Cleaned up audio code

src/Discord.Net.Core/Audio/AudioApplication.cs

@@ -0,0 +1,9 @@
+namespace Discord.Audio
+{
+    public enum AudioApplication : int
+    {
+        Voice,
+        Music,
+        Mixed
+    }
+}

src/Discord.Net.Core/Audio/AudioInStream.cs

@@ -1,8 +1,30 @@
-using System.IO;
+using System;
+using System.IO;
+using System.Threading;
 
 namespace Discord.Audio
 {
     public abstract class AudioInStream : Stream
     {
+        public override bool CanRead => true;
+        public override bool CanSeek => false;
+        public override bool CanWrite => true;
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            WriteAsync(buffer, offset, count, CancellationToken.None).GetAwaiter().GetResult();
+        }
+
+        public override void Flush() { throw new NotSupportedException(); }
+
+        public override long Length { get { throw new NotSupportedException(); } }
+        public override long Position
+        {
+            get { throw new NotSupportedException(); }
+            set { throw new NotSupportedException(); }
+        }
+
+        public override void SetLength(long value) { throw new NotSupportedException(); }
+        public override long Seek(long offset, SeekOrigin origin) { throw new NotSupportedException(); }
     }
 }

src/Discord.Net.Core/Audio/AudioOutStream.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System;
+using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 
@@ -10,7 +11,31 @@ namespace Discord.Audio
         public override bool CanSeek => false;
         public override bool CanWrite => true;
 
-        public virtual void Clear() { }
-        public virtual Task ClearAsync(CancellationToken cancelToken) { return Task.Delay(0); }
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            WriteAsync(buffer, offset, count, CancellationToken.None).GetAwaiter().GetResult();
+        }
+        public override void Flush()
+        {
+            FlushAsync(CancellationToken.None).GetAwaiter().GetResult();
+        }
+        public void Clear()
+        {
+            ClearAsync(CancellationToken.None).GetAwaiter().GetResult();
+        }
+
+        public virtual Task ClearAsync(CancellationToken cancellationToken) { return Task.Delay(0); }
+        //public virtual Task WriteSilenceAsync(CancellationToken cancellationToken) { return Task.Delay(0); }
+
+        public override long Length { get { throw new NotSupportedException(); } }
+        public override long Position
+        {
+            get { throw new NotSupportedException(); }
+            set { throw new NotSupportedException(); }
+        }
+
+        public override int Read(byte[] buffer, int offset, int count) { throw new NotSupportedException(); }
+        public override void SetLength(long value) { throw new NotSupportedException(); }
+        public override long Seek(long offset, SeekOrigin origin) { throw new NotSupportedException(); }
     }
 }

src/Discord.Net.Core/Audio/IAudioClient.cs

@@ -34,13 +34,13 @@ namespace Discord.Audio
         /// <param name="samplesPerFrame">Samples per frame. Must be 120, 240, 480, 960, 1920 or 2880, representing 2.5, 5, 10, 20, 40 or 60 milliseconds respectively.</param>
         /// <param name="bitrate"></param>
         /// <returns></returns>
-        AudioOutStream CreatePCMStream(int samplesPerFrame, int channels = 2, int? bitrate = null, int bufferMillis = 1000);
+        AudioOutStream CreatePCMStream(AudioApplication application, int samplesPerFrame, int channels = 2, int? bitrate = null, int bufferMillis = 1000);
         /// <summary>
         /// Creates a new direct outgoing stream accepting PCM (raw) data. This is a direct stream with no internal timer.
         /// </summary>
         /// <param name="samplesPerFrame">Samples per frame. Must be 120, 240, 480, 960, 1920 or 2880, representing 2.5, 5, 10, 20, 40 or 60 milliseconds respectively.</param>
         /// <param name="bitrate"></param>
         /// <returns></returns>
-        AudioOutStream CreateDirectPCMStream(int samplesPerFrame, int channels = 2, int? bitrate = null);
+        AudioOutStream CreateDirectPCMStream(AudioApplication application, int samplesPerFrame, int channels = 2, int? bitrate = null);
     }
 }

src/Discord.Net.WebSocket/Audio/AudioClient.cs

@@ -1,4 +1,5 @@
 using Discord.API.Voice;
+using Discord.Audio.Streams;
 using Discord.Logging;
 using Discord.Net.Converters;
 using Discord.WebSocket;
@@ -80,7 +81,7 @@ namespace Discord.Audio
             {
                 _audioLogger.WarningAsync(e.ErrorContext.Error).GetAwaiter().GetResult();
                 e.ErrorContext.Handled = true;
-            };            
+            };
 
