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texturedspenc.c
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1/*
2 * Texture block compression
3 * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com>
4 * Based on public domain code by Fabian Giesen, Sean Barrett and Yann Collet.
5 *
6 * This file is part of FFmpeg
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 */
25
26#include <stddef.h>
27#include <stdint.h>
28
29#include "libavutil/attributes.h"
30#include "libavutil/common.h"
31#include "libavutil/intreadwrite.h"
32
33#include "texturedsp.h"
34
35static const uint8_t expand5[32] = {
36 0, 8, 16, 24, 33, 41, 49, 57, 66, 74, 82, 90,
37 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189,
38 198, 206, 214, 222, 231, 239, 247, 255,
39};
40
41static const uint8_t expand6[64] = {
42 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44,
43 48, 52, 56, 60, 65, 69, 73, 77, 81, 85, 89, 93,
44 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142,
45 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190,
46 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239,
47 243, 247, 251, 255,
48};
49
50static const uint8_t match5[256][2] = {
51 { 0, 0 }, { 0, 0 }, { 0, 1 }, { 0, 1 }, { 1, 0 }, { 1, 0 },
52 { 1, 0 }, { 1, 1 }, { 1, 1 }, { 2, 0 }, { 2, 0 }, { 0, 4 },
53 { 2, 1 }, { 2, 1 }, { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 0 },
54 { 3, 1 }, { 1, 5 }, { 3, 2 }, { 3, 2 }, { 4, 0 }, { 4, 0 },
55 { 4, 1 }, { 4, 1 }, { 4, 2 }, { 4, 2 }, { 4, 2 }, { 3, 5 },
56 { 5, 1 }, { 5, 1 }, { 5, 2 }, { 4, 4 }, { 5, 3 }, { 5, 3 },
57 { 5, 3 }, { 6, 2 }, { 6, 2 }, { 6, 2 }, { 6, 3 }, { 5, 5 },
58 { 6, 4 }, { 6, 4 }, { 4, 8 }, { 7, 3 }, { 7, 3 }, { 7, 3 },
59 { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 5 }, { 5, 9 }, { 7, 6 },
60 { 7, 6 }, { 8, 4 }, { 8, 4 }, { 8, 5 }, { 8, 5 }, { 8, 6 },
61 { 8, 6 }, { 8, 6 }, { 7, 9 }, { 9, 5 }, { 9, 5 }, { 9, 6 },
62 { 8, 8 }, { 9, 7 }, { 9, 7 }, { 9, 7 }, { 10, 6 }, { 10, 6 },
63 { 10, 6 }, { 10, 7 }, { 9, 9 }, { 10, 8 }, { 10, 8 }, { 8, 12 },
64 { 11, 7 }, { 11, 7 }, { 11, 7 }, { 11, 8 }, { 11, 8 }, { 11, 8 },
65 { 11, 9 }, { 9, 13 }, { 11, 10 }, { 11, 10 }, { 12, 8 }, { 12, 8 },
66 { 12, 9 }, { 12, 9 }, { 12, 10 }, { 12, 10 }, { 12, 10 }, { 11, 13 },
67 { 13, 9 }, { 13, 9 }, { 13, 10 }, { 12, 12 }, { 13, 11 }, { 13, 11 },
68 { 13, 11 }, { 14, 10 }, { 14, 10 }, { 14, 10 }, { 14, 11 }, { 13, 13 },
69 { 14, 12 }, { 14, 12 }, { 12, 16 }, { 15, 11 }, { 15, 11 }, { 15, 11 },
70 { 15, 12 }, { 15, 12 }, { 15, 12 }, { 15, 13 }, { 13, 17 }, { 15, 14 },
71 { 15, 14 }, { 16, 12 }, { 16, 12 }, { 16, 13 }, { 16, 13 }, { 16, 14 },
72 { 16, 14 }, { 16, 14 }, { 15, 17 }, { 17, 13 }, { 17, 13 }, { 17, 14 },
73 { 16, 16 }, { 17, 15 }, { 17, 15 }, { 17, 15 }, { 18, 14 }, { 18, 14 },
74 { 18, 14 }, { 18, 15 }, { 17, 17 }, { 18, 16 }, { 18, 16 }, { 16, 20 },
75 { 19, 15 }, { 19, 15 }, { 19, 15 }, { 19, 16 }, { 19, 16 }, { 19, 16 },
76 { 19, 17 }, { 17, 21 }, { 19, 18 }, { 19, 18 }, { 20, 16 }, { 20, 16 },
77 { 20, 17 }, { 20, 17 }, { 20, 18 }, { 20, 18 }, { 20, 18 }, { 19, 21 },
