yading@10: /*
yading@10:  * Copyright (C) 2010 Georg Martius <georg.martius@web.de>
yading@10:  * Copyright (C) 2010 Daniel G. Taylor <dan@programmer-art.org>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * transform input video
yading@10:  */
yading@10: 
yading@10: #include "libavutil/common.h"
yading@10: #include "libavutil/avassert.h"
yading@10: 
yading@10: #include "transform.h"
yading@10: 
yading@10: #define INTERPOLATE_METHOD(name) \
yading@10:     static uint8_t name(float x, float y, const uint8_t *src, \
yading@10:                         int width, int height, int stride, uint8_t def)
yading@10: 
yading@10: #define PIXEL(img, x, y, w, h, stride, def) \
yading@10:     ((x) < 0 || (y) < 0) ? (def) : \
yading@10:     (((x) >= (w) || (y) >= (h)) ? (def) : \
yading@10:     img[(x) + (y) * (stride)])
yading@10: 
yading@10: /**
yading@10:  * Nearest neighbor interpolation
yading@10:  */
yading@10: INTERPOLATE_METHOD(interpolate_nearest)
yading@10: {
yading@10:     return PIXEL(src, (int)(x + 0.5), (int)(y + 0.5), width, height, stride, def);
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Bilinear interpolation
yading@10:  */
yading@10: INTERPOLATE_METHOD(interpolate_bilinear)
yading@10: {
yading@10:     int x_c, x_f, y_c, y_f;
yading@10:     int v1, v2, v3, v4;
yading@10: 
yading@10:     if (x < -1 || x > width || y < -1 || y > height) {
yading@10:         return def;
yading@10:     } else {
yading@10:         x_f = (int)x;
yading@10:         x_c = x_f + 1;
yading@10: 
yading@10:         y_f = (int)y;
yading@10:         y_c = y_f + 1;
yading@10: 
yading@10:         v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
yading@10:         v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
yading@10:         v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
yading@10:         v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
yading@10: 
yading@10:         return (v1*(x - x_f)*(y - y_f) + v2*((x - x_f)*(y_c - y)) +
yading@10:                 v3*(x_c - x)*(y - y_f) + v4*((x_c - x)*(y_c - y)));
yading@10:     }
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Biquadratic interpolation
yading@10:  */
yading@10: INTERPOLATE_METHOD(interpolate_biquadratic)
yading@10: {
yading@10:     int     x_c, x_f, y_c, y_f;
yading@10:     uint8_t v1,  v2,  v3,  v4;
yading@10:     float   f1,  f2,  f3,  f4;
yading@10: 
yading@10:     if (x < - 1 || x > width || y < -1 || y > height)
yading@10:         return def;
yading@10:     else {
yading@10:         x_f = (int)x;
yading@10:         x_c = x_f + 1;
yading@10:         y_f = (int)y;
yading@10:         y_c = y_f + 1;
yading@10: 
yading@10:         v1 = PIXEL(src, x_c, y_c, width, height, stride, def);
yading@10:         v2 = PIXEL(src, x_c, y_f, width, height, stride, def);
yading@10:         v3 = PIXEL(src, x_f, y_c, width, height, stride, def);
yading@10:         v4 = PIXEL(src, x_f, y_f, width, height, stride, def);
yading@10: 
yading@10:         f1 = 1 - sqrt((x_c - x) * (y_c - y));
yading@10:         f2 = 1 - sqrt((x_c - x) * (y - y_f));
yading@10:         f3 = 1 - sqrt((x - x_f) * (y_c - y));
yading@10:         f4 = 1 - sqrt((x - x_f) * (y - y_f));
yading@10:         return (v1 * f1 + v2 * f2 + v3 * f3 + v4 * f4) / (f1 + f2 + f3 + f4);
yading@10:     }
yading@10: }
yading@10: 
yading@10: void avfilter_get_matrix(float x_shift, float y_shift, float angle, float zoom, float *matrix) {
yading@10:     matrix[0] = zoom * cos(angle);
yading@10:     matrix[1] = -sin(angle);
yading@10:     matrix[2] = x_shift;
