oximedia-codec 0.1.7

//! Normative SILK constant tables for the Opus decoder (RFC 6716 §4.2).
//!
//! Every numeric value in this file is the *normative* SILK constant. The
//! tables were obtained from the BSD-licensed reference decoder (libopus
//! `silk/tables_*.c`), the authoritative companion to RFC 6716, and are
//! reproduced here as plain data — no algorithm code is copied.
//!
//! Inverse-CDF (`iCDF`) tables are stored in exactly the layout consumed by
//! [`super::silk_range::SilkRangeDecoder::decode_icdf`]: a descending run of
//! tail probabilities ending in `0`, with total-frequency precision `ftb = 8`.
//!
//! `Qn` suffixes denote fixed-point scaling by `2^n`.
#![allow(clippy::unreadable_literal)]

/// NLSF stage-1 codebook, NB/MB (32 vectors of order 10, Q8).
pub const NLSF_CB1_NB_MB_Q8: [[u8; 10]; 32] = [
    [12, 35, 60, 83, 108, 132, 157, 180, 206, 228],
    [15, 32, 55, 77, 101, 125, 151, 175, 201, 225],
    [19, 42, 66, 89, 114, 137, 162, 184, 209, 230],
    [12, 25, 50, 72, 97, 120, 147, 172, 200, 223],
    [26, 44, 69, 90, 114, 135, 159, 180, 205, 225],
    [13, 22, 53, 80, 106, 130, 156, 180, 205, 228],
    [15, 25, 44, 64, 90, 115, 142, 168, 196, 222],
    [19, 24, 62, 82, 100, 120, 145, 168, 190, 214],
    [22, 31, 50, 79, 103, 120, 151, 170, 203, 227],
    [21, 29, 45, 65, 106, 124, 150, 171, 196, 224],
    [30, 49, 75, 97, 121, 142, 165, 186, 209, 229],
    [19, 25, 52, 70, 93, 116, 143, 166, 192, 219],
    [26, 34, 62, 75, 97, 118, 145, 167, 194, 217],
    [25, 33, 56, 70, 91, 113, 143, 165, 196, 223],
    [21, 34, 51, 72, 97, 117, 145, 171, 196, 222],
    [20, 29, 50, 67, 90, 117, 144, 168, 197, 221],
    [22, 31, 48, 66, 95, 117, 146, 168, 196, 222],
    [24, 33, 51, 77, 116, 134, 158, 180, 200, 224],
    [21, 28, 70, 87, 106, 124, 149, 170, 194, 217],
    [26, 33, 53, 64, 83, 117, 152, 173, 204, 225],
    [27, 34, 65, 95, 108, 129, 155, 174, 210, 225],
    [20, 26, 72, 99, 113, 131, 154, 176, 200, 219],
    [34, 43, 61, 78, 93, 114, 155, 177, 205, 229],
    [23, 29, 54, 97, 124, 138, 163, 179, 209, 229],
    [30, 38, 56, 89, 118, 129, 158, 178, 200, 231],
    [21, 29, 49, 63, 85, 111, 142, 163, 193, 222],
    [27, 48, 77, 103, 133, 158, 179, 196, 215, 232],
    [29, 47, 74, 99, 124, 151, 176, 198, 220, 237],
    [33, 42, 61, 76, 93, 121, 155, 174, 207, 225],
    [29, 53, 87, 112, 136, 154, 170, 188, 208, 227],
    [24, 30, 52, 84, 131, 150, 166, 186, 203, 229],
    [37, 48, 64, 84, 104, 118, 156, 177, 201, 230],
];

/// NLSF stage-1 inverse weights, NB/MB (Q9).
pub const NLSF_CB1_WGHT_NB_MB_Q9: [[i16; 10]; 32] = [
    [2897, 2314, 2314, 2314, 2287, 2287, 2314, 2300, 2327, 2287],
    [2888, 2580, 2394, 2367, 2314, 2274, 2274, 2274, 2274, 2194],
    [2487, 2340, 2340, 2314, 2314, 2314, 2340, 2340, 2367, 2354],
    [3216, 2766, 2340, 2340, 2314, 2274, 2221, 2207, 2261, 2194],
    [2460, 2474, 2367, 2394, 2394, 2394, 2394, 2367, 2407, 2314],
    [3479, 3056, 2127, 2207, 2274, 2274, 2274, 2287, 2314, 2261],
    [3282, 3141, 2580, 2394, 2247, 2221, 2207, 2194, 2194, 2114],
    [4096, 3845, 2221, 2620, 2620, 2407, 2314, 2394, 2367, 2074],
    [3178, 3244, 2367, 2221, 2553, 2434, 2340, 2314, 2167, 2221],
    [3338, 3488, 2726, 2194, 2261, 2460, 2354, 2367, 2207, 2101],
    [2354, 2420, 2327, 2367, 2394, 2420, 2420, 2420, 2460, 2367],
    [3779, 3629, 2434, 2527, 2367, 2274, 2274, 2300, 2207, 2048],
    [3254, 3225, 2713, 2846, 2447, 2327, 2300, 2300, 2274, 2127],
    [3263, 3300, 2753, 2806, 2447, 2261, 2261, 2247, 2127, 2101],
    [2873, 2981, 2633, 2367, 2407, 2354, 2194, 2247, 2247, 2114],
    [3225, 3197, 2633, 2580, 2274, 2181, 2247, 2221, 2221, 2141],
    [3178, 3310, 2740, 2407, 2274, 2274, 2274, 2287, 2194, 2114],
    [3141, 3272, 2460, 2061, 2287, 2500, 2367, 2487, 2434, 2181],
    [3507, 3282, 2314, 2700, 2647, 2474, 2367, 2394, 2340, 2127],
    [3423, 3535, 3038, 3056, 2300, 1950, 2221, 2274, 2274, 2274],
    [3404, 3366, 2087, 2687, 2873, 2354, 2420, 2274, 2474, 2540],
    [3760, 3488, 1950, 2660, 2897, 2527, 2394, 2367, 2460, 2261],
    [3028, 3272, 2740, 2888, 2740, 2154, 2127, 2287, 2234, 2247],
    [3695, 3657, 2025, 1969, 2660, 2700, 2580, 2500, 2327, 2367],
    [3207, 3413, 2354, 2074, 2888, 2888, 2340, 2487, 2247, 2167],
    [3338, 3366, 2846, 2780, 2327, 2154, 2274, 2287, 2114, 2061],
    [2327, 2300, 2181, 2167, 2181, 2367, 2633, 2700, 2700, 2553],
    [2407, 2434, 2221, 2261, 2221, 2221, 2340, 2420, 2607, 2700],
    [3038, 3244, 2806, 2888, 2474, 2074, 2300, 2314, 2354, 2380],
    [2221, 2154, 2127, 2287, 2500, 2793, 2793, 2620, 2580, 2367],
    [3676, 3713, 2234, 1838, 2181, 2753, 2726, 2673, 2513, 2207],
    [2793, 3160, 2726, 2553, 2846, 2513, 2181, 2394, 2221, 2181],
];

