zenwebp 0.4.5

//! VP8 encoding tables and constants.
//!
//! This module contains the large lookup tables used for VP8 encoding,
//! including entropy costs, quantizer tables, and mode costs.

// Allow unused items - these tables are part of the complete libwebp
// cost estimation system and will be used as additional features are implemented.
#![allow(dead_code)]

//------------------------------------------------------------------------------
// Entropy cost table
//
// VP8EntropyCost[i] = -log2(i/255) * 256, scaled for integer arithmetic.
// This gives the bit cost for coding a boolean with probability i/255.

/// Entropy cost lookup table: cost = -log2(prob) * 256
/// Index is probability (0-255), value is cost in 1/256 bits.
pub const VP8_ENTROPY_COST: [u16; 256] = [
    1792, 1792, 1792, 1536, 1536, 1408, 1366, 1280, 1280, 1216, 1178, 1152, 1110, 1076, 1061, 1024,
    1024, 992, 968, 951, 939, 911, 896, 878, 871, 854, 838, 820, 811, 794, 786, 768, 768, 752, 740,
    732, 720, 709, 704, 690, 683, 672, 666, 655, 647, 640, 631, 622, 615, 607, 598, 592, 586, 576,
    572, 564, 559, 555, 547, 541, 534, 528, 522, 512, 512, 504, 500, 494, 488, 483, 477, 473, 467,
    461, 458, 452, 448, 443, 438, 434, 427, 424, 419, 415, 410, 406, 403, 399, 394, 390, 384, 384,
    377, 374, 370, 366, 362, 359, 355, 351, 347, 342, 342, 336, 333, 330, 326, 323, 320, 316, 312,
    308, 305, 302, 299, 296, 293, 288, 287, 283, 280, 277, 274, 272, 268, 266, 262, 256, 256, 256,
    251, 248, 245, 242, 240, 237, 234, 232, 228, 226, 223, 221, 218, 216, 214, 211, 208, 205, 203,
    201, 198, 196, 192, 191, 188, 187, 183, 181, 179, 176, 175, 171, 171, 168, 165, 163, 160, 159,
    156, 154, 152, 150, 148, 146, 144, 142, 139, 138, 135, 133, 131, 128, 128, 125, 123, 121, 119,
    117, 115, 113, 111, 110, 107, 105, 103, 102, 100, 98, 96, 94, 92, 91, 89, 86, 86, 83, 82, 80,
    77, 76, 74, 73, 71, 69, 67, 66, 64, 63, 61, 59, 57, 55, 54, 52, 51, 49, 47, 46, 44, 43, 41, 40,
    38, 36, 35, 33, 32, 30, 29, 27, 25, 24, 22, 21, 19, 18, 16, 15, 13, 12, 10, 9, 7, 6, 4, 3,
];

//------------------------------------------------------------------------------
// Level cost table
//
// Fixed costs for encoding coefficient levels, independent of probability state.

/// Maximum coefficient level
pub const MAX_LEVEL: usize = 2047;

/// Maximum variable level in the coding tree
pub const MAX_VARIABLE_LEVEL: usize = 67;

