| /* |
| * Texture block compression |
| * Copyright (C) 2015 Vittorio Giovara <vittorio.giovara@gmail.com> |
| * Based on public domain code by Fabian Giesen, Sean Barrett and Yann Collet. |
| * |
| * This file is part of FFmpeg |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * The above copyright notice and this permission notice shall be included |
| * in all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| * IN THE SOFTWARE. |
| */ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include "libavutil/attributes.h" |
| #include "libavutil/common.h" |
| #include "libavutil/intreadwrite.h" |
| |
| #include "texturedsp.h" |
| |
| static const uint8_t expand5[32] = { |
| 0, 8, 16, 24, 33, 41, 49, 57, 66, 74, 82, 90, |
| 99, 107, 115, 123, 132, 140, 148, 156, 165, 173, 181, 189, |
| 198, 206, 214, 222, 231, 239, 247, 255, |
| }; |
| |
| static const uint8_t expand6[64] = { |
| 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, |
| 48, 52, 56, 60, 65, 69, 73, 77, 81, 85, 89, 93, |
| 97, 101, 105, 109, 113, 117, 121, 125, 130, 134, 138, 142, |
| 146, 150, 154, 158, 162, 166, 170, 174, 178, 182, 186, 190, |
| 195, 199, 203, 207, 211, 215, 219, 223, 227, 231, 235, 239, |
| 243, 247, 251, 255, |
| }; |
| |
| static const uint8_t match5[256][2] = { |
| { 0, 0 }, { 0, 0 }, { 0, 1 }, { 0, 1 }, { 1, 0 }, { 1, 0 }, |
| { 1, 0 }, { 1, 1 }, { 1, 1 }, { 2, 0 }, { 2, 0 }, { 0, 4 }, |
| { 2, 1 }, { 2, 1 }, { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 0 }, |
| { 3, 1 }, { 1, 5 }, { 3, 2 }, { 3, 2 }, { 4, 0 }, { 4, 0 }, |
| { 4, 1 }, { 4, 1 }, { 4, 2 }, { 4, 2 }, { 4, 2 }, { 3, 5 }, |
| { 5, 1 }, { 5, 1 }, { 5, 2 }, { 4, 4 }, { 5, 3 }, { 5, 3 }, |
| { 5, 3 }, { 6, 2 }, { 6, 2 }, { 6, 2 }, { 6, 3 }, { 5, 5 }, |
| { 6, 4 }, { 6, 4 }, { 4, 8 }, { 7, 3 }, { 7, 3 }, { 7, 3 }, |
| { 7, 4 }, { 7, 4 }, { 7, 4 }, { 7, 5 }, { 5, 9 }, { 7, 6 }, |
| { 7, 6 }, { 8, 4 }, { 8, 4 }, { 8, 5 }, { 8, 5 }, { 8, 6 }, |
| { 8, 6 }, { 8, 6 }, { 7, 9 }, { 9, 5 }, { 9, 5 }, { 9, 6 }, |
| { 8, 8 }, { 9, 7 }, { 9, 7 }, { 9, 7 }, { 10, 6 }, { 10, 6 }, |
| { 10, 6 }, { 10, 7 }, { 9, 9 }, { 10, 8 }, { 10, 8 }, { 8, 12 }, |
| { 11, 7 }, { 11, 7 }, { 11, 7 }, { 11, 8 }, { 11, 8 }, { 11, 8 }, |
| { 11, 9 }, { 9, 13 }, { 11, 10 }, { 11, 10 }, { 12, 8 }, { 12, 8 }, |
| { 12, 9 }, { 12, 9 }, { 12, 10 }, { 12, 10 }, { 12, 10 }, { 11, 13 }, |
| { 13, 9 }, { 13, 9 }, { 13, 10 }, { 12, 12 }, { 13, 11 }, { 13, 11 }, |
| { 13, 11 }, { 14, 10 }, { 14, 10 }, { 14, 10 }, { 14, 11 }, { 13, 13 }, |
| { 14, 12 }, { 14, 12 }, { 12, 16 }, { 15, 11 }, { 15, 11 }, { 15, 11 }, |
| { 15, 12 }, { 15, 12 }, { 15, 12 }, { 15, 13 }, { 13, 17 }, { 15, 14 }, |
| { 15, 14 }, { 16, 12 }, { 16, 12 }, { 16, 13 }, { 16, 13 }, { 16, 14 }, |
