NAudio library question

[mitko29]

Hello guys I am using NAudio and I have this class :

public class Music
{
private string fileLocation;
       private IWavePlayer waveout;
       private WaveStream outputStream;
       WaveOutEvent audio;
       public Drum(string file)
       {
           this.fileLocation = file;
           this.waveout = new WaveOut();
           audio = new WaveOutEvent();         
       }
       static WaveStream CreateInputStream(string name)
       {
           WaveChannel32 inputStream;
           if (name.EndsWith(".wav"))
           {
               WaveStream readerStream = new WaveFileReader(name);
               if (readerStream.WaveFormat.Encoding != WaveFormatEncoding.Pcm)
               {
                   readerStream = WaveFormatConversionStream.CreatePcmStream(readerStream);
                   readerStream = new BlockAlignReductionStream(readerStream);
               }

               if (readerStream.WaveFormat.BitsPerSample != 16)
               {
                   var format = new WaveFormat(readerStream.WaveFormat.SampleRate, 16, readerStream.WaveFormat.Channels);
                   readerStream = new WaveFormatConversionStream(format, readerStream);
               }
               inputStream = new WaveChannel32(readerStream);
           }
           else
           {
               throw new InvalidOperationException("Invalid extension");
           }
           return inputStream;
       }
       public void Play()
       {        
           this.outputStream = CreateInputStream(this.fileLocation);        
           audio.Init(outputStream);
           audio.Play();          
       }
}

Sometime when I use the Play void I get this error:
AlreadyAllocated calling waveOutOpen. any idea how to resolve it ?
The other thing I notice is that each time I want to play something I need to open the file read the whole stream and save it in WaveStream, but this way I am wasting the resource and the application memory, any idea how to read it once and then just to use it.