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Sid Round 2 

Still some noise in there but not as bad and the sharp cutoff in Gianna Sisters intro is fixed
This commit is contained in:
alyosha-tas 2017-05-25 13:42:36 -04:00 committed by GitHub
parent 1a7f8b0ff8
commit 26ec802769
1 changed files with 40 additions and 8 deletions
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48
BizHawk.Emulation.Cores/Computers/Commodore64/MOS/Sid.cs
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@ -45,6 +45,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
private int _outputBufferIndex;
private int last_index;
private int filter_index;
private int last_filtered_value;
private int _potCounter;
private int _potX;
private int _potY;
@ -159,7 +160,7 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
int temp_v1 = (_voiceOutput1 * _envelopeOutput1);
int temp_v2 = (_voiceOutput2 * _envelopeOutput2);
int temp_filtered = 0;
int temp_filtered = 0;// 50000; // the filter has some DC bias in it
int temp_not_filtered = 0;
//note that voice 3 disable is relevent only if it is not going to the filter
@ -201,8 +202,20 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
//here we need to apply filtering to the samples and add them back to the buffer
if (_filterEnable[0] | _filterEnable[1] | _filterEnable[2])
if (filter_index >= 2)
if (filter_index >= 16)
{
filter_operator();
}
else
{
// the length is too short for the FFT to reliably act on the output
// instead, clamp it to the previous output.
for (int i = 0; i < filter_index ; i++)
{
_outputBuffer_filtered[i] = last_filtered_value;
}
}
for (int i = last_index; i < _outputBufferIndex; i++)
{
@ -226,12 +239,15 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
}
last_index = _outputBufferIndex;
if (filter_index > 0)
last_filtered_value = _outputBuffer_filtered[filter_index - 1];
filter_index = 0;
}
public void filter_operator()
{
double loc_filterFrequency = (double)(_filterFrequency<<2);
double loc_filterFrequency = (double)(_filterFrequency << 2) + 500;
double attenuation;
@ -259,14 +275,24 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
{
temp_buffer[(int)i] = _outputBuffer_filtered[(int)Math.Floor((i / (nsamp_2-1) * (filter_index - 1)))];
}
/*
for (int i = 0; i< filter_index; i++)
{
Console.Write(_outputBuffer_filtered[(int)i]);
Console.Write(" ");
}
Console.WriteLine(" ");
Console.WriteLine("After");
*/
// now we have everything we need to perform the FFT
fft.ComputeForward(temp_buffer);
// for each element in the frequency list, attenuate it according to the specs
for (int i = 0; i < nsamp_2; i++)
{
double freq = i * ((double)(880*50)/filter_index);
double freq = (i + 1) * ((double)(880*50)/filter_index);
// low pass filter
if (_filterSelectLoPass && freq > loc_filterFrequency)
@ -291,7 +317,8 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
{
//attenuated at 6db per octave
attenuation = Math.Log(freq / _filterFrequency, 2);
temp_buffer[i] = temp_buffer[i] - 6 * Math.Abs(attenuation);
attenuation = 6 * attenuation;
temp_buffer[i] = temp_buffer[i] * Math.Pow(2, -Math.Abs(attenuation) / 10);
}
}
@ -302,12 +329,17 @@ namespace BizHawk.Emulation.Cores.Computers.Commodore64.MOS
//re-sample back down to the original number of samples
for (double i = 0; i < filter_index; i++)
{
_outputBuffer_filtered[(int)i] = (int)(temp_buffer[(int)Math.Floor((i / (filter_index-1) * (nsamp_2 - 1)))]/(nsamp_2/2));
if (loc_filterFrequency==0)
_outputBuffer_filtered[(int)i] = (int)(temp_buffer[(int)Math.Ceiling((i / (filter_index - 1) * (nsamp_2 - 1)))]/(nsamp_2/2));
if (_outputBuffer_filtered[(int)i] < 0)
{
_outputBuffer_filtered[(int)i] = 0;
}
//Console.Write(_outputBuffer_filtered[(int)i]);
//Console.Write(" ");
}
//Console.WriteLine(" ");
//Console.WriteLine("Before");
}
// ----------------------------------