jxl-encoder 0.3.0

// Copyright (c) Imazen LLC and the JPEG XL Project Authors.
// Algorithms and constants derived from libjxl (BSD-3-Clause).
// Licensed under AGPL-3.0-or-later. Commercial licenses at https://www.imazen.io/pricing

//! Static pre-computed entropy codes.
//!
//! These are ported from libjxl-tiny's static_entropy_codes.h.

#![allow(dead_code)]
//!
//! These are the default Huffman codes used by libjxl-tiny. Using static codes
//! avoids the complexity of dynamic Huffman code optimization while still
//! producing valid bitstreams.

use crate::entropy_coding::encode::PrefixCode;

/// Number of DC prefix codes.
pub const NUM_DC_PREFIX_CODES: usize = 8;

/// Number of DC contexts.
pub const NUM_DC_CONTEXTS: usize = 45;

/// DC context map (maps context ID to prefix code index).
pub static DC_CONTEXT_MAP: [u8; NUM_DC_CONTEXTS] = [
    0, 1, 2, 2, 1, 1, 3, 0, 3, 0, 4, 5, 6, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
    6, 6, 7, 7, 7, 6, 7, 6, 7, 6, 6, 5, 5,
];

/// DC prefix codes.
pub static DC_PREFIX_CODES: [PrefixCode; NUM_DC_PREFIX_CODES] = [
    // Code 0
    PrefixCode {
        depths: [
            6, 7, 7, 7, 7, 7, 7, 7, 1, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
            7, 7, 7, 7, 7, 7,
        ],
        bits: [
            0x0001, 0x0021, 0x0061, 0x0011, 0x0051, 0x0031, 0x0071, 0x0009, 0x0000, 0x0049, 0x0029,
            0x0069, 0x0019, 0x0059, 0x0039, 0x0079, 0x0005, 0x0045, 0x0025, 0x0065, 0x0015, 0x0055,
            0x0035, 0x0075, 0x000d, 0x004d, 0x002d, 0x006d, 0x001d, 0x005d, 0x003d, 0x007d, 0x0003,
            0x0043, 0x0023, 0x0063, 0x0013, 0x0053, 0x0033, 0x0073, 0x000b, 0x004b, 0x002b, 0x006b,
            0x001b, 0x005b, 0x003b, 0x007b, 0x0007, 0x0047, 0x0027, 0x0067, 0x0017, 0x0057, 0x0037,
            0x0077, 0x000f, 0x004f, 0x002f, 0x006f, 0x001f, 0x005f, 0x003f, 0x007f,
        ],
    },
    // Code 1
    PrefixCode {
        depths: [
            1, 3, 2, 5, 4, 7, 7, 8, 8, 10, 9, 12, 10, 13, 11, 14, 13, 14, 14, 14, 14, 14, 14, 14,
            14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
            14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
        ],
        bits: [
            0x0000, 0x0003, 0x0001, 0x000f, 0x0007, 0x001f, 0x005f, 0x003f, 0x00bf, 0x017f, 0x007f,
            0x04ff, 0x037f, 0x0cff, 0x00ff, 0x02ff, 0x1cff, 0x22ff, 0x12ff, 0x32ff, 0x0aff, 0x2aff,
            0x1aff, 0x3aff, 0x06ff, 0x26ff, 0x16ff, 0x36ff, 0x0eff, 0x2eff, 0x1eff, 0x3eff, 0x01ff,
            0x21ff, 0x11ff, 0x31ff, 0x09ff, 0x29ff, 0x19ff, 0x39ff, 0x05ff, 0x25ff, 0x15ff, 0x35ff,
            0x0dff, 0x2dff, 0x1dff, 0x3dff, 0x03ff, 0x23ff, 0x13ff, 0x33ff, 0x0bff, 0x2bff, 0x1bff,
            0x3bff, 0x07ff, 0x27ff, 0x17ff, 0x37ff, 0x0fff, 0x2fff, 0x1fff, 0x3fff,
        ],
    },
    // Code 2
    PrefixCode {
        depths: [
            1, 2, 4, 4, 8, 4, 13, 5, 15, 6, 15, 7, 15, 9, 15, 12, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0001, 0x0003, 0x000b, 0x007f, 0x0007, 0x09ff, 0x000f, 0x19ff, 0x001f, 0x59ff,
            0x003f, 0x39ff, 0x00ff, 0x79ff, 0x01ff, 0x05ff, 0x45ff, 0x25ff, 0x65ff, 0x15ff, 0x55ff,
            0x35ff, 0x75ff, 0x0dff, 0x4dff, 0x2dff, 0x6dff, 0x1dff, 0x5dff, 0x3dff, 0x7dff, 0x03ff,
            0x43ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 3
    PrefixCode {
        depths: [
            1, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 3, 9, 2, 9, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
            9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
            9, 9, 9, 9, 9, 9,
        ],
        bits: [
            0x0000, 0x0007, 0x0087, 0x00c7, 0x01c7, 0x0027, 0x0127, 0x00a7, 0x01a7, 0x0067, 0x0167,
            0x00e7, 0x0003, 0x01e7, 0x0001, 0x0017, 0x0047, 0x0117, 0x0097, 0x0197, 0x0057, 0x0157,
            0x00d7, 0x01d7, 0x0037, 0x0137, 0x00b7, 0x01b7, 0x0077, 0x0177, 0x00f7, 0x01f7, 0x000f,
