public override void SetFormat(AudioFormat format)
{
// Don't need to recreate device if it's the same
if (Format.Equals(format))
{
return;
}
Format = format;
Console.WriteLine("init");
DisposeDevice();
WaveFormatEx fmt = default(WaveFormatEx);
fmt.FormatTag = 1; // WAVE_FORMAT_PCM
fmt.Channels = (ushort)format.Channels;
fmt.BitsPerSample = (ushort)format.BitsPerSample;
fmt.BlockAlign = (ushort)(fmt.Channels * fmt.BitsPerSample / 8);
fmt.SampleRate = (uint)format.SampleRate;
fmt.AverageBytesPerSecond = (int)fmt.SampleRate * fmt.BlockAlign;
uint devices = WinMM.waveOutGetNumDevs();
if (devices == 0)
{
throw new InvalidOperationException("No audio devices found");
}
uint result = WinMM.waveOutOpen(out devHandle, (IntPtr)(-1), ref fmt,
IntPtr.Zero, UIntPtr.Zero, 0);
CheckError(result, "Open");
}
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);
internal static extern uint waveOutOpen(out IntPtr handle, IntPtr deviceID, ref WaveFormatEx format,
IntPtr callback, UIntPtr callbackInstance, uint flags);
