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-rw-r--r--src/shaders/film_grain_av1.c1001
1 files changed, 1001 insertions, 0 deletions
diff --git a/src/shaders/film_grain_av1.c b/src/shaders/film_grain_av1.c
new file mode 100644
index 0000000..3b11ea3
--- /dev/null
+++ b/src/shaders/film_grain_av1.c
@@ -0,0 +1,1001 @@
+/*
+ * This file is part of libplacebo, which is normally licensed under the terms
+ * of the LGPL v2.1+. However, this file (film_grain_av1.c) is also available
+ * under the terms of the more permissive MIT license:
+ *
+ * Copyright (c) 2018-2019 Niklas Haas
+ *
+ * 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 "shaders.h"
+#include "shaders/film_grain.h"
+
+// Taken from the spec. Range is [-2048, 2047], mean is 0 and stddev is 512
+static const int16_t gaussian_sequence[2048] = {
+ 56, 568, -180, 172, 124, -84, 172, -64, -900, 24, 820,
+ 224, 1248, 996, 272, -8, -916, -388, -732, -104, -188, 800,
+ 112, -652, -320, -376, 140, -252, 492, -168, 44, -788, 588,
+ -584, 500, -228, 12, 680, 272, -476, 972, -100, 652, 368,
+ 432, -196, -720, -192, 1000, -332, 652, -136, -552, -604, -4,
+ 192, -220, -136, 1000, -52, 372, -96, -624, 124, -24, 396,
+ 540, -12, -104, 640, 464, 244, -208, -84, 368, -528, -740,
+ 248, -968, -848, 608, 376, -60, -292, -40, -156, 252, -292,
+ 248, 224, -280, 400, -244, 244, -60, 76, -80, 212, 532,
+ 340, 128, -36, 824, -352, -60, -264, -96, -612, 416, -704,
+ 220, -204, 640, -160, 1220, -408, 900, 336, 20, -336, -96,
+ -792, 304, 48, -28, -1232, -1172, -448, 104, -292, -520, 244,
+ 60, -948, 0, -708, 268, 108, 356, -548, 488, -344, -136,
+ 488, -196, -224, 656, -236, -1128, 60, 4, 140, 276, -676,
+ -376, 168, -108, 464, 8, 564, 64, 240, 308, -300, -400,
+ -456, -136, 56, 120, -408, -116, 436, 504, -232, 328, 844,
+ -164, -84, 784, -168, 232, -224, 348, -376, 128, 568, 96,
+ -1244, -288, 276, 848, 832, -360, 656, 464, -384, -332, -356,
+ 728, -388, 160, -192, 468, 296, 224, 140, -776, -100, 280,
+ 4, 196, 44, -36, -648, 932, 16, 1428, 28, 528, 808,
+ 772, 20, 268, 88, -332, -284, 124, -384, -448, 208, -228,
+ -1044, -328, 660, 380, -148, -300, 588, 240, 540, 28, 136,
+ -88, -436, 256, 296, -1000, 1400, 0, -48, 1056, -136, 264,
+ -528, -1108, 632, -484, -592, -344, 796, 124, -668, -768, 388,
+ 1296, -232, -188, -200, -288, -4, 308, 100, -168, 256, -500,
+ 204, -508, 648, -136, 372, -272, -120, -1004, -552, -548, -384,
+ 548, -296, 428, -108, -8, -912, -324, -224, -88, -112, -220,
+ -100, 996, -796, 548, 360, -216, 180, 428, -200, -212, 148,
+ 96, 148, 284, 216, -412, -320, 120, -300, -384, -604, -572,
+ -332, -8, -180, -176, 696, 116, -88, 628, 76, 44, -516,
+ 240, -208, -40, 100, -592, 344, -308, -452, -228, 20, 916,
+ -1752, -136, -340, -804, 140, 40, 512, 340, 248, 184, -492,
+ 896, -156, 932, -628, 328, -688, -448, -616, -752, -100, 560,
+ -1020, 180, -800, -64, 76, 576, 1068, 396, 660, 552, -108,
+ -28, 320, -628, 312, -92, -92, -472, 268, 16, 560, 516,
+ -672, -52, 492, -100, 260, 384, 284, 292, 304, -148, 88,
+ -152, 1012, 1064, -228, 164, -376, -684, 592, -392, 156, 196,
+ -524, -64, -884, 160, -176, 636, 648, 404, -396, -436, 864,
+ 424, -728, 988, -604, 904, -592, 296, -224, 536, -176, -920,
+ 436, -48, 1176, -884, 416, -776, -824, -884, 524, -548, -564,
+ -68, -164, -96, 692, 364, -692, -1012, -68, 260, -480, 876,
+ -1116, 452, -332, -352, 892, -1088, 1220, -676, 12, -292, 244,
+ 496, 372, -32, 280, 200, 112, -440, -96, 24, -644, -184,
+ 56, -432, 224, -980, 272, -260, 144, -436, 420, 356, 364,
+ -528, 76, 172, -744, -368, 404, -752, -416, 684, -688, 72,
+ 540, 416, 92, 444, 480, -72, -1416, 164, -1172, -68, 24,
+ 424, 264, 1040, 128, -912, -524, -356, 64, 876, -12, 4,
+ -88, 532, 272, -524, 320, 276, -508, 940, 24, -400, -120,
+ 756, 60, 236, -412, 100, 376, -484, 400, -100, -740, -108,
+ -260, 328, -268, 224, -200, -416, 184, -604, -564, -20, 296,
+ 60, 892, -888, 60, 164, 68, -760, 216, -296, 904, -336,
+ -28, 404, -356, -568, -208, -1480, -512, 296, 328, -360, -164,
+ -1560, -776, 1156, -428, 164, -504, -112, 120, -216, -148, -264,
+ 308, 32, 64, -72, 72, 116, 176, -64, -272, 460, -536,
+ -784, -280, 348, 108, -752, -132, 524, -540, -776, 116, -296,
+ -1196, -288, -560, 1040, -472, 116, -848, -1116, 116, 636, 696,
+ 284, -176, 1016, 204, -864, -648, -248, 356, 972, -584, -204,
+ 264, 880, 528, -24, -184, 116, 448, -144, 828, 524, 212,
+ -212, 52, 12, 200, 268, -488, -404, -880, 824, -672, -40,
+ 908, -248, 500, 716, -576, 492, -576, 16, 720, -108, 384,
+ 124, 344, 280, 576, -500, 252, 104, -308, 196, -188, -8,
+ 1268, 296, 1032, -1196, 436, 316, 372, -432, -200, -660, 704,
+ -224, 596, -132, 268, 32, -452, 884, 104, -1008, 424, -1348,