/// Fixed costs for coefficient levels 0..=2047
/// These costs are probability-independent and come from the VP8 coding tree structure.
#[rustfmt::skip]
pub const VP8_LEVEL_FIXED_COSTS: [u16; MAX_LEVEL + 1] = [
    0,    256,  256,  256,  256,  432,  618,  630,  731,  640,  640,  828,
    901,  948,  1021, 1101, 1174, 1221, 1294, 1042, 1085, 1115, 1158, 1202,
    1245, 1275, 1318, 1337, 1380, 1410, 1453, 1497, 1540, 1570, 1613, 1280,
    1295, 1317, 1332, 1358, 1373, 1395, 1410, 1454, 1469, 1491, 1506, 1532,
    1547, 1569, 1584, 1601, 1616, 1638, 1653, 1679, 1694, 1716, 1731, 1775,
    1790, 1812, 1827, 1853, 1868, 1890, 1905, 1727, 1733, 1742, 1748, 1759,
    1765, 1774, 1780, 1800, 1806, 1815, 1821, 1832, 1838, 1847, 1853, 1878,
    1884, 1893, 1899, 1910, 1916, 1925, 1931, 1951, 1957, 1966, 1972, 1983,
    1989, 1998, 2004, 2027, 2033, 2042, 2048, 2059, 2065, 2074, 2080, 2100,
    2106, 2115, 2121, 2132, 2138, 2147, 2153, 2178, 2184, 2193, 2199, 2210,
    2216, 2225, 2231, 2251, 2257, 2266, 2272, 2283, 2289, 2298, 2304, 2168,
    2174, 2183, 2189, 2200, 2206, 2215, 2221, 2241, 2247, 2256, 2262, 2273,
    2279, 2288, 2294, 2319, 2325, 2334, 2340, 2351, 2357, 2366, 2372, 2392,
    2398, 2407, 2413, 2424, 2430, 2439, 2445, 2468, 2474, 2483, 2489, 2500,
    2506, 2515, 2521, 2541, 2547, 2556, 2562, 2573, 2579, 2588, 2594, 2619,
    2625, 2634, 2640, 2651, 2657, 2666, 2672, 2692, 2698, 2707, 2713, 2724,
    2730, 2739, 2745, 2540, 2546, 2555, 2561, 2572, 2578, 2587, 2593, 2613,
    2619, 2628, 2634, 2645, 2651, 2660, 2666, 2691, 2697, 2706, 2712, 2723,
    2729, 2738, 2744, 2764, 2770, 2779, 2785, 2796, 2802, 2811, 2817, 2840,
    2846, 2855, 2861, 2872, 2878, 2887, 2893, 2913, 2919, 2928, 2934, 2945,
    2951, 2960, 2966, 2991, 2997, 3006, 3012, 3023, 3029, 3038, 3044, 3064,
    3070, 3079, 3085, 3096, 3102, 3111, 3117, 2981, 2987, 2996, 3002, 3013,
    3019, 3028, 3034, 3054, 3060, 3069, 3075, 3086, 3092, 3101, 3107, 3132,
    3138, 3147, 3153, 3164, 3170, 3179, 3185, 3205, 3211, 3220, 3226, 3237,
    3243, 3252, 3258, 3281, 3287, 3296, 3302, 3313, 3319, 3328, 3334, 3354,
    3360, 3369, 3375, 3386, 3392, 3401, 3407, 3432, 3438, 3447, 3453, 3464,
    3470, 3479, 3485, 3505, 3511, 3520, 3526, 3537, 3543, 3552, 3558, 2816,
    2822, 2831, 2837, 2848, 2854, 2863, 2869, 2889, 2895, 2904, 2910, 2921,
    2927, 2936, 2942, 2967, 2973, 2982, 2988, 2999, 3005, 3014, 3020, 3040,
    3046, 3055, 3061, 3072, 3078, 3087, 3093, 3116, 3122, 3131, 3137, 3148,
    3154, 3163, 3169, 3189, 3195, 3204, 3210, 3221, 3227, 3236, 3242, 3267,
    3273, 3282, 3288, 3299, 3305, 3314, 3320, 3340, 3346, 3355, 3361, 3372,
    3378, 3387, 3393, 3257, 3263, 3272, 3278, 3289, 3295, 3304, 3310, 3330,
    3336, 3345, 3351, 3362, 3368, 3377, 3383, 3408, 3414, 3423, 3429, 3440,
    3446, 3455, 3461, 3481, 3487, 3496, 3502, 3513, 3519, 3528, 3534, 3557,
    3563, 3572, 3578, 3589, 3595, 3604, 3610, 3630, 3636, 3645, 3651, 3662,
    3668, 3677, 3683, 3708, 3714, 3723, 3729, 3740, 3746, 3755, 3761, 3781,
    3787, 3796, 3802, 3813, 3819, 3828, 3834, 3629, 3635, 3644, 3650, 3661,
    3667, 3676, 3682, 3702, 3708, 3717, 3723, 3734, 3740, 3749, 3755, 3780,
    3786, 3795, 3801, 3812, 3818, 3827, 3833, 3853, 3859, 3868, 3874, 3885,
    3891, 3900, 3906, 3929, 3935, 3944, 3950, 3961, 3967, 3976, 3982, 4002,
    4008, 4017, 4023, 4034, 4040, 4049, 4055, 4080, 4086, 4095, 4101, 4112,
    4118, 4127, 4133, 4153, 4159, 4168, 4174, 4185, 4191, 4200, 4206, 4070,
    4076, 4085, 4091, 4102, 4108, 4117, 4123, 4143, 4149, 4158, 4164, 4175,
    4181, 4190, 4196, 4221, 4227, 4236, 4242, 4253, 4259, 4268, 4274, 4294,
    4300, 4309, 4315, 4326, 4332, 4341, 4347, 4370, 4376, 4385, 4391, 4402,
    4408, 4417, 4423, 4443, 4449, 4458, 4464, 4475, 4481, 4490, 4496, 4521,
    4527, 4536, 4542, 4553, 4559, 4568, 4574, 4594, 4600, 4609, 4615, 4626,
    4632, 4641, 4647, 3515, 3521, 3530, 3536, 3547, 3553, 3562, 3568, 3588,
    3594, 3603, 3609, 3620, 3626, 3635, 3641, 3666, 3672, 3681, 3687, 3698,
    3704, 3713, 3719, 3739, 3745, 3754, 3760, 3771, 3777, 3786, 3792, 3815,
    3821, 3830, 3836, 3847, 3853, 3862, 3868, 3888, 3894, 3903, 3909, 3920,
    3926, 3935, 3941, 3966, 3972, 3981, 3987, 3998, 4004, 4013, 4019, 4039,
    4045, 4054, 4060, 4071, 4077, 4086, 4092, 3956, 3962, 3971, 3977, 3988,
    3994, 4003, 4009, 4029, 4035, 4044, 4050, 4061, 4067, 4076, 4082, 4107,