/// NLSF stage-1 selection iCDF, NB/MB, indexed by voiced flag.
pub const NLSF_CB1_ICDF_NB_MB: [[u8; 32]; 2] = [
    [
        212, 178, 148, 129, 108, 96, 85, 82, 79, 77, 61, 59, 57, 56, 51, 49, 48, 45, 42, 41, 40,
        38, 36, 34, 31, 30, 21, 12, 10, 3, 1, 0,
    ],
    [
        255, 245, 244, 236, 233, 225, 217, 203, 190, 176, 175, 161, 149, 136, 125, 114, 102, 91,
        81, 71, 60, 52, 43, 35, 28, 20, 19, 18, 12, 11, 5, 0,
    ],
];

/// NLSF stage-2 backward-prediction weights, NB/MB (Q8), 2 selectable rows.
pub const NLSF_PRED_NB_MB_Q8: [[u8; 9]; 2] = [
    [179, 138, 140, 148, 151, 149, 153, 151, 163],
    [116, 67, 82, 59, 92, 72, 100, 89, 92],
];

/// NLSF stage-2 selector bytes, NB/MB. Flat array indexed `[i1*5 + coeff/2]`;
/// each byte packs the residual-codebook index and prediction-weight selector
/// for an even/odd coefficient pair (libopus `silk_NLSF_unpack`).
pub const NLSF_CB2_SELECT_NB_MB: [u8; 160] = [
    16, 0, 0, 0, 0, 99, 66, 36, 36, 34, 36, 34, 34, 34, 34, 83, 69, 36, 52, 34, 116, 102, 70, 68,
    68, 176, 102, 68, 68, 34, 65, 85, 68, 84, 36, 116, 141, 152, 139, 170, 132, 187, 184, 216, 137,
    132, 249, 168, 185, 139, 104, 102, 100, 68, 68, 178, 218, 185, 185, 170, 244, 216, 187, 187,
    170, 244, 187, 187, 219, 138, 103, 155, 184, 185, 137, 116, 183, 155, 152, 136, 132, 217, 184,
    184, 170, 164, 217, 171, 155, 139, 244, 169, 184, 185, 170, 164, 216, 223, 218, 138, 214, 143,
    188, 218, 168, 244, 141, 136, 155, 170, 168, 138, 220, 219, 139, 164, 219, 202, 216, 137, 168,
    186, 246, 185, 139, 116, 185, 219, 185, 138, 100, 100, 134, 100, 102, 34, 68, 68, 100, 68, 168,
    203, 221, 218, 168, 167, 154, 136, 104, 70, 164, 246, 171, 137, 139, 137, 155, 218, 219, 139,
];

/// NLSF stage-2 residual iCDF set, NB/MB (8 codebooks).
pub const NLSF_CB2_ICDF_NB_MB: [[u8; 9]; 8] = [
    [255, 254, 253, 238, 14, 3, 2, 1, 0],
    [255, 254, 252, 218, 35, 3, 2, 1, 0],
    [255, 254, 250, 208, 59, 4, 2, 1, 0],
    [255, 254, 246, 194, 71, 10, 2, 1, 0],
    [255, 252, 236, 183, 82, 8, 2, 1, 0],
    [255, 252, 235, 180, 90, 17, 2, 1, 0],
    [255, 248, 224, 171, 97, 30, 4, 1, 0],
    [255, 254, 236, 173, 95, 37, 7, 1, 0],
];

/// Minimum NLSF spacing, NB/MB (Q15), order+1 entries.
pub const NLSF_DELTA_MIN_NB_MB_Q15: [i16; 11] = [250, 3, 6, 3, 3, 3, 4, 3, 3, 3, 461];