+ -280, 4, -1168, 368, 476, 696, 300, -8, 24, 180, -592,
+ -196, 388, 304, 500, 724, -160, 244, -84, 272, -256, -420,
+ 320, 208, -144, -156, 156, 364, 452, 28, 540, 316, 220,
+ -644, -248, 464, 72, 360, 32, -388, 496, -680, -48, 208,
+ -116, -408, 60, -604, -392, 548, -840, 784, -460, 656, -544,
+ -388, -264, 908, -800, -628, -612, -568, 572, -220, 164, 288,
+ -16, -308, 308, -112, -636, -760, 280, -668, 432, 364, 240,
+ -196, 604, 340, 384, 196, 592, -44, -500, 432, -580, -132,
+ 636, -76, 392, 4, -412, 540, 508, 328, -356, -36, 16,
+ -220, -64, -248, -60, 24, -192, 368, 1040, 92, -24, -1044,
+ -32, 40, 104, 148, 192, -136, -520, 56, -816, -224, 732,
+ 392, 356, 212, -80, -424, -1008, -324, 588, -1496, 576, 460,
+ -816, -848, 56, -580, -92, -1372, -112, -496, 200, 364, 52,
+ -140, 48, -48, -60, 84, 72, 40, 132, -356, -268, -104,
+ -284, -404, 732, -520, 164, -304, -540, 120, 328, -76, -460,
+ 756, 388, 588, 236, -436, -72, -176, -404, -316, -148, 716,
+ -604, 404, -72, -88, -888, -68, 944, 88, -220, -344, 960,
+ 472, 460, -232, 704, 120, 832, -228, 692, -508, 132, -476,
+ 844, -748, -364, -44, 1116, -1104, -1056, 76, 428, 552, -692,
+ 60, 356, 96, -384, -188, -612, -576, 736, 508, 892, 352,
+ -1132, 504, -24, -352, 324, 332, -600, -312, 292, 508, -144,
+ -8, 484, 48, 284, -260, -240, 256, -100, -292, -204, -44,
+ 472, -204, 908, -188, -1000, -256, 92, 1164, -392, 564, 356,
+ 652, -28, -884, 256, 484, -192, 760, -176, 376, -524, -452,
+ -436, 860, -736, 212, 124, 504, -476, 468, 76, -472, 552,
+ -692, -944, -620, 740, -240, 400, 132, 20, 192, -196, 264,
+ -668, -1012, -60, 296, -316, -828, 76, -156, 284, -768, -448,
+ -832, 148, 248, 652, 616, 1236, 288, -328, -400, -124, 588,
+ 220, 520, -696, 1032, 768, -740, -92, -272, 296, 448, -464,
+ 412, -200, 392, 440, -200, 264, -152, -260, 320, 1032, 216,
+ 320, -8, -64, 156, -1016, 1084, 1172, 536, 484, -432, 132,
+ 372, -52, -256, 84, 116, -352, 48, 116, 304, -384, 412,
+ 924, -300, 528, 628, 180, 648, 44, -980, -220, 1320, 48,
+ 332, 748, 524, -268, -720, 540, -276, 564, -344, -208, -196,
+ 436, 896, 88, -392, 132, 80, -964, -288, 568, 56, -48,
+ -456, 888, 8, 552, -156, -292, 948, 288, 128, -716, -292,
+ 1192, -152, 876, 352, -600, -260, -812, -468, -28, -120, -32,
+ -44, 1284, 496, 192, 464, 312, -76, -516, -380, -456, -1012,
+ -48, 308, -156, 36, 492, -156, -808, 188, 1652, 68, -120,
+ -116, 316, 160, -140, 352, 808, -416, 592, 316, -480, 56,
+ 528, -204, -568, 372, -232, 752, -344, 744, -4, 324, -416,
+ -600, 768, 268, -248, -88, -132, -420, -432, 80, -288, 404,
+ -316, -1216, -588, 520, -108, 92, -320, 368, -480, -216, -92,
+ 1688, -300, 180, 1020, -176, 820, -68, -228, -260, 436, -904,
+ 20, 40, -508, 440, -736, 312, 332, 204, 760, -372, 728,
+ 96, -20, -632, -520, -560, 336, 1076, -64, -532, 776, 584,
+ 192, 396, -728, -520, 276, -188, 80, -52, -612, -252, -48,
+ 648, 212, -688, 228, -52, -260, 428, -412, -272, -404, 180,
+ 816, -796, 48, 152, 484, -88, -216, 988, 696, 188, -528,
+ 648, -116, -180, 316, 476, 12, -564, 96, 476, -252, -364,
+ -376, -392, 556, -256, -576, 260, -352, 120, -16, -136, -260,
+ -492, 72, 556, 660, 580, 616, 772, 436, 424, -32, -324,
+ -1268, 416, -324, -80, 920, 160, 228, 724, 32, -516, 64,
+ 384, 68, -128, 136, 240, 248, -204, -68, 252, -932, -120,
+ -480, -628, -84, 192, 852, -404, -288, -132, 204, 100, 168,
+ -68, -196, -868, 460, 1080, 380, -80, 244, 0, 484, -888,
+ 64, 184, 352, 600, 460, 164, 604, -196, 320, -64, 588,
+ -184, 228, 12, 372, 48, -848, -344, 224, 208, -200, 484,
+ 128, -20, 272, -468, -840, 384, 256, -720, -520, -464, -580,
+ 112, -120, 644, -356, -208, -608, -528, 704, 560, -424, 392,
+ 828, 40, 84, 200, -152, 0, -144, 584, 280, -120, 80,
+ -556, -972, -196, -472, 724, 80, 168, -32, 88, 160, -688,
+ 0, 160, 356, 372, -776, 740, -128, 676, -248, -480, 4,
+ -364, 96, 544, 232, -1032, 956, 236, 356, 20, -40, 300,
+ 24, -676, -596, 132, 1120, -104, 532, -1096, 568, 648, 444,
+ 508, 380, 188, -376, -604, 1488, 424, 24, 756, -220, -192,
+ 716, 120, 920, 688, 168, 44, -460, 568, 284, 1144, 1160,
+ 600, 424, 888, 656, -356, -320, 220, 316, -176, -724, -188,
+ -816, -628, -348, -228, -380, 1012, -452, -660, 736, 928, 404,
+ -696, -72, -268, -892, 128, 184, -344, -780, 360, 336, 400,
+ 344, 428, 548, -112, 136, -228, -216, -820, -516, 340, 92,
+ -136, 116, -300, 376, -244, 100, -316, -520, -284, -12, 824,
+ 164, -548, -180, -128, 116, -924, -828, 268, -368, -580, 620,
+ 192, 160, 0, -1676, 1068, 424, -56, -360, 468, -156, 720,
+ 288, -528, 556, -364, 548, -148, 504, 316, 152, -648, -620,
+ -684, -24, -376, -384, -108, -920, -1032, 768, 180, -264, -508,
+ -1268, -260, -60, 300, -240, 988, 724, -376, -576, -212, -736,
+ 556, 192, 1092, -620, -880, 376, -56, -4, -216, -32, 836,