78 { 21, 17 }, { 21, 17 }, { 21, 18 }, { 20, 20 }, { 21, 19 }, { 21, 19 },
79 { 21, 19 }, { 22, 18 }, { 22, 18 }, { 22, 18 }, { 22, 19 }, { 21, 21 },
80 { 22, 20 }, { 22, 20 }, { 20, 24 }, { 23, 19 }, { 23, 19 }, { 23, 19 },
81 { 23, 20 }, { 23, 20 }, { 23, 20 }, { 23, 21 }, { 21, 25 }, { 23, 22 },
82 { 23, 22 }, { 24, 20 }, { 24, 20 }, { 24, 21 }, { 24, 21 }, { 24, 22 },
83 { 24, 22 }, { 24, 22 }, { 23, 25 }, { 25, 21 }, { 25, 21 }, { 25, 22 },
84 { 24, 24 }, { 25, 23 }, { 25, 23 }, { 25, 23 }, { 26, 22 }, { 26, 22 },
85 { 26, 22 }, { 26, 23 }, { 25, 25 }, { 26, 24 }, { 26, 24 }, { 24, 28 },
86 { 27, 23 }, { 27, 23 }, { 27, 23 }, { 27, 24 }, { 27, 24 }, { 27, 24 },
87 { 27, 25 }, { 25, 29 }, { 27, 26 }, { 27, 26 }, { 28, 24 }, { 28, 24 },
88 { 28, 25 }, { 28, 25 }, { 28, 26 }, { 28, 26 }, { 28, 26 }, { 27, 29 },
89 { 29, 25 }, { 29, 25 }, { 29, 26 }, { 28, 28 }, { 29, 27 }, { 29, 27 },
90 { 29, 27 }, { 30, 26 }, { 30, 26 }, { 30, 26 }, { 30, 27 }, { 29, 29 },
91 { 30, 28 }, { 30, 28 }, { 30, 28 }, { 31, 27 }, { 31, 27 }, { 31, 27 },
92 { 31, 28 }, { 31, 28 }, { 31, 28 }, { 31, 29 }, { 31, 29 }, { 31, 30 },
93 { 31, 30 }, { 31, 30 }, { 31, 31 }, { 31, 31 },
94};
95
96static const uint8_t match6[256][2] = {
97 { 0, 0 }, { 0, 1 }, { 1, 0 }, { 1, 0 }, { 1, 1 }, { 2, 0 },
98 { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 1 }, { 4, 0 }, { 4, 0 },
99 { 4, 1 }, { 5, 0 }, { 5, 1 }, { 6, 0 }, { 6, 0 }, { 6, 1 },
100 { 7, 0 }, { 7, 0 }, { 7, 1 }, { 8, 0 }, { 8, 1 }, { 8, 1 },
101 { 8, 2 }, { 9, 1 }, { 9, 2 }, { 9, 2 }, { 9, 3 }, { 10, 2 },
102 { 10, 3 }, { 10, 3 }, { 10, 4 }, { 11, 3 }, { 11, 4 }, { 11, 4 },
103 { 11, 5 }, { 12, 4 }, { 12, 5 }, { 12, 5 }, { 12, 6 }, { 13, 5 },
104 { 13, 6 }, { 8, 16 }, { 13, 7 }, { 14, 6 }, { 14, 7 }, { 9, 17 },
105 { 14, 8 }, { 15, 7 }, { 15, 8 }, { 11, 16 }, { 15, 9 }, { 15, 10 },
106 { 16, 8 }, { 16, 9 }, { 16, 10 }, { 15, 13 }, { 17, 9 }, { 17, 10 },
107 { 17, 11 }, { 15, 16 }, { 18, 10 }, { 18, 11 }, { 18, 12 }, { 16, 16 },
108 { 19, 11 }, { 19, 12 }, { 19, 13 }, { 17, 17 }, { 20, 12 }, { 20, 13 },
109 { 20, 14 }, { 19, 16 }, { 21, 13 }, { 21, 14 }, { 21, 15 }, { 20, 17 },
110 { 22, 14 }, { 22, 15 }, { 25, 10 }, { 22, 16 }, { 23, 15 }, { 23, 16 },
111 { 26, 11 }, { 23, 17 }, { 24, 16 }, { 24, 17 }, { 27, 12 }, { 24, 18 },
112 { 25, 17 }, { 25, 18 }, { 28, 13 }, { 25, 19 }, { 26, 18 }, { 26, 19 },
113 { 29, 14 }, { 26, 20 }, { 27, 19 }, { 27, 20 }, { 30, 15 }, { 27, 21 },
114 { 28, 20 }, { 28, 21 }, { 28, 21 }, { 28, 22 }, { 29, 21 }, { 29, 22 },
115 { 24, 32 }, { 29, 23 }, { 30, 22 }, { 30, 23 }, { 25, 33 }, { 30, 24 },
116 { 31, 23 }, { 31, 24 }, { 27, 32 }, { 31, 25 }, { 31, 26 }, { 32, 24 },
117 { 32, 25 }, { 32, 26 }, { 31, 29 }, { 33, 25 }, { 33, 26 }, { 33, 27 },
118 { 31, 32 }, { 34, 26 }, { 34, 27 }, { 34, 28 }, { 32, 32 }, { 35, 27 },
119 { 35, 28 }, { 35, 29 }, { 33, 33 }, { 36, 28 }, { 36, 29 }, { 36, 30 },
120 { 35, 32 }, { 37, 29 }, { 37, 30 }, { 37, 31 }, { 36, 33 }, { 38, 30 },
121 { 38, 31 }, { 41, 26 }, { 38, 32 }, { 39, 31 }, { 39, 32 }, { 42, 27 },
