Apple-2-Tools
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Virtu
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Included missing changes from last checkin. 

--HG--
extra : convert_revision : svn%3Affd33b8c-2492-42e0-bdc5-587b920b7d6d/trunk%4043069
This commit is contained in:
Sean Fausett 2010-03-14 22:01:22 +00:00
parent ea2a892113
commit 0d1a883260
1 changed files with 24 additions and 54 deletions
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78
Virtu/Services/AudioService.cs
View File

@ -1,5 +1,5 @@
using System;
using System.Linq;
using System.Threading;
namespace Jellyfish.Virtu.Services
{
@ -10,19 +10,26 @@ namespace Jellyfish.Virtu.Services
{
}
public void ToggleOutput() // machine thread
public void Output(int data) // machine thread
{
lock (_lock)
_buffer[_index] = (byte)data;
_index = (_index + 1) % SampleSize;
if (_index == 0)
{
long cycles = Machine.Cpu.Cycles;
int toggleDelta = (int)(cycles - _toggleCycles);
_toggleCycles = cycles;
_deltaBuffer[_writeIndex] = toggleDelta;
_writeIndex = (_writeIndex + 1) % DeltaBufferSize;
_readEvent.Set();
if (Machine.Settings.Cpu.IsThrottled)
{
_writeEvent.WaitOne();
}
}
}
public override void Stop() // main thread
{
_readEvent.Set(); // signal events; avoids deadlock
_writeEvent.Set();
}
protected void Update(int bufferSize, Action<byte[], int> updateBuffer) // audio thread
{
if (updateBuffer == null)
@ -30,39 +37,12 @@ namespace Jellyfish.Virtu.Services
throw new ArgumentNullException("updateBuffer");
}
lock (_lock)
if (Machine.State == MachineState.Running)
{
long cycles = Machine.Cpu.Cycles;
int updateDelta = (int)(cycles - _updateCycles);
_updateCycles = _toggleCycles = cycles; // reset audio frame
if (updateDelta > 0)
{
double bytesPerCycle = (double)bufferSize / (Machine.Settings.Cpu.IsThrottled ? CyclesPerSample : updateDelta);
while (_readIndex != _writeIndex)
{
int deltaSize = (int)(_deltaBuffer[_readIndex] * bytesPerCycle);
if (deltaSize > bufferSize)
{
_deltaBuffer[_readIndex] -= (int)((double)bufferSize / bytesPerCycle);
break;
}
updateBuffer(_isOutputHigh ? SampleHigh : SampleZero, deltaSize);
_isOutputHigh ^= true;
bufferSize -= deltaSize;
_readIndex = (_readIndex + 1) % DeltaBufferSize;
}
updateBuffer(_isOutputHigh ? SampleHigh : SampleZero, bufferSize);
}
else
{
updateBuffer(SampleZero, bufferSize);
}
_readEvent.WaitOne();
}
updateBuffer(_buffer, bufferSize);
_writeEvent.Set();
}
public const int SampleRate = 44100; // hz
@ -71,20 +51,10 @@ namespace Jellyfish.Virtu.Services
public const int SampleLatency = 40; // ms
public const int SampleSize = (int)(SampleRate * SampleLatency / 1000f) * SampleChannels * SampleBits / 8;
private const int CyclesPerSecond = 1022730;
private const int CyclesPerSample = (int)(CyclesPerSecond * SampleLatency / 1000f);
private byte[] _buffer = new byte[SampleSize];
private int _index;
private static readonly byte[] SampleHigh = Enumerable.Repeat((byte)0xFF, SampleSize).ToArray();
private static readonly byte[] SampleZero = new byte[SampleSize];
private const int DeltaBufferSize = 8192;
private int[] _deltaBuffer = new int[DeltaBufferSize];
private uint _readIndex;
private uint _writeIndex;
private bool _isOutputHigh;
private long _toggleCycles;
private long _updateCycles;
private object _lock = new object();
private AutoResetEvent _readEvent = new AutoResetEvent(false);
private AutoResetEvent _writeEvent = new AutoResetEvent(false);
}
}