+ 268, 396, 1332, 864, -600, 100, 56, -412, -92, 356, 180,
+ 884, -468, -436, 292, -388, -804, -704, -840, 368, -348, 140,
+ -724, 1536, 940, 372, 112, -372, 436, -480, 1136, 296, -32,
+ -228, 132, -48, -220, 868, -1016, -60, -1044, -464, 328, 916,
+ 244, 12, -736, -296, 360, 468, -376, -108, -92, 788, 368,
+ -56, 544, 400, -672, -420, 728, 16, 320, 44, -284, -380,
+ -796, 488, 132, 204, -596, -372, 88, -152, -908, -636, -572,
+ -624, -116, -692, -200, -56, 276, -88, 484, -324, 948, 864,
+ 1000, -456, -184, -276, 292, -296, 156, 676, 320, 160, 908,
+ -84, -1236, -288, -116, 260, -372, -644, 732, -756, -96, 84,
+ 344, -520, 348, -688, 240, -84, 216, -1044, -136, -676, -396,
+ -1500, 960, -40, 176, 168, 1516, 420, -504, -344, -364, -360,
+ 1216, -940, -380, -212, 252, -660, -708, 484, -444, -152, 928,
+ -120, 1112, 476, -260, 560, -148, -344, 108, -196, 228, -288,
+ 504, 560, -328, -88, 288, -1008, 460, -228, 468, -836, -196,
+ 76, 388, 232, 412, -1168, -716, -644, 756, -172, -356, -504,
+ 116, 432, 528, 48, 476, -168, -608, 448, 160, -532, -272,
+ 28, -676, -12, 828, 980, 456, 520, 104, -104, 256, -344,
+ -4, -28, -368, -52, -524, -572, -556, -200, 768, 1124, -208,
+ -512, 176, 232, 248, -148, -888, 604, -600, -304, 804, -156,
+ -212, 488, -192, -804, -256, 368, -360, -916, -328, 228, -240,
+ -448, -472, 856, -556, -364, 572, -12, -156, -368, -340, 432,
+ 252, -752, -152, 288, 268, -580, -848, -592, 108, -76, 244,
+ 312, -716, 592, -80, 436, 360, 4, -248, 160, 516, 584,
+ 732, 44, -468, -280, -292, -156, -588, 28, 308, 912, 24,
+ 124, 156, 180, -252, 944, -924, -772, -520, -428, -624, 300,
+ -212, -1144, 32, -724, 800, -1128, -212, -1288, -848, 180, -416,
+ 440, 192, -576, -792, -76, -1080, 80, -532, -352, -132, 380,
+ -820, 148, 1112, 128, 164, 456, 700, -924, 144, -668, -384,
+ 648, -832, 508, 552, -52, -100, -656, 208, -568, 748, -88,
+ 680, 232, 300, 192, -408, -1012, -152, -252, -268, 272, -876,
+ -664, -648, -332, -136, 16, 12, 1152, -28, 332, -536, 320,
+ -672, -460, -316, 532, -260, 228, -40, 1052, -816, 180, 88,
+ -496, -556, -672, -368, 428, 92, 356, 404, -408, 252, 196,
+ -176, -556, 792, 268, 32, 372, 40, 96, -332, 328, 120,
+ 372, -900, -40, 472, -264, -592, 952, 128, 656, 112, 664,
+ -232, 420, 4, -344, -464, 556, 244, -416, -32, 252, 0,
+ -412, 188, -696, 508, -476, 324, -1096, 656, -312, 560, 264,
+ -136, 304, 160, -64, -580, 248, 336, -720, 560, -348, -288,
+ -276, -196, -500, 852, -544, -236, -1128, -992, -776, 116, 56,
+ 52, 860, 884, 212, -12, 168, 1020, 512, -552, 924, -148,
+ 716, 188, 164, -340, -520, -184, 880, -152, -680, -208, -1156,
+ -300, -528, -472, 364, 100, -744, -1056, -32, 540, 280, 144,
+ -676, -32, -232, -280, -224, 96, 568, -76, 172, 148, 148,
+ 104, 32, -296, -32, 788, -80, 32, -16, 280, 288, 944,
+ 428, -484
+};
+
+static inline int get_random_number(int bits, uint16_t *state)
+{
+ int r = *state;
+ uint16_t bit = ((r >> 0) ^ (r >> 1) ^ (r >> 3) ^ (r >> 12)) & 1;
+ *state = (r >> 1) | (bit << 15);
+
+ return (*state >> (16 - bits)) & ((1 << bits) - 1);
+}
+
+static inline int round2(int x, int shift)
+{
+ if (!shift)
+ return x;
+
+ return (x + (1 << (shift - 1))) >> shift;
+}
+
+enum {
+ BLOCK_SIZE = 32,
+ SCALING_LUT_SIZE = 256,
+
+ GRAIN_WIDTH = 82,
+ GRAIN_HEIGHT = 73,
+ // On the GPU we only need a subsection of this
+ GRAIN_WIDTH_LUT = 64,
+ GRAIN_HEIGHT_LUT = 64,
+ GRAIN_PAD_LUT = 9,
+
+ // For subsampled grain textures
+ SUB_GRAIN_WIDTH = 44,
+ SUB_GRAIN_HEIGHT = 38,
+ SUB_GRAIN_WIDTH_LUT = GRAIN_WIDTH_LUT >> 1,
+ SUB_GRAIN_HEIGHT_LUT = GRAIN_HEIGHT_LUT >> 1,
+ SUB_GRAIN_PAD_LUT = 6,
+};
+
+// Contains the shift by which the offsets are indexed
+enum offset {
+ OFFSET_TL = 24,
+ OFFSET_T = 16,
+ OFFSET_L = 8,
+ OFFSET_N = 0,
+};
+
+// Helper function to compute some common constants
+struct grain_scale {
+ int grain_center;
+ int grain_min;
+ int grain_max;
+ float texture_scale;
+ float grain_scale;
+};
+
+static inline int bit_depth(const struct pl_color_repr *repr)
+{
+ int depth = PL_DEF(repr->bits.color_depth,
+ PL_DEF(repr->bits.sample_depth, 8));
+ pl_assert(depth >= 8);
+ return PL_MIN(depth, 12);
+}
+
+static struct grain_scale get_grain_scale(const struct pl_film_grain_params *params)
+{
+ int bits = bit_depth(params->repr);
+ struct grain_scale ret = {
+ .grain_center = 128 << (bits - 8),
+ };
+
+ ret.grain_min = -ret.grain_center;
+ ret.grain_max = (256 << (bits - 8)) - 1 - ret.grain_center;
+
+ struct pl_color_repr repr = *params->repr;
+ ret.texture_scale = pl_color_repr_normalize(&repr);
+
+ // Since our color samples are normalized to the range [0, 1], we need to
+ // scale down grain values from the scale [0, 2^b - 1] to this range.