            0x010f, 0x008f, 0x018f, 0x004f, 0x014f, 0x00cf, 0x01cf, 0x002f, 0x012f, 0x00af, 0x01af,
            0x006f, 0x016f, 0x00ef, 0x01ef, 0x001f, 0x011f, 0x009f, 0x019f, 0x005f, 0x015f, 0x00df,
            0x01df, 0x003f, 0x013f, 0x00bf, 0x01bf, 0x007f, 0x017f, 0x00ff, 0x01ff,
        ],
    },
    // Code 4
    PrefixCode {
        depths: [
            1, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 3, 9, 2, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
            9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9,
            9, 9, 9, 9, 9, 9,
        ],
        bits: [
            0x0000, 0x0007, 0x0087, 0x0047, 0x00c7, 0x01c7, 0x0027, 0x0127, 0x00a7, 0x01a7, 0x0067,
            0x0167, 0x0003, 0x00e7, 0x0001, 0x01e7, 0x0017, 0x0117, 0x0097, 0x0197, 0x0057, 0x0157,
            0x00d7, 0x01d7, 0x0037, 0x0137, 0x00b7, 0x01b7, 0x0077, 0x0177, 0x00f7, 0x01f7, 0x000f,
            0x010f, 0x008f, 0x018f, 0x004f, 0x014f, 0x00cf, 0x01cf, 0x002f, 0x012f, 0x00af, 0x01af,
            0x006f, 0x016f, 0x00ef, 0x01ef, 0x001f, 0x011f, 0x009f, 0x019f, 0x005f, 0x015f, 0x00df,
            0x01df, 0x003f, 0x013f, 0x00bf, 0x01bf, 0x007f, 0x017f, 0x00ff, 0x01ff,
        ],
    },
    // Code 5
    PrefixCode {
        depths: [
            5, 6, 6, 6, 6, 7, 6, 7, 6, 7, 7, 7, 7, 8, 7, 8, 6, 6, 6, 6, 6, 6, 6, 6, 5, 5, 5, 5, 5,
            5, 5, 5, 4, 5, 5, 5, 4, 5, 5, 5, 5, 5, 6, 6, 6, 7, 8, 9, 10, 11, 14, 14, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0004, 0x0015, 0x0035, 0x000d, 0x002d, 0x0037, 0x001d, 0x0077, 0x003d, 0x000f, 0x004f,
            0x002f, 0x006f, 0x003f, 0x001f, 0x00bf, 0x0003, 0x0023, 0x0013, 0x0033, 0x000b, 0x002b,
            0x001b, 0x003b, 0x0014, 0x000c, 0x001c, 0x0002, 0x0012, 0x000a, 0x001a, 0x0006, 0x0000,
            0x0016, 0x000e, 0x001e, 0x0008, 0x0001, 0x0011, 0x0009, 0x0019, 0x0005, 0x0007, 0x0027,
            0x0017, 0x005f, 0x007f, 0x00ff, 0x01ff, 0x03ff, 0x07ff, 0x27ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 6
    PrefixCode {
        depths: [
            4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 4, 5, 5, 5, 5, 5, 6, 6, 5, 6, 6, 7, 7,
            7, 8, 8, 8, 9, 9, 10, 10, 10, 11, 11, 10, 11, 11, 12, 11, 12, 13, 14, 14, 14, 14, 14,
            14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0008, 0x0004, 0x000c, 0x0002, 0x000a, 0x000e, 0x001e, 0x0001, 0x0011, 0x0009,
            0x0019, 0x0005, 0x001b, 0x003b, 0x0007, 0x0006, 0x0015, 0x000d, 0x001d, 0x0003, 0x0013,
            0x0027, 0x0017, 0x000b, 0x0037, 0x000f, 0x002f, 0x006f, 0x001f, 0x005f, 0x00df, 0x003f,
            0x00bf, 0x01bf, 0x007f, 0x027f, 0x017f, 0x00ff, 0x04ff, 0x037f, 0x02ff, 0x06ff, 0x05ff,
            0x01ff, 0x0dff, 0x03ff, 0x13ff, 0x33ff, 0x0bff, 0x2bff, 0x1bff, 0x3bff, 0x07ff, 0x27ff,
            0x17ff, 0x37ff, 0x0fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 7
    PrefixCode {
        depths: [
            5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 4, 4, 5, 5, 4, 4, 5, 5, 4, 5, 5, 5, 5,
            6, 7, 7, 7, 8, 8, 9, 9, 9, 9, 10, 9, 10, 10, 11, 10, 12, 13, 13, 14, 14, 14, 14, 14,
            14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
        ],
        bits: [
            0x000a, 0x001a, 0x0006, 0x0016, 0x000e, 0x001e, 0x0001, 0x0011, 0x000b, 0x002b, 0x001b,
            0x003b, 0x0007, 0x0027, 0x0017, 0x0037, 0x0000, 0x0008, 0x0009, 0x0019, 0x0004, 0x000c,
            0x0005, 0x0015, 0x0002, 0x000d, 0x001d, 0x0003, 0x0013, 0x000f, 0x002f, 0x006f, 0x001f,
            0x005f, 0x00df, 0x003f, 0x013f, 0x00bf, 0x01bf, 0x017f, 0x007f, 0x037f, 0x00ff, 0x01ff,
            0x02ff, 0x05ff, 0x0dff, 0x1dff, 0x03ff, 0x23ff, 0x13ff, 0x33ff, 0x0bff, 0x2bff, 0x1bff,
            0x3bff, 0x07ff, 0x27ff, 0x17ff, 0x37ff, 0x0fff, 0x2fff, 0x1fff, 0x3fff,
        ],
    },
];

