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465 lines
13 KiB
465 lines
13 KiB
//C- -------------------------------------------------------------------
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//C- DjVuLibre-3.5
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//C- Copyright (c) 2002 Leon Bottou and Yann Le Cun.
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//C- Copyright (c) 2001 AT&T
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//C-
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//C- This software is subject to, and may be distributed under, the
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//C- GNU General Public License, Version 2. The license should have
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//C- accompanied the software or you may obtain a copy of the license
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//C- from the Free Software Foundation at http://www.fsf.org .
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//C-
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//C- This program is distributed in the hope that it will be useful,
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//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
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//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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//C- GNU General Public License for more details.
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//C-
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//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library
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//C- distributed by Lizardtech Software. On July 19th 2002, Lizardtech
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//C- Software authorized us to replace the original DjVu(r) Reference
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//C- Library notice by the following text (see doc/lizard2002.djvu):
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//C-
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//C- ------------------------------------------------------------------
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//C- | DjVu (r) Reference Library (v. 3.5)
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//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
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//C- | The DjVu Reference Library is protected by U.S. Pat. No.
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//C- | 6,058,214 and patents pending.
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//C- |
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//C- | This software is subject to, and may be distributed under, the
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//C- | GNU General Public License, Version 2. The license should have
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//C- | accompanied the software or you may obtain a copy of the license
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//C- | from the Free Software Foundation at http://www.fsf.org .
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//C- |
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//C- | The computer code originally released by LizardTech under this
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//C- | license and unmodified by other parties is deemed "the LIZARDTECH
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//C- | ORIGINAL CODE." Subject to any third party intellectual property
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//C- | claims, LizardTech grants recipient a worldwide, royalty-free,
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//C- | non-exclusive license to make, use, sell, or otherwise dispose of
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//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the
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//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU
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//C- | General Public License. This grant only confers the right to
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//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to
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//C- | the extent such infringement is reasonably necessary to enable
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//C- | recipient to make, have made, practice, sell, or otherwise dispose
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//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to
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//C- | any greater extent that may be necessary to utilize further
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//C- | modifications or combinations.
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//C- |
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//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
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//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
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//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
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//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
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//C- +------------------------------------------------------------------
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//
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// $Id: BSByteStream.cpp,v 1.8 2003/11/07 22:08:20 leonb Exp $
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// $Name: release_3_5_15 $
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#if NEED_GNUG_PRAGMAS
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# pragma implementation
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#endif
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// - Author: Leon Bottou, 07/1998
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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#include "BSByteStream.h"
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#undef BSORT_TIMER
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#ifdef BSORT_TIMER
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#include "GOS.h"
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#endif
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#ifdef HAVE_NAMESPACES
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namespace DJVU {
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# ifdef NOT_DEFINED // Just to fool emacs c++ mode
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}
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#endif
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#endif
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class BSByteStream::Decode : public BSByteStream
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{
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public:
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/** Creates a Static object for allocating the memory area of
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length #sz# starting at address #buffer#. */
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Decode(GP<ByteStream> bs);
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~Decode();
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void init(void);
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// Virtual functions
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virtual size_t read(void *buffer, size_t sz);
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virtual void flush(void);
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protected:
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unsigned int decode(void);
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private:
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bool eof;
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};
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// ========================================
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// --- Assertion
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#define ASSERT(expr) do{if(!(expr))G_THROW("assertion ("#expr") failed");}while(0)
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// ========================================
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// --- Construction
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BSByteStream::BSByteStream(GP<ByteStream> xbs)
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: offset(0), bptr(0), blocksize(0), size(0), bs(xbs),
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gbs(xbs), gdata(data,0)
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{
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// Initialize context array
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memset(ctx, 0, sizeof(ctx));
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}
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BSByteStream::~BSByteStream() {}
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BSByteStream::Decode::Decode(GP<ByteStream> xbs)
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: BSByteStream(xbs), eof(false) {}
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void
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BSByteStream::Decode::init(void)
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{
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gzp=ZPCodec::create(gbs,false,true);
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}
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BSByteStream::Decode::~Decode() {}
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GP<ByteStream>
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BSByteStream::create(GP<ByteStream> xbs)
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{
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BSByteStream::Decode *rbs=new BSByteStream::Decode(xbs);
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GP<ByteStream> retval=rbs;
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rbs->init();
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return retval;
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}
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void
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BSByteStream::Decode::flush()
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{
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size = bptr = 0;
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}
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// ========================================
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// -- Decoding
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static int
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decode_raw(ZPCodec &zp, int bits)
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{
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int n = 1;
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const int m = (1<<bits);
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while (n < m)
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{
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const int b = zp.decoder();
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n = (n<<1) | b;
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}
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return n - m;
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}
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static inline int
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decode_binary(ZPCodec &zp, BitContext *ctx, int bits)
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{
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int n = 1;
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int m = (1<<bits);
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ctx = ctx - 1;
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while (n < m)
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{
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int b = zp.decoder(ctx[n]);
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n = (n<<1) | b;
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}
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return n - m;
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}
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static inline void