    4113, 4122, 4128, 4139, 4145, 4154, 4160, 4180, 4186, 4195, 4201, 4212,
    4218, 4227, 4233, 4256, 4262, 4271, 4277, 4288, 4294, 4303, 4309, 4329,
    4335, 4344, 4350, 4361, 4367, 4376, 4382, 4407, 4413, 4422, 4428, 4439,
    4445, 4454, 4460, 4480, 4486, 4495, 4501, 4512, 4518, 4527, 4533, 4328,
    4334, 4343, 4349, 4360, 4366, 4375, 4381, 4401, 4407, 4416, 4422, 4433,
    4439, 4448, 4454, 4479, 4485, 4494, 4500, 4511, 4517, 4526, 4532, 4552,
    4558, 4567, 4573, 4584, 4590, 4599, 4605, 4628, 4634, 4643, 4649, 4660,
    4666, 4675, 4681, 4701, 4707, 4716, 4722, 4733, 4739, 4748, 4754, 4779,
    4785, 4794, 4800, 4811, 4817, 4826, 4832, 4852, 4858, 4867, 4873, 4884,
    4890, 4899, 4905, 4769, 4775, 4784, 4790, 4801, 4807, 4816, 4822, 4842,
    4848, 4857, 4863, 4874, 4880, 4889, 4895, 4920, 4926, 4935, 4941, 4952,
    4958, 4967, 4973, 4993, 4999, 5008, 5014, 5025, 5031, 5040, 5046, 5069,
    5075, 5084, 5090, 5101, 5107, 5116, 5122, 5142, 5148, 5157, 5163, 5174,
    5180, 5189, 5195, 5220, 5226, 5235, 5241, 5252, 5258, 5267, 5273, 5293,
    5299, 5308, 5314, 5325, 5331, 5340, 5346, 4604, 4610, 4619, 4625, 4636,
    4642, 4651, 4657, 4677, 4683, 4692, 4698, 4709, 4715, 4724, 4730, 4755,
    4761, 4770, 4776, 4787, 4793, 4802, 4808, 4828, 4834, 4843, 4849, 4860,
    4866, 4875, 4881, 4904, 4910, 4919, 4925, 4936, 4942, 4951, 4957, 4977,
    4983, 4992, 4998, 5009, 5015, 5024, 5030, 5055, 5061, 5070, 5076, 5087,
    5093, 5102, 5108, 5128, 5134, 5143, 5149, 5160, 5166, 5175, 5181, 5045,
    5051, 5060, 5066, 5077, 5083, 5092, 5098, 5118, 5124, 5133, 5139, 5150,
    5156, 5165, 5171, 5196, 5202, 5211, 5217, 5228, 5234, 5243, 5249, 5269,
    5275, 5284, 5290, 5301, 5307, 5316, 5322, 5345, 5351, 5360, 5366, 5377,
    5383, 5392, 5398, 5418, 5424, 5433, 5439, 5450, 5456, 5465, 5471, 5496,
    5502, 5511, 5517, 5528, 5534, 5543, 5549, 5569, 5575, 5584, 5590, 5601,
    5607, 5616, 5622, 5417, 5423, 5432, 5438, 5449, 5455, 5464, 5470, 5490,
    5496, 5505, 5511, 5522, 5528, 5537, 5543, 5568, 5574, 5583, 5589, 5600,
    5606, 5615, 5621, 5641, 5647, 5656, 5662, 5673, 5679, 5688, 5694, 5717,
    5723, 5732, 5738, 5749, 5755, 5764, 5770, 5790, 5796, 5805, 5811, 5822,
    5828, 5837, 5843, 5868, 5874, 5883, 5889, 5900, 5906, 5915, 5921, 5941,
    5947, 5956, 5962, 5973, 5979, 5988, 5994, 5858, 5864, 5873, 5879, 5890,
    5896, 5905, 5911, 5931, 5937, 5946, 5952, 5963, 5969, 5978, 5984, 6009,
    6015, 6024, 6030, 6041, 6047, 6056, 6062, 6082, 6088, 6097, 6103, 6114,
    6120, 6129, 6135, 6158, 6164, 6173, 6179, 6190, 6196, 6205, 6211, 6231,
    6237, 6246, 6252, 6263, 6269, 6278, 6284, 6309, 6315, 6324, 6330, 6341,
    6347, 6356, 6362, 6382, 6388, 6397, 6403, 6414, 6420, 6429, 6435, 3515,
    3521, 3530, 3536, 3547, 3553, 3562, 3568, 3588, 3594, 3603, 3609, 3620,
    3626, 3635, 3641, 3666, 3672, 3681, 3687, 3698, 3704, 3713, 3719, 3739,
    3745, 3754, 3760, 3771, 3777, 3786, 3792, 3815, 3821, 3830, 3836, 3847,
    3853, 3862, 3868, 3888, 3894, 3903, 3909, 3920, 3926, 3935, 3941, 3966,
    3972, 3981, 3987, 3998, 4004, 4013, 4019, 4039, 4045, 4054, 4060, 4071,
    4077, 4086, 4092, 3956, 3962, 3971, 3977, 3988, 3994, 4003, 4009, 4029,
    4035, 4044, 4050, 4061, 4067, 4076, 4082, 4107, 4113, 4122, 4128, 4139,
    4145, 4154, 4160, 4180, 4186, 4195, 4201, 4212, 4218, 4227, 4233, 4256,
    4262, 4271, 4277, 4288, 4294, 4303, 4309, 4329, 4335, 4344, 4350, 4361,
    4367, 4376, 4382, 4407, 4413, 4422, 4428, 4439, 4445, 4454, 4460, 4480,
    4486, 4495, 4501, 4512, 4518, 4527, 4533, 4328, 4334, 4343, 4349, 4360,
    4366, 4375, 4381, 4401, 4407, 4416, 4422, 4433, 4439, 4448, 4454, 4479,
    4485, 4494, 4500, 4511, 4517, 4526, 4532, 4552, 4558, 4567, 4573, 4584,
    4590, 4599, 4605, 4628, 4634, 4643, 4649, 4660, 4666, 4675, 4681, 4701,
    4707, 4716, 4722, 4733, 4739, 4748, 4754, 4779, 4785, 4794, 4800, 4811,
    4817, 4826, 4832, 4852, 4858, 4867, 4873, 4884, 4890, 4899, 4905, 4769,
    4775, 4784, 4790, 4801, 4807, 4816, 4822, 4842, 4848, 4857, 4863, 4874,
    4880, 4889, 4895, 4920, 4926, 4935, 4941, 4952, 4958, 4967, 4973, 4993,
    4999, 5008, 5014, 5025, 5031, 5040, 5046, 5069, 5075, 5084, 5090, 5101,
    5107, 5116, 5122, 5142, 5148, 5157, 5163, 5174, 5180, 5189, 5195, 5220,
    5226, 5235, 5241, 5252, 5258, 5267, 5273, 5293, 5299, 5308, 5314, 5325,
    5331, 5340, 5346, 4604, 4610, 4619, 4625, 4636, 4642, 4651, 4657, 4677,