122 { 39, 33 }, { 40, 32 }, { 40, 33 }, { 43, 28 }, { 40, 34 }, { 41, 33 },
123 { 41, 34 }, { 44, 29 }, { 41, 35 }, { 42, 34 }, { 42, 35 }, { 45, 30 },
124 { 42, 36 }, { 43, 35 }, { 43, 36 }, { 46, 31 }, { 43, 37 }, { 44, 36 },
125 { 44, 37 }, { 44, 37 }, { 44, 38 }, { 45, 37 }, { 45, 38 }, { 40, 48 },
126 { 45, 39 }, { 46, 38 }, { 46, 39 }, { 41, 49 }, { 46, 40 }, { 47, 39 },
127 { 47, 40 }, { 43, 48 }, { 47, 41 }, { 47, 42 }, { 48, 40 }, { 48, 41 },
128 { 48, 42 }, { 47, 45 }, { 49, 41 }, { 49, 42 }, { 49, 43 }, { 47, 48 },
129 { 50, 42 }, { 50, 43 }, { 50, 44 }, { 48, 48 }, { 51, 43 }, { 51, 44 },
130 { 51, 45 }, { 49, 49 }, { 52, 44 }, { 52, 45 }, { 52, 46 }, { 51, 48 },
131 { 53, 45 }, { 53, 46 }, { 53, 47 }, { 52, 49 }, { 54, 46 }, { 54, 47 },
132 { 57, 42 }, { 54, 48 }, { 55, 47 }, { 55, 48 }, { 58, 43 }, { 55, 49 },
133 { 56, 48 }, { 56, 49 }, { 59, 44 }, { 56, 50 }, { 57, 49 }, { 57, 50 },
134 { 60, 45 }, { 57, 51 }, { 58, 50 }, { 58, 51 }, { 61, 46 }, { 58, 52 },
135 { 59, 51 }, { 59, 52 }, { 62, 47 }, { 59, 53 }, { 60, 52 }, { 60, 53 },
136 { 60, 53 }, { 60, 54 }, { 61, 53 }, { 61, 54 }, { 61, 54 }, { 61, 55 },
137 { 62, 54 }, { 62, 55 }, { 62, 55 }, { 62, 56 }, { 63, 55 }, { 63, 56 },
138 { 63, 56 }, { 63, 57 }, { 63, 58 }, { 63, 59 }, { 63, 59 }, { 63, 60 },
139 { 63, 61 }, { 63, 62 }, { 63, 62 }, { 63, 63 },
140};
141
142/* Multiplication over 8 bit emulation */
143#define mul8(a, b) (((a) * (b) + 128 + (((a) * (b) + 128) >> 8)) >> 8)
144
145/* Conversion from rgb24 to rgb565 */
146#define rgb2rgb565(r, g, b) \
147 ((mul8(r, 31) << 11) | (mul8(g, 63) << 5) | (mul8(b, 31) << 0))
148
149/* Linear interpolation at 1/3 point between a and b */
150#define lerp13(a, b) ((2 * (a) + (b)) / 3)
151
152/* Linear interpolation on an RGB pixel */
153static inline void lerp13rgb(uint8_t *out, uint8_t *p1, uint8_t *p2)
154{
155 out[0] = lerp13(p1[0], p2[0]);
156 out[1] = lerp13(p1[1], p2[1]);
157 out[2] = lerp13(p1[2], p2[2]);
158}
159
160/* Conversion from rgb565 to rgb24 */
161static inline void rgb5652rgb(uint8_t *out, uint16_t v)
162{
163 int rv = (v & 0xf800) >> 11;
164 int gv = (v & 0x07e0) >> 5;
165 int bv = (v & 0x001f) >> 0;
166
167 out[0] = expand5[rv];
168 out[1] = expand6[gv];
169 out[2] = expand5[bv];
170 out[3] = 0;
171}
172
173/* Color matching function */
174static unsigned int match_colors(const uint8_t *block, ptrdiff_t stride,
175 uint16_t c0, uint16_t c1)
176{
177 uint32_t mask = 0;
178 int dirr, dirg, dirb;
179 int dots[16];
180 int stops[4];
181 int x, y, k = 0;
182 int c0_point, half_point, c3_point;
183 uint8_t color[16];
184 static const uint32_t indexMap[8] = {
185 0U << 30, 2U << 30, 0U << 30, 2U << 30,
186 3U << 30, 3U << 30, 1U << 30, 1U << 30,
187 };
188
189 /* Fill color and compute direction for each component */
190 rgb5652rgb(color + 0, c0);
191 rgb5652rgb(color + 4, c1);
192 lerp13rgb(color + 8, color + 0, color + 4);
193 lerp13rgb(color + 12, color + 4, color + 0);
194
195 dirr = color[0 * 4 + 0] - color[1 * 4 + 0];
196 dirg = color[0 * 4 + 1] - color[1 * 4 + 1];