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assignmtf(unsigned char xmtf[256])
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{
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static const unsigned char mtf[256]={
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0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
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0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
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0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
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0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
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0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,
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0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
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0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,
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0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
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0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,
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0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,
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0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,
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0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,
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0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,
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0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
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0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,
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0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
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0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,
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0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
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0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,
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0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
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0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
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0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,
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0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,
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0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
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0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,
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0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,
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0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,
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0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
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0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,
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0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
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0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,
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0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF};
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memcpy(xmtf,mtf,sizeof(mtf));
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}
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unsigned int
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BSByteStream::Decode::decode(void)
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{
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/////////////////////////////////
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//////////// Decode input stream
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int i;
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// Decode block size
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ZPCodec &zp=*gzp;
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size = decode_raw(zp, 24);
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if (!size)
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return 0;
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if (size>MAXBLOCK*1024)
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G_THROW( ERR_MSG("ByteStream.corrupt") );
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// Allocate
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if ((int)blocksize < size)
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{
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blocksize = size;
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if (data)
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{
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gdata.resize(0);
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}
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}
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if (! data)
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gdata.resize(blocksize);
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// Decode Estimation Speed
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int fshift = 0;
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if (zp.decoder())
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{
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fshift += 1;
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if (zp.decoder())
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fshift += 1;
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}
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// Prepare Quasi MTF
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static const unsigned char xmtf[256]={
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0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,
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0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
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0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,
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0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
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0x20,0x21,0x22,0x23,0x24,0x25,0x26,0x27,
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0x28,0x29,0x2A,0x2B,0x2C,0x2D,0x2E,0x2F,
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0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,
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0x38,0x39,0x3A,0x3B,0x3C,0x3D,0x3E,0x3F,
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0x40,0x41,0x42,0x43,0x44,0x45,0x46,0x47,
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0x48,0x49,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,
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0x50,0x51,0x52,0x53,0x54,0x55,0x56,0x57,
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0x58,0x59,0x5A,0x5B,0x5C,0x5D,0x5E,0x5F,
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0x60,0x61,0x62,0x63,0x64,0x65,0x66,0x67,
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0x68,0x69,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,
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0x70,0x71,0x72,0x73,0x74,0x75,0x76,0x77,
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0x78,0x79,0x7A,0x7B,0x7C,0x7D,0x7E,0x7F,
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0x80,0x81,0x82,0x83,0x84,0x85,0x86,0x87,
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0x88,0x89,0x8A,0x8B,0x8C,0x8D,0x8E,0x8F,
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0x90,0x91,0x92,0x93,0x94,0x95,0x96,0x97,
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0x98,0x99,0x9A,0x9B,0x9C,0x9D,0x9E,0x9F,
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0xA0,0xA1,0xA2,0xA3,0xA4,0xA5,0xA6,0xA7,
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0xA8,0xA9,0xAA,0xAB,0xAC,0xAD,0xAE,0xAF,
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0xB0,0xB1,0xB2,0xB3,0xB4,0xB5,0xB6,0xB7,
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0xB8,0xB9,0xBA,0xBB,0xBC,0xBD,0xBE,0xBF,
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0xC0,0xC1,0xC2,0xC3,0xC4,0xC5,0xC6,0xC7,
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0xC8,0xC9,0xCA,0xCB,0xCC,0xCD,0xCE,0xCF,
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0xD0,0xD1,0xD2,0xD3,0xD4,0xD5,0xD6,0xD7,
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0xD8,0xD9,0xDA,0xDB,0xDC,0xDD,0xDE,0xDF,
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0xE0,0xE1,0xE2,0xE3,0xE4,0xE5,0xE6,0xE7,
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0xE8,0xE9,0xEA,0xEB,0xEC,0xED,0xEE,0xEF,
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0xF0,0xF1,0xF2,0xF3,0xF4,0xF5,0xF6,0xF7,
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0xF8,0xF9,0xFA,0xFB,0xFC,0xFD,0xFE,0xFF};
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unsigned char mtf[256];
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memcpy(mtf,xmtf,sizeof(xmtf));
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unsigned int freq[FREQMAX];
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memset(freq,0,sizeof(freq));
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int fadd = 4;
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// Decode
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int mtfno = 3;
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int markerpos = -1;
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for (i=0; i<size; i++)
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{
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int ctxid = CTXIDS-1;
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if (ctxid>mtfno) ctxid=mtfno;
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BitContext *cx = ctx;
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if (zp.decoder(cx[ctxid]))
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{ mtfno=0; data[i]=mtf[mtfno]; goto rotate; }
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cx+=CTXIDS;
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if (zp.decoder(cx[ctxid]))
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{ mtfno=1; data[i]=mtf[mtfno]; goto rotate; }
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cx+=CTXIDS;
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if (zp.decoder(cx[0]))
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{ mtfno=2+decode_binary(zp,cx+1,1); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+1;
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if (zp.decoder(cx[0]))
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{ mtfno=4+decode_binary(zp,cx+1,2); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+3;
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if (zp.decoder(cx[0]))
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{ mtfno=8+decode_binary(zp,cx+1,3); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+7;
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if (zp.decoder(cx[0]))
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{ mtfno=16+decode_binary(zp,cx+1,4); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+15;
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if (zp.decoder(cx[0]))
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{ mtfno=32+decode_binary(zp,cx+1,5); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+31;
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if (zp.decoder(cx[0]))
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{ mtfno=64+decode_binary(zp,cx+1,6); data[i]=mtf[mtfno]; goto rotate; }
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cx+=1+63;
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if (zp.decoder(cx[0]))
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{ mtfno=128+decode_binary(zp,cx+1,7); data[i]=mtf[mtfno]; goto rotate; }
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mtfno=256;
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data[i]=0;
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markerpos=i;
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continue;
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// Rotate mtf according to empirical frequencies (new!)
