}
void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix) {
matrix
[0] = zoom
* cos(angle
); matrix[2] = x_shift;
matrix[3] = -matrix[1];
matrix[4] = matrix[0];
matrix[5] = y_shift;
matrix[6] = 0;
matrix[7] = 0;
matrix[8] = 1;
}
void avfilter_add_matrix(const float *m1, const float *m2, float *result)
{
int i;
for (i = 0; i < 9; i++)
result[i] = m1[i] + m2[i];
}
void avfilter_sub_matrix(const float *m1, const float *m2, float *result)
{
int i;
for (i = 0; i < 9; i++)
result[i] = m1[i] - m2[i];
}
void avfilter_mul_matrix(const float *m1, float scalar, float *result)
{
int i;
for (i = 0; i < 9; i++)
result[i] = m1[i] * scalar;
}
static inline int mirror(int v, int m)
{
while ((unsigned)v > (unsigned)m) {
v = -v;
if (v < 0)
v += 2 * m;
}
return v;
}
int 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)
{
int x, y;
float x_s, y_s;
uint8_t def = 0;
uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
switch(interpolate) {
case INTERPOLATE_NEAREST:
func = interpolate_nearest;
break;
case INTERPOLATE_BILINEAR:
func = interpolate_bilinear;
break;
case INTERPOLATE_BIQUADRATIC:
func = interpolate_biquadratic;
break;
default:
return AVERROR(EINVAL);
}
for (y = 0; y < height; y++) {
for(x = 0; x < width; x++) {
x_s = x * matrix[0] + y * matrix[1] + matrix[2];
y_s = x * matrix[3] + y * matrix[4] + matrix[5];
switch(fill) {
case FILL_ORIGINAL:
def = src[y * src_stride + x];
break;
case FILL_CLAMP:
y_s = av_clipf(y_s, 0, height - 1);
x_s = av_clipf(x_s, 0, width - 1);
def = src[(int)y_s * src_stride + (int)x_s];
break;
case FILL_MIRROR:
x_s = mirror(x_s, width-1);
y_s = mirror(y_s, height-1);
av_assert2(x_s >= 0 && y_s >= 0);
av_assert2(x_s < width && y_s < height);
def = src[(int)y_s * src_stride + (int)x_s];
}
dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);
}
}
return 0;
}