197 dirb = color[0 * 4 + 2] - color[1 * 4 + 2];
198
199 for (y = 0; y < 4; y++) {
200 for (x = 0; x < 4; x++)
201 dots[k++] = block[0 + x * 4 + y * stride] * dirr +
202 block[1 + x * 4 + y * stride] * dirg +
203 block[2 + x * 4 + y * stride] * dirb;
204
205 stops[y] = color[0 + y * 4] * dirr +
206 color[1 + y * 4] * dirg +
207 color[2 + y * 4] * dirb;
208 }
209
210 /* Think of the colors as arranged on a line; project point onto that line,
211 * then choose next color out of available ones. we compute the crossover
212 * points for 'best color in top half'/'best in bottom half' and then
213 * the same inside that subinterval.
214 *
215 * Relying on this 1d approximation isn't always optimal in terms of
216 * Euclidean distance, but it's very close and a lot faster.
217 *
218 * http://cbloomrants.blogspot.com/2008/12/12-08-08-dxtc-summary.html */
219 c0_point = (stops[1] + stops[3]) >> 1;
220 half_point = (stops[3] + stops[2]) >> 1;
221 c3_point = (stops[2] + stops[0]) >> 1;
222
223 for (x = 0; x < 16; x++) {
224 int dot = dots[x];
225 int bits = (dot < half_point ? 4 : 0) |
226 (dot < c0_point ? 2 : 0) |
227 (dot < c3_point ? 1 : 0);
228
229 mask >>= 2;
230 mask |= indexMap[bits];
231 }
232
233 return mask;
234}
235
236/* Color optimization function */
237static void optimize_colors(const uint8_t *block, ptrdiff_t stride,
238 uint16_t *pmax16, uint16_t *pmin16)
239{
240 const uint8_t *minp;
241 const uint8_t *maxp;
242 const int iter_power = 4;
243 double magn;
244 int v_r, v_g, v_b;
245 float covf[6], vfr, vfg, vfb;
246 int mind, maxd;
247 int cov[6] = { 0 };
248 int mu[3], min[3], max[3];
249 int ch, iter, x, y;
250
251 /* Determine color distribution */
252 for (ch = 0; ch < 3; ch++) {
253 const uint8_t *bp = &block[ch];
254 int muv, minv, maxv;
255
256 muv = minv = maxv = bp[0];
257 for (y = 0; y < 4; y++) {
258 for (x = 0; x < 4; x++) {
259 muv += bp[x * 4 + y * stride];
260 if (bp[x * 4 + y * stride] < minv)
261 minv = bp[x * 4 + y * stride];
262 else if (bp[x * 4 + y * stride] > maxv)
263 maxv = bp[x * 4 + y * stride];
264 }
265 }
266
267 mu[ch] = (muv + 8) >> 4;
268 min[ch] = minv;
269 max[ch] = maxv;
270 }
271
272 /* Determine covariance matrix */
273 for (y = 0; y < 4; y++) {
274 for (x = 0; x < 4; x++) {
275 int r = block[x * 4 + stride * y + 0] - mu[0];
276 int g = block[x * 4 + stride * y + 1] - mu[1];
277 int b = block[x * 4 + stride * y + 2] - mu[2];
278
279 cov[0] += r * r;
280 cov[1] += r * g;
281 cov[2] += r * b;
282 cov[3] += g * g;
283 cov[4] += g * b;
284 cov[5] += b * b;
285 }
286 }
287
288 /* Convert covariance matrix to float, find principal axis via power iter */
289 for (x = 0; x < 6; x++)
290 covf[x] = cov[x] / 255.0f;
291
292 vfr = (float) (max[0] - min[0]);
293 vfg = (float) (max[1] - min[1]);
294 vfb = (float) (max[2] - min[2]);
295
296 for (iter = 0; iter < iter_power; iter++) {
297 float r = vfr * covf[0] + vfg * covf[1] + vfb * covf[2];
298 float g = vfr * covf[1] + vfg * covf[3] + vfb * covf[4];
299 float b = vfr * covf[2] + vfg * covf[4] + vfb * covf[5];
300
301 vfr = r;
302 vfg = g;
303 vfb = b;
304 }