+ ret.grain_scale = 1.0 / ((1 << bits) - 1);
+
+ return ret;
+}
+
+// Generates the basic grain table (LumaGrain in the spec).
+static void generate_grain_y(float out[GRAIN_HEIGHT_LUT][GRAIN_WIDTH_LUT],
+ int16_t buf[GRAIN_HEIGHT][GRAIN_WIDTH],
+ const struct pl_film_grain_params *params)
+{
+ const struct pl_av1_grain_data *data = &params->data.params.av1;
+ struct grain_scale scale = get_grain_scale(params);
+ uint16_t seed = (uint16_t) params->data.seed;
+ int bits = bit_depth(params->repr);
+ int shift = 12 - bits + data->grain_scale_shift;
+ pl_assert(shift >= 0);
+
+ for (int y = 0; y < GRAIN_HEIGHT; y++) {
+ for (int x = 0; x < GRAIN_WIDTH; x++) {
+ int16_t value = gaussian_sequence[ get_random_number(11, &seed) ];
+ buf[y][x] = round2(value, shift);
+ }
+ }
+
+ const int ar_pad = 3;
+ int ar_lag = data->ar_coeff_lag;
+
+ for (int y = ar_pad; y < GRAIN_HEIGHT; y++) {
+ for (int x = ar_pad; x < GRAIN_WIDTH - ar_pad; x++) {
+ const int8_t *coeff = data->ar_coeffs_y;
+ int sum = 0;
+ for (int dy = -ar_lag; dy <= 0; dy++) {
+ for (int dx = -ar_lag; dx <= ar_lag; dx++) {
+ if (!dx && !dy)
+ break;
+ sum += *(coeff++) * buf[y + dy][x + dx];
+ }
+ }
+
+ int16_t grain = buf[y][x] + round2(sum, data->ar_coeff_shift);
+ grain = PL_CLAMP(grain, scale.grain_min, scale.grain_max);
+ buf[y][x] = grain;
+ }
+ }
+
+ for (int y = 0; y < GRAIN_HEIGHT_LUT; y++) {
+ for (int x = 0; x < GRAIN_WIDTH_LUT; x++) {
+ int16_t grain = buf[y + GRAIN_PAD_LUT][x + GRAIN_PAD_LUT];
+ out[y][x] = grain * scale.grain_scale;
+ }
+ }
+}
+
+static void generate_grain_uv(float *out, int16_t buf[GRAIN_HEIGHT][GRAIN_WIDTH],
+ const int16_t buf_y[GRAIN_HEIGHT][GRAIN_WIDTH],
+ enum pl_channel channel, int sub_x, int sub_y,
+ const struct pl_film_grain_params *params)
+{
+ const struct pl_av1_grain_data *data = &params->data.params.av1;
+ struct grain_scale scale = get_grain_scale(params);
+ int bits = bit_depth(params->repr);
+ int shift = 12 - bits + data->grain_scale_shift;
+ pl_assert(shift >= 0);
+
+ uint16_t seed = params->data.seed;
+ if (channel == PL_CHANNEL_CB) {
+ seed ^= 0xb524;
+ } else if (channel == PL_CHANNEL_CR) {
+ seed ^= 0x49d8;
+ }
+
+ int chromaW = sub_x ? SUB_GRAIN_WIDTH : GRAIN_WIDTH;
+ int chromaH = sub_y ? SUB_GRAIN_HEIGHT : GRAIN_HEIGHT;
+
+ const int8_t *coeffs[] = {
+ [PL_CHANNEL_CB] = data->ar_coeffs_uv[0],
+ [PL_CHANNEL_CR] = data->ar_coeffs_uv[1],
+ };
+
+ for (int y = 0; y < chromaH; y++) {
+ for (int x = 0; x < chromaW; x++) {
+ int16_t value = gaussian_sequence[ get_random_number(11, &seed) ];
+ buf[y][x] = round2(value, shift);
+ }
+ }
+
+ const int ar_pad = 3;
+ int ar_lag = data->ar_coeff_lag;
+
+ for (int y = ar_pad; y < chromaH; y++) {
+ for (int x = ar_pad; x < chromaW - ar_pad; x++) {
+ const int8_t *coeff = coeffs[channel];
+ pl_assert(coeff);
+ int sum = 0;
+ for (int dy = -ar_lag; dy <= 0; dy++) {
+ for (int dx = -ar_lag; dx <= ar_lag; dx++) {
+ // For the final (current) pixel, we need to add in the
+ // contribution from the luma grain texture
+ if (!dx && !dy) {
+ if (!data->num_points_y)
+ break;
+ int luma = 0;
+ int lumaX = ((x - ar_pad) << sub_x) + ar_pad;
+ int lumaY = ((y - ar_pad) << sub_y) + ar_pad;
+ for (int i = 0; i <= sub_y; i++) {
+ for (int j = 0; j <= sub_x; j++) {
+ luma += buf_y[lumaY + i][lumaX + j];
+ }
+ }
+ luma = round2(luma, sub_x + sub_y);
+ sum += luma * (*coeff);
+ break;
+ }
+
+ sum += *(coeff++) * buf[y + dy][x + dx];
+ }
+ }
+
+ int16_t grain = buf[y][x] + round2(sum, data->ar_coeff_shift);
+ grain = PL_CLAMP(grain, scale.grain_min, scale.grain_max);
+ buf[y][x] = grain;
+ }
+ }
+
+ int lutW = GRAIN_WIDTH_LUT >> sub_x;
+ int lutH = GRAIN_HEIGHT_LUT >> sub_y;
+ int padX = sub_x ? SUB_GRAIN_PAD_LUT : GRAIN_PAD_LUT;