| { 16, 14 }, { 16, 14 }, { 15, 17 }, { 17, 13 }, { 17, 13 }, { 17, 14 }, |
| { 16, 16 }, { 17, 15 }, { 17, 15 }, { 17, 15 }, { 18, 14 }, { 18, 14 }, |
| { 18, 14 }, { 18, 15 }, { 17, 17 }, { 18, 16 }, { 18, 16 }, { 16, 20 }, |
| { 19, 15 }, { 19, 15 }, { 19, 15 }, { 19, 16 }, { 19, 16 }, { 19, 16 }, |
| { 19, 17 }, { 17, 21 }, { 19, 18 }, { 19, 18 }, { 20, 16 }, { 20, 16 }, |
| { 20, 17 }, { 20, 17 }, { 20, 18 }, { 20, 18 }, { 20, 18 }, { 19, 21 }, |
| { 21, 17 }, { 21, 17 }, { 21, 18 }, { 20, 20 }, { 21, 19 }, { 21, 19 }, |
| { 21, 19 }, { 22, 18 }, { 22, 18 }, { 22, 18 }, { 22, 19 }, { 21, 21 }, |
| { 22, 20 }, { 22, 20 }, { 20, 24 }, { 23, 19 }, { 23, 19 }, { 23, 19 }, |
| { 23, 20 }, { 23, 20 }, { 23, 20 }, { 23, 21 }, { 21, 25 }, { 23, 22 }, |
| { 23, 22 }, { 24, 20 }, { 24, 20 }, { 24, 21 }, { 24, 21 }, { 24, 22 }, |
| { 24, 22 }, { 24, 22 }, { 23, 25 }, { 25, 21 }, { 25, 21 }, { 25, 22 }, |
| { 24, 24 }, { 25, 23 }, { 25, 23 }, { 25, 23 }, { 26, 22 }, { 26, 22 }, |
| { 26, 22 }, { 26, 23 }, { 25, 25 }, { 26, 24 }, { 26, 24 }, { 24, 28 }, |
| { 27, 23 }, { 27, 23 }, { 27, 23 }, { 27, 24 }, { 27, 24 }, { 27, 24 }, |
| { 27, 25 }, { 25, 29 }, { 27, 26 }, { 27, 26 }, { 28, 24 }, { 28, 24 }, |
| { 28, 25 }, { 28, 25 }, { 28, 26 }, { 28, 26 }, { 28, 26 }, { 27, 29 }, |
| { 29, 25 }, { 29, 25 }, { 29, 26 }, { 28, 28 }, { 29, 27 }, { 29, 27 }, |
| { 29, 27 }, { 30, 26 }, { 30, 26 }, { 30, 26 }, { 30, 27 }, { 29, 29 }, |
| { 30, 28 }, { 30, 28 }, { 30, 28 }, { 31, 27 }, { 31, 27 }, { 31, 27 }, |
| { 31, 28 }, { 31, 28 }, { 31, 28 }, { 31, 29 }, { 31, 29 }, { 31, 30 }, |
| { 31, 30 }, { 31, 30 }, { 31, 31 }, { 31, 31 }, |
| }; |
| |
| static const uint8_t match6[256][2] = { |
| { 0, 0 }, { 0, 1 }, { 1, 0 }, { 1, 0 }, { 1, 1 }, { 2, 0 }, |
| { 2, 1 }, { 3, 0 }, { 3, 0 }, { 3, 1 }, { 4, 0 }, { 4, 0 }, |
| { 4, 1 }, { 5, 0 }, { 5, 1 }, { 6, 0 }, { 6, 0 }, { 6, 1 }, |
| { 7, 0 }, { 7, 0 }, { 7, 1 }, { 8, 0 }, { 8, 1 }, { 8, 1 }, |
| { 8, 2 }, { 9, 1 }, { 9, 2 }, { 9, 2 }, { 9, 3 }, { 10, 2 }, |
| { 10, 3 }, { 10, 3 }, { 10, 4 }, { 11, 3 }, { 11, 4 }, { 11, 4 }, |
| { 11, 5 }, { 12, 4 }, { 12, 5 }, { 12, 5 }, { 12, 6 }, { 13, 5 }, |
| { 13, 6 }, { 8, 16 }, { 13, 7 }, { 14, 6 }, { 14, 7 }, { 9, 17 }, |
| { 14, 8 }, { 15, 7 }, { 15, 8 }, { 11, 16 }, { 15, 9 }, { 15, 10 }, |
| { 16, 8 }, { 16, 9 }, { 16, 10 }, { 15, 13 }, { 17, 9 }, { 17, 10 }, |
| { 17, 11 }, { 15, 16 }, { 18, 10 }, { 18, 11 }, { 18, 12 }, { 16, 16 }, |
| { 19, 11 }, { 19, 12 }, { 19, 13 }, { 17, 17 }, { 20, 12 }, { 20, 13 }, |
| { 20, 14 }, { 19, 16 }, { 21, 13 }, { 21, 14 }, { 21, 15 }, { 20, 17 }, |
| { 22, 14 }, { 22, 15 }, { 25, 10 }, { 22, 16 }, { 23, 15 }, { 23, 16 }, |
| { 26, 11 }, { 23, 17 }, { 24, 16 }, { 24, 17 }, { 27, 12 }, { 24, 18 }, |