305
306 magn = fabs(vfr);
307 if (fabs(vfg) > magn)
308 magn = fabs(vfg);
309 if (fabs(vfb) > magn)
310 magn = fabs(vfb);
311
312 /* if magnitude is too small, default to luminance */
313 if (magn < 4.0f) {
314 /* JPEG YCbCr luma coefs, scaled by 1000 */
315 v_r = 299;
316 v_g = 587;
317 v_b = 114;
318 } else {
319 magn = 512.0 / magn;
320 v_r = (int) (vfr * magn);
321 v_g = (int) (vfg * magn);
322 v_b = (int) (vfb * magn);
323 }
324
325 /* Pick colors at extreme points */
326 mind = maxd = block[0] * v_r + block[1] * v_g + block[2] * v_b;
327 minp = maxp = block;
328 for (y = 0; y < 4; y++) {
329 for (x = 0; x < 4; x++) {
330 int dot = block[x * 4 + y * stride + 0] * v_r +
331 block[x * 4 + y * stride + 1] * v_g +
332 block[x * 4 + y * stride + 2] * v_b;
333
334 if (dot < mind) {
335 mind = dot;
336 minp = block + x * 4 + y * stride;
337 } else if (dot > maxd) {
338 maxd = dot;
339 maxp = block + x * 4 + y * stride;
340 }
341 }
342 }
343
344 *pmax16 = rgb2rgb565(maxp[0], maxp[1], maxp[2]);
345 *pmin16 = rgb2rgb565(minp[0], minp[1], minp[2]);
346}
347
348/* Try to optimize colors to suit block contents better, by solving
349 * a least squares system via normal equations + Cramer's rule. */
350static int refine_colors(const uint8_t *block, ptrdiff_t stride,
351 uint16_t *pmax16, uint16_t *pmin16, uint32_t mask)
352{
353 uint32_t cm = mask;
354 uint16_t oldMin = *pmin16;
355 uint16_t oldMax = *pmax16;
356 uint16_t min16, max16;
357 int x, y;
358
359 /* Additional magic to save a lot of multiplies in the accumulating loop.
360 * The tables contain precomputed products of weights for least squares
361 * system, accumulated inside one 32-bit register */
362 static const int w1tab[4] = { 3, 0, 2, 1 };
363 static const int prods[4] = { 0x090000, 0x000900, 0x040102, 0x010402 };
364
365 /* Check if all pixels have the same index */
366 if ((mask ^ (mask << 2)) < 4) {
367 /* If so, linear system would be singular; solve using optimal
368 * single-color match on average color. */
369 int r = 8, g = 8, b = 8;
370 for (y = 0; y < 4; y++) {
371 for (x = 0; x < 4; x++) {
372 r += block[0 + x * 4 + y * stride];
373 g += block[1 + x * 4 + y * stride];
374 b += block[2 + x * 4 + y * stride];
375 }
376 }
377
378 r >>= 4;
379 g >>= 4;
380 b >>= 4;
381
382 max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0];
383 min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1];
384 } else {
385 float fr, fg, fb;
386 int at1_r = 0, at1_g = 0, at1_b = 0;
387 int at2_r = 0, at2_g = 0, at2_b = 0;
388 int akku = 0;
389 int xx, xy, yy;
390
391 for (y = 0; y < 4; y++) {
392 for (x = 0; x < 4; x++) {
393 int step = cm & 3;
394 int w1 = w1tab[step];
395 int r = block[0 + x * 4 + y * stride];
396 int g = block[1 + x * 4 + y * stride];
397 int b = block[2 + x * 4 + y * stride];
398
399 akku += prods[step];
400 at1_r += w1 * r;
401 at1_g += w1 * g;
402 at1_b += w1 * b;
403 at2_r += r;
404 at2_g += g;
405 at2_b += b;
406
407 cm >>= 2;
408 }
409 }
410
411 at2_r = 3 * at2_r - at1_r;
412 at2_g = 3 * at2_g - at1_g;
413 at2_b = 3 * at2_b - at1_b;
414