/// NLSF stage-1 codebook, WB (32 vectors of order 16, Q8).
pub const NLSF_CB1_WB_Q8: [[u8; 16]; 32] = [
    [
        7, 23, 38, 54, 69, 85, 100, 116, 131, 147, 162, 178, 193, 208, 223, 239,
    ],
    [
        13, 25, 41, 55, 69, 83, 98, 112, 127, 142, 157, 171, 187, 203, 220, 236,
    ],
    [
        15, 21, 34, 51, 61, 78, 92, 106, 126, 136, 152, 167, 185, 205, 225, 240,
    ],
    [
        10, 21, 36, 50, 63, 79, 95, 110, 126, 141, 157, 173, 189, 205, 221, 237,
    ],
    [
        17, 20, 37, 51, 59, 78, 89, 107, 123, 134, 150, 164, 184, 205, 224, 240,
    ],
    [
        10, 15, 32, 51, 67, 81, 96, 112, 129, 142, 158, 173, 189, 204, 220, 236,
    ],
    [
        8, 21, 37, 51, 65, 79, 98, 113, 126, 138, 155, 168, 179, 192, 209, 218,
    ],
    [
        12, 15, 34, 55, 63, 78, 87, 108, 118, 131, 148, 167, 185, 203, 219, 236,
    ],
    [
        16, 19, 32, 36, 56, 79, 91, 108, 118, 136, 154, 171, 186, 204, 220, 237,
    ],
    [
        11, 28, 43, 58, 74, 89, 105, 120, 135, 150, 165, 180, 196, 211, 226, 241,
    ],
    [
        6, 16, 33, 46, 60, 75, 92, 107, 123, 137, 156, 169, 185, 199, 214, 225,
    ],
    [
        11, 19, 30, 44, 57, 74, 89, 105, 121, 135, 152, 169, 186, 202, 218, 234,
    ],
    [
        12, 19, 29, 46, 57, 71, 88, 100, 120, 132, 148, 165, 182, 199, 216, 233,
    ],
    [
        17, 23, 35, 46, 56, 77, 92, 106, 123, 134, 152, 167, 185, 204, 222, 237,
    ],
    [
        14, 17, 45, 53, 63, 75, 89, 107, 115, 132, 151, 171, 188, 206, 221, 240,
    ],
    [
        9, 16, 29, 40, 56, 71, 88, 103, 119, 137, 154, 171, 189, 205, 222, 237,
    ],
    [
        16, 19, 36, 48, 57, 76, 87, 105, 118, 132, 150, 167, 185, 202, 218, 236,
    ],
    [
        12, 17, 29, 54, 71, 81, 94, 104, 126, 136, 149, 164, 182, 201, 221, 237,
    ],
    [
        15, 28, 47, 62, 79, 97, 115, 129, 142, 155, 168, 180, 194, 208, 223, 238,
    ],
    [
        8, 14, 30, 45, 62, 78, 94, 111, 127, 143, 159, 175, 192, 207, 223, 239,
    ],
    [
        17, 30, 49, 62, 79, 92, 107, 119, 132, 145, 160, 174, 190, 204, 220, 235,
    ],
    [
        14, 19, 36, 45, 61, 76, 91, 108, 121, 138, 154, 172, 189, 205, 222, 238,
    ],
    [
        12, 18, 31, 45, 60, 76, 91, 107, 123, 138, 154, 171, 187, 204, 221, 236,
    ],
    [
        13, 17, 31, 43, 53, 70, 83, 103, 114, 131, 149, 167, 185, 203, 220, 237,
    ],
    [
        17, 22, 35, 42, 58, 78, 93, 110, 125, 139, 155, 170, 188, 206, 224, 240,
    ],
    [
        8, 15, 34, 50, 67, 83, 99, 115, 131, 146, 162, 178, 193, 209, 224, 239,
    ],
    [
        13, 16, 41, 66, 73, 86, 95, 111, 128, 137, 150, 163, 183, 206, 225, 241,
    ],
    [
        17, 25, 37, 52, 63, 75, 92, 102, 119, 132, 144, 160, 175, 191, 212, 231,
    ],
    [
        19, 31, 49, 65, 83, 100, 117, 133, 147, 161, 174, 187, 200, 213, 227, 242,
    ],
    [
        18, 31, 52, 68, 88, 103, 117, 126, 138, 149, 163, 177, 192, 207, 223, 239,
    ],
    [
        16, 29, 47, 61, 76, 90, 106, 119, 133, 147, 161, 176, 193, 209, 224, 240,
    ],
    [
        15, 21, 35, 50, 61, 73, 86, 97, 110, 119, 129, 141, 175, 198, 218, 237,
    ],
];