             LatencyUpdated += async (old, val) => await _audioLogger.VerboseAsync($"Latency = {val} ms").ConfigureAwait(false);
         }
@@ -129,26 +130,34 @@ namespace Discord.Audio
         public AudioOutStream CreateOpusStream(int samplesPerFrame, int bufferMillis)
         {
             CheckSamplesPerFrame(samplesPerFrame);
-            var target = new BufferedAudioTarget(ApiClient, samplesPerFrame, bufferMillis, _connection.CancelToken);
-            return new RTPWriteStream(target, _secretKey, samplesPerFrame, _ssrc);
+            var outputStream = new OutputStream(ApiClient);
+            var sodiumEncrypter = new SodiumEncryptStream(outputStream, _secretKey);
+            var rtpWriter = new RTPWriteStream(sodiumEncrypter, samplesPerFrame, _ssrc);
+            return new BufferedWriteStream(rtpWriter, samplesPerFrame, bufferMillis, _connection.CancelToken, _audioLogger);
         }
         public AudioOutStream CreateDirectOpusStream(int samplesPerFrame)
         {
             CheckSamplesPerFrame(samplesPerFrame);
-            var target = new DirectAudioTarget(ApiClient);
-            return new RTPWriteStream(target, _secretKey, samplesPerFrame, _ssrc);
+            var outputStream = new OutputStream(ApiClient);
+            var sodiumEncrypter = new SodiumEncryptStream(outputStream, _secretKey);
+            return new RTPWriteStream(sodiumEncrypter, samplesPerFrame, _ssrc);
         }
-        public AudioOutStream CreatePCMStream(int samplesPerFrame, int channels, int? bitrate, int bufferMillis)
+        public AudioOutStream CreatePCMStream(AudioApplication application, int samplesPerFrame, int channels, int? bitrate, int bufferMillis)
         {
             CheckSamplesPerFrame(samplesPerFrame);
-            var target = new BufferedAudioTarget(ApiClient, samplesPerFrame, bufferMillis, _connection.CancelToken);
-            return new OpusEncodeStream(target, _secretKey, channels, samplesPerFrame, _ssrc, bitrate);
+            var outputStream = new OutputStream(ApiClient);
+            var sodiumEncrypter = new SodiumEncryptStream(outputStream, _secretKey);
+            var rtpWriter = new RTPWriteStream(sodiumEncrypter, samplesPerFrame, _ssrc);
+            var bufferedStream = new BufferedWriteStream(rtpWriter, samplesPerFrame, bufferMillis, _connection.CancelToken, _audioLogger);
+            return new OpusEncodeStream(bufferedStream, channels, samplesPerFrame, bitrate ?? (96 * 1024), application);
         }
-        public AudioOutStream CreateDirectPCMStream(int samplesPerFrame, int channels, int? bitrate)
+        public AudioOutStream CreateDirectPCMStream(AudioApplication application, int samplesPerFrame, int channels, int? bitrate)
         {
             CheckSamplesPerFrame(samplesPerFrame);
-            var target = new DirectAudioTarget(ApiClient);
-            return new OpusEncodeStream(target, _secretKey, channels, samplesPerFrame, _ssrc, bitrate);
+            var outputStream = new OutputStream(ApiClient);
+            var sodiumEncrypter = new SodiumEncryptStream(outputStream, _secretKey);
+            var rtpWriter = new RTPWriteStream(sodiumEncrypter, samplesPerFrame, _ssrc);
+            return new OpusEncodeStream(rtpWriter, channels, samplesPerFrame, bitrate ?? (96 * 1024), application);
         }
         private void CheckSamplesPerFrame(int samplesPerFrame)
         {

src/Discord.Net.WebSocket/Audio/Opus/OpusApplication.cs

@@ -1,6 +1,6 @@
 namespace Discord.Audio
 {
-    public enum OpusApplication : int
+    internal enum OpusApplication : int
     {
         Voice = 2048,
         MusicOrMixed = 2049,

src/Discord.Net.WebSocket/Audio/Opus/OpusCtl.cs

@@ -1,10 +1,12 @@
 namespace Discord.Audio
 {
+    //https://github.com/gcp/opus/blob/master/include/opus_defines.h
     internal enum OpusCtl : int
     {
-        SetBitrateRequest = 4002,
-        GetBitrateRequest = 4003,
-        SetInbandFECRequest = 4012,
-        GetInbandFECRequest = 4013
+        SetBitrate = 4002,
+        SetBandwidth = 4008,
+        SetInbandFEC = 4012,
+        SetPacketLossPercent = 4014,
+        SetSignal = 4024
     }
 }

src/Discord.Net.WebSocket/Audio/Opus/OpusEncoder.cs

@@ -15,17 +15,62 @@ namespace Discord.Audio
         private static extern int EncoderCtl(IntPtr st, OpusCtl request, int value);
         
         /// <summary> Gets the coding mode of the encoder. </summary>
-        public OpusApplication Application { get; }
+        public AudioApplication Application { get; }
+        public int BitRate { get;}
 
-        public OpusEncoder(int samplingRate, int channels, OpusApplication application = OpusApplication.MusicOrMixed)
+        public OpusEncoder(int samplingRate, int channels, int bitrate, AudioApplication application)
             : base(samplingRate, channels)
         {
+            if (bitrate < 1 || bitrate > DiscordVoiceAPIClient.MaxBitrate)
+                throw new ArgumentOutOfRangeException(nameof(bitrate));
+
             Application = application;
+            BitRate = bitrate;
+
+            OpusApplication opusApplication;
+            OpusSignal opusSignal;
+            switch (application)
+            {
+                case AudioApplication.Mixed:
+                    opusApplication = OpusApplication.MusicOrMixed;
+                    opusSignal = OpusSignal.Auto;
+                    break;
+                case AudioApplication.Music:
+                    opusApplication = OpusApplication.MusicOrMixed;
+                    opusSignal = OpusSignal.Music;
+                    break;
+                case AudioApplication.Voice:
+                    opusApplication = OpusApplication.Voice;
+                    opusSignal = OpusSignal.Voice;
+                    break;
+                default:
+                    throw new ArgumentOutOfRangeException(nameof(application));
+            }
 