| { 25, 17 }, { 25, 18 }, { 28, 13 }, { 25, 19 }, { 26, 18 }, { 26, 19 }, |
| { 29, 14 }, { 26, 20 }, { 27, 19 }, { 27, 20 }, { 30, 15 }, { 27, 21 }, |
| { 28, 20 }, { 28, 21 }, { 28, 21 }, { 28, 22 }, { 29, 21 }, { 29, 22 }, |
| { 24, 32 }, { 29, 23 }, { 30, 22 }, { 30, 23 }, { 25, 33 }, { 30, 24 }, |
| { 31, 23 }, { 31, 24 }, { 27, 32 }, { 31, 25 }, { 31, 26 }, { 32, 24 }, |
| { 32, 25 }, { 32, 26 }, { 31, 29 }, { 33, 25 }, { 33, 26 }, { 33, 27 }, |
| { 31, 32 }, { 34, 26 }, { 34, 27 }, { 34, 28 }, { 32, 32 }, { 35, 27 }, |
| { 35, 28 }, { 35, 29 }, { 33, 33 }, { 36, 28 }, { 36, 29 }, { 36, 30 }, |
| { 35, 32 }, { 37, 29 }, { 37, 30 }, { 37, 31 }, { 36, 33 }, { 38, 30 }, |
| { 38, 31 }, { 41, 26 }, { 38, 32 }, { 39, 31 }, { 39, 32 }, { 42, 27 }, |
| { 39, 33 }, { 40, 32 }, { 40, 33 }, { 43, 28 }, { 40, 34 }, { 41, 33 }, |
| { 41, 34 }, { 44, 29 }, { 41, 35 }, { 42, 34 }, { 42, 35 }, { 45, 30 }, |
| { 42, 36 }, { 43, 35 }, { 43, 36 }, { 46, 31 }, { 43, 37 }, { 44, 36 }, |
| { 44, 37 }, { 44, 37 }, { 44, 38 }, { 45, 37 }, { 45, 38 }, { 40, 48 }, |
| { 45, 39 }, { 46, 38 }, { 46, 39 }, { 41, 49 }, { 46, 40 }, { 47, 39 }, |
| { 47, 40 }, { 43, 48 }, { 47, 41 }, { 47, 42 }, { 48, 40 }, { 48, 41 }, |
| { 48, 42 }, { 47, 45 }, { 49, 41 }, { 49, 42 }, { 49, 43 }, { 47, 48 }, |
| { 50, 42 }, { 50, 43 }, { 50, 44 }, { 48, 48 }, { 51, 43 }, { 51, 44 }, |
| { 51, 45 }, { 49, 49 }, { 52, 44 }, { 52, 45 }, { 52, 46 }, { 51, 48 }, |
| { 53, 45 }, { 53, 46 }, { 53, 47 }, { 52, 49 }, { 54, 46 }, { 54, 47 }, |
| { 57, 42 }, { 54, 48 }, { 55, 47 }, { 55, 48 }, { 58, 43 }, { 55, 49 }, |
| { 56, 48 }, { 56, 49 }, { 59, 44 }, { 56, 50 }, { 57, 49 }, { 57, 50 }, |
| { 60, 45 }, { 57, 51 }, { 58, 50 }, { 58, 51 }, { 61, 46 }, { 58, 52 }, |
| { 59, 51 }, { 59, 52 }, { 62, 47 }, { 59, 53 }, { 60, 52 }, { 60, 53 }, |
| { 60, 53 }, { 60, 54 }, { 61, 53 }, { 61, 54 }, { 61, 54 }, { 61, 55 }, |
| { 62, 54 }, { 62, 55 }, { 62, 55 }, { 62, 56 }, { 63, 55 }, { 63, 56 }, |
| { 63, 56 }, { 63, 57 }, { 63, 58 }, { 63, 59 }, { 63, 59 }, { 63, 60 }, |
| { 63, 61 }, { 63, 62 }, { 63, 62 }, { 63, 63 }, |
| }; |
| |
| /* Multiplication over 8 bit emulation */ |
| #define mul8(a, b) (((a) * (b) + 128 + (((a) * (b) + 128) >> 8)) >> 8) |
| |
| /* Conversion from rgb24 to rgb565 */ |
| #define rgb2rgb565(r, g, b) \ |
| ((mul8(r, 31) << 11) | (mul8(g, 63) << 5) | (mul8(b, 31) << 0)) |
| |
| /* Linear interpolation at 1/3 point between a and b */ |
| #define lerp13(a, b) ((2 * (a) + (b)) / 3) |
| |
| /* Linear interpolation on an RGB pixel */ |
| static inline void lerp13rgb(uint8_t *out, uint8_t *p1, uint8_t *p2) |
| { |
| out[0] = lerp13(p1[0], p2[0]); |
| out[1] = lerp13(p1[1], p2[1]); |
| out[2] = lerp13(p1[2], p2[2]); |
| } |
| |
| /* Conversion from rgb565 to rgb24 */ |