/// NLSF stage-1 inverse weights, WB (Q9).
pub const NLSF_CB1_WGHT_WB_Q9: [[i16; 16]; 32] = [
    [
        3657, 2925, 2925, 2925, 2925, 2925, 2925, 2925, 2925, 2925, 2925, 2925, 2963, 2963, 2925,
        2846,
    ],
    [
        3216, 3085, 2972, 3056, 3056, 3010, 3010, 3010, 2963, 2963, 3010, 2972, 2888, 2846, 2846,
        2726,
    ],
    [
        3920, 4014, 2981, 3207, 3207, 2934, 3056, 2846, 3122, 3244, 2925, 2846, 2620, 2553, 2780,
        2925,
    ],
    [
        3516, 3197, 3010, 3103, 3019, 2888, 2925, 2925, 2925, 2925, 2888, 2888, 2888, 2888, 2888,
        2753,
    ],
    [
        5054, 5054, 2934, 3573, 3385, 3056, 3085, 2793, 3160, 3160, 2972, 2846, 2513, 2540, 2753,
        2888,
    ],
    [
        4428, 4149, 2700, 2753, 2972, 3010, 2925, 2846, 2981, 3019, 2925, 2925, 2925, 2925, 2888,
        2726,
    ],
    [
        3620, 3019, 2972, 3056, 3056, 2873, 2806, 3056, 3216, 3047, 2981, 3291, 3291, 2981, 3310,
        2991,
    ],
    [
        5227, 5014, 2540, 3338, 3526, 3385, 3197, 3094, 3376, 2981, 2700, 2647, 2687, 2793, 2846,
        2673,
    ],
    [
        5081, 5174, 4615, 4428, 2460, 2897, 3047, 3207, 3169, 2687, 2740, 2888, 2846, 2793, 2846,
        2700,
    ],
    [
        3122, 2888, 2963, 2925, 2925, 2925, 2925, 2963, 2963, 2963, 2963, 2925, 2925, 2963, 2963,
        2963,
    ],
    [
        4202, 3207, 2981, 3103, 3010, 2888, 2888, 2925, 2972, 2873, 2916, 3019, 2972, 3010, 3197,
        2873,
    ],
    [
        3760, 3760, 3244, 3103, 2981, 2888, 2925, 2888, 2972, 2934, 2793, 2793, 2846, 2888, 2888,
        2660,
    ],
    [
        3854, 4014, 3207, 3122, 3244, 2934, 3047, 2963, 2963, 3085, 2846, 2793, 2793, 2793, 2793,
        2580,
    ],
    [
        3845, 4080, 3357, 3516, 3094, 2740, 3010, 2934, 3122, 3085, 2846, 2846, 2647, 2647, 2846,
        2806,
    ],
    [
        5147, 4894, 3225, 3845, 3441, 3169, 2897, 3413, 3451, 2700, 2580, 2673, 2740, 2846, 2806,
        2753,
    ],
    [
        4109, 3789, 3291, 3160, 2925, 2888, 2888, 2925, 2793, 2740, 2793, 2740, 2793, 2846, 2888,
        2806,
    ],
    [
        5081, 5054, 3047, 3545, 3244, 3056, 3085, 2944, 3103, 2897, 2740, 2740, 2740, 2846, 2793,
        2620,
    ],
    [
        4309, 4309, 2860, 2527, 3207, 3376, 3376, 3075, 3075, 3376, 3056, 2846, 2647, 2580, 2726,
        2753,
    ],
    [
        3056, 2916, 2806, 2888, 2740, 2687, 2897, 3103, 3150, 3150, 3216, 3169, 3056, 3010, 2963,
        2846,
    ],
    [
        4375, 3882, 2925, 2888, 2846, 2888, 2846, 2846, 2888, 2888, 2888, 2846, 2888, 2925, 2888,
        2846,
    ],
    [
        2981, 2916, 2916, 2981, 2981, 3056, 3122, 3216, 3150, 3056, 3010, 2972, 2972, 2972, 2925,
        2740,
    ],
    [
        4229, 4149, 3310, 3347, 2925, 2963, 2888, 2981, 2981, 2846, 2793, 2740, 2846, 2846, 2846,
        2793,
    ],
    [
        4080, 4014, 3103, 3010, 2925, 2925, 2925, 2888, 2925, 2925, 2846, 2846, 2846, 2793, 2888,
        2780,
    ],
    [
        4615, 4575, 3169, 3441, 3207, 2981, 2897, 3038, 3122, 2740, 2687, 2687, 2687, 2740, 2793,
        2700,
    ],
    [
        4149, 4269, 3789, 3657, 2726, 2780, 2888, 2888, 3010, 2972, 2925, 2846, 2687, 2687, 2793,
        2888,
    ],
    [
        4215, 3554, 2753, 2846, 2846, 2888, 2888, 2888, 2925, 2925, 2888, 2925, 2925, 2925, 2963,
        2888,
    ],
    [
        5174, 4921, 2261, 3432, 3789, 3479, 3347, 2846, 3310, 3479, 3150, 2897, 2460, 2487, 2753,
        2925,
    ],
    [
        3451, 3685, 3122, 3197, 3357, 3047, 3207, 3207, 2981, 3216, 3085, 2925, 2925, 2687, 2540,
        2434,
    ],
    [
        2981, 3010, 2793, 2793, 2740, 2793, 2846, 2972, 3056, 3103, 3150, 3150, 3150, 3103, 3010,
        3010,
    ],
    [
        2944, 2873, 2687, 2726, 2780, 3010, 3432, 3545, 3357, 3244, 3056, 3010, 2963, 2925, 2888,
        2846,
    ],
    [
        3019, 2944, 2897, 3010, 3010, 2972, 3019, 3103, 3056, 3056, 3010, 2888, 2846, 2925, 2925,
        2888,
    ],
    [
        3920, 3967, 3010, 3197, 3357, 3216, 3291, 3291, 3479, 3704, 3441, 2726, 2181, 2460, 2580,
        2607,
    ],
];

/// NLSF stage-1 selection iCDF, WB, indexed by voiced flag.
pub const NLSF_CB1_ICDF_WB: [[u8; 32]; 2] = [
    [
        225, 204, 201, 184, 183, 175, 158, 154, 153, 135, 119, 115, 113, 110, 109, 99, 98, 95, 79,
        68, 52, 50, 48, 45, 43, 32, 31, 27, 18, 10, 3, 0,
    ],
    [
        255, 251, 235, 230, 212, 201, 196, 182, 167, 166, 163, 151, 138, 124, 110, 104, 90, 78, 76,
        70, 69, 57, 45, 34, 24, 21, 11, 6, 5, 4, 3, 0,
    ],
];

/// NLSF stage-2 backward-prediction weights, WB (Q8), 2 selectable rows.
pub const NLSF_PRED_WB_Q8: [[u8; 15]; 2] = [
    [
        175, 148, 160, 176, 178, 173, 174, 164, 177, 174, 196, 182, 198, 192, 182,
    ],
    [
        68, 62, 66, 60, 72, 117, 85, 90, 118, 136, 151, 142, 160, 142, 155,
    ],
];