             OpusError error;
-            _ptr = CreateEncoder(samplingRate, channels, (int)application, out error);
+            _ptr = CreateEncoder(samplingRate, channels, (int)opusApplication, out error);
             if (error != OpusError.OK)
                 throw new Exception($"Opus Error: {error}");
+
+            var result = EncoderCtl(_ptr, OpusCtl.SetSignal, (int)opusSignal);
+            if (result < 0)
+                throw new Exception($"Opus Error: {(OpusError)result}");
+
+            result = EncoderCtl(_ptr, OpusCtl.SetPacketLossPercent, 5); //%%
+            if (result < 0)
+                throw new Exception($"Opus Error: {(OpusError)result}");
+
+            result = EncoderCtl(_ptr, OpusCtl.SetInbandFEC, 1); //True
+            if (result < 0)
+                throw new Exception($"Opus Error: {(OpusError)result}");
+
+            result = EncoderCtl(_ptr, OpusCtl.SetBitrate, bitrate);
+            if (result < 0)
+                throw new Exception($"Opus Error: {(OpusError)result}");
+
+            /*result = EncoderCtl(_ptr, OpusCtl.SetBandwidth, 1105);
+            if (result < 0)
+                throw new Exception($"Opus Error: {(OpusError)result}");*/
         }
 
         /// <summary> Produces Opus encoded audio from PCM samples. </summary>
@@ -44,25 +89,6 @@ namespace Discord.Audio
             return result;
         }
 
-        /// <summary> Gets or sets whether Forward Error Correction is enabled. </summary>
-        public void SetForwardErrorCorrection(bool value)
-        {
-            var result = EncoderCtl(_ptr, OpusCtl.SetInbandFECRequest, value ? 1 : 0);
-            if (result < 0)
-                throw new Exception($"Opus Error: {(OpusError)result}");
-        }
-
-        /// <summary> Gets or sets the encoder's bitrate. </summary>
-        public void SetBitrate(int value)
-        {
-            if (value < 1 || value > DiscordVoiceAPIClient.MaxBitrate)
-                throw new ArgumentOutOfRangeException(nameof(value));
-
-            var result = EncoderCtl(_ptr, OpusCtl.SetBitrateRequest, value);
-            if (result < 0)
-                throw new Exception($"Opus Error: {(OpusError)result}");
-        }
-
         protected override void Dispose(bool disposing)
         {
             if (_ptr != IntPtr.Zero)

src/Discord.Net.WebSocket/Audio/Opus/OpusSignal.cs

@@ -0,0 +1,9 @@
+namespace Discord.Audio
+{
+    internal enum OpusSignal : int
+    {
+        Auto = -1000,
+        Voice = 3001,
+        Music = 3002,
+    }
+}

