/* * 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[1] = -sin(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;} void 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;    }     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);        }    }}