/// Number of AC prefix codes.
pub const NUM_AC_PREFIX_CODES: usize = 8;

/// Number of AC contexts.
pub const NUM_AC_CONTEXTS: usize = super::ac_context::NUM_AC_CONTEXTS;

/// AC context map (maps context ID to prefix code index).
/// This maps all 1980 AC contexts (148 non-zero buckets + 4 * 458 zero density contexts).
#[rustfmt::skip]
pub static AC_CONTEXT_MAP: [u8; 1980] = [
    // Context map for number of nonzeros (148 entries = 37 buckets * 4 block types)
    //   8x8   8x16  8x8   8x16
    //    Y     Y    X,B   X,B
          0,    1,    2,    1,    // pred:  0
          3,    4,    2,    2,    // pred:  1
          0,    2,    5,    5,    // pred:  2
          2,    2,    5,    5,    // pred:  3
          0,    2,    5,    5,    // pred:  4
          3,    2,    5,    5,    // pred:  5
          0,    0,    5,    5,    // pred:  6
          3,    0,    5,    0,    // pred:  7
          0,    2,    5,    0,    // pred:  8 -  9
          3,    0,    5,    0,    // pred: 10 - 11
          3,    3,    5,    3,    // pred: 12 - 13
          3,    3,    0,    3,    // pred: 14 - 15
          3,    3,    0,    3,    // pred: 16 - 17
          3,    3,    0,    3,    // pred: 18 - 19
          3,    3,    3,    3,    // pred: 20 - 21
          3,    3,    3,    3,    // pred: 22 - 23
          3,    3,    3,    3,    // pred: 24 - 25
          3,    3,    3,    6,    // pred: 26 - 27
          3,    6,    3,    6,    // pred: 28 - 29
          6,    6,    3,    6,    // pred: 30 - 31
          6,    7,    3,    6,    // pred: 32 - 33
          3,    7,    3,    6,    // pred: 34 - 35
          3,    7,    3,    6,    // pred: 36 - 37
          3,    7,    3,    6,    // pred: 38 - 39
          3,    7,    3,    6,    // pred: 40 - 41
          6,    7,    3,    7,    // pred: 42 - 43
          6,    7,    3,    7,    // pred: 44 - 45
          6,    7,    3,    6,    // pred: 46 - 47
          6,    7,    3,    7,    // pred: 48 - 49
          6,    7,    0,    0,    // pred: 50 - 51
          6,    7,    0,    0,    // pred: 52 - 53
          6,    7,    0,    0,    // pred: 54 - 55
          6,    7,    0,    0,    // pred: 56 - 57
          6,    7,    0,    0,    // pred: 58 - 59
          6,    7,    0,    0,    // pred: 60 - 61
          6,    7,    0,    0,    // pred: 62 - 63
          0,    0,    0,    0,    // pred: 64 -

    // Zero density context map for 8x8 Y blocks (458 entries)
    // Nonzeros left: 1 (k: 1-63, 62 pairs of entries = 124 entries before compression)
               0,  1,    1,  1,    1,  1,  // k:  1 -  3
     4,  1,    4,  1,    1,  1,    4,  1,  // k:  4 -  7
     4,  4,    1,  4,    1,  4,    1,  4,  // k:  8 - 11
     1,  4,    4,  4,    1,  4,    1,  4,  // k: 12 - 15
     4,  1,    1,  4,    1,  4,    1,  1,  // k: 16 - 23
     1,  4,    1,  1,    1,  2,    1,  4,  // k: 24 - 31
     1,  2,    1,  4,    1,  4,    1,  1,  // k: 32 - 47
     1,  1,    4,  4,    4,  4,    2,  2,  // k: 48 - 63
    // Nonzeros left: 2
               0,  4,    4,  4,    1,  4,  // k:  1 -  3
     4,  1,    4,  4,    1,  4,    4,  4,  // k:  4 -  7
     4,  1,    1,  1,    1,  4,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    1,  2,  // k: 12 - 15
     4,  4,    1,  4,    1,  2,    1,  4,  // k: 16 - 23
     1,  1,    4,  2,    1,  2,    1,  4,  // k: 24 - 31
     1,  4,    1,  4,    4,  4,    4,  4,  // k: 32 - 47
     1,  4,    4,  4,    4,  4,    2,  2,  // k: 48 - 63
    // Nonzeros left: 3 - 4
               0,  4,    4,  2,    1,  4,  // k:  1 -  3
     4,  4,    4,  4,    1,  2,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    1,  2,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    2,  4,    1,  2,  // k: 12 - 15
     1,  4,    4,  4,    4,  2,    1,  4,  // k: 16 - 23
     4,  4,    4,  4,    1,  2,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  4,    4,  4,    2,  2,    2,  5,  // k: 48 - 63
    // Nonzeros left: 5 - 8
               2,  0,    2,  4,    4,  2,  // k:  1 -  3
     4,  2,    2,  4,    1,  2,    4,  4,  // k:  4 -  7
     2,  4,    1,  2,    1,  0,    4,  2,  // k:  8 - 11
     4,  4,    4,  4,    1,  2,    1,  2,  // k: 12 - 15
     4,  4,    4,  4,    1,  2,    4,  4,  // k: 16 - 23
     4,  4,    4,  2,    1,  2,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  2,    2,  2,    5,  5,            // k: 48 - 59
    // Nonzeros left: 9 - 12
               2,  0,    0,  2,    4,  0,  // k:  1 -  3
     2,  2,    0,  2,    1,  2,    4,  2,  // k:  4 -  7
     2,  2,    4,  2,    4,  4,    4,  2,  // k:  8 - 11
     2,  4,    2,  4,    2,  2,    1,  0,  // k: 12 - 15
     4,  2,    4,  4,    4,  2,    4,  2,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  2,    2,  2,  // k: 32 - 47
     2,  5,    5,  5,                      // k: 48 - 55
    // Nonzeros left: 13 - 20
               2,  0,    2,  0,    2,  2,  // k:  1 -  3
     2,  2,    2,  2,    4,  2,    2,  2,  // k:  4 -  7
     2,  2,    4,  2,    4,  2,    4,  2,  // k:  8 - 11
     2,  2,    2,  2,    4,  2,    4,  4,  // k: 12 - 15
     4,  2,    2,  2,    4,  4,    4,  2,  // k: 16 - 23
     2,  2,    4,  4,    4,  4,    2,  2,  // k: 24 - 31
     2,  2,    2,  2,    2,  5,    5,  5,  // k: 32 - 47
     5,  5,                                // k: 48 - 51
    // Nonzeros left: 21 - 32
               5,  0,    2,  5,    2,  2,  // k:  1 -  3
     2,  2,    2,  2,    2,  2,    2,  2,  // k:  4 -  7
     2,  2,    2,  2,    2,  2,    2,  2,  // k:  8 - 11
     2,  2,    2,  2,    2,  2,    2,  2,  // k: 12 - 15
     2,  2,    2,  2,    2,  2,    2,  2,  // k: 16 - 23
     2,  5,    2,  0,    2,  5,    5,  0,  // k: 24 - 31
     5,  0,    5,  0,    0,  0,            // k: 32 - 43
    // Nonzeros left: 33 - 63
               7,  0,    0,  7,    0,  7,  // k:  1 -  3
     0,  7,    7,  7,    0,  7,    7,  7,  // k:  4 -  7
     0,  7,    0,  7,    0,  3,    0,  7,  // k:  8 - 11
     3,  7,    3,  7,    0,  3,    0,  3,  // k: 12 - 15
     3,  3,    0,  3,    0,  0,    0,  3,  // k: 16 - 23
     3,  3,    0,  0,    0,  0,    0,  3,  // k: 24 - 31

    // Zero density context map for 8x16 and 16x8 Y blocks
    // Nonzeros left: 1
               4,  4,    1,  1,    4,  4,  // k:  1 -  3
     1,  1,    1,  1,    4,  4,    1,  1,  // k:  4 -  7
     1,  1,    1,  1,    4,  4,    1,  4,  // k:  8 - 11
     1,  1,    1,  1,    1,  1,    4,  1,  // k: 12 - 15
     1,  1,    1,  1,    4,  4,    1,  1,  // k: 16 - 23
     1,  1,    1,  4,    4,  4,    1,  1,  // k: 24 - 31
     1,  4,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    1,  1,    4,  4,  // k: 48 - 63
    // Nonzeros left: 2
               4,  4,    1,  1,    2,  4,  // k:  1 -  3
     1,  4,    1,  4,    2,  4,    1,  4,  // k:  4 -  7
     1,  4,    4,  1,    2,  4,    1,  4,  // k:  8 - 11
     1,  1,    1,  4,    4,  4,    2,  2,  // k: 12 - 15
     1,  1,    1,  4,    4,  2,    1,  1,  // k: 16 - 23
     1,  1,    4,  4,    1,  4,    1,  1,  // k: 24 - 31
     1,  4,    1,  4,    1,  4,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    4,  4,    4,  2,  // k: 48 - 63
    // Nonzeros left: 3 - 4
               4,  2,    4,  4,    5,  2,  // k:  1 -  3
     1,  1,    4,  1,    2,  2,    1,  1,  // k:  4 -  7
     1,  4,    4,  4,    2,  2,    1,  1,  // k:  8 - 11
     1,  4,    1,  1,    4,  2,    4,  5,  // k: 12 - 15
     1,  1,    1,  4,    4,  2,    1,  1,  // k: 16 - 23
     1,  1,    4,  4,    4,  2,    1,  1,  // k: 24 - 31
     4,  4,    1,  4,    1,  4,    1,  4,  // k: 32 - 47
     4,  4,    4,  4,    4,  2,    2,  2,  // k: 48 - 63
    // Nonzeros left: 5 - 8
               0,  4,    2,  2,    2,  0,  // k:  1 -  3
     1,  4,    2,  5,    2,  0,    1,  4,  // k:  4 -  7
     1,  4,    2,  2,    4,  5,    4,  4,  // k:  8 - 11
     1,  1,    4,  4,    4,  2,    4,  2,  // k: 12 - 15
     4,  4,    1,  4,    2,  0,    4,  4,  // k: 16 - 23
     1,  4,    4,  4,    4,  2,    1,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  4,    4,  2,    2,  2,            // k: 48 - 59
    // Nonzeros left: 9 - 12
               3,  2,    5,  2,    0,  0,  // k:  1 -  3
     4,  4,    2,  2,    4,  0,    4,  4,  // k:  4 -  7
     4,  4,    2,  2,    4,  0,    4,  4,  // k:  8 - 11
     1,  4,    4,  4,    2,  2,    4,  0,  // k: 12 - 15
     4,  4,    4,  4,    4,  2,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     2,  2,    5,  5,                      // k: 48 - 55
    // Nonzeros left: 13 - 20
               7,  2,    0,  5,    5,  0,  // k:  1 -  3
     4,  2,    2,  2,    4,  2,    4,  4,  // k:  4 -  7
     4,  4,    2,  2,    4,  4,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 12 - 15
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  2,    2,  2,    2,  5,  // k: 32 - 47
     5,  5,                                // k: 48 - 51
    // Nonzeros left: 21 - 32
               0,  5,    2,  5,    2,  5,  // k:  1 -  3
     2,  2,    2,  2,    2,  2,    2,  2,  // k:  4 -  7
     2,  2,    2,  2,    4,  2,    2,  2,  // k:  8 - 11
     4,  4,    2,  2,    2,  2,    4,  2,  // k: 12 - 15
     2,  2,    2,  2,    2,  2,    2,  2,  // k: 16 - 23
     2,  2,    2,  5,    2,  5,    2,  5,  // k: 24 - 31
     2,  5,    5,  5,    5,  5,            // k: 32 - 43
    // Nonzeros left: 33 - 63
               7,  7,    0,  7,    5,  7,  // k:  1 -  3
     5,  7,    0,  7,    5,  7,    5,  7,  // k:  4 -  7
     5,  3,    0,  7,    0,  3,    0,  3,  // k:  8 - 11
     5,  0,    0,  3,    0,  3,    5,  0,  // k: 12 - 15
     0,  0,    5,  0,    0,  0,    0,  0,  // k: 16 - 23
     5,  0,    0,  0,    0,  0,    3,  3,  // k: 24 - 31