+ int padY = sub_y ? SUB_GRAIN_PAD_LUT : GRAIN_PAD_LUT;
+
+ for (int y = 0; y < lutH; y++) {
+ for (int x = 0; x < lutW; x++) {
+ int16_t grain = buf[y + padY][x + padX];
+ out[y * lutW + x] = grain * scale.grain_scale;
+ }
+ }
+}
+
+static void generate_offsets(void *pbuf, const struct sh_lut_params *params)
+{
+ const struct pl_film_grain_data *data = params->priv;
+ unsigned int *buf = pbuf;
+ pl_static_assert(sizeof(unsigned int) >= sizeof(uint32_t));
+
+ for (int y = 0; y < params->height; y++) {
+ uint16_t state = data->seed;
+ state ^= ((y * 37 + 178) & 0xFF) << 8;
+ state ^= ((y * 173 + 105) & 0xFF);
+
+ for (int x = 0; x < params->width; x++) {
+ unsigned int *offsets = &buf[y * params->width + x];
+
+ uint8_t val = get_random_number(8, &state);
+ uint8_t val_l = x ? (offsets - 1)[0] : 0;
+ uint8_t val_t = y ? (offsets - params->width)[0] : 0;
+ uint8_t val_tl = x && y ? (offsets - params->width - 1)[0] : 0;
+
+ // Encode four offsets into a single 32-bit integer for the
+ // convenience of the GPU. That way only one LUT fetch is
+ // required for the entire block.
+ *offsets = ((uint32_t) val_tl << OFFSET_TL)
+ | ((uint32_t) val_t << OFFSET_T)
+ | ((uint32_t) val_l << OFFSET_L)
+ | ((uint32_t) val << OFFSET_N);
+ }
+ }
+}
+
+static void generate_scaling(void *pdata, const struct sh_lut_params *params)
+{
+ assert(params->width == SCALING_LUT_SIZE && params->comps == 1);
+ float *data = pdata;
+
+ struct {
+ int num;
+ uint8_t (*points)[2];
+ const struct pl_av1_grain_data *data;
+ } *ctx = params->priv;
+
+ float range = 1 << ctx->data->scaling_shift;
+
+ // Fill up the preceding entries with the initial value
+ for (int i = 0; i < ctx->points[0][0]; i++)
+ data[i] = ctx->points[0][1] / range;
+
+ // Linearly interpolate the values in the middle
+ for (int i = 0; i < ctx->num - 1; i++) {
+ int bx = ctx->points[i][0];
+ int by = ctx->points[i][1];
+ int dx = ctx->points[i + 1][0] - bx;
+ int dy = ctx->points[i + 1][1] - by;
+ int delta = dy * ((0x10000 + (dx >> 1)) / dx);
+ for (int x = 0; x < dx; x++) {
+ int v = by + ((x * delta + 0x8000) >> 16);
+ data[bx + x] = v / range;
+ }
+ }
+
+ // Fill up the remaining entries with the final value
+ for (int i = ctx->points[ctx->num - 1][0]; i < SCALING_LUT_SIZE; i++)
+ data[i] = ctx->points[ctx->num - 1][1] / range;
+}
+
+static void sample(pl_shader sh, enum offset off, ident_t lut, int idx,
+ int sub_x, int sub_y)
+{
+ int dx = (off & OFFSET_L) ? 1 : 0,
+ dy = (off & OFFSET_T) ? 1 : 0;
+
+ static const char *index_strs[] = {
+ [0] = ".x",
+ [1] = ".y",
+ };
+
+ GLSL("offset = uvec2(%du, %du) * uvec2((data >> %d) & 0xFu, \n"
+ " (data >> %d) & 0xFu);\n"
+ "pos = offset + local_id.xy + uvec2(%d, %d); \n"
+ "val = "$"(pos)%s; \n",
+ sub_x ? 1 : 2, sub_y ? 1 : 2, off + 4, off,
+ (BLOCK_SIZE >> sub_x) * dx,
+ (BLOCK_SIZE >> sub_y) * dy,
+ lut, idx >= 0 ? index_strs[idx] : "");
+}
+
+struct grain_obj_av1 {
+ // LUT objects for the offsets, grain and scaling luts
+ pl_shader_obj lut_offsets;
+ pl_shader_obj lut_grain[2];
+ pl_shader_obj lut_scaling[3];
+
+ // Previous parameters used to check reusability
+ struct pl_film_grain_data data;
+ struct pl_color_repr repr;
+ bool fg_has_y;
+ bool fg_has_u;
+ bool fg_has_v;
+
+ // Space to store the temporary arrays, reused
+ uint32_t *offsets;
+ float grain[2][GRAIN_HEIGHT_LUT][GRAIN_WIDTH_LUT];
+ int16_t grain_tmp_y[GRAIN_HEIGHT][GRAIN_WIDTH];
+ int16_t grain_tmp_uv[GRAIN_HEIGHT][GRAIN_WIDTH];
+};
+
+static void av1_grain_uninit(pl_gpu gpu, void *ptr)
+{
+ struct grain_obj_av1 *obj = ptr;
+ pl_shader_obj_destroy(&obj->lut_offsets);
+ for (int i = 0; i < PL_ARRAY_SIZE(obj->lut_grain); i++)
+ pl_shader_obj_destroy(&obj->lut_grain[i]);