    4683, 4692, 4698, 4709, 4715, 4724, 4730, 4755, 4761, 4770, 4776, 4787,
    4793, 4802, 4808, 4828, 4834, 4843, 4849, 4860, 4866, 4875, 4881, 4904,
    4910, 4919, 4925, 4936, 4942, 4951, 4957, 4977, 4983, 4992, 4998, 5009,
    5015, 5024, 5030, 5055, 5061, 5070, 5076, 5087, 5093, 5102, 5108, 5128,
    5134, 5143, 5149, 5160, 5166, 5175, 5181, 5045, 5051, 5060, 5066, 5077,
    5083, 5092, 5098, 5118, 5124, 5133, 5139, 5150, 5156, 5165, 5171, 5196,
    5202, 5211, 5217, 5228, 5234, 5243, 5249, 5269, 5275, 5284, 5290, 5301,
    5307, 5316, 5322, 5345, 5351, 5360, 5366, 5377, 5383, 5392, 5398, 5418,
    5424, 5433, 5439, 5450, 5456, 5465, 5471, 5496, 5502, 5511, 5517, 5528,
    5534, 5543, 5549, 5569, 5575, 5584, 5590, 5601, 5607, 5616, 5622, 5417,
    5423, 5432, 5438, 5449, 5455, 5464, 5470, 5490, 5496, 5505, 5511, 5522,
    5528, 5537, 5543, 5568, 5574, 5583, 5589, 5600, 5606, 5615, 5621, 5641,
    5647, 5656, 5662, 5673, 5679, 5688, 5694, 5717, 5723, 5732, 5738, 5749,
    5755, 5764, 5770, 5790, 5796, 5805, 5811, 5822, 5828, 5837, 5843, 5868,
    5874, 5883, 5889, 5900, 5906, 5915, 5921, 5941, 5947, 5956, 5962, 5973,
    5979, 5988, 5994, 5858, 5864, 5873, 5879, 5890, 5896, 5905, 5911, 5931,
    5937, 5946, 5952, 5963, 5969, 5978, 5984, 6009, 6015, 6024, 6030, 6041,
    6047, 6056, 6062, 6082, 6088, 6097, 6103, 6114, 6120, 6129, 6135, 6158,
    6164, 6173, 6179, 6190, 6196, 6205, 6211, 6231, 6237, 6246, 6252, 6263,
    6269, 6278, 6284, 6309, 6315, 6324, 6330, 6341, 6347, 6356, 6362, 6382,
    6388, 6397, 6403, 6414, 6420, 6429, 6435, 5303, 5309, 5318, 5324, 5335,
    5341, 5350, 5356, 5376, 5382, 5391, 5397, 5408, 5414, 5423, 5429, 5454,
    5460, 5469, 5475, 5486, 5492, 5501, 5507, 5527, 5533, 5542, 5548, 5559,
    5565, 5574, 5580, 5603, 5609, 5618, 5624, 5635, 5641, 5650, 5656, 5676,
    5682, 5691, 5697, 5708, 5714, 5723, 5729, 5754, 5760, 5769, 5775, 5786,
    5792, 5801, 5807, 5827, 5833, 5842, 5848, 5859, 5865, 5874, 5880, 5744,
    5750, 5759, 5765, 5776, 5782, 5791, 5797, 5817, 5823, 5832, 5838, 5849,
    5855, 5864, 5870, 5895, 5901, 5910, 5916, 5927, 5933, 5942, 5948, 5968,
    5974, 5983, 5989, 6000, 6006, 6015, 6021, 6044, 6050, 6059, 6065, 6076,
    6082, 6091, 6097, 6117, 6123, 6132, 6138, 6149, 6155, 6164, 6170, 6195,
    6201, 6210, 6216, 6227, 6233, 6242, 6248, 6268, 6274, 6283, 6289, 6300,
    6306, 6315, 6321, 6116, 6122, 6131, 6137, 6148, 6154, 6163, 6169, 6189,
    6195, 6204, 6210, 6221, 6227, 6236, 6242, 6267, 6273, 6282, 6288, 6299,
    6305, 6314, 6320, 6340, 6346, 6355, 6361, 6372, 6378, 6387, 6393, 6416,
    6422, 6431, 6437, 6448, 6454, 6463, 6469, 6489, 6495, 6504, 6510, 6521,
    6527, 6536, 6542, 6567, 6573, 6582, 6588, 6599, 6605, 6614, 6620, 6640,
    6646, 6655, 6661, 6672, 6678, 6687, 6693, 6557, 6563, 6572, 6578, 6589,
    6595, 6604, 6610, 6630, 6636, 6645, 6651, 6662, 6668, 6677, 6683, 6708,
    6714, 6723, 6729, 6740, 6746, 6755, 6761, 6781, 6787, 6796, 6802, 6813,
    6819, 6828, 6834, 6857, 6863, 6872, 6878, 6889, 6895, 6904, 6910, 6930,
    6936, 6945, 6951, 6962, 6968, 6977, 6983, 7008, 7014, 7023, 7029, 7040,
    7046, 7055, 7061, 7081, 7087, 7096, 7102, 7113, 7119, 7128, 7134, 6392,
    6398, 6407, 6413, 6424, 6430, 6439, 6445, 6465, 6471, 6480, 6486, 6497,
    6503, 6512, 6518, 6543, 6549, 6558, 6564, 6575, 6581, 6590, 6596, 6616,
    6622, 6631, 6637, 6648, 6654, 6663, 6669, 6692, 6698, 6707, 6713, 6724,
    6730, 6739, 6745, 6765, 6771, 6780, 6786, 6797, 6803, 6812, 6818, 6843,
    6849, 6858, 6864, 6875, 6881, 6890, 6896, 6916, 6922, 6931, 6937, 6948,
    6954, 6963, 6969, 6833, 6839, 6848, 6854, 6865, 6871, 6880, 6886, 6906,
    6912, 6921, 6927, 6938, 6944, 6953, 6959, 6984, 6990, 6999, 7005, 7016,
    7022, 7031, 7037, 7057, 7063, 7072, 7078, 7089, 7095, 7104, 7110, 7133,
    7139, 7148, 7154, 7165, 7171, 7180, 7186, 7206, 7212, 7221, 7227, 7238,
    7244, 7253, 7259, 7284, 7290, 7299, 7305, 7316, 7322, 7331, 7337, 7357,
    7363, 7372, 7378, 7389, 7395, 7404, 7410, 7205, 7211, 7220, 7226, 7237,
    7243, 7252, 7258, 7278, 7284, 7293, 7299, 7310, 7316, 7325, 7331, 7356,
    7362, 7371, 7377, 7388, 7394, 7403, 7409, 7429, 7435, 7444, 7450, 7461,
    7467, 7476, 7482, 7505, 7511, 7520, 7526, 7537, 7543, 7552, 7558, 7578,
    7584, 7593, 7599, 7610, 7616, 7625, 7631, 7656, 7662, 7671, 7677, 7688,
    7694, 7703, 7709, 7729, 7735, 7744, 7750, 7761,
];

