103 lines
2.5 KiB
C++
103 lines
2.5 KiB
C++
/***************************************************************************\
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*
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* MPEG Layer3-Audio Decoder
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* © 1997-2006 by Fraunhofer IIS
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* All Rights Reserved
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*
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* filename: huffmantable.h
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* project : MPEG Decoder
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* author : Martin Sieler
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* date : 1998-01-05
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* contents/description: HEADER - huffman table object
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*
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*
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\***************************************************************************/
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/*
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* $Date: 2011/01/18 23:00:53 $
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* $Id: huffmantable.h,v 1.3 2011/01/18 23:00:53 audiodsp Exp $
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*/
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#ifndef __HUFFMANTABLE_H__
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#define __HUFFMANTABLE_H__
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/* ------------------------ includes --------------------------------------*/
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/*-------------------------- defines --------------------------------------*/
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#define HUFFMAN_BITS_4
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/*-------------------------------------------------------------------------*/
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// Huffman tables.
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//
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// This object holds the huffman table for ISO/MPEG Layer-3.
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//
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typedef struct
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{
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const unsigned char length;
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const unsigned char value;
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} huffman_entry_t;
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class CHuffmanTable
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{
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public:
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/*unsigned int nTableIndex; */
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CHuffmanTable();
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virtual ~CHuffmanTable();
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void SetTableIndex(unsigned int _nTableIndex)
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{ nTableIndex = _nTableIndex; }
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unsigned int GetBitsPerLevel() const
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{ return BITS_PER_LEVEL; }
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unsigned int GetLinBits() const
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{ return ht[nTableIndex].linbits; }
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unsigned char GetCode (unsigned int nIndex, unsigned int nValue) const
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{ return (ht[nTableIndex].table[nIndex][nValue] & 0xff); }
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unsigned char GetLength(unsigned int nIndex, unsigned int nValue) const
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{ return ((ht[nTableIndex].table[nIndex][nValue] >> 8) & 0xff); }
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bool IsTableValid() const
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{ return (ht[nTableIndex].table ? true:false); }
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bool IsLengthZero(unsigned int nIndex, unsigned int nValue) const
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{ return ((ht[nTableIndex].table[nIndex][nValue] & 0xff00) == 0); }
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enum
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{
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#if defined HUFFMAN_BITS_2 /* HuffmanBits parallel huffman tables */
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BITS_PER_LEVEL = 2,
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ENTRIES_PER_LEVEL = 4
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#elif defined HUFFMAN_BITS_3
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BITS_PER_LEVEL = 3,
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ENTRIES_PER_LEVEL = 8
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#elif defined HUFFMAN_BITS_4 /* HuffmanBits parallel huffman tables */
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BITS_PER_LEVEL = 4,
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ENTRIES_PER_LEVEL = 16
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#endif
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};
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protected:
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private:
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typedef struct
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{
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unsigned int linbits;
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const unsigned short(*table)[ENTRIES_PER_LEVEL];
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} huffmantab;
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static const huffmantab ht[];
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unsigned int nTableIndex;
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};
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/*-------------------------------------------------------------------------*/
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#endif
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