src/Discord.Net.WebSocket/Audio/Streams/BufferedWriteStream.cs

@@ -0,0 +1,156 @@
+using Discord.Logging;
+using System;
+using System.Collections.Concurrent;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Discord.Audio.Streams
+{
+    ///<summary> Wraps another stream with a timed buffer. </summary>
+    public class BufferedWriteStream : AudioOutStream
+    {
+        private struct Frame
+        {
+            public Frame(byte[] buffer, int bytes)
+            {
+                Buffer = buffer;
+                Bytes = bytes;
+            }
+
+            public readonly byte[] Buffer;
+            public readonly int Bytes;
+        }
+
+        private static readonly byte[] _silenceFrame = new byte[0];
+
+        private readonly AudioOutStream _next;
+        private readonly CancellationTokenSource _cancelTokenSource;
+        private readonly CancellationToken _cancelToken;
+        private readonly Task _task;
+        private readonly ConcurrentQueue<Frame> _queuedFrames;
+        private readonly ConcurrentQueue<byte[]> _bufferPool;
+        private readonly SemaphoreSlim _queueLock;
+        private readonly Logger _logger;
+        private readonly int _ticksPerFrame, _queueLength;
+        private bool _isPreloaded;
+
+        internal BufferedWriteStream(AudioOutStream next, int samplesPerFrame, int bufferMillis, CancellationToken cancelToken, Logger logger, int maxFrameSize = 1500)
+        {
+            //maxFrameSize = 1275 was too limiting at 128*1024
+            _next = next;
+            _ticksPerFrame = samplesPerFrame / 48;
+            _logger = logger;
+            _queueLength = (bufferMillis + (_ticksPerFrame - 1)) / _ticksPerFrame; //Round up
+
+            _cancelTokenSource = new CancellationTokenSource();
+            _cancelToken = CancellationTokenSource.CreateLinkedTokenSource(_cancelTokenSource.Token, cancelToken).Token;
+            _queuedFrames = new ConcurrentQueue<Frame>();
+            _bufferPool = new ConcurrentQueue<byte[]>();
+            for (int i = 0; i < _queueLength; i++)
+                _bufferPool.Enqueue(new byte[maxFrameSize]); 
+            _queueLock = new SemaphoreSlim(_queueLength, _queueLength);
+
+            _task = Run();
+        }
+
+        private Task Run()
+        {
+            uint num = 0;
+            return Task.Run(async () =>
+            {
+                try
+                {
+                    while (!_isPreloaded && !_cancelToken.IsCancellationRequested)
+                        await Task.Delay(1).ConfigureAwait(false);
+
+                    long nextTick = Environment.TickCount;
+                    while (!_cancelToken.IsCancellationRequested)
+                    {
+                        const int limit = 1;
+                        long tick = Environment.TickCount;
+                        long dist = nextTick - tick;
+                        if (dist <= limit)
+                        {
+                            Frame frame;
+                            if (_queuedFrames.TryDequeue(out frame))
+                            {
+                                await _next.WriteAsync(frame.Buffer, 0, frame.Bytes).ConfigureAwait(false);
+                                _bufferPool.Enqueue(frame.Buffer);
+                                _queueLock.Release();
+                                nextTick += _ticksPerFrame;
+#if DEBUG
+                                var _ = _logger.DebugAsync($"{num++}: Sent {frame.Bytes} bytes ({_queuedFrames.Count} frames buffered)");
+#endif
+                            }
+                            else if (dist == 0)
+                            {
+                                await _next.WriteAsync(_silenceFrame, 0, _silenceFrame.Length).ConfigureAwait(false);
+                                nextTick += _ticksPerFrame;
+#if DEBUG
+                                var _ = _logger.DebugAsync($"{num++}: Buffer underrun");
+#endif
+                            }
+                        }
+                        else
+                            await Task.Delay((int)(dist - (limit - 1))).ConfigureAwait(false);
+                    }
+                }
+                catch (OperationCanceledException) { }
+            });
+        }
+
+        public override async Task WriteAsync(byte[] data, int offset, int count, CancellationToken cancelToken)
+        {
+            if (cancelToken.CanBeCanceled)
+                cancelToken = CancellationTokenSource.CreateLinkedTokenSource(cancelToken, _cancelToken).Token;
+            else
+                cancelToken = _cancelToken;
+
+            await _queueLock.WaitAsync(-1, cancelToken).ConfigureAwait(false);
+            byte[] buffer;
+            if (!_bufferPool.TryDequeue(out buffer))
+            {
+#if DEBUG
+                var _ = _logger.DebugAsync($"Buffer overflow"); //Should never happen because of the queueLock
+#endif
+                return;
+            }
+            Buffer.BlockCopy(data, offset, buffer, 0, count);
+            _queuedFrames.Enqueue(new Frame(buffer, count));
+#if DEBUG
+            //var _ await _logger.DebugAsync($"Queued {count} bytes ({_queuedFrames.Count} frames buffered)");
+#endif
+            if (!_isPreloaded && _queuedFrames.Count == _queueLength)
+            {
+#if DEBUG
+                var _ = _logger.DebugAsync($"Preloaded");
+#endif
+                _isPreloaded = true;
+            }
+        }
+
+        public override async Task FlushAsync(CancellationToken cancelToken)
+        {
+            while (true)
+            {
+                cancelToken.ThrowIfCancellationRequested();
+                if (_queuedFrames.Count == 0)
+                    return;
+                await Task.Delay(250, cancelToken).ConfigureAwait(false);
+            }
+        }
+        public override Task ClearAsync(CancellationToken cancelToken)
+        {
+            Frame ignored;
+            do
+                cancelToken.ThrowIfCancellationRequested();
+            while (_queuedFrames.TryDequeue(out ignored));
+            return Task.Delay(0);
+        }
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+                _cancelTokenSource.Cancel();
+        }
+    }
+}

src/Discord.Net.WebSocket/Audio/Streams/OpusDecodeStream.cs

@@ -1,22 +1,34 @@
-namespace Discord.Audio
+using System;
+using System.Collections.Concurrent;
+
+namespace Discord.Audio.Streams
 {
-    internal class OpusDecodeStream : RTPReadStream
+    ///<summary> Converts Opus to PCM </summary>
+    public class OpusDecodeStream : AudioInStream
     {
+        private readonly BlockingCollection<byte[]> _queuedData; //TODO: Replace with max-length ring buffer
         private readonly byte[] _buffer;
         private readonly OpusDecoder _decoder;
 
-        internal OpusDecodeStream(AudioClient audioClient, byte[] secretKey, int samplingRate, 
-            int channels = OpusConverter.MaxChannels, int bufferSize = 4000)
-            : base(audioClient, secretKey)
+        internal OpusDecodeStream(AudioClient audioClient, int samplingRate, int channels = OpusConverter.MaxChannels, int bufferSize = 4000)
         {
             _buffer = new byte[bufferSize];
             _decoder = new OpusDecoder(samplingRate, channels);
+            _queuedData = new BlockingCollection<byte[]>(100);
         }
 
         public override int Read(byte[] buffer, int offset, int count)
+        {
+            var queuedData = _queuedData.Take();
+            Buffer.BlockCopy(queuedData, 0, buffer, offset, Math.Min(queuedData.Length, count));
+            return queuedData.Length;
+        }
+        public override void Write(byte[] buffer, int offset, int count)
         {
             count = _decoder.DecodeFrame(buffer, offset, count, _buffer, 0);
-            return base.Read(_buffer, 0, count);
+            var newBuffer = new byte[count];
+            Buffer.BlockCopy(_buffer, 0, newBuffer, 0, count);
+            _queuedData.Add(newBuffer);
         }
 
         protected override void Dispose(bool disposing)

src/Discord.Net.WebSocket/Audio/Streams/OpusEncodeStream.cs

@@ -2,27 +2,28 @@
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Discord.Audio
+namespace Discord.Audio.Streams
 {
-    internal class OpusEncodeStream : RTPWriteStream
+    ///<summary> Converts PCM to Opus </summary>
+    public class OpusEncodeStream : AudioOutStream
     {
         public const int SampleRate = 48000;
+        
+        private readonly AudioOutStream _next;
+        private readonly OpusEncoder _encoder;
+        private readonly byte[] _buffer;
+
         private int _frameSize;
         private byte[] _partialFrameBuffer;
         private int _partialFramePos;
 