yading@10:     matrix[3] = -matrix[1];
yading@10:     matrix[4] = matrix[0];
yading@10:     matrix[5] = y_shift;
yading@10:     matrix[6] = 0;
yading@10:     matrix[7] = 0;
yading@10:     matrix[8] = 1;
yading@10: }
yading@10: 
yading@10: void avfilter_add_matrix(const float *m1, const float *m2, float *result)
yading@10: {
yading@10:     int i;
yading@10:     for (i = 0; i < 9; i++)
yading@10:         result[i] = m1[i] + m2[i];
yading@10: }
yading@10: 
yading@10: void avfilter_sub_matrix(const float *m1, const float *m2, float *result)
yading@10: {
yading@10:     int i;
yading@10:     for (i = 0; i < 9; i++)
yading@10:         result[i] = m1[i] - m2[i];
yading@10: }
yading@10: 
yading@10: void avfilter_mul_matrix(const float *m1, float scalar, float *result)
yading@10: {
yading@10:     int i;
yading@10:     for (i = 0; i < 9; i++)
yading@10:         result[i] = m1[i] * scalar;
yading@10: }
yading@10: 
yading@10: static inline int mirror(int v, int m)
yading@10: {
yading@10:     while ((unsigned)v > (unsigned)m) {
yading@10:         v = -v;
yading@10:         if (v < 0)
yading@10:             v += 2 * m;
yading@10:     }
yading@10:     return v;
yading@10: }
yading@10: 
yading@10: int avfilter_transform(const uint8_t *src, uint8_t *dst,
yading@10:                         int src_stride, int dst_stride,
yading@10:                         int width, int height, const float *matrix,
yading@10:                         enum InterpolateMethod interpolate,
yading@10:                         enum FillMethod fill)
yading@10: {
yading@10:     int x, y;
yading@10:     float x_s, y_s;
yading@10:     uint8_t def = 0;
yading@10:     uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL;
yading@10: 
yading@10:     switch(interpolate) {
yading@10:         case INTERPOLATE_NEAREST:
yading@10:             func = interpolate_nearest;
yading@10:             break;
yading@10:         case INTERPOLATE_BILINEAR:
yading@10:             func = interpolate_bilinear;
yading@10:             break;
yading@10:         case INTERPOLATE_BIQUADRATIC:
yading@10:             func = interpolate_biquadratic;
yading@10:             break;
yading@10:         default:
yading@10:             return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     for (y = 0; y < height; y++) {
yading@10:         for(x = 0; x < width; x++) {
yading@10:             x_s = x * matrix[0] + y * matrix[1] + matrix[2];
yading@10:             y_s = x * matrix[3] + y * matrix[4] + matrix[5];
yading@10: 
yading@10:             switch(fill) {
yading@10:                 case FILL_ORIGINAL:
yading@10:                     def = src[y * src_stride + x];
yading@10:                     break;
yading@10:                 case FILL_CLAMP:
yading@10:                     y_s = av_clipf(y_s, 0, height - 1);
yading@10:                     x_s = av_clipf(x_s, 0, width - 1);
yading@10:                     def = src[(int)y_s * src_stride + (int)x_s];
yading@10:                     break;
yading@10:                 case FILL_MIRROR:
yading@10:                     x_s = mirror(x_s,  width-1);
yading@10:                     y_s = mirror(y_s, height-1);
yading@10: 
yading@10:                     av_assert2(x_s >= 0 && y_s >= 0);
yading@10:                     av_assert2(x_s < width && y_s < height);
yading@10:                     def = src[(int)y_s * src_stride + (int)x_s];
yading@10:             }
yading@10: 
yading@10:             dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def);
yading@10:         }
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: