rockbox/apps/codecs/libmusepack/huffman.h

/*
  Copyright (c) 2005-2009, The Musepack Development Team
  All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are
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  * Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.

  * Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the following
  disclaimer in the documentation and/or other materials provided
  with the distribution.

  * Neither the name of the The Musepack Development Team nor the
  names of its contributors may be used to endorse or promote
  products derived from this software without specific prior
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  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/
/// \file huffman.h
/// Data structures and functions for huffman coding.

#ifndef _MPCDEC_HUFFMAN_H_
#define _MPCDEC_HUFFMAN_H_
#ifdef WIN32
#pragma once
#endif

#include "mpc_types.h"

#ifdef __cplusplus
extern "C" {
#endif

// LUT size parameter, LUT size is 1 << LUT_DEPTH
#define LUT_DEPTH 6

/// Huffman table entry.
typedef struct mpc_huffman_t {
    mpc_uint16_t  Code;
    mpc_uint8_t  Length;
    mpc_int8_t   Value;
} mpc_huffman;

/// Huffman LUT entry.
typedef struct mpc_huff_lut_t {
    mpc_uint8_t  Length;
    mpc_int8_t   Value;
} mpc_huff_lut;

/// Type used for huffman LUT decoding
typedef struct mpc_lut_data_t {
    mpc_huffman const *table;
    mpc_huff_lut lut[1 << LUT_DEPTH];
} mpc_lut_data;

/// Type used for canonical huffman decoding
typedef struct mpc_can_data_t {
    mpc_huffman const *table;
    mpc_int8_t const *sym;
    mpc_huff_lut lut[1 << LUT_DEPTH];
} mpc_can_data;

void huff_init_lut(const int bits);

#ifdef __cplusplus
}
#endif
#endif