| static inline void rgb5652rgb(uint8_t *out, uint16_t v) |
| { |
| int rv = (v & 0xf800) >> 11; |
| int gv = (v & 0x07e0) >> 5; |
| int bv = (v & 0x001f) >> 0; |
| |
| out[0] = expand5[rv]; |
| out[1] = expand6[gv]; |
| out[2] = expand5[bv]; |
| out[3] = 0; |
| } |
| |
| /* Color matching function */ |
| static unsigned int match_colors(const uint8_t *block, ptrdiff_t stride, |
| uint16_t c0, uint16_t c1) |
| { |
| uint32_t mask = 0; |
| int dirr, dirg, dirb; |
| int dots[16]; |
| int stops[4]; |
| int x, y, k = 0; |
| int c0_point, half_point, c3_point; |
| uint8_t color[16]; |
| static const int indexMap[8] = { |
| 0 << 30, 2 << 30, 0 << 30, 2 << 30, |
| 3 << 30, 3 << 30, 1 << 30, 1 << 30, |
| }; |
| |
| /* Fill color and compute direction for each component */ |
| rgb5652rgb(color + 0, c0); |
| rgb5652rgb(color + 4, c1); |
| lerp13rgb(color + 8, color + 0, color + 4); |
| lerp13rgb(color + 12, color + 4, color + 0); |
| |
| dirr = color[0 * 4 + 0] - color[1 * 4 + 0]; |
| dirg = color[0 * 4 + 1] - color[1 * 4 + 1]; |
| dirb = color[0 * 4 + 2] - color[1 * 4 + 2]; |
| |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) |
| dots[k++] = block[0 + x * 4 + y * stride] * dirr + |
| block[1 + x * 4 + y * stride] * dirg + |
| block[2 + x * 4 + y * stride] * dirb; |
| |
| stops[y] = color[0 + y * 4] * dirr + |
| color[1 + y * 4] * dirg + |
| color[2 + y * 4] * dirb; |
| } |
| |
| /* Think of the colors as arranged on a line; project point onto that line, |
| * then choose next color out of available ones. we compute the crossover |
| * points for 'best color in top half'/'best in bottom half' and then |
| * the same inside that subinterval. |
| * |
| * Relying on this 1d approximation isn't always optimal in terms of |
| * Euclidean distance, but it's very close and a lot faster. |
| * |
| * http://cbloomrants.blogspot.com/2008/12/12-08-08-dxtc-summary.html */ |
| c0_point = (stops[1] + stops[3]) >> 1; |
| half_point = (stops[3] + stops[2]) >> 1; |
| c3_point = (stops[2] + stops[0]) >> 1; |
| |
| for (x = 0; x < 16; x++) { |
| int dot = dots[x]; |
| int bits = (dot < half_point ? 4 : 0) | |
| (dot < c0_point ? 2 : 0) | |
| (dot < c3_point ? 1 : 0); |
| |
| mask >>= 2; |
| mask |= indexMap[bits]; |
| } |
| |
| return mask; |
| } |
| |
| /* Color optimization function */ |
| static void optimize_colors(const uint8_t *block, ptrdiff_t stride, |
| uint16_t *pmax16, uint16_t *pmin16) |
| { |
| const uint8_t *minp; |
| const uint8_t *maxp; |
| const int iter_power = 4; |
| double magn; |
| int v_r, v_g, v_b; |
| float covf[6], vfr, vfg, vfb; |
| int mind, maxd; |
| int cov[6] = { 0 }; |
| int mu[3], min[3], max[3]; |
| int ch, iter, x, y; |
| |
| /* Determine color distribution */ |
| for (ch = 0; ch < 3; ch++) { |