    // Zero density context map for 8x8 X and B blocks
    // Nonzeros left: 1
               0,  1,    4,  4,    1,  1,  // k:  1 -  3
     4,  4,    1,  1,    1,  1,    1,  1,  // k:  4 -  7
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  8 - 11
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    4,  4,    4,  4,  // k: 48 - 63
    // Nonzeros left: 2
               0,  4,    4,  2,    1,  1,  // k:  1 -  3
     4,  4,    4,  4,    1,  1,    1,  4,  // k:  4 -  7
     4,  4,    1,  1,    1,  1,    1,  1,  // k:  8 - 11
     1,  4,    1,  1,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    4,  4,    4,  4,  // k: 48 - 63
    // Nonzeros left: 3 - 4
               0,  2,    2,  2,    4,  4,  // k:  1 -  3
     4,  4,    4,  4,    1,  1,    4,  4,  // k:  4 -  7
     4,  4,    1,  4,    1,  1,    1,  4,  // k:  8 - 11
     4,  4,    1,  4,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 48 - 63
    // Nonzeros left: 5 - 8
               2,  0,    2,  5,    4,  4,  // k:  1 -  3
     2,  2,    4,  4,    1,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    1,  1,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    1,  1,    1,  1,  // k: 12 - 15
     1,  4,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  4,    4,  4,    4,  4,            // k: 48 - 59
    // Nonzeros left: 9 - 12
               5,  0,    2,  5,    4,  2,  // k:  1 -  3
     2,  2,    4,  2,    4,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    1,  1,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    1,  4,  // k: 12 - 15
     4,  4,    4,  4,    1,  1,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  4,    2,  4,                      // k: 48 - 55
    // Nonzeros left: 13 - 20
               5,  0,    2,  5,    4,  2,  // k:  1 -  3
     2,  2,    4,  2,    4,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    4,  4,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 12 - 15
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     2,  2,                                // k: 48 - 51
    // Nonzeros left: 21 - 32
               5,  0,    2,  5,    2,  2,  // k:  1 -  3
     2,  2,    2,  2,    4,  2,    2,  2,  // k:  4 -  7
     2,  2,    4,  2,    4,  4,    4,  2,  // k:  8 - 11
     4,  2,    4,  2,    4,  2,    4,  4,  // k: 12 - 15
     4,  2,    4,  2,    4,  4,    4,  4,  // k: 16 - 23
     4,  2,    4,  2,    4,  4,    4,  2,  // k: 24 - 31
     2,  2,    2,  5,    0,  0,            // k: 32 - 43
    // Nonzeros left: 33 - 63
               0,  0,    2,  0,    2,  5,  // k:  1 -  3
     2,  5,    2,  5,    2,  2,    2,  5,  // k:  4 -  7
     2,  5,    2,  5,    2,  2,    2,  5,  // k:  8 - 11
     2,  5,    2,  5,    2,  5,    2,  2,  // k: 12 - 15
     2,  2,    2,  2,    5,  2,    2,  0,  // k: 16 - 23
     0,  0,    0,  0,    0,  0,    0,  0,  // k: 24 - 31

    // Zero density context map for 8x16 and 16x8 X and B blocks
    // Nonzeros left: 1
               1,  1,    1,  1,    1,  1,  // k:  1 -  3
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  4 -  7
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  8 - 11
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 48 - 63
    // Nonzeros left: 2
               1,  4,    1,  1,    1,  1,  // k:  1 -  3
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  4 -  7
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  8 - 11
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    1,  1,    4,  4,  // k: 48 - 63
    // Nonzeros left: 3 - 4
               4,  4,    4,  4,    4,  4,  // k:  1 -  3
     1,  1,    1,  4,    1,  1,    1,  1,  // k:  4 -  7
     1,  1,    1,  1,    1,  1,    1,  1,  // k:  8 - 11
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 32 - 47
     1,  1,    1,  1,    4,  4,    4,  4,  // k: 48 - 63
    // Nonzeros left: 5 - 8
               2,  2,    4,  4,    4,  4,  // k:  1 -  3
     1,  4,    4,  4,    4,  4,    1,  4,  // k:  4 -  7
     1,  4,    4,  4,    1,  1,    4,  4,  // k:  8 - 11
     1,  1,    4,  4,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 24 - 31
     1,  1,    1,  1,    1,  1,    4,  4,  // k: 32 - 47
     4,  4,    4,  4,    4,  4,            // k: 48 - 59
    // Nonzeros left: 9 - 12
               2,  2,    4,  2,    4,  4,  // k:  1 -  3
     4,  4,    4,  4,    4,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    1,  1,    4,  4,  // k:  8 - 11
     1,  1,    1,  4,    1,  1,    1,  1,  // k: 12 - 15
     1,  1,    1,  1,    1,  1,    1,  1,  // k: 16 - 23
     1,  1,    1,  1,    1,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     4,  4,    4,  4,                      // k: 48 - 55
    // Nonzeros left: 13 - 20
               2,  2,    4,  2,    4,  2,  // k:  1 -  3
     4,  4,    4,  4,    4,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    4,  4,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 12 - 15
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 32 - 47
     0,  0,                                // k: 48 - 51
    // Nonzeros left: 21 - 32
               5,  5,    2,  2,    2,  2,  // k:  1 -  3
     4,  2,    2,  2,    4,  4,    4,  4,  // k:  4 -  7
     4,  4,    4,  4,    4,  4,    4,  4,  // k:  8 - 11
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 12 - 15
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 16 - 23
     4,  4,    4,  4,    4,  4,    4,  4,  // k: 24 - 31
     2,  2,    0,  0,    0,  0,            // k: 32 - 43
    // Nonzeros left: 33 - 63
               0,  5,    2,  5,    2,  5,  // k:  1 -  3
     2,  2,    2,  2,    2,  2,    2,  2,  // k:  4 -  7
     2,  2,    2,  2,    2,  2,    2,  2,  // k:  8 - 11
     4,  4,    2,  4,    2,  2,    0,  0,  // k: 12 - 15
     0,  2,    0,  1,    0,  0,    0,  0,  // k: 16 - 23
     0,  0,    0,  0,    0,  0,    0,  0,  // k: 24 - 31
];