/// Coefficient position to band mapping
pub const VP8_ENC_BANDS: [u8; 17] = [0, 1, 2, 3, 6, 4, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 0];

//------------------------------------------------------------------------------
// Level codes for variable-length coefficient encoding

/// VP8LevelCodes table for encoding coefficient levels > 4
/// Format: [pattern, bits] where pattern encodes which probas to use
/// and bits encodes the actual bit values.
#[rustfmt::skip]
pub const VP8_LEVEL_CODES: [[u16; 2]; 67] = [
    [0x001, 0x000], [0x007, 0x001], [0x00f, 0x005], [0x00f, 0x00d],
    [0x033, 0x003], [0x033, 0x003], [0x033, 0x023], [0x033, 0x023],
    [0x033, 0x023], [0x033, 0x023], [0x0d3, 0x013], [0x0d3, 0x013],
    [0x0d3, 0x013], [0x0d3, 0x013], [0x0d3, 0x013], [0x0d3, 0x013],
    [0x0d3, 0x013], [0x0d3, 0x013], [0x0d3, 0x093], [0x0d3, 0x093],
    [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093],
    [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093],
    [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093], [0x0d3, 0x093],
    [0x0d3, 0x093], [0x0d3, 0x093], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x053], [0x153, 0x053],
    [0x153, 0x053], [0x153, 0x053], [0x153, 0x153],
];

//------------------------------------------------------------------------------
// Quantizer lookup tables

/// DC quantizer lookup table (index 0-127 -> quantizer step)
#[rustfmt::skip]
pub const VP8_DC_TABLE: [u16; 128] = [
    4, 5, 6, 7, 8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 17,
    18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 28,
    29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43,
    44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
    59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,
    75, 76, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
    91, 93, 95, 96, 98, 100, 101, 102, 104, 106, 108, 110, 112, 114, 116, 118,
    122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 143, 145, 148, 151, 154, 157,
];

/// AC quantizer lookup table (index 0-127 -> quantizer step)
#[rustfmt::skip]
pub const VP8_AC_TABLE: [u16; 128] = [
    4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
    20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
    36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
    52, 53, 54, 55, 56, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76,
    78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108,
    110, 112, 114, 116, 119, 122, 125, 128, 131, 134, 137, 140, 143, 146, 149, 152,
    155, 158, 161, 164, 167, 170, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209,
    213, 217, 221, 225, 229, 234, 239, 245, 249, 254, 259, 264, 269, 274, 279, 284,
];

// VP8_AC_TABLE2 (Y2 AC quantizer) lives in `crate::common::types` so the
// decoder can use it without reaching into the encoder module.

/// Zig-zag scan order for 4x4 block
pub const VP8_ZIGZAG: [usize; 16] = [0, 1, 4, 8, 5, 2, 3, 6, 9, 12, 13, 10, 7, 11, 14, 15];

/// Frequency-based sharpening weights
#[rustfmt::skip]
pub const VP8_FREQ_SHARPENING: [u8; 16] = [
    0, 30, 60, 90, 30, 60, 90, 90,
    60, 90, 90, 90, 90, 90, 90, 90,
];

/// Trellis distortion weights (for USE_TDISTO=1)
#[rustfmt::skip]
pub const VP8_WEIGHT_TRELLIS: [u16; 16] = [
    30, 27, 19, 11, 27, 24, 17, 10,
    19, 17, 12, 8, 11, 10, 8, 6,
];

//------------------------------------------------------------------------------
// Spectral distortion (TDisto) weights

/// Spectral distortion weights for luma (kWeightY in libwebp)
/// Higher weights for low-frequency components (visually more important)
#[rustfmt::skip]
pub const VP8_WEIGHT_Y: [u16; 16] = [
    38, 32, 20,  9,
    32, 28, 17,  7,
    20, 17, 10,  4,
     9,  7,  4,  2,
];

/// Spectral distortion weights for chroma (kWeightUV in libwebp)
#[rustfmt::skip]
pub const VP8_WEIGHT_UV: [u16; 16] = [
    38, 32, 20,  9,
    32, 28, 17,  7,
    20, 17, 10,  4,
     9,  7,  4,  2,
];

//------------------------------------------------------------------------------
// Filter strength lookup table

/// Maximum delta size for filter strength lookup
pub(crate) const MAX_DELTA_SIZE: usize = 64;