-        private readonly OpusEncoder _encoder;
-
-        internal OpusEncodeStream(IAudioTarget target, byte[] secretKey, int channels, int samplesPerFrame, uint ssrc, int? bitrate = null)
-            : base(target, secretKey, samplesPerFrame, ssrc)
+        internal OpusEncodeStream(AudioOutStream next, int channels, int samplesPerFrame, int bitrate, AudioApplication application, int bufferSize = 4000)
         {
-            _encoder = new OpusEncoder(SampleRate, channels);
+            _next = next;
+            _encoder = new OpusEncoder(SampleRate, channels, bitrate, application);
             _frameSize = samplesPerFrame * channels * 2;
+            _buffer = new byte[bufferSize];
             _partialFrameBuffer = new byte[_frameSize];
-
-            _encoder.SetForwardErrorCorrection(true);
-            if (bitrate != null)
-                _encoder.SetBitrate(bitrate.Value);
         }
 
         public override void Write(byte[] buffer, int offset, int count)
@@ -43,7 +44,7 @@ namespace Discord.Audio
                     _partialFramePos = 0;
 
                     int encFrameSize = _encoder.EncodeFrame(_partialFrameBuffer, 0, _frameSize, _buffer, 0);
-                    await base.WriteAsync(_buffer, 0, encFrameSize, cancellationToken).ConfigureAwait(false);
+                    await _next.WriteAsync(_buffer, 0, encFrameSize, cancellationToken).ConfigureAwait(false);
                 }
                 else
                 {
@@ -54,10 +55,7 @@ namespace Discord.Audio
             }
         }
 
-        /*public override void Flush()
-        {
-            FlushAsync(CancellationToken.None).GetAwaiter().GetResult();
-        }
+        /*
         public override async Task FlushAsync(CancellationToken cancellationToken)
         {
             try
@@ -70,6 +68,15 @@ namespace Discord.Audio
             await base.FlushAsync(cancellationToken).ConfigureAwait(false);
         }*/
 
+        public override async Task FlushAsync(CancellationToken cancelToken)
+        {
+            await _next.FlushAsync(cancelToken).ConfigureAwait(false);
+        }
+        public override async Task ClearAsync(CancellationToken cancelToken)
+        {
+            await _next.ClearAsync(cancelToken).ConfigureAwait(false);
+        }
+
         protected override void Dispose(bool disposing)
         {
             base.Dispose(disposing);

src/Discord.Net.WebSocket/Audio/Streams/OutputStream.cs

@@ -0,0 +1,23 @@
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Discord.Audio.Streams
+{
+    ///<summary> Wraps an IAudioClient, sending voice data on write. </summary>
+    public class OutputStream : AudioOutStream
+    {
+        private readonly DiscordVoiceAPIClient _client;
+        public OutputStream(IAudioClient client)
+            : this((client as AudioClient).ApiClient) { }
+        internal OutputStream(DiscordVoiceAPIClient client)
+        {
+            _client = client;
+        }
+
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancelToken)
+        {
+            cancelToken.ThrowIfCancellationRequested();
+            await _client.SendAsync(buffer, offset, count).ConfigureAwait(false);
+        }
+    }
+}

src/Discord.Net.WebSocket/Audio/Streams/RTPReadStream.cs

@@ -2,11 +2,13 @@
 using System.Collections.Concurrent;
 using System.IO;
 
-namespace Discord.Audio
+namespace Discord.Audio.Streams
 {
-    internal class RTPReadStream : Stream
+    ///<summary> Reads the payload from an RTP frame </summary>
+    public class RTPReadStream : AudioInStream
     {
         private readonly BlockingCollection<byte[]> _queuedData; //TODO: Replace with max-length ring buffer
+        //private readonly BlockingCollection<RTPFrame> _queuedData; //TODO: Replace with max-length ring buffer
         private readonly AudioClient _audioClient;
         private readonly byte[] _buffer, _nonce, _secretKey;
 
@@ -23,6 +25,12 @@ namespace Discord.Audio
             _nonce = new byte[24];
         }
 