/// NLSF stage-2 selector bytes, WB. Flat array indexed `[i1*8 + coeff/2]`;
/// each byte packs the residual-codebook index and prediction-weight selector
/// for an even/odd coefficient pair (libopus `silk_NLSF_unpack`).
pub const NLSF_CB2_SELECT_WB: [u8; 256] = [
    0, 0, 0, 0, 0, 0, 0, 1, 100, 102, 102, 68, 68, 36, 34, 96, 164, 107, 158, 185, 180, 185, 139,
    102, 64, 66, 36, 34, 34, 0, 1, 32, 208, 139, 141, 191, 152, 185, 155, 104, 96, 171, 104, 166,
    102, 102, 102, 132, 1, 0, 0, 0, 0, 16, 16, 0, 80, 109, 78, 107, 185, 139, 103, 101, 208, 212,
    141, 139, 173, 153, 123, 103, 36, 0, 0, 0, 0, 0, 0, 1, 48, 0, 0, 0, 0, 0, 0, 32, 68, 135, 123,
    119, 119, 103, 69, 98, 68, 103, 120, 118, 118, 102, 71, 98, 134, 136, 157, 184, 182, 153, 139,
    134, 208, 168, 248, 75, 189, 143, 121, 107, 32, 49, 34, 34, 34, 0, 17, 2, 210, 235, 139, 123,
    185, 137, 105, 134, 98, 135, 104, 182, 100, 183, 171, 134, 100, 70, 68, 70, 66, 66, 34, 131,
    64, 166, 102, 68, 36, 2, 1, 0, 134, 166, 102, 68, 34, 34, 66, 132, 212, 246, 158, 139, 107,
    107, 87, 102, 100, 219, 125, 122, 137, 118, 103, 132, 114, 135, 137, 105, 171, 106, 50, 34,
    164, 214, 141, 143, 185, 151, 121, 103, 192, 34, 0, 0, 0, 0, 0, 1, 208, 109, 74, 187, 134, 249,
    159, 137, 102, 110, 154, 118, 87, 101, 119, 101, 0, 2, 0, 36, 36, 66, 68, 35, 96, 164, 102,
    100, 36, 0, 2, 33, 167, 138, 174, 102, 100, 84, 2, 2, 100, 107, 120, 119, 36, 197, 24, 0,
];

/// NLSF stage-2 residual iCDF set, WB (8 codebooks).
pub const NLSF_CB2_ICDF_WB: [[u8; 9]; 8] = [
    [255, 254, 253, 244, 12, 3, 2, 1, 0],
    [255, 254, 252, 224, 38, 3, 2, 1, 0],
    [255, 254, 251, 209, 57, 4, 2, 1, 0],
    [255, 254, 244, 195, 69, 4, 2, 1, 0],
    [255, 251, 232, 184, 84, 7, 2, 1, 0],
    [255, 254, 240, 186, 86, 14, 2, 1, 0],
    [255, 254, 239, 178, 91, 30, 5, 1, 0],
    [255, 248, 227, 177, 100, 19, 2, 1, 0],
];

/// Minimum NLSF spacing, WB (Q15), order+1 entries.
pub const NLSF_DELTA_MIN_WB_Q15: [i16; 17] =
    [100, 3, 40, 3, 3, 3, 5, 14, 14, 10, 11, 3, 8, 9, 7, 3, 347];

/// Q12 cosine table for NLSF-to-LPC conversion (129 points, peak 2.0 in Q12).
pub const LSF_COS_Q12: [i32; 129] = [
    8192, 8190, 8182, 8170, 8152, 8130, 8104, 8072, 8034, 7994, 7946, 7896, 7840, 7778, 7714, 7644,
    7568, 7490, 7406, 7318, 7226, 7128, 7026, 6922, 6812, 6698, 6580, 6458, 6332, 6204, 6070, 5934,
    5792, 5648, 5502, 5352, 5198, 5040, 4880, 4718, 4552, 4382, 4212, 4038, 3862, 3684, 3502, 3320,
    3136, 2948, 2760, 2570, 2378, 2186, 1990, 1794, 1598, 1400, 1202, 1002, 802, 602, 402, 202, 0,
    -202, -402, -602, -802, -1002, -1202, -1400, -1598, -1794, -1990, -2186, -2378, -2570, -2760,
    -2948, -3136, -3320, -3502, -3684, -3862, -4038, -4212, -4382, -4552, -4718, -4880, -5040,
    -5198, -5352, -5502, -5648, -5792, -5934, -6070, -6204, -6332, -6458, -6580, -6698, -6812,
    -6922, -7026, -7128, -7226, -7318, -7406, -7490, -7568, -7644, -7714, -7778, -7840, -7896,
    -7946, -7994, -8034, -8072, -8104, -8130, -8152, -8170, -8182, -8190, -8192,
];

/// Independent-gain MSB iCDF, indexed by signal type.
pub const GAIN_ICDF: [[u8; 8]; 3] = [
    [224, 112, 44, 15, 3, 2, 1, 0],
    [254, 237, 192, 132, 70, 23, 4, 0],
    [255, 252, 226, 155, 61, 11, 2, 0],
];

/// Delta-coded gain iCDF.
pub const DELTA_GAIN_ICDF: [u8; 41] = [
    250, 245, 234, 203, 71, 50, 42, 38, 35, 33, 31, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18,
    17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
];

/// LTP filter codebook, periodicity 0 (8 entries of 5 taps, Q7).
pub const LTP_FILTER_CB0_Q7: [[i8; 5]; 8] = [
    [4, 6, 24, 7, 5],
    [0, 0, 2, 0, 0],
    [12, 28, 41, 13, -4],
    [-9, 15, 42, 25, 14],
    [1, -2, 62, 41, -9],
    [-10, 37, 65, -4, 3],
    [-6, 4, 66, 7, -8],
    [16, 14, 38, -3, 33],
];

