| 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 | static inline int mirror(int v, int m) |
| 140 | { |
| 141 | while ((unsigned)v > (unsigned)m) { |
| 142 | v = -v; |
| 143 | if (v < 0) |
| 144 | v += 2 * m; |
| 145 | } |
| 146 | return v; |
| 147 | } |
| 148 | |
| 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) |
| 154 | { |
| 155 | int x, y; |
| 156 | float x_s, y_s; |
| 157 | uint8_t def = 0; |
| 158 | uint8_t (*func)(float, float, const uint8_t *, int, int, int, uint8_t) = NULL; |
| 159 | |
| 160 | switch(interpolate) { |
| 161 | case INTERPOLATE_NEAREST: |
| 162 | func = interpolate_nearest; |
| 163 | break; |
| 164 | case INTERPOLATE_BILINEAR: |
| 165 | func = interpolate_bilinear; |
| 166 | break; |
| 167 | case INTERPOLATE_BIQUADRATIC: |
| 168 | func = interpolate_biquadratic; |
| 169 | break; |
| 170 | default: |
| 171 | return AVERROR(EINVAL); |
| 172 | } |
| 173 | |
| 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]; |
| 178 | |
| 179 | switch(fill) { |
| 180 | case FILL_ORIGINAL: |
| 181 | def = src[y * src_stride + x]; |
| 182 | break; |
| 183 | case FILL_CLAMP: |
| 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]; |
| 187 | break; |
| 188 | case FILL_MIRROR: |
| 189 | x_s = mirror(x_s, width-1); |
| 190 | y_s = mirror(y_s, height-1); |
| 191 | |
| 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]; |
| 195 | } |
| 196 | |
| 197 | dst[y * dst_stride + x] = func(x_s, y_s, src, width, height, src_stride, def); |
| 198 | } |
| 199 | } |
| 200 | return 0; |
| 201 | } |