/// AC prefix codes.
pub static AC_PREFIX_CODES: [PrefixCode; NUM_AC_PREFIX_CODES] = [
    // Code 0
    PrefixCode {
        depths: [
            4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 4, 4, 5, 5, 4, 5, 6, 6, 6, 7, 9, 9, 9,
            11, 12, 13, 13, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0008, 0x0004, 0x000c, 0x0002, 0x0001, 0x0011, 0x0009, 0x0019, 0x0005, 0x0015,
            0x000d, 0x001d, 0x0003, 0x0013, 0x000b, 0x000a, 0x0006, 0x001b, 0x0007, 0x000e, 0x0017,
            0x000f, 0x002f, 0x001f, 0x003f, 0x007f, 0x017f, 0x00ff, 0x01ff, 0x05ff, 0x0dff, 0x1dff,
            0x03ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 1
    PrefixCode {
        depths: [
            1, 2, 3, 5, 4, 6, 7, 9, 9, 11, 11, 12, 12, 12, 13, 13, 12, 12, 14, 15, 14, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0001, 0x0003, 0x000f, 0x0007, 0x001f, 0x003f, 0x007f, 0x017f, 0x00ff, 0x04ff,
            0x02ff, 0x0aff, 0x06ff, 0x09ff, 0x19ff, 0x0eff, 0x01ff, 0x05ff, 0x15ff, 0x25ff, 0x55ff,
            0x35ff, 0x75ff, 0x0dff, 0x4dff, 0x2dff, 0x6dff, 0x1dff, 0x5dff, 0x3dff, 0x7dff, 0x03ff,
            0x43ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 2
    PrefixCode {
        depths: [
            2, 3, 3, 4, 3, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 6, 7, 8, 8, 8, 10, 11, 12, 11, 12, 13,
            13, 13, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0002, 0x0006, 0x0005, 0x0001, 0x000d, 0x0003, 0x000b, 0x001b, 0x0007, 0x0027,
            0x0017, 0x0037, 0x002f, 0x006f, 0x001f, 0x000f, 0x005f, 0x003f, 0x00bf, 0x007f, 0x00ff,
            0x02ff, 0x01ff, 0x06ff, 0x09ff, 0x05ff, 0x15ff, 0x0dff, 0x1dff, 0x3dff, 0x7dff, 0x03ff,
            0x43ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 3
    PrefixCode {
        depths: [
            5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 5, 6, 6, 6, 6, 6, 4, 4, 4, 4, 4, 4, 5, 5, 4, 5, 6, 6, 6,
            7, 8, 10, 10, 11, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x000e, 0x001e, 0x0001, 0x0011, 0x0009, 0x0019, 0x0005, 0x0015, 0x000d, 0x001b, 0x001d,
            0x003b, 0x0007, 0x0027, 0x0017, 0x0037, 0x0000, 0x0008, 0x0004, 0x000c, 0x0002, 0x000a,
            0x0003, 0x0013, 0x0006, 0x000b, 0x000f, 0x002f, 0x001f, 0x003f, 0x007f, 0x00ff, 0x02ff,
            0x01ff, 0x05ff, 0x15ff, 0x35ff, 0x0dff, 0x2dff, 0x1dff, 0x3dff, 0x03ff, 0x23ff, 0x13ff,
            0x33ff, 0x0bff, 0x2bff, 0x1bff, 0x3bff, 0x07ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 4
    PrefixCode {
        depths: [
            1, 3, 2, 5, 4, 7, 7, 8, 8, 9, 9, 11, 11, 12, 12, 12, 11, 12, 14, 15, 14, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0003, 0x0001, 0x000f, 0x0007, 0x001f, 0x005f, 0x003f, 0x00bf, 0x007f, 0x017f,
            0x00ff, 0x04ff, 0x06ff, 0x0eff, 0x01ff, 0x02ff, 0x09ff, 0x05ff, 0x15ff, 0x25ff, 0x55ff,
            0x35ff, 0x75ff, 0x0dff, 0x4dff, 0x2dff, 0x6dff, 0x1dff, 0x5dff, 0x3dff, 0x7dff, 0x03ff,
