private short ADPCM_Decode(byte originalSample)
{
int num = 0;
num = this.stepsize * originalSample / 4 + this.stepsize / 8;
if ((originalSample & 4) == 4)
{
num = num + this.stepsize;
}
if ((originalSample & 2) == 2)
{
num = num + (this.stepsize >> 1);
}
if ((originalSample & 1) == 1)
{
num = num + (this.stepsize >> 2);
}
num = num + (this.stepsize >> 3);
if ((originalSample & 8) == 8)
{
num = -num;
}
this.newSample = num;
if (this.newSample > 32767)
{
this.newSample = 32767;
}
else if (this.newSample < -32768)
{
this.newSample = -32768;
}
ADPCMCodec aDPCMCodec = this;
aDPCMCodec.index = aDPCMCodec.index + ADPCMCodec.indexTable[originalSample];
if (this.index < 0)
{
this.index = 0;
}
if (this.index > 88)
{
this.index = 88;
}
this.stepsize = ADPCMCodec.stepsizeTable[this.index];
return((short)this.newSample);
}
private byte ADPCM_Encode(short originalSample)
{
int num = originalSample - this.predictedSample;
if (num < 0)
{
this.newSample = 8;
num = -num;
}
else
{
this.newSample = 0;
}
byte num1 = 4;
int num2 = this.stepsize;
for (int i = 0; i < 3; i++)
{
if (num >= num2)
{
ADPCMCodec aDPCMCodec = this;
aDPCMCodec.newSample = aDPCMCodec.newSample | num1;
num = num - num2;
}
num2 = num2 >> 1;
num1 = (byte)(num1 >> 1);
}
num = this.stepsize >> 3;
if ((this.newSample & 4) != 0)
{
num = num + this.stepsize;
}
if ((this.newSample & 2) != 0)
{
num = num + (this.stepsize >> 1);
}
if ((this.newSample & 1) != 0)
{
num = num + (this.stepsize >> 2);
}
if ((this.newSample & 8) != 0)
{
num = -num;
}
ADPCMCodec aDPCMCodec1 = this;
aDPCMCodec1.predictedSample = aDPCMCodec1.predictedSample + num;
if (this.predictedSample > 32767)
{
this.predictedSample = 32767;
}
if (this.predictedSample < -32768)
{
this.predictedSample = -32768;
}
ADPCMCodec aDPCMCodec2 = this;
aDPCMCodec2.index = aDPCMCodec2.index + ADPCMCodec.indexTable[this.newSample];
if (this.index < 0)
{
this.index = 0;
}
else if (this.index > 88)
{
this.index = 88;
}
this.stepsize = ADPCMCodec.stepsizeTable[this.index];
return((byte)this.newSample);
}