Added in-memory audio stream and audio level event

Plugin.AudioRecorder.Shared/AudioRecorderService.cs

@@ -82,6 +82,18 @@ public partial class AudioRecorderService
 		/// <remarks>This event will be raised on a background thread to allow for any further processing needed.  The audio file will be <c>null</c> in the case that no audio was recorded.</remarks>
 		public event EventHandler<string> AudioInputReceived;
 
+		/// <summary>
+		/// This event is raised when the most recent audio level has been calculated.
+		/// </summary>
+		/// <remarks>This event will be raised on a background thread to allow for any further processing needed.  The audio level will be <c>0.0f</c> in the case that no audio was recorded.</remarks>
+		public event EventHandler<float> AudioLevelUpdated;
+
+		/// <summary>
+		/// Gets/sets a value indicating if the <see cref="AudioRecorderService"/> should write audio data to a file.
+		/// </summary>
+		/// <remarks>Defaults to <c>true</c></remarks>
+		public bool WriteAudioDataToFile { get; set; } = true;
+
 		partial void Init ();
 
 		/// <summary>
@@ -146,6 +158,8 @@ void AudioStream_OnBroadcast (object sender, byte [] bytes)
 		{
 			var level = AudioFunctions.CalculateLevel (bytes);
 
+			AudioLevelUpdated?.Invoke(this, level);
+
 			if (level < NearZero && !audioDetected) // discard any initial 0s so we don't jump the gun on timing out
 			{
 				Debug.WriteLine ("level == {0} && !audioDetected", level);
@@ -247,7 +261,9 @@ void InitializeStream (int sampleRate)
 
 				if (recorder == null)
 				{
-					recorder = new WaveRecorder ();
+					recorder = new WaveRecorder {
+						WriteAudioDataToFile = WriteAudioDataToFile
+					};
 				}
 			}
 			catch (Exception ex)
@@ -264,5 +280,14 @@ public string GetAudioFilePath ()
 		{
 			return audioDetected ? FilePath : null;
 		}
+
+		/// <summary>
+		/// Gets a new <see cref="Stream"/> to the audio data in readonly mode.
+		/// </summary>
+		/// <returns>A <see cref="Stream"/> object that can be used to read the audio memory from the beginning.</returns>
+		public Stream GetAudioMemoryStream()
+		{
+			return recorder.GetAudioMemoryStream();
+		}
 	}
 }

Plugin.AudioRecorder.Shared/WaveRecorder.cs

@@ -10,11 +10,18 @@ internal class WaveRecorder : IDisposable
 	{
 		string audioFilePath;
 		FileStream fileStream;
+		MemoryStream memoryStream;
 		StreamWriter streamWriter;
 		BinaryWriter writer;
 		int byteCount;
-		IAudioStream audioStream;
-
+		IAudioStream audioStream;
+
+		/// <summary>
+		/// Gets/sets a value indicating if the <see cref="WaveRecorder"/> should write audio data to a file.
+		/// </summary>
+		/// <remarks>Defaults to <c>true</c></remarks>
+		public bool WriteAudioDataToFile { get; set; } = true;
+
 		/// <summary>
 		/// Starts recording WAVE format audio from the audio stream.
 		/// </summary>
@@ -38,8 +45,16 @@ public async Task StartRecorder (IAudioStream stream, string filePath)
 				audioFilePath = filePath;
 				audioStream = stream;
 
-				fileStream = new FileStream (filePath, FileMode.Create, FileAccess.Write, FileShare.Read);
-				streamWriter = new StreamWriter (fileStream);
+				if (WriteAudioDataToFile)
+				{
+					fileStream = new FileStream(filePath, FileMode.Create, FileAccess.Write, FileShare.Read);
+					streamWriter = new StreamWriter(fileStream);
+				}
+				else
+				{
+					memoryStream = new MemoryStream();
+					streamWriter = new StreamWriter(memoryStream);
+				}
 				writer = new BinaryWriter (streamWriter.BaseStream, Encoding.UTF8);
 
 				byteCount = 0;
@@ -68,6 +83,15 @@ public Stream GetAudioFileStream ()
 		{
 			//return a new stream to the same audio file, in Read mode
 			return new FileStream (audioFilePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
+		}
+
+		/// <summary>
+		/// Gets a new <see cref="Stream"/> to the audio data in readonly mode.
+		/// </summary>
+		/// <returns>A <see cref="Stream"/> object that can be used to read the audio memory from the beginning.</returns>
+		public Stream GetAudioMemoryStream()
+		{
+			return memoryStream;
 		}
 
 		void StreamActiveChanged (object sender, bool active)
@@ -121,6 +145,7 @@ public void StopRecorder ()
 					writer.Dispose (); //this should properly close/dispose the underlying stream as well
 					writer = null;
 					fileStream = null;
+					memoryStream = null;
 					streamWriter = null;
 				}
 

Samples/Forms/AudioRecord.Forms/MainPage.xaml.cs

@@ -20,11 +20,16 @@ public MainPage ()
 				TotalAudioTimeout = TimeSpan.FromSeconds (15),
 				AudioSilenceTimeout = TimeSpan.FromSeconds (2)
 			};
+			recorder.AudioLevelUpdated += Recorder_AudioLevelUpdated;
 
 			player = new AudioPlayer ();
 			player.FinishedPlaying += Player_FinishedPlaying;
 		}
 
+		public void Recorder_AudioLevelUpdated (object sender, float level)
+		{
+		}
+
 		async void Record_Clicked (object sender, EventArgs e)
 		{
 			await RecordAudio ();