+        /*public RTPFrame ReadFrame()
+        {          
+            var queuedData = _queuedData.Take();
+            Buffer.BlockCopy(queuedData, 0, buffer, offset, Math.Min(queuedData.Length, count));
+            return queuedData.Length;  
+        }*/
         public override int Read(byte[] buffer, int offset, int count)
         {
             var queuedData = _queuedData.Take();
@@ -31,10 +39,8 @@ namespace Discord.Audio
         }
         public override void Write(byte[] buffer, int offset, int count)
         {
-            Buffer.BlockCopy(buffer, 0, _nonce, 0, 12);
-            count = SecretBox.Decrypt(buffer, offset, count, _buffer, 0, _nonce, _secretKey);
             var newBuffer = new byte[count];
-            Buffer.BlockCopy(_buffer, 0, newBuffer, 0, count);
+            Buffer.BlockCopy(buffer, 0, newBuffer, 0, count);
             _queuedData.Add(newBuffer);
         }
 

src/Discord.Net.WebSocket/Audio/Streams/RTPWriteStream.cs

@@ -1,33 +1,32 @@
 using System;
-using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 
-namespace Discord.Audio
+namespace Discord.Audio.Streams
 {
-    internal class RTPWriteStream : AudioOutStream
+    ///<summary> Wraps data in an RTP frame </summary>
+    public class RTPWriteStream : AudioOutStream
     {
-        private readonly IAudioTarget _target;
-        private readonly byte[] _nonce, _secretKey;
+        private readonly AudioOutStream _next;
+        private readonly byte[] _header;
         private int _samplesPerFrame;
         private uint _ssrc, _timestamp = 0;
 
         protected readonly byte[] _buffer;
 
-        internal RTPWriteStream(IAudioTarget target, byte[] secretKey, int samplesPerFrame, uint ssrc)
+        internal RTPWriteStream(AudioOutStream next, int samplesPerFrame, uint ssrc, int bufferSize = 4000)
         {
-            _target = target;
-            _secretKey = secretKey;
+            _next = next;
             _samplesPerFrame = samplesPerFrame;
             _ssrc = ssrc;
-            _buffer = new byte[4000];
-            _nonce = new byte[24];
-            _nonce[0] = 0x80;
-            _nonce[1] = 0x78;
-            _nonce[8] = (byte)(_ssrc >> 24);
-            _nonce[9] = (byte)(_ssrc >> 16);
-            _nonce[10] = (byte)(_ssrc >> 8);
-            _nonce[11] = (byte)(_ssrc >> 0);
+            _buffer = new byte[bufferSize];
+            _header = new byte[24];
+            _header[0] = 0x80;
+            _header[1] = 0x78;
+            _header[8] = (byte)(_ssrc >> 24);
+            _header[9] = (byte)(_ssrc >> 16);
+            _header[10] = (byte)(_ssrc >> 8);
+            _header[11] = (byte)(_ssrc >> 0);
         }
 
         public override void Write(byte[] buffer, int offset, int count)
@@ -39,48 +38,28 @@ namespace Discord.Audio
             cancellationToken.ThrowIfCancellationRequested();
             unchecked
             {
-                if (_nonce[3]++ == byte.MaxValue)
-                    _nonce[2]++;
+                if (_header[3]++ == byte.MaxValue)
+                    _header[2]++;
 
                 _timestamp += (uint)_samplesPerFrame;
-                _nonce[4] = (byte)(_timestamp >> 24);
-                _nonce[5] = (byte)(_timestamp >> 16);
-                _nonce[6] = (byte)(_timestamp >> 8);
-                _nonce[7] = (byte)(_timestamp >> 0);
+                _header[4] = (byte)(_timestamp >> 24);
+                _header[5] = (byte)(_timestamp >> 16);
+                _header[6] = (byte)(_timestamp >> 8);
+                _header[7] = (byte)(_timestamp >> 0);
             }
+            Buffer.BlockCopy(_header, 0, _buffer, 0, 12); //Copy RTP header from to the buffer
+            Buffer.BlockCopy(buffer, offset, _buffer, 12, count);
 
-            count = SecretBox.Encrypt(buffer, offset, count, _buffer, 12, _nonce, _secretKey);
-            Buffer.BlockCopy(_nonce, 0, _buffer, 0, 12); //Copy the RTP header from nonce to buffer
-            await _target.SendAsync(_buffer, count + 12).ConfigureAwait(false);
+            await _next.WriteAsync(_buffer, 0, count + 12).ConfigureAwait(false);
         }
 
-        public override void Flush()
+        public override async Task FlushAsync(CancellationToken cancelToken)
         {
-            FlushAsync(CancellationToken.None).GetAwaiter().GetResult();
-        }
-        public override async Task FlushAsync(CancellationToken cancellationToken)
-        {
-            await _target.FlushAsync(cancellationToken).ConfigureAwait(false);
-        }
-
-        public override void Clear()
-        {
-            ClearAsync(CancellationToken.None).GetAwaiter().GetResult();
+            await _next.FlushAsync(cancelToken).ConfigureAwait(false);
         }
         public override async Task ClearAsync(CancellationToken cancelToken)
         {
-            await _target.ClearAsync(cancelToken).ConfigureAwait(false);
+            await _next.ClearAsync(cancelToken).ConfigureAwait(false);
         }
-
-        public override long Length { get { throw new NotSupportedException(); } }
-        public override long Position
-        {
-            get { throw new NotSupportedException(); }
-            set { throw new NotSupportedException(); }
-        }
-
-        public override int Read(byte[] buffer, int offset, int count) { throw new NotSupportedException(); }
-        public override void SetLength(long value) { throw new NotSupportedException(); }
-        public override long Seek(long offset, SeekOrigin origin) { throw new NotSupportedException(); }
     }
 }

