void InitWinMm( AudioChunk chunk )
{
handle = IntPtr.Zero;
WaveFormatEx format = new WaveFormatEx();
format.Channels = (ushort)chunk.Channels;
format.ExtraSize = 0;
format.FormatTag = WaveFormatTag.Pcm;
format.BitsPerSample = (ushort)chunk.BitsPerSample;
format.BlockAlign = (ushort)( format.Channels * format.BitsPerSample / 8 );
format.SampleRate = (uint)chunk.Frequency;
format.AverageBytesPerSecond = chunk.Frequency * format.BlockAlign;
WaveOpenFlags flags = WaveOpenFlags.CallbackFunction;
callback = ProcessWaveOutCallback;
uint result = Open( out handle, new UIntPtr( (uint)0xFFFF ), ref format, callback, UIntPtr.Zero, flags );
CheckError( result );
}
static extern uint Open( out IntPtr handle, UIntPtr deviceID, ref WaveFormatEx format,
WaveOutCallback callback, UIntPtr callbackInstance, WaveOpenFlags flags);