/// Filter strength lookup table: [sharpness][delta] -> filter_level
/// This gives, for a given sharpness, the filtering strength to be
/// used (at least) in order to filter a given edge step delta.
/// Ported from libwebp's kLevelsFromDelta.
#[rustfmt::skip]
pub(crate) const LEVELS_FROM_DELTA: [[u8; MAX_DELTA_SIZE]; 8] = [
    [0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10, 11, 12, 13, 14, 15,
     16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,
     32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,
     48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63],
    [0,  1,  2,  3,  5,  6,  7,  8,  9,  11, 12, 13, 14, 15, 17, 18,
     20, 21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42,
     44, 45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  3,  5,  6,  7,  8,  9,  11, 12, 13, 14, 16, 17, 19,
     20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40, 41, 43,
     44, 46, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 62, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  3,  5,  6,  7,  8,  9,  11, 12, 13, 15, 16, 18, 19,
     21, 22, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 39, 40, 42, 43,
     45, 46, 48, 49, 51, 52, 54, 55, 57, 58, 60, 61, 63, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  3,  5,  6,  7,  8,  9,  11, 12, 14, 15, 17, 18, 20,
     21, 23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44,
     45, 47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  4,  5,  7,  8,  9,  11, 12, 13, 15, 16, 17, 19, 20,
     22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 38, 40, 41, 43, 44,
     46, 47, 49, 50, 52, 53, 55, 56, 58, 59, 61, 62, 63, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  4,  5,  7,  8,  9,  11, 12, 13, 15, 16, 18, 19, 21,
     22, 24, 25, 27, 28, 30, 31, 33, 34, 36, 37, 39, 40, 42, 43, 45,
     46, 48, 49, 51, 52, 54, 55, 57, 58, 60, 61, 63, 63, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
    [0,  1,  2,  4,  5,  7,  8,  9,  11, 12, 14, 15, 17, 18, 20, 21,
     23, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45,
     47, 48, 50, 51, 53, 54, 56, 57, 59, 60, 62, 63, 63, 63, 63, 63,
     63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63, 63],
];

//------------------------------------------------------------------------------
// Mode costs

/// Fixed mode costs for Intra16 modes, indexed in zenwebp's `LumaMode` order
/// `[DC, V, H, TM]` (i.e., `MODES` in `pick_best_intra16`).
///
/// libwebp's `VP8FixedCostsI16` (`cost_enc.c:105`) is `[663, 919, 872, 919]` in
/// libwebp's enum order `[DC=0, TM=1, V=2, H=3]`. Re-permuted here to zenwebp's
/// enum: DC=663, V=872, H=919, TM=919. Includes the fixed `VP8BitCost(1, 145)`
/// mode-selection cost.
pub const FIXED_COSTS_I16: [u16; 4] = [663, 872, 919, 919];

/// Fixed mode costs for chroma modes, indexed in zenwebp's `ChromaMode` order
/// `[DC, V, H, TM]` (i.e., `MODES` in `pick_best_uv`).
///
/// libwebp's `VP8FixedCostsUV` (`cost_enc.c:103`) is `[302, 984, 439, 642]` in
/// libwebp's enum order `[DC=0, TM=1, V=2, H=3]`. Re-permuted here to zenwebp's
/// enum: DC=302, V=439, H=642, TM=984.
pub const FIXED_COSTS_UV: [u16; 4] = [302, 439, 642, 984];

/// Number of Intra4 prediction modes
pub const NUM_BMODES: usize = 10;

/// Permutation mapping zenwebp's `B_*_PRED` enum to libwebp's. zenwebp has
/// `B_LD=4, B_RD=5, B_VR=6, B_VL=7`; libwebp has `B_RD=4, B_VR=5, B_LD=6, B_VL=7`.
/// `PERM_LIBWEBP_TO_ZEN[zen_idx] = libwebp_idx_for_same_mode`.
const PERM_LIBWEBP_TO_ZEN: [usize; NUM_BMODES] = [0, 1, 2, 3, 6, 4, 5, 7, 8, 9];

/// Apply the libwebp→zenwebp enum permutation to all three dimensions of the I4
/// cost table (top_ctx, left_ctx, mode). `out[i][j][k] = src[perm[i]][perm[j]][perm[k]]`.
const fn permute_i4_table(
    src: &[[[u16; NUM_BMODES]; NUM_BMODES]; NUM_BMODES],
) -> [[[u16; NUM_BMODES]; NUM_BMODES]; NUM_BMODES] {
    let mut out = [[[0u16; NUM_BMODES]; NUM_BMODES]; NUM_BMODES];
    let mut i = 0;
    while i < NUM_BMODES {
        let mut j = 0;
        while j < NUM_BMODES {
            let mut k = 0;
            while k < NUM_BMODES {
                out[i][j][k] =
                    src[PERM_LIBWEBP_TO_ZEN[i]][PERM_LIBWEBP_TO_ZEN[j]][PERM_LIBWEBP_TO_ZEN[k]];
                k += 1;
            }
            j += 1;
        }
        i += 1;
    }
    out
}

/// Context-dependent Intra4 mode costs. The values come from libwebp's
/// `VP8FixedCostsI4` (`cost_enc.c:106-206`), which is indexed in libwebp's
/// `B_*_PRED` enum order. zenwebp's `B_*_PRED` enum permutes positions 4/5/6,
/// so the table is re-permuted at compile time to be indexed in zenwebp's
/// order: `VP8_FIXED_COSTS_I4[top_zen][left_zen][mode_zen]`.
///
/// Companion probability table `KEYFRAME_BPRED_MODE_PROBS` is hand-permuted in
/// `src/common/types.rs`; the cost table now uses const-fn permutation so the
/// raw libwebp data is preserved verbatim for future audits.
pub const VP8_FIXED_COSTS_I4: [[[u16; NUM_BMODES]; NUM_BMODES]; NUM_BMODES] =
    permute_i4_table(&VP8_FIXED_COSTS_I4_LIBWEBP_ORDER);