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rotate:
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// Adjust frequencies for overflow
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int k;
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fadd = fadd + (fadd>>fshift);
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if (fadd > 0x10000000)
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{
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fadd >>= 24;
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freq[0] >>= 24;
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freq[1] >>= 24;
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freq[2] >>= 24;
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freq[3] >>= 24;
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for (k=4; k<FREQMAX; k++)
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freq[k] = freq[k]>>24;
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}
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// Relocate new char according to new freq
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unsigned int fc = fadd;
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if (mtfno < FREQMAX)
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fc += freq[mtfno];
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for (k=mtfno; k>=FREQMAX; k--)
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mtf[k] = mtf[k-1];
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for (; k>0 && fc>=freq[k-1]; k--)
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{
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mtf[k] = mtf[k-1];
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freq[k] = freq[k-1];
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}
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mtf[k] = data[i];
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freq[k] = fc;
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}
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/////////////////////////////////
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////////// Reconstruct the string
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if (markerpos<1 || markerpos>=size)
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G_THROW( ERR_MSG("ByteStream.corrupt") );
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// Allocate pointers
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unsigned int *posn;
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GPBuffer<unsigned int> gposn(posn,blocksize);
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memset(posn, 0, sizeof(unsigned int)*size);
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// Prepare count buffer
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int count[256];
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for (i=0; i<256; i++)
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count[i] = 0;
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// Fill count buffer
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for (i=0; i<markerpos; i++)
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{
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unsigned char c = data[i];
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posn[i] = (c<<24) | (count[c] & 0xffffff);
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count[c] += 1;
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}
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for (i=markerpos+1; i<size; i++)
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{
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unsigned char c = data[i];
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posn[i] = (c<<24) | (count[c] & 0xffffff);
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count[c] += 1;
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}
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// Compute sorted char positions
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int last = 1;
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for (i=0; i<256; i++)
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{
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int tmp = count[i];
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count[i] = last;
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last += tmp;
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}
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// Undo the sort transform
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i = 0;
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last = size-1;
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while (last>0)
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{
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unsigned int n = posn[i];
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unsigned char c = (posn[i]>>24);
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data[--last] = c;
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i = count[c] + (n & 0xffffff);
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}
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// Free and check
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if (i != markerpos)
|
|
G_THROW( ERR_MSG("ByteStream.corrupt") );
|
|
return size;
|
|
}
|
|
|
|
|
|
|
|
// ========================================
|
|
// -- ByteStream interface
|
|
|
|
|
|
|
|
long
|
|
BSByteStream::tell() const
|
|
{
|
|
return offset;
|
|
}
|
|
|
|
size_t
|
|
BSByteStream::Decode::read(void *buffer, size_t sz)
|
|
{
|
|
if (eof)
|
|
return 0;
|
|
// Loop
|
|
int copied = 0;
|
|
while (sz>0 && !eof)
|
|
{
|
|
// Decode if needed
|
|
if (!size)
|
|
{
|
|
bptr = 0;
|
|
if (! decode())
|
|
{
|
|
size = 1 ;
|
|
eof = true;
|
|
}
|
|
size -= 1;
|
|
}
|
|
// Compute remaining
|
|
int bytes = size;
|
|
if (bytes > (int)sz)
|
|
bytes = sz;
|
|
// Transfer
|
|
if (buffer && bytes)
|
|
{
|
|
memcpy(buffer, data+bptr, bytes);
|
|
buffer = (void*)((char*)buffer + bytes);
|
|
}
|
|
size -= bytes;
|
|
bptr += bytes;
|
|
sz -= bytes;
|
|
copied += bytes;
|
|
offset += bytes;
|
|
}
|
|
// Return copied bytes
|
|
return copied;
|
|
}
|
|
|
|
|
|
#ifdef HAVE_NAMESPACES
|
|
}
|
|
# ifndef NOT_USING_DJVU_NAMESPACE
|
|
using namespace DJVU;
|
|
# endif
|
|
#endif
|