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// Copyright 2014 PDFium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
#include "core/fxcodec/jbig2/JBig2_HuffmanTable.h"
#include <algorithm>
#include <vector>
#include "core/fxcodec/jbig2/JBig2_BitStream.h"
#include "core/fxcodec/jbig2/JBig2_Define.h"
#include "core/fxcodec/jbig2/JBig2_HuffmanTable_Standard.h"
#include "core/fxcrt/include/fx_memory.h"
CJBig2_HuffmanTable::CJBig2_HuffmanTable(const JBig2TableLine* pTable,
FX_DWORD nLines,
bool bHTOOB)
: m_bOK(true), HTOOB(bHTOOB), NTEMP(nLines) {
ParseFromStandardTable(pTable);
}
CJBig2_HuffmanTable::CJBig2_HuffmanTable(CJBig2_BitStream* pStream)
: HTOOB(false), NTEMP(0) {
m_bOK = ParseFromCodedBuffer(pStream);
}
CJBig2_HuffmanTable::~CJBig2_HuffmanTable() {}
void CJBig2_HuffmanTable::ParseFromStandardTable(const JBig2TableLine* pTable) {
PREFLEN.resize(NTEMP);
RANGELEN.resize(NTEMP);
RANGELOW.resize(NTEMP);
for (FX_DWORD i = 0; i < NTEMP; ++i) {
PREFLEN[i] = pTable[i].PREFLEN;
RANGELEN[i] = pTable[i].RANDELEN;
RANGELOW[i] = pTable[i].RANGELOW;
}
InitCodes();
}
bool CJBig2_HuffmanTable::ParseFromCodedBuffer(CJBig2_BitStream* pStream) {
unsigned char cTemp;
if (pStream->read1Byte(&cTemp) == -1)
return false;
HTOOB = !!(cTemp & 0x01);
unsigned char HTPS = ((cTemp >> 1) & 0x07) + 1;
unsigned char HTRS = ((cTemp >> 4) & 0x07) + 1;
FX_DWORD HTLOW;
FX_DWORD HTHIGH;
if (pStream->readInteger(&HTLOW) == -1 ||
pStream->readInteger(&HTHIGH) == -1) {
return false;
}
const int low = static_cast<int>(HTLOW);
const int high = static_cast<int>(HTHIGH);
if (low > high)
return false;
ExtendBuffers(false);
int cur_low = low;
do {
if ((pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1) ||
(pStream->readNBits(HTRS, &RANGELEN[NTEMP]) == -1)) {
return false;
}
RANGELOW[NTEMP] = cur_low;
cur_low += (1 << RANGELEN[NTEMP]);
ExtendBuffers(true);
} while (cur_low < high);
if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
return false;
RANGELEN[NTEMP] = 32;
RANGELOW[NTEMP] = low - 1;
ExtendBuffers(true);
if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
return false;
RANGELEN[NTEMP] = 32;
RANGELOW[NTEMP] = high;
ExtendBuffers(true);
if (HTOOB) {
if (pStream->readNBits(HTPS, &PREFLEN[NTEMP]) == -1)
return false;
++NTEMP;
}
InitCodes();
return true;
}
void CJBig2_HuffmanTable::InitCodes() {
int lenmax = 0;
for (FX_DWORD i = 0; i < NTEMP; ++i)
lenmax = std::max(PREFLEN[i], lenmax);
CODES.resize(NTEMP);
std::vector<int> LENCOUNT(lenmax + 1);
std::vector<int> FIRSTCODE(lenmax + 1);
for (int len : PREFLEN)
++LENCOUNT[len];
FIRSTCODE[0] = 0;
LENCOUNT[0] = 0;
for (int i = 1; i <= lenmax; ++i) {
FIRSTCODE[i] = (FIRSTCODE[i - 1] + LENCOUNT[i - 1]) << 1;
int CURCODE = FIRSTCODE[i];
for (FX_DWORD j = 0; j < NTEMP; ++j) {
if (PREFLEN[j] == i)
CODES[j] = CURCODE++;
}
}
}
void CJBig2_HuffmanTable::ExtendBuffers(bool increment) {
if (increment)
++NTEMP;
size_t size = PREFLEN.size();
if (NTEMP < size)
return;
size += 16;
ASSERT(NTEMP < size);
PREFLEN.resize(size);
RANGELEN.resize(size);
RANGELOW.resize(size);
}
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