/// Raw libwebp `VP8FixedCostsI4` table, indexed in libwebp's `B_*_PRED` order
/// (`B_DC=0, B_TM=1, B_VE=2, B_HE=3, B_RD=4, B_VR=5, B_LD=6, B_VL=7, B_HD=8,
/// B_HU=9`). Do NOT use directly — use `VP8_FIXED_COSTS_I4` (the permuted
/// version indexed in zenwebp's enum order).
#[rustfmt::skip]
const VP8_FIXED_COSTS_I4_LIBWEBP_ORDER: [[[u16; NUM_BMODES]; NUM_BMODES]; NUM_BMODES] = [
    [[40, 1151, 1723, 1874, 2103, 2019, 1628, 1777, 2226, 2137],
     [192, 469, 1296, 1308, 1849, 1794, 1781, 1703, 1713, 1522],
     [142, 910, 762, 1684, 1849, 1576, 1460, 1305, 1801, 1657],
     [559, 641, 1370, 421, 1182, 1569, 1612, 1725, 863, 1007],
     [299, 1059, 1256, 1108, 636, 1068, 1581, 1883, 869, 1142],
     [277, 1111, 707, 1362, 1089, 672, 1603, 1541, 1545, 1291],
     [214, 781, 1609, 1303, 1632, 2229, 726, 1560, 1713, 918],
     [152, 1037, 1046, 1759, 1983, 2174, 1358, 742, 1740, 1390],
     [512, 1046, 1420, 753, 752, 1297, 1486, 1613, 460, 1207],
     [424, 827, 1362, 719, 1462, 1202, 1199, 1476, 1199, 538]],
    [[240, 402, 1134, 1491, 1659, 1505, 1517, 1555, 1979, 2099],
     [467, 242, 960, 1232, 1714, 1620, 1834, 1570, 1676, 1391],
     [500, 455, 463, 1507, 1699, 1282, 1564, 982, 2114, 2114],
     [672, 643, 1372, 331, 1589, 1667, 1453, 1938, 996, 876],
     [458, 783, 1037, 911, 738, 968, 1165, 1518, 859, 1033],
     [504, 815, 504, 1139, 1219, 719, 1506, 1085, 1268, 1268],
     [333, 630, 1445, 1239, 1883, 3672, 799, 1548, 1865, 598],
     [399, 644, 746, 1342, 1856, 1350, 1493, 613, 1855, 1015],
     [622, 749, 1205, 608, 1066, 1408, 1290, 1406, 546, 971],
     [500, 753, 1041, 668, 1230, 1617, 1297, 1425, 1383, 523]],
    [[394, 553, 523, 1502, 1536, 981, 1608, 1142, 1666, 2181],
     [655, 430, 375, 1411, 1861, 1220, 1677, 1135, 1978, 1553],
     [690, 640, 245, 1954, 2070, 1194, 1528, 982, 1972, 2232],
     [559, 834, 741, 867, 1131, 980, 1225, 852, 1092, 784],
     [690, 875, 516, 959, 673, 894, 1056, 1190, 1528, 1126],
     [740, 951, 384, 1277, 1177, 492, 1579, 1155, 1846, 1513],
     [323, 775, 1062, 1776, 3062, 1274, 813, 1188, 1372, 655],
     [488, 971, 484, 1767, 1515, 1775, 1115, 503, 1539, 1461],
     [740, 1006, 998, 709, 851, 1230, 1337, 788, 741, 721],
     [522, 1073, 573, 1045, 1346, 887, 1046, 1146, 1203, 697]],
    [[105, 864, 1442, 1009, 1934, 1840, 1519, 1920, 1673, 1579],
     [534, 305, 1193, 683, 1388, 2164, 1802, 1894, 1264, 1170],
     [305, 518, 877, 1108, 1426, 3215, 1425, 1064, 1320, 1242],
     [683, 732, 1927, 257, 1493, 2048, 1858, 1552, 1055, 947],
     [394, 814, 1024, 660, 959, 1556, 1282, 1289, 893, 1047],
     [528, 615, 996, 940, 1201, 635, 1094, 2515, 803, 1358],
     [347, 614, 1609, 1187, 3133, 1345, 1007, 1339, 1017, 667],
     [218, 740, 878, 1605, 3650, 3650, 1345, 758, 1357, 1617],
     [672, 750, 1541, 558, 1257, 1599, 1870, 2135, 402, 1087],
     [592, 684, 1161, 430, 1092, 1497, 1475, 1489, 1095, 822]],
    [[228, 1056, 1059, 1368, 752, 982, 1512, 1518, 987, 1782],
     [494, 514, 818, 942, 965, 892, 1610, 1356, 1048, 1363],
     [512, 648, 591, 1042, 761, 991, 1196, 1454, 1309, 1463],
     [683, 749, 1043, 676, 841, 1396, 1133, 1138, 654, 939],
     [622, 1101, 1126, 994, 361, 1077, 1203, 1318, 877, 1219],
     [631, 1068, 857, 1650, 651, 477, 1650, 1419, 828, 1170],
     [555, 727, 1068, 1335, 3127, 1339, 820, 1331, 1077, 429],
     [504, 879, 624, 1398, 889, 889, 1392, 808, 891, 1406],
     [683, 1602, 1289, 977, 578, 983, 1280, 1708, 406, 1122],
     [399, 865, 1433, 1070, 1072, 764, 968, 1477, 1223, 678]],
    [[333, 760, 935, 1638, 1010, 529, 1646, 1410, 1472, 2219],
     [512, 494, 750, 1160, 1215, 610, 1870, 1868, 1628, 1169],
     [572, 646, 492, 1934, 1208, 603, 1580, 1099, 1398, 1995],
     [786, 789, 942, 581, 1018, 951, 1599, 1207, 731, 768],
     [690, 1015, 672, 1078, 582, 504, 1693, 1438, 1108, 2897],
     [768, 1267, 571, 2005, 1243, 244, 2881, 1380, 1786, 1453],
     [452, 899, 1293, 903, 1311, 3100, 465, 1311, 1319, 813],
     [394, 927, 942, 1103, 1358, 1104, 946, 593, 1363, 1109],
     [559, 1005, 1007, 1016, 658, 1173, 1021, 1164, 623, 1028],
     [564, 796, 632, 1005, 1014, 863, 2316, 1268, 938, 764]],
    [[266, 606, 1098, 1228, 1497, 1243, 948, 1030, 1734, 1461],
     [366, 585, 901, 1060, 1407, 1247, 876, 1134, 1620, 1054],
     [452, 565, 542, 1729, 1479, 1479, 1016, 886, 2938, 1150],
     [555, 1088, 1533, 950, 1354, 895, 834, 1019, 1021, 496],
     [704, 815, 1193, 971, 973, 640, 1217, 2214, 832, 578],
     [672, 1245, 579, 871, 875, 774, 872, 1273, 1027, 949],
     [296, 1134, 2050, 1784, 1636, 3425, 442, 1550, 2076, 722],
     [342, 982, 1259, 1846, 1848, 1848, 622, 568, 1847, 1052],
     [555, 1064, 1304, 828, 746, 1343, 1075, 1329, 1078, 494],
     [288, 1167, 1285, 1174, 1639, 1639, 833, 2254, 1304, 509]],
    [[342, 719, 767, 1866, 1757, 1270, 1246, 550, 1746, 2151],
     [483, 653, 694, 1509, 1459, 1410, 1218, 507, 1914, 1266],
     [488, 757, 447, 2979, 1813, 1268, 1654, 539, 1849, 2109],
     [522, 1097, 1085, 851, 1365, 1111, 851, 901, 961, 605],
     [709, 716, 841, 728, 736, 945, 941, 862, 2845, 1057],
     [512, 1323, 500, 1336, 1083, 681, 1342, 717, 1604, 1350],
     [452, 1155, 1372, 1900, 1501, 3290, 311, 944, 1919, 922],
     [403, 1520, 977, 2132, 1733, 3522, 1076, 276, 3335, 1547],
     [559, 1374, 1101, 615, 673, 2462, 974, 795, 984, 984],
     [547, 1122, 1062, 812, 1410, 951, 1140, 622, 1268, 651]],
    [[165, 982, 1235, 938, 1334, 1366, 1659, 1578, 964, 1612],
     [592, 422, 925, 847, 1139, 1112, 1387, 2036, 861, 1041],
     [403, 837, 732, 770, 941, 1658, 1250, 809, 1407, 1407],
     [896, 874, 1071, 381, 1568, 1722, 1437, 2192, 480, 1035],
     [640, 1098, 1012, 1032, 684, 1382, 1581, 2106, 416, 865],
     [559, 1005, 819, 914, 710, 770, 1418, 920, 838, 1435],
     [415, 1258, 1245, 870, 1278, 3067, 770, 1021, 1287, 522],
     [406, 990, 601, 1009, 1265, 1265, 1267, 759, 1017, 1277],
     [968, 1182, 1329, 788, 1032, 1292, 1705, 1714, 203, 1403],
     [732, 877, 1279, 471, 901, 1161, 1545, 1294, 755, 755]],
    [[111, 931, 1378, 1185, 1933, 1648, 1148, 1714, 1873, 1307],
     [406, 414, 1030, 1023, 1910, 1404, 1313, 1647, 1509, 793],
     [342, 640, 575, 1088, 1241, 1349, 1161, 1350, 1756, 1502],
     [559, 766, 1185, 357, 1682, 1428, 1329, 1897, 1219, 802],
     [473, 909, 1164, 771, 719, 2508, 1427, 1432, 722, 782],
     [342, 892, 785, 1145, 1150, 794, 1296, 1550, 973, 1057],
     [208, 1036, 1326, 1343, 1606, 3395, 815, 1455, 1618, 712],
     [228, 928, 890, 1046, 3499, 1711, 994, 829, 1720, 1318],
     [768, 724, 1058, 636, 991, 1075, 1319, 1324, 616, 825],
     [305, 1167, 1358, 899, 1587, 1587, 987, 1988, 1332, 501]],
];