+ for (int i = 0; i < PL_ARRAY_SIZE(obj->lut_scaling); i++)
+ pl_shader_obj_destroy(&obj->lut_scaling[i]);
+ *obj = (struct grain_obj_av1) {0};
+}
+
+bool pl_needs_fg_av1(const struct pl_film_grain_params *params)
+{
+ const struct pl_av1_grain_data *data = &params->data.params.av1;
+ bool has_y = data->num_points_y > 0;
+ bool has_u = data->num_points_uv[0] > 0 || data->chroma_scaling_from_luma;
+ bool has_v = data->num_points_uv[1] > 0 || data->chroma_scaling_from_luma;
+
+ for (int i = 0; i < 3; i++) {
+ enum pl_channel channel = channel_map(i, params);
+ if (channel == PL_CHANNEL_Y && has_y)
+ return true;
+ if (channel == PL_CHANNEL_CB && has_u)
+ return true;
+ if (channel == PL_CHANNEL_CR && has_v)
+ return true;
+ }
+
+ return false;
+}
+
+static inline bool av1_grain_data_eq(const struct pl_film_grain_data *da,
+ const struct pl_film_grain_data *db)
+{
+ const struct pl_av1_grain_data *a = &da->params.av1, *b = &db->params.av1;
+
+ // Only check the fields that are relevant for grain LUT generation
+ return da->seed == db->seed &&
+ a->chroma_scaling_from_luma == b->chroma_scaling_from_luma &&
+ a->scaling_shift == b->scaling_shift &&
+ a->ar_coeff_lag == b->ar_coeff_lag &&
+ a->ar_coeff_shift == b->ar_coeff_shift &&
+ a->grain_scale_shift == b->grain_scale_shift &&
+ !memcmp(a->ar_coeffs_y, b->ar_coeffs_y, sizeof(a->ar_coeffs_y)) &&
+ !memcmp(a->ar_coeffs_uv, b->ar_coeffs_uv, sizeof(a->ar_coeffs_uv));
+}
+
+static void fill_grain_lut(void *data, const struct sh_lut_params *params)
+{
+ struct grain_obj_av1 *obj = params->priv;
+ size_t entries = params->width * params->height * params->comps;
+ memcpy(data, obj->grain, entries * sizeof(float));
+}
+
+bool pl_shader_fg_av1(pl_shader sh, pl_shader_obj *grain_state,
+ const struct pl_film_grain_params *params)
+{
+ int sub_x = 0, sub_y = 0;
+ int tex_w = params->tex->params.w,
+ tex_h = params->tex->params.h;
+
+ if (params->luma_tex) {
+ sub_x = params->luma_tex->params.w > tex_w;
+ sub_y = params->luma_tex->params.h > tex_h;
+ }
+
+ const struct pl_av1_grain_data *data = &params->data.params.av1;
+ bool fg_has_y = data->num_points_y > 0;
+ bool fg_has_u = data->num_points_uv[0] > 0 || data->chroma_scaling_from_luma;
+ bool fg_has_v = data->num_points_uv[1] > 0 || data->chroma_scaling_from_luma;
+
+ bool tex_is_y = false, tex_is_cb = false, tex_is_cr = false;
+ for (int i = 0; i < 3; i++) {
+ switch (channel_map(i, params)) {
+ case PL_CHANNEL_Y: tex_is_y = true; break;
+ case PL_CHANNEL_CB: tex_is_cb = true; break;
+ case PL_CHANNEL_CR: tex_is_cr = true; break;
+ default: break;
+ };
+ }
+
+ if (tex_is_y && (sub_x || sub_y)) {
+ PL_WARN(sh, "pl_film_grain_params.channels includes PL_CHANNEL_Y but "
+ "plane is subsampled, this makes no sense. Continuing anyway "
+ "but output is likely incorrect.");
+ }
+
+ if (!sh_require(sh, PL_SHADER_SIG_NONE, tex_w, tex_h))
+ return false;
+
+ pl_gpu gpu = SH_GPU(sh);
+ if (!gpu) {
+ PL_ERR(sh, "AV1 film grain synthesis requires a non-NULL pl_gpu!");
+ return false;
+ }
+
+ // Disable generation for unneeded component types
+ fg_has_y &= tex_is_y;
+ fg_has_u &= tex_is_cb;
+ fg_has_v &= tex_is_cr;
+
+ int bw = BLOCK_SIZE >> sub_x;
+ int bh = BLOCK_SIZE >> sub_y;
+ bool is_compute = sh_try_compute(sh, bw, bh, false, sizeof(uint32_t));
+
+ struct grain_obj_av1 *obj;
+ obj = SH_OBJ(sh, grain_state, PL_SHADER_OBJ_AV1_GRAIN,
+ struct grain_obj_av1, av1_grain_uninit);
+ if (!obj)
+ return false;
+
+ // Note: In theory we could check only the parameters related to luma or
+ // only related to chroma and skip updating for changes to irrelevant
+ // parts, but this is probably not worth it since the seed is expected to
+ // change per frame anyway.