415 /* Extract solutions and decide solvability */
416 xx = akku >> 16;
417 yy = (akku >> 8) & 0xFF;
418 xy = (akku >> 0) & 0xFF;
419
420 fr = 3.0f * 31.0f / 255.0f / (xx * yy - xy * xy);
421 fg = fr * 63.0f / 31.0f;
422 fb = fr;
423
424 /* Solve */
425 max16 = av_clip_uintp2((at1_r * yy - at2_r * xy) * fr + 0.5f, 5) << 11;
426 max16 |= av_clip_uintp2((at1_g * yy - at2_g * xy) * fg + 0.5f, 6) << 5;
427 max16 |= av_clip_uintp2((at1_b * yy - at2_b * xy) * fb + 0.5f, 5) << 0;
428
429 min16 = av_clip_uintp2((at2_r * xx - at1_r * xy) * fr + 0.5f, 5) << 11;
430 min16 |= av_clip_uintp2((at2_g * xx - at1_g * xy) * fg + 0.5f, 6) << 5;
431 min16 |= av_clip_uintp2((at2_b * xx - at1_b * xy) * fb + 0.5f, 5) << 0;
432 }
433
434 *pmin16 = min16;
435 *pmax16 = max16;
436 return oldMin != min16 || oldMax != max16;
437}
438
439/* Check if input block is a constant color */
440static int constant_color(const uint8_t *block, ptrdiff_t stride)
441{
442 int x, y;
443 uint32_t first = AV_RL32(block);
444
445 for (y = 0; y < 4; y++)
446 for (x = 0; x < 4; x++)
447 if (first != AV_RL32(block + x * 4 + y * stride))
448 return 0;
449 return 1;
450}
451
452/* Main color compression function */
453static void compress_color(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
454{
455 uint32_t mask;
456 uint16_t max16, min16;
457 int constant = constant_color(block, stride);
458
459 /* Constant color will load values from tables */
460 if (constant) {
461 int r = block[0];
462 int g = block[1];
463 int b = block[2];
464 mask = 0xAAAAAAAA;
465 max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0];
466 min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1];
467 } else {
468 int refine;
469
470 /* Otherwise find pca and map along principal axis */
471 optimize_colors(block, stride, &max16, &min16);
472 if (max16 != min16)
473 mask = match_colors(block, stride, max16, min16);
474 else
475 mask = 0;
476
477 /* One pass refinement */
478 refine = refine_colors(block, stride, &max16, &min16, mask);
479 if (refine) {
480 if (max16 != min16)
481 mask = match_colors(block, stride, max16, min16);
482 else
483 mask = 0;
484 }
485 }
486
487 /* Finally write the color block */
488 if (max16 < min16) {
489 FFSWAP(uint16_t, min16, max16);
490 mask ^= 0x55555555;
491 }
492
493 AV_WL16(dst + 0, max16);
494 AV_WL16(dst + 2, min16);
495 AV_WL32(dst + 4, mask);
496}
497
498/* Alpha compression function */
499static void compress_alpha(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
500{
501 int x, y;
502 int dist, bias, dist4, dist2;
503 int mn, mx;
504 int bits = 0;
505 int mask = 0;
506
507 memset(dst, 0, 8);
508
509 /* Find min/max color */
510 mn = mx = block[3];
511 for (y = 0; y < 4; y++) {
512 for (x = 0; x < 4; x++) {
513 int val = block[3 + x * 4 + y * stride];
514 if (val < mn)
515 mn = val;
516 else if (val > mx)
517 mx = val;
518 }
519 }
520
521 /* Encode them */
522 dst[0] = (uint8_t) mx;
523 dst[1] = (uint8_t) mn;
524 dst += 2;
525
526 /* Mono-alpha shortcut */
527 if (mn == mx)
528 return;
529
530 /* Determine bias and emit color indices.