#[cfg(test)]
mod fixed_costs_i4_perm_tests {
    use super::*;

    /// The const-fn permutation must produce the same values as a manual
    /// permutation (zen[i][j][k] = libwebp[perm[i]][perm[j]][perm[k]]).
    #[test]
    fn permutation_matches_manual_lookup() {
        for i in 0..NUM_BMODES {
            for j in 0..NUM_BMODES {
                for k in 0..NUM_BMODES {
                    let zen = VP8_FIXED_COSTS_I4[i][j][k];
                    let manual = VP8_FIXED_COSTS_I4_LIBWEBP_ORDER[PERM_LIBWEBP_TO_ZEN[i]]
                        [PERM_LIBWEBP_TO_ZEN[j]][PERM_LIBWEBP_TO_ZEN[k]];
                    assert_eq!(zen, manual, "mismatch at zen[{i}][{j}][{k}]");
                }
            }
        }
    }

    /// Spot-checks predicted by the audit (`differences/01-mode-selection.md` #1).
    /// zen[i][j][k] reads the libwebp value at position `perm[i],perm[j],perm[k]`.
    /// At zen [0][0][4] (B_LD) we should now get the libwebp value at [0][0][6]
    /// (libwebp's B_LD), which is 1628. Likewise the other two slots rotate.
    #[test]
    fn audit_spot_checks() {
        // From the original libwebp-ordered table, [0][0] row is:
        //   [40, 1151, 1723, 1874, 2103, 2019, 1628, 1777, 2226, 2137]
        //                          ^RD=4 ^VR=5 ^LD=6
        // After permutation to zen order, slots 4/5/6 become:
        //   [...,  LD=1628, RD=2103, VR=2019, ...]
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][4], 1628, "zen LD"); // was libwebp[0][0][6]
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][5], 2103, "zen RD"); // was libwebp[0][0][4]
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][6], 2019, "zen VR"); // was libwebp[0][0][5]
        // Slots 0,1,2,3,7,8,9 are unchanged (perm is identity there).
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][0], 40);
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][7], 1777);
        assert_eq!(VP8_FIXED_COSTS_I4[0][0][9], 2137);
    }
}