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129 lines
2.6 KiB
C++
Executable File
129 lines
2.6 KiB
C++
Executable File
// Rar20Multimedia.cpp
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// According to unRAR license,
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// this code may not be used to develop a
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// RAR (WinRAR) compatible archiver
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#include "StdAfx.h"
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#include "Rar20Multimedia.h"
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namespace NCompress {
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namespace NRar20 {
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namespace NMultimedia {
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void CAudioVariables::Init()
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{
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memset(this, 0, sizeof(CAudioVariables));
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}
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void CPredictor::Init()
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{
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for(int i = 0; i < kNumChanelsMax; i++)
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m_AudioVariablesArray[i].Init();
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m_ChannelDelta = 0;
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CurrentChannel = 0;
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}
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Byte CPredictor::Predict()
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{
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CAudioVariables *v = &m_AudioVariablesArray[CurrentChannel];
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v->ByteCount++;
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v->D4 = v->D3;
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v->D3 = v->D2;
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v->D2 = v->LastDelta-v->D1;
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v->D1 = v->LastDelta;
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int pCh = 8 * v->LastChar +
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v->K1 * v->D1 +
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v->K2 * v->D2 +
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v->K3 * v->D3 +
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v->K4 * v->D4 +
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v->K5*m_ChannelDelta;
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pCh = (pCh >> 3) & 0xFF;
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return Byte(pCh);
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}
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void CPredictor::Update(Byte realValue, int predictedValue)
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{
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struct CAudioVariables *v = &m_AudioVariablesArray[CurrentChannel];
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int delta = predictedValue - realValue;
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int i = ((signed char)delta) << 3;
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v->Dif[0] += abs(i);
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v->Dif[1] += abs(i - v->D1);
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v->Dif[2] += abs(i + v->D1);
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v->Dif[3] += abs(i - v->D2);
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v->Dif[4] += abs(i + v->D2);
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v->Dif[5] += abs(i - v->D3);
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v->Dif[6] += abs(i + v->D3);
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v->Dif[7] += abs(i - v->D4);
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v->Dif[8] += abs(i + v->D4);
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v->Dif[9] += abs(i - m_ChannelDelta);
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v->Dif[10] += abs(i + m_ChannelDelta);
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m_ChannelDelta = v->LastDelta = (signed char)(realValue - v->LastChar);
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v->LastChar = realValue;
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UInt32 numMinDif, minDif;
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if ((v->ByteCount & 0x1F)==0)
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{
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minDif = v->Dif[0];
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numMinDif = 0;
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v->Dif[0] = 0;
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for (i = 1; i < sizeof(v->Dif) / sizeof(v->Dif[0]); i++)
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{
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if (v->Dif[i] < minDif)
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{
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minDif = v->Dif[i];
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numMinDif = i;
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}
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v->Dif[i] = 0;
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}
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switch(numMinDif)
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{
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case 1:
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if (v->K1 >= -16)
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v->K1--;
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break;
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case 2:
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if (v->K1 < 16)
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v->K1++;
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break;
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case 3:
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if (v->K2 >= -16)
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v->K2--;
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break;
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case 4:
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if (v->K2 < 16)
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v->K2++;
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break;
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case 5:
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if (v->K3 >= -16)
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v->K3--;
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break;
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case 6:
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if (v->K3 < 16)
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v->K3++;
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break;
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case 7:
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if (v->K4 >= -16)
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v->K4--;
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break;
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case 8:
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if (v->K4 < 16)
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v->K4++;
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break;
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case 9:
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if (v->K5 >= -16)
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v->K5--;
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break;
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case 10:
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if (v->K5 < 16)
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v->K5++;
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break;
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}
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}
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}
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}}}
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