531 * Given the choice of mx/mn, these indices are optimal:
532 * fgiesen.wordpress.com/2009/12/15/dxt5-alpha-block-index-determination */
533 dist = mx - mn;
534
535 dist4 = dist * 4;
536 dist2 = dist * 2;
537 if (dist < 8)
538 bias = dist - 1 - mn * 7;
539 else
540 bias = dist / 2 + 2 - mn * 7;
541
542 for (y = 0; y < 4; y++) {
543 for (x = 0; x < 4; x++) {
544 int alp = block[3 + x * 4 + y * stride] * 7 + bias;
545 int ind, tmp;
546
547 /* This is a "linear scale" lerp factor between 0 (val=min)
548 * and 7 (val=max) to select index. */
549 tmp = (alp >= dist4) ? -1 : 0;
550 ind = tmp & 4;
551 alp -= dist4 & tmp;
552 tmp = (alp >= dist2) ? -1 : 0;
553 ind += tmp & 2;
554 alp -= dist2 & tmp;
555 ind += (alp >= dist);
556
557 /* Turn linear scale into DXT index (0/1 are extreme points) */
558 ind = -ind & 7;
559 ind ^= (2 > ind);
560
561 /* Write index */
562 mask |= ind << bits;
563 bits += 3;
564 if (bits >= 8) {
565 *dst++ = mask;
566 mask >>= 8;
567 bits -= 8;
568 }
569 }
570 }
571}
572
573/**
574 * Convert a RGBA buffer to unscaled YCoCg.
575 * Scale is usually introduced to avoid banding over a certain range of colors,
576 * but this version of the algorithm does not introduce it as much as other
577 * implementations, allowing for a simpler and faster conversion.
578 */
579static void rgba2ycocg(uint8_t *dst, const uint8_t *pixel)
580{
581 int r = pixel[0];
582 int g = (pixel[1] + 1) >> 1;
583 int b = pixel[2];
584 int t = (2 + r + b) >> 2;
585
586 dst[0] = av_clip_uint8(128 + ((r - b + 1) >> 1)); /* Co */
587 dst[1] = av_clip_uint8(128 + g - t); /* Cg */
588 dst[2] = 0;
589 dst[3] = av_clip_uint8(g + t); /* Y */
590}
591
592/**
593 * Compress one block of RGBA pixels in a DXT1 texture and store the
594 * resulting bytes in 'dst'. Alpha is not preserved.
595 *
596 * @param dst output buffer.
597 * @param stride scanline in bytes.
598 * @param block block to compress.
599 * @return how much texture data has been written.
600 */
601static int dxt1_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
602{
603 compress_color(dst, stride, block);
604
605 return 8;
606}
607
608/**
609 * Compress one block of RGBA pixels in a DXT5 texture and store the
610 * resulting bytes in 'dst'. Alpha is preserved.
611 *
612 * @param dst output buffer.
613 * @param stride scanline in bytes.
614 * @param block block to compress.
615 * @return how much texture data has been written.
616 */
617static int dxt5_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
618{
619 compress_alpha(dst, stride, block);
620 compress_color(dst + 8, stride, block);
621
622 return 16;
623}
624
625/**
626 * Compress one block of RGBA pixels in a DXT5-YCoCg texture and store the
627 * resulting bytes in 'dst'. Alpha is not preserved.
628 *
629 * @param dst output buffer.
630 * @param stride scanline in bytes.
631 * @param block block to compress.
632 * @return how much texture data has been written.
633 */
634static int dxt5ys_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
635{
636 int x, y;
637 uint8_t reorder[64];
638
639 /* Reorder the components and then run a normal DXT5 compression. */
640 for (y = 0; y < 4; y++)
641 for (x = 0; x < 4; x++)
642 rgba2ycocg(reorder + x * 4 + y * 16, block + x * 4 + y * stride);
643
644 compress_alpha(dst + 0, 16, reorder);
645 compress_color(dst + 8, 16, reorder);
646
647 return 16;
648}
649
650av_cold void ff_texturedspenc_init(TextureDSPEncContext *c)
651{
652 c->dxt1_block = dxt1_block;
653 c->dxt5_block = dxt5_block;
654 c->dxt5ys_block = dxt5ys_block;
655}
656
657#define TEXTUREDSP_FUNC_NAME ff_texturedsp_exec_compress_threads
658#define TEXTUREDSP_TEX_FUNC(a, b, c) tex_funct(c, b, a)
659#include "texturedsp_template.c"
mx
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t mx
Definition dsp.h:57
dst
uint8_t ptrdiff_t const uint8_t ptrdiff_t int intptr_t intptr_t int int16_t * dst
Definition dsp.h:87
val
static double val(void *priv, double ch)
Definition aeval.c:77
float
float
Definition af_crystalizer.c:122
U
#define U(x)
Definition vpx_arith.h:37
pixel
#define pixel
Definition bit_depth_template.c:82
common.h
common internal and external API header
av_clip_uint8
#define av_clip_uint8
Definition common.h:106
av_clip_uintp2
#define av_clip_uintp2
Definition common.h:124
fabs
static __device__ float fabs(float a)
Definition cuda_runtime.h:182
min
#define min(a, b)
Definition cuda_runtime.h:34
max
#define max(a, b)
Definition cuda_runtime.h:33
block
static int16_t block[64]
Definition dct.c:125
cm
#define cm
Definition dvbsubdec.c:40
bits
static const uint8_t bits[8]
Definition fastaudio.c:100
r
#define r
Definition input.c:42
b
#define b
Definition input.c:43
AV_WL32
#define AV_WL32(p, v)
Definition intreadwrite.h:422
AV_RL32
#define AV_RL32(p)
Definition intreadwrite.h:419
AV_WL16
#define AV_WL16(p, v)
Definition intreadwrite.h:408
attributes.h
Macro definitions for various function/variable attributes.