| const uint8_t *bp = &block[ch]; |
| int muv, minv, maxv; |
| |
| muv = minv = maxv = bp[0]; |
| for (y = 0; y < 4; y++) { |
| for (x = 4; x < 4; x += 4) { |
| muv += bp[x * 4 + y * stride]; |
| if (bp[x] < minv) |
| minv = bp[x * 4 + y * stride]; |
| else if (bp[x] > maxv) |
| maxv = bp[x * 4 + y * stride]; |
| } |
| } |
| |
| mu[ch] = (muv + 8) >> 4; |
| min[ch] = minv; |
| max[ch] = maxv; |
| } |
| |
| /* Determine covariance matrix */ |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| int r = block[x * 4 + stride * y + 0] - mu[0]; |
| int g = block[x * 4 + stride * y + 1] - mu[1]; |
| int b = block[x * 4 + stride * y + 2] - mu[2]; |
| |
| cov[0] += r * r; |
| cov[1] += r * g; |
| cov[2] += r * b; |
| cov[3] += g * g; |
| cov[4] += g * b; |
| cov[5] += b * b; |
| } |
| } |
| |
| /* Convert covariance matrix to float, find principal axis via power iter */ |
| for (x = 0; x < 6; x++) |
| covf[x] = cov[x] / 255.0f; |
| |
| vfr = (float) (max[0] - min[0]); |
| vfg = (float) (max[1] - min[1]); |
| vfb = (float) (max[2] - min[2]); |
| |
| for (iter = 0; iter < iter_power; iter++) { |
| float r = vfr * covf[0] + vfg * covf[1] + vfb * covf[2]; |
| float g = vfr * covf[1] + vfg * covf[3] + vfb * covf[4]; |
| float b = vfr * covf[2] + vfg * covf[4] + vfb * covf[5]; |
| |
| vfr = r; |
| vfg = g; |
| vfb = b; |
| } |
| |
| magn = fabs(vfr); |
| if (fabs(vfg) > magn) |
| magn = fabs(vfg); |
| if (fabs(vfb) > magn) |
| magn = fabs(vfb); |
| |
| /* if magnitude is too small, default to luminance */ |
| if (magn < 4.0f) { |
| /* JPEG YCbCr luma coefs, scaled by 1000 */ |
| v_r = 299; |
| v_g = 587; |
| v_b = 114; |
| } else { |
| magn = 512.0 / magn; |
| v_r = (int) (vfr * magn); |
| v_g = (int) (vfg * magn); |
| v_b = (int) (vfb * magn); |
| } |
| |
| /* Pick colors at extreme points */ |
| mind = maxd = block[0] * v_r + block[1] * v_g + block[2] * v_b; |
| minp = maxp = block; |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| int dot = block[x * 4 + y * stride + 0] * v_r + |
| block[x * 4 + y * stride + 1] * v_g + |
| block[x * 4 + y * stride + 2] * v_b; |
| |
| if (dot < mind) { |
| mind = dot; |
| minp = block + x * 4 + y * stride; |
| } else if (dot > maxd) { |
| maxd = dot; |
| maxp = block + x * 4 + y * stride; |
| } |
| } |
| } |
| |
| *pmax16 = rgb2rgb565(maxp[0], maxp[1], maxp[2]); |
| *pmin16 = rgb2rgb565(minp[0], minp[1], minp[2]); |
| } |
| |
| /* Try to optimize colors to suit block contents better, by solving |
| * a least squares system via normal equations + Cramer's rule. */ |
| static int refine_colors(const uint8_t *block, ptrdiff_t stride, |
| uint16_t *pmax16, uint16_t *pmin16, uint32_t mask) |
| { |
| uint32_t cm = mask; |
| uint16_t oldMin = *pmin16; |
| uint16_t oldMax = *pmax16; |