            0x43ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 5
    PrefixCode {
        depths: [
            3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 6, 4, 5, 5, 6, 6, 7, 9, 9, 10, 11, 12, 12,
            12, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x0000, 0x0004, 0x000c, 0x0002, 0x000a, 0x0006, 0x000e, 0x0001, 0x0009, 0x000d, 0x001d,
            0x0003, 0x0013, 0x000b, 0x001b, 0x000f, 0x0005, 0x0007, 0x0017, 0x002f, 0x001f, 0x003f,
            0x007f, 0x017f, 0x00ff, 0x02ff, 0x06ff, 0x0eff, 0x01ff, 0x09ff, 0x29ff, 0x19ff, 0x39ff,
            0x05ff, 0x25ff, 0x15ff, 0x35ff, 0x0dff, 0x2dff, 0x1dff, 0x3dff, 0x03ff, 0x23ff, 0x13ff,
            0x33ff, 0x0bff, 0x2bff, 0x1bff, 0x3bff, 0x07ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 6
    PrefixCode {
        depths: [
            9, 13, 13, 14, 13, 14, 13, 13, 13, 12, 12, 12, 11, 12, 11, 12, 10, 9, 8, 6, 5, 3, 2, 1,
            4, 9, 11, 12, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
            15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x00bf, 0x01ff, 0x11ff, 0x0dff, 0x09ff, 0x2dff, 0x19ff, 0x05ff, 0x15ff, 0x04ff, 0x0cff,
            0x02ff, 0x037f, 0x0aff, 0x077f, 0x06ff, 0x017f, 0x01bf, 0x003f, 0x001f, 0x000f, 0x0003,
            0x0001, 0x0000, 0x0007, 0x007f, 0x00ff, 0x0eff, 0x1dff, 0x5dff, 0x3dff, 0x7dff, 0x03ff,
            0x43ff, 0x23ff, 0x63ff, 0x13ff, 0x53ff, 0x33ff, 0x73ff, 0x0bff, 0x4bff, 0x2bff, 0x6bff,
            0x1bff, 0x5bff, 0x3bff, 0x7bff, 0x07ff, 0x47ff, 0x27ff, 0x67ff, 0x17ff, 0x57ff, 0x37ff,
            0x77ff, 0x0fff, 0x4fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
    // Code 7
    PrefixCode {
        depths: [
            5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 5, 5, 5, 5, 4, 5, 5, 5, 4, 4, 4, 5, 4,
            5, 5, 6, 5, 6, 7, 8, 8, 8, 10, 10, 11, 12, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14,
            14, 14, 14, 14, 14, 15, 15, 15, 15, 15, 15,
        ],
        bits: [
            0x000a, 0x001a, 0x0006, 0x0003, 0x0023, 0x0013, 0x0033, 0x000b, 0x002b, 0x001b, 0x003b,
            0x0007, 0x0027, 0x0017, 0x0037, 0x001f, 0x0016, 0x000e, 0x001e, 0x0001, 0x0000, 0x0011,
            0x0009, 0x0019, 0x0008, 0x0004, 0x000c, 0x0005, 0x0002, 0x0015, 0x000d, 0x000f, 0x001d,
            0x002f, 0x005f, 0x003f, 0x00bf, 0x007f, 0x00ff, 0x02ff, 0x01ff, 0x05ff, 0x0dff, 0x1dff,
            0x3dff, 0x03ff, 0x23ff, 0x13ff, 0x33ff, 0x0bff, 0x2bff, 0x1bff, 0x3bff, 0x07ff, 0x27ff,
            0x17ff, 0x37ff, 0x0fff, 0x2fff, 0x6fff, 0x1fff, 0x5fff, 0x3fff, 0x7fff,
        ],
    },
];

/// Get a reference to DC entropy code.
pub fn get_dc_entropy_code() -> crate::entropy_coding::encode::EntropyCode<'static> {
    crate::entropy_coding::encode::EntropyCode::new(&DC_CONTEXT_MAP, &DC_PREFIX_CODES)
}

/// Get a reference to AC entropy code.
pub fn get_ac_entropy_code() -> crate::entropy_coding::encode::EntropyCode<'static> {
    crate::entropy_coding::encode::EntropyCode::new(&AC_CONTEXT_MAP, &AC_PREFIX_CODES)
}