New Post: Sound won't play in exclusive mode

Neither DirectSoundOut nor WaveOutEvent was an option for me. Both DirectSoundOut and WaveOutEvent made audible pops at the beginning and end of playback on all the machines I used for testing. Wasapi produces no pops with the same audio files on the same test machines.

Here is how I got around the five second cut off with Wasapi used in shared mode in a Windows service.

1) I installed NuGet. http://docs.nuget.org/docs/start-here/installing-nuget
2) I got the latest version of NAudio (1.7.1) using NuGet. https://www.nuget.org/packages/NAudio
3) I used the code from this blog: http://bresleveloper.blogspot.co.il/2012/06/c-service-play-sound-with-naudio.html.
4) I modified that code. The code is reproduced below with my modification, which checks the playstate every second and waits until the file is done playing before exiting the procedure.

I hope this helps someone because getting audio to work nicely in a windows service is a pain.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.ComponentModel.Composition;

using NAudio.Wave;
using NAudio.CoreAudioApi;
using NAudio.Wave.SampleProviders;

namespace CallAndRead
{
    public interface IInputFileFormatPlugin
    {
        string Name { get; }
        string Extension { get; }
        WaveStream CreateWaveStream(string fileName);
    }

    [Export(typeof(IInputFileFormatPlugin))]
    class WaveInputFilePlugin : IInputFileFormatPlugin
    {
        public string Name
        { get { return "WAV file"; } }
        public string Extension
        { get { return ".wav"; } }

        public WaveStream CreateWaveStream(string fileName)
        {
            WaveStream readerStream = new WaveFileReader(fileName);
            if (readerStream.WaveFormat.Encoding != WaveFormatEncoding.Pcm
                  && readerStream.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
            {
                readerStream = WaveFormatConversionStream.CreatePcmStream(readerStream);
                readerStream = new BlockAlignReductionStream(readerStream);
            }
            return readerStream;
        }
    }

    class WASAPI
    {
        public static void Concatenate(string outputFile, IEnumerable<string> sourceFiles)
        {
            byte[] buffer = new byte[1024];
            WaveFileWriter waveFileWriter = null;
            try
            {
                foreach (string sourceFile in sourceFiles)
                {
                    using (WaveFileReader reader = new WaveFileReader(sourceFile))
                    {
                        if (waveFileWriter == null)
                            waveFileWriter = new WaveFileWriter(outputFile, reader.WaveFormat);
                        else
                        {
                            if (!reader.WaveFormat.Equals(waveFileWriter.WaveFormat))
                                throw new InvalidOperationException(
                                         "Can't concatenate WAV Files that don't share the same format");
                        }
                        int read;
                        while ((read = reader.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            waveFileWriter.Write(buffer, 0, read);
                        }
                    }
                }
            }
            finally
            {
                if (waveFileWriter != null)
                    waveFileWriter.Dispose();
            }
        }

        private IWavePlayer waveOut = new WasapiOut(AudioClientShareMode.Shared, 300);
        WaveStream fileWaveStream;
        Action<float> setVolumeDelegate;

        [ImportMany(typeof(IInputFileFormatPlugin))]
        public IEnumerable<IInputFileFormatPlugin> InputFileFormats { get; set; }

        void OnPreVolumeMeter(object sender, StreamVolumeEventArgs e)
        {
            // we know it is stereo
            //w aveformPainter1.AddMax(e.MaxSampleValues[0]);
            //waveformPainter2.AddMax(e.MaxSampleValues[1]);
        }

        public ISampleProvider CreateInputStream(string fileName)
        {
            var plugin = new WaveInputFilePlugin();
            if (plugin == null)
                throw new InvalidOperationException("Unsupported file extension");
            fileWaveStream = plugin.CreateWaveStream(fileName);
            var waveChannel = new SampleChannel(fileWaveStream);
            setVolumeDelegate = (vol) => waveChannel.Volume = vol;
            waveChannel.PreVolumeMeter += OnPreVolumeMeter;
            var postVolumeMeter = new MeteringSampleProvider(waveChannel);
            postVolumeMeter.StreamVolume += OnPostVolumeMeter;
            return postVolumeMeter;
        }

        void OnPostVolumeMeter(object sender, StreamVolumeEventArgs e)
        {
            // we know it is stereo
            //volumeMeter1.Amplitude = e.MaxSampleValues[0];
            //volumeMeter2.Amplitude = e.MaxSampleValues[1];
        }

        public WASAPI(string fileName)
        {
            ISampleProvider sampleProvider = null;
            sampleProvider = CreateInputStream(fileName);
            waveOut.Init(new SampleToWaveProvider(sampleProvider));
            waveOut.Play();
            while (waveOut.PlaybackState == PlaybackState.Playing)
            {
                Thread.Sleep(1000);
            }
            return;
        }
    }
}

To play a file just call this:

CallAndRead.WASAPI Player = new CallAndRead.WASAPI(<string path to audio file>);

Yeah, I know, NUTS! but it works.

-Tom