| uint16_t min16, max16; |
| int x, y; |
| |
| /* Additional magic to save a lot of multiplies in the accumulating loop. |
| * The tables contain precomputed products of weights for least squares |
| * system, accumulated inside one 32-bit register */ |
| static const int w1tab[4] = { 3, 0, 2, 1 }; |
| static const int prods[4] = { 0x090000, 0x000900, 0x040102, 0x010402 }; |
| |
| /* Check if all pixels have the same index */ |
| if ((mask ^ (mask << 2)) < 4) { |
| /* If so, linear system would be singular; solve using optimal |
| * single-color match on average color. */ |
| int r = 8, g = 8, b = 8; |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| r += block[0 + x * 4 + y * stride]; |
| g += block[1 + x * 4 + y * stride]; |
| b += block[2 + x * 4 + y * stride]; |
| } |
| } |
| |
| r >>= 4; |
| g >>= 4; |
| b >>= 4; |
| |
| max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0]; |
| min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1]; |
| } else { |
| float fr, fg, fb; |
| int at1_r = 0, at1_g = 0, at1_b = 0; |
| int at2_r = 0, at2_g = 0, at2_b = 0; |
| int akku = 0; |
| int xx, xy, yy; |
| |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| int step = cm & 3; |
| int w1 = w1tab[step]; |
| int r = block[0 + x * 4 + y * stride]; |
| int g = block[1 + x * 4 + y * stride]; |
| int b = block[2 + x * 4 + y * stride]; |
| |
| akku += prods[step]; |
| at1_r += w1 * r; |
| at1_g += w1 * g; |
| at1_b += w1 * b; |
| at2_r += r; |
| at2_g += g; |
| at2_b += b; |
| |
| cm >>= 2; |
| } |
| } |
| |
| at2_r = 3 * at2_r - at1_r; |
| at2_g = 3 * at2_g - at1_g; |
| at2_b = 3 * at2_b - at1_b; |
| |
| /* Extract solutions and decide solvability */ |
| xx = akku >> 16; |
| yy = (akku >> 8) & 0xFF; |
| xy = (akku >> 0) & 0xFF; |
| |
| fr = 3.0f * 31.0f / 255.0f / (xx * yy - xy * xy); |
| fg = fr * 63.0f / 31.0f; |
| fb = fr; |
| |
| /* Solve */ |
| max16 = av_clip_uintp2((at1_r * yy - at2_r * xy) * fr + 0.5f, 5) << 11; |
| max16 |= av_clip_uintp2((at1_g * yy - at2_g * xy) * fg + 0.5f, 6) << 5; |
| max16 |= av_clip_uintp2((at1_b * yy - at2_b * xy) * fb + 0.5f, 5) << 0; |
| |
| min16 = av_clip_uintp2((at2_r * xx - at1_r * xy) * fr + 0.5f, 5) << 11; |
| min16 |= av_clip_uintp2((at2_g * xx - at1_g * xy) * fg + 0.5f, 6) << 5; |
| min16 |= av_clip_uintp2((at2_b * xx - at1_b * xy) * fb + 0.5f, 5) << 0; |
| } |
| |
| *pmin16 = min16; |
| *pmax16 = max16; |
| return oldMin != min16 || oldMax != max16; |
| } |
| |
| /* Check if input block is a constant color */ |
| static int constant_color(const uint8_t *block, ptrdiff_t stride) |
| { |
| int x, y; |
| uint32_t first = AV_RL32(block); |
| |
| for (y = 0; y < 4; y++) |
| for (x = 0; x < 4; x++) |
| if (first != AV_RL32(block + x * 4 + y * stride)) |
| return 0; |
| return 1; |