/// LTP filter codebook, periodicity 1 (16 entries of 5 taps, Q7).
pub const LTP_FILTER_CB1_Q7: [[i8; 5]; 16] = [
    [13, 22, 39, 23, 12],
    [-1, 36, 64, 27, -6],
    [-7, 10, 55, 43, 17],
    [1, 1, 8, 1, 1],
    [6, -11, 74, 53, -9],
    [-12, 55, 76, -12, 8],
    [-3, 3, 93, 27, -4],
    [26, 39, 59, 3, -8],
    [2, 0, 77, 11, 9],
    [-8, 22, 44, -6, 7],
    [40, 9, 26, 3, 9],
    [-7, 20, 101, -7, 4],
    [3, -8, 42, 26, 0],
    [-15, 33, 68, 2, 23],
    [-2, 55, 46, -2, 15],
    [3, -1, 21, 16, 41],
];

/// LTP filter codebook, periodicity 2 (32 entries of 5 taps, Q7).
pub const LTP_FILTER_CB2_Q7: [[i8; 5]; 32] = [
    [-6, 27, 61, 39, 5],
    [-11, 42, 88, 4, 1],
    [-2, 60, 65, 6, -4],
    [-1, -5, 73, 56, 1],
    [-9, 19, 94, 29, -9],
    [0, 12, 99, 6, 4],
    [8, -19, 102, 46, -13],
    [3, 2, 13, 3, 2],
    [9, -21, 84, 72, -18],
    [-11, 46, 104, -22, 8],
    [18, 38, 48, 23, 0],
    [-16, 70, 83, -21, 11],
    [5, -11, 117, 22, -8],
    [-6, 23, 117, -12, 3],
    [3, -8, 95, 28, 4],
    [-10, 15, 77, 60, -15],
    [-1, 4, 124, 2, -4],
    [3, 38, 84, 24, -25],
    [2, 13, 42, 13, 31],
    [21, -4, 56, 46, -1],
    [-1, 35, 79, -13, 19],
    [-7, 65, 88, -9, -14],
    [20, 4, 81, 49, -29],
    [20, 0, 75, 3, -17],
    [5, -9, 44, 92, -8],
    [1, -3, 22, 69, 31],
    [-6, 95, 41, -12, 5],
    [39, 67, 16, -4, 1],
    [0, -6, 120, 55, -36],
    [-13, 44, 122, 4, -24],
    [81, 5, 11, 3, 7],
    [2, 0, 9, 10, 88],
];

/// LTP filter-index iCDF for periodicity 0.
pub const LTP_GAIN_ICDF_0: [u8; 8] = [71, 56, 43, 30, 21, 12, 6, 0];

/// LTP filter-index iCDF for periodicity 1.
pub const LTP_GAIN_ICDF_1: [u8; 16] = [
    199, 165, 144, 124, 109, 96, 84, 71, 61, 51, 42, 32, 23, 15, 8, 0,
];

/// LTP filter-index iCDF for periodicity 2.
pub const LTP_GAIN_ICDF_2: [u8; 32] = [
    241, 225, 211, 199, 187, 175, 164, 153, 142, 132, 123, 114, 105, 96, 88, 80, 72, 64, 57, 50,
    44, 38, 33, 29, 24, 20, 16, 12, 9, 5, 2, 0,
];

/// LTP periodicity-index iCDF.
pub const LTP_PER_INDEX_ICDF: [u8; 3] = [179, 99, 0];

/// LTP scaling-factor index iCDF.
pub const LTP_SCALE_ICDF: [u8; 3] = [128, 64, 0];

/// LTP scaling values selected by the scaling index (Q14).
pub const LTP_SCALES_Q14: [i32; 3] = [15565, 12288, 8192];

/// High part of the absolute primary pitch lag iCDF.
pub const PITCH_LAG_ICDF: [u8; 32] = [
    253, 250, 244, 233, 212, 182, 150, 131, 120, 110, 98, 85, 72, 60, 49, 40, 32, 25, 19, 15, 13,
    11, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
];

/// Relative (delta) primary pitch lag iCDF.
pub const PITCH_DELTA_ICDF: [u8; 21] = [
    210, 208, 206, 203, 199, 193, 183, 168, 142, 104, 74, 52, 37, 27, 20, 14, 10, 6, 4, 2, 0,
];

/// Pitch contour iCDF, MB/WB, 20 ms frames.
pub const PITCH_CONTOUR_ICDF: [u8; 34] = [
    223, 201, 183, 167, 152, 138, 124, 111, 98, 88, 79, 70, 62, 56, 50, 44, 39, 35, 31, 27, 24, 21,
    18, 16, 14, 12, 10, 8, 6, 4, 3, 2, 1, 0,
];

/// Pitch contour iCDF, NB, 20 ms frames.
pub const PITCH_CONTOUR_NB_ICDF: [u8; 11] = [188, 176, 155, 138, 119, 97, 67, 43, 26, 10, 0];

/// Pitch contour iCDF, MB/WB, 10 ms frames.
pub const PITCH_CONTOUR_10MS_ICDF: [u8; 12] = [165, 119, 80, 61, 47, 35, 27, 20, 14, 9, 4, 0];

/// Pitch contour iCDF, NB, 10 ms frames.
pub const PITCH_CONTOUR_10MS_NB_ICDF: [u8; 3] = [113, 63, 0];

/// Uniform-3 iCDF.
pub const UNIFORM3_ICDF: [u8; 3] = [171, 85, 0];