src/Discord.Net.WebSocket/Audio/Streams/SodiumDecryptStream.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Concurrent;
+
+namespace Discord.Audio.Streams
+{
+    ///<summary> Decrypts an RTP frame using libsodium </summary>
+    public class SodiumDecryptStream : AudioInStream
+    {
+        private readonly BlockingCollection<byte[]> _queuedData; //TODO: Replace with max-length ring buffer
+        private readonly AudioClient _audioClient;
+        private readonly byte[] _buffer, _nonce, _secretKey;
+
+        public override bool CanRead => true;
+        public override bool CanSeek => false;
+        public override bool CanWrite => true;
+
+        internal SodiumDecryptStream(AudioClient audioClient, byte[] secretKey, int bufferSize = 4000)
+        {
+            _audioClient = audioClient;
+            _secretKey = secretKey;
+            _buffer = new byte[bufferSize];
+            _queuedData = new BlockingCollection<byte[]>(100);
+            _nonce = new byte[24];
+        }
+
+        public override int Read(byte[] buffer, int offset, int count)
+        {
+            var queuedData = _queuedData.Take();
+            Buffer.BlockCopy(queuedData, 0, buffer, offset, Math.Min(queuedData.Length, count));
+            return queuedData.Length;
+        }
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            Buffer.BlockCopy(buffer, 0, _nonce, 0, 12); //Copy RTP header to nonce
+            count = SecretBox.Decrypt(buffer, offset, count, _buffer, 0, _nonce, _secretKey);
+
+            var newBuffer = new byte[count];
+            Buffer.BlockCopy(_buffer, 0, newBuffer, 0, count);
+            _queuedData.Add(newBuffer);
+        }
+    }
+}

src/Discord.Net.WebSocket/Audio/Streams/SodiumEncryptStream.cs

@@ -0,0 +1,45 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Discord.Audio.Streams
+{
+    ///<summary> Encrypts an RTP frame using libsodium </summary>
+    public class SodiumEncryptStream : AudioOutStream
+    {
+        private readonly AudioOutStream _next;
+        private readonly byte[] _nonce, _secretKey;
+
+        //protected readonly byte[] _buffer;
+
+        internal SodiumEncryptStream(AudioOutStream next, byte[] secretKey/*, int bufferSize = 4000*/)
+        {
+            _next = next;
+            _secretKey = secretKey;
+            //_buffer = new byte[bufferSize]; //TODO: Can Sodium do an in-place encrypt?
+            _nonce = new byte[24];
+        }
+
+        public override void Write(byte[] buffer, int offset, int count)
+        {
+            WriteAsync(buffer, offset, count, CancellationToken.None).GetAwaiter().GetResult();
+        }
+        public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+
+            Buffer.BlockCopy(buffer, offset, _nonce, 0, 12); //Copy nonce from RTP header
+            count = SecretBox.Encrypt(buffer, offset + 12, count - 12, buffer, 12, _nonce, _secretKey);
+            await _next.WriteAsync(buffer, 0, count + 12, cancellationToken).ConfigureAwait(false);
+        }
+
+        public override async Task FlushAsync(CancellationToken cancelToken)
+        {
+            await _next.FlushAsync(cancelToken).ConfigureAwait(false);
+        }
+        public override async Task ClearAsync(CancellationToken cancelToken)
+        {
+            await _next.ClearAsync(cancelToken).ConfigureAwait(false);
+        }
+    }
+}