| } |
| |
| /* Main color compression function */ |
| static void compress_color(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) |
| { |
| uint32_t mask; |
| uint16_t max16, min16; |
| int constant = constant_color(block, stride); |
| |
| /* Constant color will load values from tables */ |
| if (constant) { |
| int r = block[0]; |
| int g = block[1]; |
| int b = block[2]; |
| mask = 0xAAAAAAAA; |
| max16 = (match5[r][0] << 11) | (match6[g][0] << 5) | match5[b][0]; |
| min16 = (match5[r][1] << 11) | (match6[g][1] << 5) | match5[b][1]; |
| } else { |
| int refine; |
| |
| /* Otherwise find pca and map along principal axis */ |
| optimize_colors(block, stride, &max16, &min16); |
| if (max16 != min16) |
| mask = match_colors(block, stride, max16, min16); |
| else |
| mask = 0; |
| |
| /* One pass refinement */ |
| refine = refine_colors(block, stride, &max16, &min16, mask); |
| if (refine) { |
| if (max16 != min16) |
| mask = match_colors(block, stride, max16, min16); |
| else |
| mask = 0; |
| } |
| } |
| |
| /* Finally write the color block */ |
| if (max16 < min16) { |
| FFSWAP(uint16_t, min16, max16); |
| mask ^= 0x55555555; |
| } |
| |
| AV_WL16(dst + 0, max16); |
| AV_WL16(dst + 2, min16); |
| AV_WL32(dst + 4, mask); |
| } |
| |
| /* Alpha compression function */ |
| static void compress_alpha(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) |
| { |
| int x, y; |
| int dist, bias, dist4, dist2; |
| int mn, mx; |
| int bits = 0; |
| int mask = 0; |
| |
| memset(dst, 0, 8); |
| |
| /* Find min/max color */ |
| mn = mx = block[3]; |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| int val = block[3 + x * 4 + y * stride]; |
| if (val < mn) |
| mn = val; |
| else if (val > mx) |
| mx = val; |
| } |
| } |
| |
| /* Encode them */ |
| dst[0] = (uint8_t) mx; |
| dst[1] = (uint8_t) mn; |
| dst += 2; |
| |
| /* Mono-alpha shortcut */ |
| if (mn == mx) |
| return; |
| |
| /* Determine bias and emit color indices. |
| * Given the choice of mx/mn, these indices are optimal: |
| * fgiesen.wordpress.com/2009/12/15/dxt5-alpha-block-index-determination */ |
| dist = mx - mn; |
| |
| dist4 = dist * 4; |
| dist2 = dist * 2; |
| if (dist < 8) |
| bias = dist - 1 - mn * 7; |
| else |
| bias = dist / 2 + 2 - mn * 7; |
| |
| for (y = 0; y < 4; y++) { |
| for (x = 0; x < 4; x++) { |
| int alp = block[3 + x * 4 + y * stride] * 7 + bias; |
| int ind, tmp; |
| |
| /* This is a "linear scale" lerp factor between 0 (val=min) |
| * and 7 (val=max) to select index. */ |
| tmp = (alp >= dist4) ? -1 : 0; |
| ind = tmp & 4; |
| alp -= dist4 & tmp; |
| tmp = (alp >= dist2) ? -1 : 0; |
| ind += tmp & 2; |
| alp -= dist2 & tmp; |
| ind += (alp >= dist); |
| |
| /* Turn linear scale into DXT index (0/1 are extreme points) */ |