+ bool needs_update = !av1_grain_data_eq(&params->data, &obj->data) ||
+ !pl_color_repr_equal(params->repr, &obj->repr) ||
+ fg_has_y != obj->fg_has_y ||
+ fg_has_u != obj->fg_has_u ||
+ fg_has_v != obj->fg_has_v;
+
+ if (needs_update) {
+ // This is needed even for chroma, so statically generate it
+ generate_grain_y(obj->grain[0], obj->grain_tmp_y, params);
+ }
+
+ ident_t lut[3];
+ int idx[3] = {-1};
+
+ if (fg_has_y) {
+ lut[0] = sh_lut(sh, sh_lut_params(
+ .object = &obj->lut_grain[0],
+ .var_type = PL_VAR_FLOAT,
+ .lut_type = SH_LUT_TEXTURE,
+ .width = GRAIN_WIDTH_LUT,
+ .height = GRAIN_HEIGHT_LUT,
+ .comps = 1,
+ .update = needs_update,
+ .dynamic = true,
+ .fill = fill_grain_lut,
+ .priv = obj,
+ ));
+
+ if (!lut[0]) {
+ SH_FAIL(sh, "Failed generating/uploading luma grain LUT!");
+ return false;
+ }
+ }
+
+ // Try merging the chroma LUTs into a single texture
+ int chroma_comps = 0;
+ if (fg_has_u) {
+ generate_grain_uv(&obj->grain[chroma_comps][0][0], obj->grain_tmp_uv,
+ obj->grain_tmp_y, PL_CHANNEL_CB, sub_x, sub_y,
+ params);
+ idx[1] = chroma_comps++;
+ }
+ if (fg_has_v) {
+ generate_grain_uv(&obj->grain[chroma_comps][0][0], obj->grain_tmp_uv,
+ obj->grain_tmp_y, PL_CHANNEL_CR, sub_x, sub_y,
+ params);
+ idx[2] = chroma_comps++;
+ }
+
+ if (chroma_comps > 0) {
+ lut[1] = lut[2] = sh_lut(sh, sh_lut_params(
+ .object = &obj->lut_grain[1],
+ .var_type = PL_VAR_FLOAT,
+ .lut_type = SH_LUT_TEXTURE,
+ .width = GRAIN_WIDTH_LUT >> sub_x,
+ .height = GRAIN_HEIGHT_LUT >> sub_y,
+ .comps = chroma_comps,
+ .update = needs_update,
+ .dynamic = true,
+ .fill = fill_grain_lut,
+ .priv = obj,
+ ));
+
+ if (!lut[1]) {
+ SH_FAIL(sh, "Failed generating/uploading chroma grain LUT!");
+ return false;
+ }
+
+ if (chroma_comps == 1)
+ idx[1] = idx[2] = -1;
+ }
+
+ ident_t offsets = sh_lut(sh, sh_lut_params(
+ .object = &obj->lut_offsets,
+ .var_type = PL_VAR_UINT,
+ .lut_type = SH_LUT_AUTO,
+ .width = PL_ALIGN2(tex_w << sub_x, 128) / 32,
+ .height = PL_ALIGN2(tex_h << sub_y, 128) / 32,
+ .comps = 1,
+ .update = needs_update,
+ .dynamic = true,
+ .fill = generate_offsets,
+ .priv = (void *) &params->data,
+ ));
+
+ if (!offsets) {
+ SH_FAIL(sh, "Failed generating/uploading block offsets LUT!");
+ return false;
+ }
+
+ // For the scaling LUTs, we assume they'll be relatively constant
+ // throughout the video so doing some extra work to avoid reinitializing
+ // them constantly is probably worth it. Probably.
+ const struct pl_av1_grain_data *obj_data = &obj->data.params.av1;
+ bool scaling_changed = false;
+ if (fg_has_y || data->chroma_scaling_from_luma) {
+ scaling_changed |= data->num_points_y != obj_data->num_points_y;
+ scaling_changed |= memcmp(data->points_y, obj_data->points_y,
+ sizeof(data->points_y));
+ }
+
+ if (fg_has_u && !data->chroma_scaling_from_luma) {
+ scaling_changed |= data->num_points_uv[0] != obj_data->num_points_uv[0];
+ scaling_changed |= memcmp(data->points_uv[0],
+ obj_data->points_uv[0],
+ sizeof(data->points_uv[0]));
+ }
+
+ if (fg_has_v && !data->chroma_scaling_from_luma) {
+ scaling_changed |= data->num_points_uv[1] != obj_data->num_points_uv[1];
+ scaling_changed |= memcmp(data->points_uv[1],
+ obj_data->points_uv[1],
+ sizeof(data->points_uv[1]));
+ }
+
+ ident_t scaling[3] = {0};
+ for (int i = 0; i < 3; i++) {
+ struct {
+ int num;
+ const uint8_t (*points)[2];
+ const struct pl_av1_grain_data *data;
+ } priv;
+
+ priv.data = data;
+ if (i == 0 || data->chroma_scaling_from_luma) {
+ priv.num = data->num_points_y;
+ priv.points = &data->points_y[0];
+ } else {
+ priv.num = data->num_points_uv[i - 1];
+ priv.points = &data->points_uv[i - 1][0];
+ }
+
+ // Skip scaling for unneeded channels
+ bool has_c[3] = { fg_has_y, fg_has_u, fg_has_v };
+ if (has_c[i] && priv.num > 0) {
+ scaling[i] = sh_lut(sh, sh_lut_params(
+ .object = &obj->lut_scaling[i],
+ .var_type = PL_VAR_FLOAT,
+ .method = SH_LUT_LINEAR,
+ .width = SCALING_LUT_SIZE,
+ .comps = 1,
+ .update = scaling_changed,
+ .dynamic = true,
+ .fill = generate_scaling,
+ .priv = &priv,
+ ));
+
+ if (!scaling[i]) {
+ SH_FAIL(sh, "Failed generating/uploading scaling LUTs!");
+ return false;
+ }
+ }
+ }
+
+ // Done updating LUTs
+ obj->data = params->data;
+ obj->repr = *params->repr;
+ obj->fg_has_y = fg_has_y;
+ obj->fg_has_u = fg_has_u;
+ obj->fg_has_v = fg_has_v;
+
+ sh_describe(sh, "AV1 film grain");
+ GLSL("vec4 color; \n"
+ "// pl_shader_film_grain (AV1) \n"
+ "{ \n"
+ "uvec2 offset; \n"
+ "uvec2 pos; \n"
+ "float val; \n"
+ "float grain; \n");
+
+ if (is_compute) {
+ GLSL("uvec2 block_id = gl_WorkGroupID.xy; \n"
+ "uvec2 local_id = gl_LocalInvocationID.xy; \n"
+ "uvec2 global_id = gl_GlobalInvocationID.xy; \n");
+ } else {
+ GLSL("uvec2 global_id = uvec2(gl_FragCoord); \n"
+ "uvec2 block_id = global_id / uvec2(%d, %d); \n"
+ "uvec2 local_id = global_id - uvec2(%d, %d) * block_id; \n",
+ bw, bh, bw, bh);
+ }
+
+ // Load the data vector which holds the offsets
+ if (is_compute) {
+ ident_t id = sh_fresh(sh, "data");