/// Uniform-4 iCDF.
pub const UNIFORM4_ICDF: [u8; 4] = [192, 128, 64, 0];

/// Uniform-5 iCDF.
pub const UNIFORM5_ICDF: [u8; 5] = [205, 154, 102, 51, 0];

/// Uniform-6 iCDF.
pub const UNIFORM6_ICDF: [u8; 6] = [213, 171, 128, 85, 43, 0];

/// Uniform-8 iCDF.
pub const UNIFORM8_ICDF: [u8; 8] = [224, 192, 160, 128, 96, 64, 32, 0];

/// Excitation rate-level iCDF, indexed by voiced flag.
pub const RATE_LEVELS_ICDF: [[u8; 9]; 2] = [
    [241, 190, 178, 132, 87, 74, 41, 14, 0],
    [223, 193, 157, 140, 106, 57, 39, 18, 0],
];

/// Pulse-count-per-shell-block iCDF, indexed by rate level (10 rows + escape row).
pub const PULSES_PER_BLOCK_ICDF: [[u8; 18]; 10] = [
    [
        125, 51, 26, 18, 15, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
    ],
    [
        198, 105, 45, 22, 15, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
    ],
    [
        213, 162, 116, 83, 59, 43, 32, 24, 18, 15, 12, 9, 7, 6, 5, 3, 2, 0,
    ],
    [
        239, 187, 116, 59, 28, 16, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0,
    ],
    [
        250, 229, 188, 135, 86, 51, 30, 19, 13, 10, 8, 6, 5, 4, 3, 2, 1, 0,
    ],
    [
        249, 235, 213, 185, 156, 128, 103, 83, 66, 53, 42, 33, 26, 21, 17, 13, 10, 0,
    ],
    [
        254, 249, 235, 206, 164, 118, 77, 46, 27, 16, 10, 7, 5, 4, 3, 2, 1, 0,
    ],
    [
        255, 253, 249, 239, 220, 191, 156, 119, 85, 57, 37, 23, 15, 10, 6, 4, 2, 0,
    ],
    [
        255, 253, 251, 246, 237, 223, 203, 179, 152, 124, 98, 75, 55, 40, 29, 21, 15, 0,
    ],
    [
        255, 254, 253, 247, 220, 162, 106, 67, 42, 28, 18, 12, 9, 6, 4, 3, 2, 0,
    ],
];

/// Maximum pulses per shell block before LSB extension, per rate-level group.
pub const MAX_PULSES_TABLE: [u8; 4] = [8, 10, 12, 16];

/// Offsets into the shell pulse-split tables, indexed by pulse count.
pub const SHELL_CODE_TABLE_OFFSETS: [u8; 17] = [
    0, 0, 2, 5, 9, 14, 20, 27, 35, 44, 54, 65, 77, 90, 104, 119, 135,
];

/// Shell pulse-split iCDF table, depth 0 (16-sample blocks).
pub const SHELL_CODE_TABLE0: [u8; 152] = [
    128, 0, 214, 42, 0, 235, 128, 21, 0, 244, 184, 72, 11, 0, 248, 214, 128, 42, 7, 0, 248, 225,
    170, 80, 25, 5, 0, 251, 236, 198, 126, 54, 18, 3, 0, 250, 238, 211, 159, 82, 35, 15, 5, 0, 250,
    231, 203, 168, 128, 88, 53, 25, 6, 0, 252, 238, 216, 185, 148, 108, 71, 40, 18, 4, 0, 253, 243,
    225, 199, 166, 128, 90, 57, 31, 13, 3, 0, 254, 246, 233, 212, 183, 147, 109, 73, 44, 23, 10, 2,
    0, 255, 250, 240, 223, 198, 166, 128, 90, 58, 33, 16, 6, 1, 0, 255, 251, 244, 231, 210, 181,
    146, 110, 75, 46, 25, 12, 5, 1, 0, 255, 253, 248, 238, 221, 196, 164, 128, 92, 60, 35, 18, 8,
    3, 1, 0, 255, 253, 249, 242, 229, 208, 180, 146, 110, 76, 48, 27, 14, 7, 3, 1, 0,
];

/// Shell pulse-split iCDF table, depth 1 (8-sample blocks).
pub const SHELL_CODE_TABLE1: [u8; 152] = [
    129, 0, 207, 50, 0, 236, 129, 20, 0, 245, 185, 72, 10, 0, 249, 213, 129, 42, 6, 0, 250, 226,
    169, 87, 27, 4, 0, 251, 233, 194, 130, 62, 20, 4, 0, 250, 236, 207, 160, 99, 47, 17, 3, 0, 255,
    240, 217, 182, 131, 81, 41, 11, 1, 0, 255, 254, 233, 201, 159, 107, 61, 20, 2, 1, 0, 255, 249,
    233, 206, 170, 128, 86, 50, 23, 7, 1, 0, 255, 250, 238, 217, 186, 148, 108, 70, 39, 18, 6, 1,
    0, 255, 252, 243, 226, 200, 166, 128, 90, 56, 30, 13, 4, 1, 0, 255, 252, 245, 231, 209, 180,
    146, 110, 76, 47, 25, 11, 4, 1, 0, 255, 253, 248, 237, 219, 194, 163, 128, 93, 62, 37, 19, 8,
    3, 1, 0, 255, 254, 250, 241, 226, 205, 177, 145, 111, 79, 51, 30, 15, 6, 2, 1, 0,
];