| ind = -ind & 7; |
| ind ^= (2 > ind); |
| |
| /* Write index */ |
| mask |= ind << bits; |
| bits += 3; |
| if (bits >= 8) { |
| *dst++ = mask; |
| mask >>= 8; |
| bits -= 8; |
| } |
| } |
| } |
| } |
| |
| /** |
| * Convert a RGBA buffer to unscaled YCoCg. |
| * Scale is usually introduced to avoid banding over a certain range of colors, |
| * but this version of the algorithm does not introduce it as much as other |
| * implementations, allowing for a simpler and faster conversion. |
| */ |
| static void rgba2ycocg(uint8_t *dst, const uint8_t *pixel) |
| { |
| int r = pixel[0]; |
| int g = (pixel[1] + 1) >> 1; |
| int b = pixel[2]; |
| int t = (2 + r + b) >> 2; |
| |
| dst[0] = av_clip_uint8(128 + ((r - b + 1) >> 1)); /* Co */ |
| dst[1] = av_clip_uint8(128 + g - t); /* Cg */ |
| dst[2] = 0; |
| dst[3] = av_clip_uint8(g + t); /* Y */ |
| } |
| |
| /** |
| * Compress one block of RGBA pixels in a DXT1 texture and store the |
| * resulting bytes in 'dst'. Alpha is not preserved. |
| * |
| * @param dst output buffer. |
| * @param stride scanline in bytes. |
| * @param block block to compress. |
| * @return how much texture data has been written. |
| */ |
| static int dxt1_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) |
| { |
| compress_color(dst, stride, block); |
| |
| return 8; |
| } |
| |
| /** |
| * Compress one block of RGBA pixels in a DXT5 texture and store the |
| * resulting bytes in 'dst'. Alpha is preserved. |
| * |
| * @param dst output buffer. |
| * @param stride scanline in bytes. |
| * @param block block to compress. |
| * @return how much texture data has been written. |
| */ |
| static int dxt5_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) |
| { |
| compress_alpha(dst, stride, block); |
| compress_color(dst + 8, stride, block); |
| |
| return 16; |
| } |
| |
| /** |
| * Compress one block of RGBA pixels in a DXT5-YCoCg texture and store the |
| * resulting bytes in 'dst'. Alpha is not preserved. |
| * |
| * @param dst output buffer. |
| * @param stride scanline in bytes. |
| * @param block block to compress. |
| * @return how much texture data has been written. |
| */ |
| static int dxt5ys_block(uint8_t *dst, ptrdiff_t stride, const uint8_t *block) |
| { |
| int x, y; |
| uint8_t reorder[64]; |
| |
| /* Reorder the components and then run a normal DXT5 compression. */ |
| for (y = 0; y < 4; y++) |
| for (x = 0; x < 4; x++) |
| rgba2ycocg(reorder + x * 4 + y * 16, block + x * 4 + y * stride); |
| |
| compress_alpha(dst + 0, 16, reorder); |
| compress_color(dst + 8, 16, reorder); |
| |
| return 16; |
| } |
| |
| av_cold void ff_texturedspenc_init(TextureDSPContext *c) |
| { |
| c->dxt1_block = dxt1_block; |
| c->dxt5_block = dxt5_block; |
| c->dxt5ys_block = dxt5ys_block; |
| } |
