Aegisub/aegisub/universalchardet/nsEUCJPProber.cpp

100 lines
3.3 KiB
C++

/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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// for japanese encoding, obeserve characteristic:
// 1, kana character (or hankaku?) often have hight frequency of appereance
// 2, kana character often exist in group
// 3, certain combination of kana is never used in japanese language
#include "nsEUCJPProber.h"
void nsEUCJPProber::Reset(void)
{
mCodingSM->Reset();
mState = eDetecting;
mContextAnalyser.Reset(mIsPreferredLanguage);
mDistributionAnalyser.Reset(mIsPreferredLanguage);
}
nsProbingState nsEUCJPProber::HandleData(const char* aBuf, PRUint32 aLen)
{
nsSMState codingState;
for (PRUint32 i = 0; i < aLen; i++)
{
codingState = mCodingSM->NextState(aBuf[i]);
if (codingState == eItsMe)
{
mState = eFoundIt;
break;
}
if (codingState == eStart)
{
PRUint32 charLen = mCodingSM->GetCurrentCharLen();
if (i == 0)
{
mLastChar[1] = aBuf[0];
mContextAnalyser.HandleOneChar(mLastChar, charLen);
mDistributionAnalyser.HandleOneChar(mLastChar, charLen);
}
else
{
mContextAnalyser.HandleOneChar(aBuf+i-1, charLen);
mDistributionAnalyser.HandleOneChar(aBuf+i-1, charLen);
}
}
}
mLastChar[0] = aBuf[aLen-1];
if (mState == eDetecting)
if (mContextAnalyser.GotEnoughData() && GetConfidence() > SHORTCUT_THRESHOLD)
mState = eFoundIt;
return mState;
}
float nsEUCJPProber::GetConfidence(void)
{
float contxtCf = mContextAnalyser.GetConfidence();
float distribCf = mDistributionAnalyser.GetConfidence();
return (contxtCf > distribCf ? contxtCf : distribCf);
}