/// Shell pulse-split iCDF table, depth 2 (4-sample blocks).
pub const SHELL_CODE_TABLE2: [u8; 152] = [
    129, 0, 203, 54, 0, 234, 129, 23, 0, 245, 184, 73, 10, 0, 250, 215, 129, 41, 5, 0, 252, 232,
    173, 86, 24, 3, 0, 253, 240, 200, 129, 56, 15, 2, 0, 253, 244, 217, 164, 94, 38, 10, 1, 0, 253,
    245, 226, 189, 132, 71, 27, 7, 1, 0, 253, 246, 231, 203, 159, 105, 56, 23, 6, 1, 0, 255, 248,
    235, 213, 179, 133, 85, 47, 19, 5, 1, 0, 255, 254, 243, 221, 194, 159, 117, 70, 37, 12, 2, 1,
    0, 255, 254, 248, 234, 208, 171, 128, 85, 48, 22, 8, 2, 1, 0, 255, 254, 250, 240, 220, 189,
    149, 107, 67, 36, 16, 6, 2, 1, 0, 255, 254, 251, 243, 227, 201, 166, 128, 90, 55, 29, 13, 5, 2,
    1, 0, 255, 254, 252, 246, 234, 213, 183, 147, 109, 73, 43, 22, 10, 4, 2, 1, 0,
];

/// Shell pulse-split iCDF table, depth 3 (2-sample blocks).
pub const SHELL_CODE_TABLE3: [u8; 152] = [
    130, 0, 200, 58, 0, 231, 130, 26, 0, 244, 184, 76, 12, 0, 249, 214, 130, 43, 6, 0, 252, 232,
    173, 87, 24, 3, 0, 253, 241, 203, 131, 56, 14, 2, 0, 254, 246, 221, 167, 94, 35, 8, 1, 0, 254,
    249, 232, 193, 130, 65, 23, 5, 1, 0, 255, 251, 239, 211, 162, 99, 45, 15, 4, 1, 0, 255, 251,
    243, 223, 186, 131, 74, 33, 11, 3, 1, 0, 255, 252, 245, 230, 202, 158, 105, 57, 24, 8, 2, 1, 0,
    255, 253, 247, 235, 214, 179, 132, 84, 44, 19, 7, 2, 1, 0, 255, 254, 250, 240, 223, 196, 159,
    112, 69, 36, 15, 6, 2, 1, 0, 255, 254, 253, 245, 231, 209, 176, 136, 93, 55, 27, 11, 3, 2, 1,
    0, 255, 254, 253, 252, 239, 221, 194, 158, 117, 76, 42, 18, 4, 3, 2, 1, 0,
];

/// Excitation LSB iCDF.
pub const LSB_ICDF: [u8; 2] = [120, 0];

/// Excitation pulse-sign iCDF, 6 context rows (signal-type/quant-offset/pulse-count).
pub const SIGN_ICDF: [[u8; 7]; 6] = [
    [254, 49, 67, 77, 82, 93, 99],
    [198, 11, 18, 24, 31, 36, 45],
    [255, 46, 66, 78, 87, 94, 104],
    [208, 14, 21, 32, 42, 51, 66],
    [255, 94, 104, 109, 112, 115, 118],
    [248, 53, 69, 80, 88, 95, 102],
];

/// Frame-type iCDF when the VAD flag is clear (inactive frame).
pub const TYPE_OFFSET_NO_VAD_ICDF: [u8; 2] = [230, 0];

/// Frame-type iCDF when the VAD flag is set (active frame).
pub const TYPE_OFFSET_VAD_ICDF: [u8; 4] = [232, 158, 10, 0];

/// Excitation quantization offsets (Q10), indexed by `[voiced][quant_offset_type]`.
pub const QUANTIZATION_OFFSETS_Q10: [[i16; 2]; 2] = [[100, 240], [32, 100]];

/// NLSF interpolation-factor iCDF (20 ms frames).
pub const NLSF_INTERP_ICDF: [u8; 5] = [243, 221, 192, 181, 0];

/// LBRR per-frame flag iCDF for 40 ms packets (3 combinations).
pub const LBRR_FLAGS_2_ICDF: [u8; 3] = [203, 150, 0];

/// LBRR per-frame flag iCDF for 60 ms packets (7 combinations).
pub const LBRR_FLAGS_3_ICDF: [u8; 7] = [215, 195, 166, 125, 110, 82, 0];

/// Stereo: iCDF for the 'mid only' flag.
pub const STEREO_ONLY_CODE_MID_ICDF: [u8; 2] = [64, 0];

/// Stereo: iCDF for the joint stereo-prediction-weight stage-1 index.
pub const STEREO_PRED_JOINT_ICDF: [u8; 25] = [
    249, 247, 246, 245, 244, 234, 210, 202, 201, 200, 197, 174, 82, 59, 56, 55, 54, 46, 22, 12, 11,
    10, 9, 7, 0,
];

/// Stereo: quantized prediction-weight reconstruction levels (Q13).
pub const STEREO_PRED_QUANT_Q13: [i32; 16] = [
    -13732, -10050, -8266, -7526, -6500, -5000, -2950, -820, 820, 2950, 5000, 6500, 7526, 8266,
    10050, 13732,
];

/// NLSF stage-2 residual extension iCDF (used when a residual saturates at
/// magnitude 4; RFC 6716 §4.2.7.5.2).
pub const NLSF_EXT_ICDF: [u8; 7] = [100, 40, 16, 7, 3, 1, 0];

/// SILK NLSF quantization step size for NB/MB (RFC 6716 §4.2.7.5.3, Q16).
pub const NLSF_QSTEP_NB_MB: i32 = 11_796;

/// SILK NLSF quantization step size for WB (RFC 6716 §4.2.7.5.3, Q16).
pub const NLSF_QSTEP_WB: i32 = 9_830;