src/Discord.Net.WebSocket/Audio/Targets/BufferedAudioTarget.cs

@@ -1,119 +0,0 @@
-using System;
-using System.Collections.Concurrent;
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace Discord.Audio
-{
-    internal class BufferedAudioTarget : IAudioTarget, IDisposable
-    {
-        private struct Frame
-        {
-            public Frame(byte[] buffer, int bytes)
-            {
-                Buffer = buffer;
-                Bytes = bytes;
-            }
-
-            public readonly byte[] Buffer;
-            public readonly int Bytes;
-        }
-
-        private static readonly byte[] _silenceFrame = new byte[] { 0xF8, 0xFF, 0xFE };
-        
-        private Task _task;
-        private DiscordVoiceAPIClient _client;
-        private CancellationTokenSource _cancelTokenSource;
-        private CancellationToken _cancelToken;
-        private ConcurrentQueue<Frame> _queuedFrames;
-        private ConcurrentQueue<byte[]> _bufferPool;
-        private SemaphoreSlim _queueLock;
-        private int _ticksPerFrame;
-
-        internal BufferedAudioTarget(DiscordVoiceAPIClient client, int samplesPerFrame, int bufferMillis, CancellationToken cancelToken)
-        {
-            _client = client;
-            _ticksPerFrame = samplesPerFrame / 48;
-            int queueLength = (bufferMillis + (_ticksPerFrame - 1)) / _ticksPerFrame; //Round up
-
-            _cancelTokenSource = new CancellationTokenSource();
-            _cancelToken = CancellationTokenSource.CreateLinkedTokenSource(_cancelTokenSource.Token, cancelToken).Token;
-            _queuedFrames = new ConcurrentQueue<Frame>();
-            _bufferPool = new ConcurrentQueue<byte[]>();
-            for (int i = 0; i < queueLength; i++)
-                _bufferPool.Enqueue(new byte[1275]);
-            _queueLock = new SemaphoreSlim(queueLength, queueLength);
-
-            _task = Run();
-        }
-
-        private Task Run()
-        {
-            return Task.Run(async () =>
-            {
-                try
-                {
-                    long nextTick = Environment.TickCount;
-                    while (!_cancelToken.IsCancellationRequested)
-                    {
-                        long tick = Environment.TickCount;
-                        long dist = nextTick - tick;
-                        if (dist <= 0)
-                        {
-                            Frame frame;
-                            if (_queuedFrames.TryDequeue(out frame))
-                            {
-                                await _client.SendAsync(frame.Buffer, frame.Bytes).ConfigureAwait(false);
-                                _bufferPool.Enqueue(frame.Buffer);
-                                _queueLock.Release();
-                            }
-                            else
-                                await _client.SendAsync(_silenceFrame, _silenceFrame.Length).ConfigureAwait(false);
-                            nextTick += _ticksPerFrame;
-                        }
-                        else if (dist > 1)
-                            await Task.Delay((int)dist).ConfigureAwait(false);
-                    }
-                }
-                catch (OperationCanceledException) { }
-            });
-        }
-
-        public async Task SendAsync(byte[] data, int count)
-        {
-            await _queueLock.WaitAsync(-1, _cancelToken).ConfigureAwait(false);
-            byte[] buffer;
-            _bufferPool.TryDequeue(out buffer);
-            Buffer.BlockCopy(data, 0, buffer, 0, count);
-            _queuedFrames.Enqueue(new Frame(buffer, count));
-        }
-        
-        public async Task FlushAsync(CancellationToken cancelToken)
-        {
-            while (true)
-            {
-                cancelToken.ThrowIfCancellationRequested();
-                if (_queuedFrames.Count == 0)
-                    return;
-                await Task.Delay(250, cancelToken).ConfigureAwait(false);
-            }
-        }
-        public Task ClearAsync(CancellationToken cancelToken)
-        {
-            Frame ignored;
-            do
-                cancelToken.ThrowIfCancellationRequested();
-            while (_queuedFrames.TryDequeue(out ignored));
-            return Task.Delay(0);
-        }
-        protected void Dispose(bool disposing)
-        {
-            if (disposing)
-                _cancelTokenSource.Cancel();
-        }
-        public void Dispose()
-        {
-            Dispose(true);
-        }
-    }
-}

src/Discord.Net.WebSocket/Audio/Targets/DirectAudioTarget.cs

@@ -1,22 +0,0 @@
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace Discord.Audio
-{
-    internal class DirectAudioTarget : IAudioTarget
-    {
-        private readonly DiscordVoiceAPIClient _client;
-        public DirectAudioTarget(DiscordVoiceAPIClient client)
-        {
-            _client = client;
-        }
-
-        public Task SendAsync(byte[] buffer, int count)
-            => _client.SendAsync(buffer, count);
-
-        public Task FlushAsync(CancellationToken cancelToken)
-            => Task.Delay(0);
-        public Task ClearAsync(CancellationToken cancelToken)
-            => Task.Delay(0);
-    }
-}

src/Discord.Net.WebSocket/Audio/Targets/IAudioTarget.cs

@@ -1,12 +0,0 @@
-using System.Threading;
-using System.Threading.Tasks;
-
-namespace Discord.Audio
-{
-    internal interface IAudioTarget
-    {
-        Task SendAsync(byte[] buffer, int count);
-        Task FlushAsync(CancellationToken cancelToken);
-        Task ClearAsync(CancellationToken cancelToken);
-    }
-}

src/Discord.Net.WebSocket/DiscordVoiceApiClient.cs

@@ -64,7 +64,7 @@ namespace Discord.Audio
             };
 
             WebSocketClient = webSocketProvider();
-            //_gatewayClient.SetHeader("user-agent", DiscordConfig.UserAgent); (Causes issues in .Net 4.6+)
+            //_gatewayClient.SetHeader("user-agent", DiscordConfig.UserAgent); //(Causes issues in .Net 4.6+)
             WebSocketClient.BinaryMessage += async (data, index, count) =>
             {
                 using (var compressed = new MemoryStream(data, index + 2, count - 2))
@@ -117,9 +117,9 @@ namespace Discord.Audio
             await WebSocketClient.SendAsync(bytes, 0, bytes.Length, true).ConfigureAwait(false);
             await _sentGatewayMessageEvent.InvokeAsync(opCode).ConfigureAwait(false);
         }
-        public async Task SendAsync(byte[] data, int bytes)
+        public async Task SendAsync(byte[] data, int offset, int bytes)
         {
-            await _udp.SendAsync(data, 0, bytes).ConfigureAwait(false);                
+            await _udp.SendAsync(data, offset, bytes).ConfigureAwait(false);                
             await _sentDataEvent.InvokeAsync(bytes).ConfigureAwait(false);
         }
 
@@ -224,7 +224,7 @@ namespace Discord.Audio
             packet[1] = (byte)(ssrc >> 16);
             packet[2] = (byte)(ssrc >> 8);
             packet[3] = (byte)(ssrc >> 0);
-            await SendAsync(packet, 70).ConfigureAwait(false);
+            await SendAsync(packet, 0, 70).ConfigureAwait(false);
             await _sentDiscoveryEvent.InvokeAsync().ConfigureAwait(false);
         }