av_cold
#define av_cold
Definition attributes.h:117
mask
static const uint16_t mask[17]
Definition lzw.c:38
FFSWAP
#define FFSWAP(type, a, b)
Definition macros.h:52
c1
static const uint64_t c1
Definition murmur3.c:52
v_b
static RasmOp v_b(RasmOp op)
Definition rasm.h:430
stride
#define stride
Definition h264pred_template.c:536
tmp
static uint8_t tmp[40]
Definition aes_ctr.c:52
out
static FILE * out
Definition movenc.c:55
dxt5_block
static int dxt5_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Decompress one block of a DXT5 texture and store the resulting RGBA pixels in 'dst'.
Definition texturedsp.c:338
dxt1_block
static int dxt1_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Decompress one block of a DXT1 texture and store the resulting RGBA pixels in 'dst'.
Definition texturedsp.c:115
dxt5ys_block
static int dxt5ys_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Decompress one block of a DXT5 texture with scaled YCoCg and store the resulting RGBA pixels in 'dst'...
Definition texturedsp.c:402
texturedsp.h
Texture block (4x4) module.
texturedsp_template.c
match5
static const uint8_t match5[256][2]
Definition texturedspenc.c:50
compress_color
static void compress_color(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition texturedspenc.c:453
dxt5_block
static int dxt5_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Compress one block of RGBA pixels in a DXT5 texture and store the resulting bytes in 'dst'.
Definition texturedspenc.c:617
expand5
static const uint8_t expand5[32]
Definition texturedspenc.c:35
refine_colors
static int refine_colors(const uint8_t *block, ptrdiff_t stride, uint16_t *pmax16, uint16_t *pmin16, uint32_t mask)
Definition texturedspenc.c:350
constant_color
static int constant_color(const uint8_t *block, ptrdiff_t stride)
Definition texturedspenc.c:440
lerp13rgb
static void lerp13rgb(uint8_t *out, uint8_t *p1, uint8_t *p2)
Definition texturedspenc.c:153
compress_alpha
static void compress_alpha(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Definition texturedspenc.c:499
optimize_colors
static void optimize_colors(const uint8_t *block, ptrdiff_t stride, uint16_t *pmax16, uint16_t *pmin16)
Definition texturedspenc.c:237
dxt1_block
static int dxt1_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Compress one block of RGBA pixels in a DXT1 texture and store the resulting bytes in 'dst'.
Definition texturedspenc.c:601
lerp13
#define lerp13(a, b)
Definition texturedspenc.c:150
dxt5ys_block
static int dxt5ys_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block)
Compress one block of RGBA pixels in a DXT5-YCoCg texture and store the resulting bytes in 'dst'.
Definition texturedspenc.c:634
ff_texturedspenc_init
av_cold void ff_texturedspenc_init(TextureDSPEncContext *c)
Definition texturedspenc.c:650
match6
static const uint8_t match6[256][2]
Definition texturedspenc.c:96
match_colors
static unsigned int match_colors(const uint8_t *block, ptrdiff_t stride, uint16_t c0, uint16_t c1)
Definition texturedspenc.c:174
expand6
static const uint8_t expand6[64]
Definition texturedspenc.c:41
rgba2ycocg
static void rgba2ycocg(uint8_t *dst, const uint8_t *pixel)
Convert a RGBA buffer to unscaled YCoCg.
Definition texturedspenc.c:579
rgb2rgb565
#define rgb2rgb565(r, g, b)
Definition texturedspenc.c:146
rgb5652rgb
static void rgb5652rgb(uint8_t *out, uint16_t v)
Definition texturedspenc.c:161
g
const char * g
Definition vf_curves.c:128
bias
static int bias(int x, int c)
Definition vqcdec.c:115
c
static double c[64]
Definition vsrc_mptestsrc.c:89
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