private GCHandle callbackHandle; // for the user callback
/// <summary>
/// Initializes a new instance of the <see cref="WaveOutBuffer"/> class.
/// </summary>
/// <param name="hWaveOut">WaveOut device to write to</param>
/// <param name="bufferSize">Buffer size in bytes</param>
/// <param name="bufferFillStream">Stream to provide more data</param>
/// <param name="waveOutLock">Lock to protect WaveOut API's from being called on >1 thread</param>
public WaveOutBuffer(IntPtr hWaveOut, Int32 bufferSize, IWaveProvider bufferFillStream, object waveOutLock)
{
this.bufferSize = bufferSize;
buffer = new byte[bufferSize];
bufferHandle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
this.waveOutPtr = hWaveOut;
waveStream = bufferFillStream;
this.waveOutLock = waveOutLock;
header = new WaveHeader();
headerHandle = GCHandle.Alloc(header, GCHandleType.Pinned);
header.DataBuffer = bufferHandle.AddrOfPinnedObject();
header.BufferLength = bufferSize;
header.Loops = 1;
callbackHandle = GCHandle.Alloc(this);
header.UserData = (IntPtr)callbackHandle;
lock (waveOutLock)
{
MmException.Try(WaveInterop.NativeMethods.waveOutPrepareHeader(hWaveOut, header, Marshal.SizeOf(header)), "waveOutPrepareHeader");
}
}
public static extern MmResult waveOutWrite(IntPtr hWaveOut, WaveHeader lpWaveOutHdr, int uSize);
public static extern MmResult waveOutUnprepareHeader(IntPtr hWaveOut, WaveHeader lpWaveOutHdr, int uSize);