+ GLSLH("shared uint "$"; \n", id);
+ GLSL("if (gl_LocalInvocationIndex == 0u) \n"
+ " "$" = uint("$"(block_id)); \n"
+ "barrier(); \n"
+ "uint data = "$"; \n",
+ id, offsets, id);
+ } else {
+ GLSL("uint data = uint("$"(block_id)); \n", offsets);
+ }
+
+ struct grain_scale scale = get_grain_scale(params);
+ pl_color_repr_normalize(params->repr);
+ int bits = PL_DEF(params->repr->bits.color_depth, 8);
+ pl_assert(bits >= 8);
+
+ ident_t minValue, maxLuma, maxChroma;
+ if (pl_color_levels_guess(params->repr) == PL_COLOR_LEVELS_LIMITED) {
+ float out_scale = (1 << bits) / ((1 << bits) - 1.0);
+ minValue = SH_FLOAT(16 / 256.0 * out_scale);
+ maxLuma = SH_FLOAT(235 / 256.0 * out_scale);
+ maxChroma = SH_FLOAT(240 / 256.0 * out_scale);
+ if (!pl_color_system_is_ycbcr_like(params->repr->sys))
+ maxChroma = maxLuma;
+ } else {
+ minValue = SH_FLOAT(0.0);
+ maxLuma = SH_FLOAT(1.0);
+ maxChroma = SH_FLOAT(1.0);
+ }
+
+ // Load the color value of the tex itself
+ ident_t tex = sh_desc(sh, (struct pl_shader_desc) {
+ .binding.object = params->tex,
+ .desc = (struct pl_desc) {
+ .name = "tex",
+ .type = PL_DESC_SAMPLED_TEX,
+ },
+ });
+
+ ident_t tex_scale = SH_FLOAT(scale.texture_scale);
+ GLSL("color = vec4("$") * texelFetch("$", ivec2(global_id), 0); \n",
+ tex_scale, tex);
+
+ // If we need access to the external luma plane, load it now
+ if (tex_is_cb || tex_is_cr) {
+ GLSL("float averageLuma; \n");
+ if (tex_is_y) {
+ // We already have the luma channel as part of the pre-sampled color
+ for (int i = 0; i < 3; i++) {
+ if (channel_map(i, params) == PL_CHANNEL_Y) {
+ GLSL("averageLuma = color["$"]; \n", SH_INT(i));
+ break;
+ }
+ }
+ } else {
+ // Luma channel not present in image, attach it separately
+ pl_assert(params->luma_tex);
+ ident_t luma = sh_desc(sh, (struct pl_shader_desc) {
+ .binding.object = params->luma_tex,
+ .desc = (struct pl_desc) {
+ .name = "luma",
+ .type = PL_DESC_SAMPLED_TEX,
+ },
+ });
+
+ GLSL("pos = global_id * uvec2(%du, %du); \n"
+ "averageLuma = texelFetch("$", ivec2(pos), 0)["$"]; \n"
+ "averageLuma *= "$"; \n",
+ 1 << sub_x, 1 << sub_y,
+ luma, SH_INT(params->luma_comp),
+ tex_scale);
+ }
+ }
+
+ ident_t grain_min = SH_FLOAT(scale.grain_min * scale.grain_scale);
+ ident_t grain_max = SH_FLOAT(scale.grain_max * scale.grain_scale);
+
+ for (int i = 0; i < params->components; i++) {
+ enum pl_channel c = channel_map(i, params);
+ if (c == PL_CHANNEL_NONE)
+ continue;
+ if (!scaling[c])
+ continue;
+
+ sample(sh, OFFSET_N, lut[c], idx[c], sub_x, sub_y);
+ GLSL("grain = val; \n");
+
+ if (data->overlap) {
+ const char *weights[] = { "vec2(27.0, 17.0)", "vec2(23.0, 22.0)" };
+
+ // X-direction overlapping
+ GLSL("if (block_id.x > 0u && local_id.x < %du) { \n"
+ "vec2 w = %s / 32.0; \n"
+ "if (local_id.x == 1u) w.xy = w.yx; \n",
+ 2 >> sub_x, weights[sub_x]);
+ sample(sh, OFFSET_L, lut[c], idx[c], sub_x, sub_y);
+ GLSL("grain = dot(vec2(val, grain), w); \n"
+ "} \n");
+
+ // Y-direction overlapping
+ GLSL("if (block_id.y > 0u && local_id.y < %du) { \n"
+ "vec2 w = %s / 32.0; \n"
+ "if (local_id.y == 1u) w.xy = w.yx; \n",
+ 2 >> sub_y, weights[sub_y]);
+
+ // We need to special-case the top left pixels since these need to
+ // pre-blend the top-left offset block before blending vertically
+ GLSL(" if (block_id.x > 0u && local_id.x < %du) {\n"
+ " vec2 w2 = %s / 32.0; \n"
+ " if (local_id.x == 1u) w2.xy = w2.yx; \n",
+ 2 >> sub_x, weights[sub_x]);
+ sample(sh, OFFSET_TL, lut[c], idx[c], sub_x, sub_y);
+ GLSL(" float tmp = val; \n");
+ sample(sh, OFFSET_T, lut[c], idx[c], sub_x, sub_y);
+ GLSL(" val = dot(vec2(tmp, val), w2); \n"
+ " } else { \n");
+ sample(sh, OFFSET_T, lut[c], idx[c], sub_x, sub_y);
+ GLSL(" } \n"
+ "grain = dot(vec2(val, grain), w); \n"
+ "} \n");
+
+ // Correctly clip the interpolated grain
+ GLSL("grain = clamp(grain, "$", "$"); \n", grain_min, grain_max);
+ }
+
+ if (c == PL_CHANNEL_Y) {
+ GLSL("color[%d] += "$"(color[%d]) * grain; \n"
+ "color[%d] = clamp(color[%d], "$", "$"); \n",
+ i, scaling[c], i,
+ i, i, minValue, maxLuma);
+ } else {
+ GLSL("val = averageLuma; \n");
+ if (!data->chroma_scaling_from_luma) {
+ // We need to load some extra variables for the mixing. Do this
+ // using sh_var instead of hard-coding them to avoid shader
+ // recompilation when these values change.
+ ident_t mult = sh_var(sh, (struct pl_shader_var) {
+ .var = pl_var_vec2("mult"),
+ .data = &(float[2]){
+ data->uv_mult_luma[c - 1] / 64.0,
+ data->uv_mult[c - 1] / 64.0,
+ },
+ });
+
+ int c_offset = (unsigned) data->uv_offset[c - 1] << (bits - 8);
+ ident_t offset = sh_var(sh, (struct pl_shader_var) {
+ .var = pl_var_float("offset"),
+ .data = &(float) { c_offset * scale.grain_scale },
+ });
+
+ GLSL("val = dot(vec2(val, color[%d]), "$"); \n"
+ "val += "$"; \n",
+ i, mult, offset);
+ }
+ GLSL("color[%d] += "$"(val) * grain; \n"
+ "color[%d] = clamp(color[%d], "$", "$"); \n",
+ i, scaling[c],
+ i, i, minValue, maxChroma);
+ }
+ }
+
+ GLSL("} \n");
+ return true;
+}