Various audio fixes

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

@@ -11,6 +11,7 @@ namespace Discord.Audio
         public override bool CanSeek => false;
         public override bool CanWrite => false;
 
+        public virtual void WriteHeader(ushort seq, uint timestamp, bool missed) { }
         public override void Write(byte[] buffer, int offset, int count)
         {
             WriteAsync(buffer, offset, count, CancellationToken.None).GetAwaiter().GetResult();

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

@@ -5,12 +5,14 @@ namespace Discord.Audio
         public readonly ushort Sequence;
         public readonly uint Timestamp;
         public readonly byte[] Payload;
+        public readonly bool Missed;
 
-        public RTPFrame(ushort sequence, uint timestamp, byte[] payload)
+        public RTPFrame(ushort sequence, uint timestamp, byte[] payload, bool missed)
         {
             Sequence = sequence;
             Timestamp = timestamp;
             Payload = payload;
+            Missed = missed;
         }
     }
 }

src/Discord.Net.Core/Net/Udp/IUdpSocket.cs

@@ -8,6 +8,8 @@ namespace Discord.Net.Udp
     {
         event Func<byte[], int, int, Task> ReceivedDatagram;
 
+        ushort Port { get; }
+
         void SetCancelToken(CancellationToken cancelToken);
         void SetDestination(string ip, int port);
 

src/Discord.Net.Providers.UdpClient/UDPClient.cs

@@ -19,6 +19,8 @@ namespace Discord.Net.Providers.UDPClient
         private Task _task;
         private bool _isDisposed;
         
+        public ushort Port => (ushort)((_udp?.Client.LocalEndPoint as IPEndPoint)?.Port ?? 0);
+
         public UDPClient()
         {
             _lock = new SemaphoreSlim(1, 1);

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

@@ -107,6 +107,7 @@ namespace Discord.Audio
         {
             await _audioLogger.DebugAsync("Connecting ApiClient").ConfigureAwait(false);
             await ApiClient.ConnectAsync("wss://" + _url).ConfigureAwait(false);
+            await _audioLogger.DebugAsync("Listening on port " + ApiClient.UdpPort).ConfigureAwait(false);
             await _audioLogger.DebugAsync("Sending Identity").ConfigureAwait(false);
             await ApiClient.SendIdentityAsync(_userId, _sessionId, _token).ConfigureAwait(false);
 
@@ -175,7 +176,8 @@ namespace Discord.Audio
             {
                 var readerStream = new InputStream();
                 var opusDecoder = new OpusDecodeStream(readerStream);
-                var rtpReader = new RTPReadStream(readerStream, opusDecoder);
+                //var jitterBuffer = new JitterBuffer(opusDecoder, _audioLogger);
+                var rtpReader = new RTPReadStream(opusDecoder);
                 var decryptStream = new SodiumDecryptStream(rtpReader, this);
                 _streams.TryAdd(userId, new StreamPair(readerStream, decryptStream));
                 await _streamCreatedEvent.InvokeAsync(userId, readerStream);

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

@@ -14,7 +14,7 @@ namespace Discord.Audio
 
         public const int FrameSamplesPerChannel = SamplingRate / 1000 * FrameMillis;
         public const int FrameSamples = FrameSamplesPerChannel * Channels;
-        public const int FrameBytes = FrameSamples * SampleBytes;
+        public const int FrameBytes = FrameSamplesPerChannel * SampleBytes;
         
         protected bool _isDisposed = false;
 

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

@@ -20,12 +20,12 @@ namespace Discord.Audio
             CheckError(error);
         }
         
-        public unsafe int DecodeFrame(byte[] input, int inputOffset, int inputCount, byte[] output, int outputOffset)
+        public unsafe int DecodeFrame(byte[] input, int inputOffset, int inputCount, byte[] output, int outputOffset, bool decodeFEC)
         {
             int result = 0;
             fixed (byte* inPtr = input)
             fixed (byte* outPtr = output)
-                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, FrameSamplesPerChannel, 1);
+                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, FrameSamplesPerChannel, decodeFEC ? 1 : 0);
             CheckError(result);
             return result * SampleBytes;
         }

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

@@ -35,7 +35,7 @@ namespace Discord.Audio.Streams
         private readonly SemaphoreSlim _queueLock;
         private readonly Logger _logger;
         private readonly int _ticksPerFrame, _queueLength;
-        private bool _isPreloaded;
+        private bool _isPreloaded, _isSpeaking;
         private int _silenceFrames;
 
         public BufferedWriteStream(AudioStream next, IAudioClient client, int bufferMillis, CancellationToken cancelToken, int maxFrameSize = 1500)
@@ -45,7 +45,7 @@ namespace Discord.Audio.Streams
             //maxFrameSize = 1275 was too limiting at 128kbps,2ch,60ms
             _next = next;
             _client = client;
-            _ticksPerFrame = OpusEncoder.FrameSamples / 48;
+            _ticksPerFrame = OpusEncoder.FrameMillis;
             _logger = logger;
             _queueLength = (bufferMillis + (_ticksPerFrame - 1)) / _ticksPerFrame; //Round up
 
@@ -60,6 +60,12 @@ namespace Discord.Audio.Streams
 
             _task = Run();
         }
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing)
+                _cancelTokenSource.Cancel();
+            base.Dispose(disposing);
+        }
 
         private Task Run()
         {
@@ -71,6 +77,8 @@ namespace Discord.Audio.Streams
                         await Task.Delay(1).ConfigureAwait(false);
 
                     long nextTick = Environment.TickCount;
+                    ushort seq = 0;
+                    uint timestamp = 0;
                     while (!_cancelToken.IsCancellationRequested)
                     {
                         long tick = Environment.TickCount;
@@ -80,14 +88,20 @@ namespace Discord.Audio.Streams
                             Frame frame;
                             if (_queuedFrames.TryDequeue(out frame))
                             {
-                                await _client.ApiClient.SendSetSpeaking(true).ConfigureAwait(false);
+                                if (!_isSpeaking)
+                                {
+                                    await _client.ApiClient.SendSetSpeaking(true).ConfigureAwait(false);
+                                    _isSpeaking = true;
+                                }
+                                _next.WriteHeader(seq++, timestamp, false);
                                 await _next.WriteAsync(frame.Buffer, 0, frame.Bytes).ConfigureAwait(false);
                                 _bufferPool.Enqueue(frame.Buffer);
                                 _queueLock.Release();
                                 nextTick += _ticksPerFrame;
+                                timestamp += OpusEncoder.FrameSamplesPerChannel;
                                 _silenceFrames = 0;
 #if DEBUG
-                                var _ = _logger.DebugAsync($"Sent {frame.Bytes} bytes ({_queuedFrames.Count} frames buffered)");
+                                var _ = _logger?.DebugAsync($"Sent {frame.Bytes} bytes ({_queuedFrames.Count} frames buffered)");
 #endif
                             }
                             else 
@@ -95,13 +109,20 @@ namespace Discord.Audio.Streams
                                 while ((nextTick - tick) <= 0)
                                 {
                                     if (_silenceFrames++ < MaxSilenceFrames)
+                                    {
+                                        _next.WriteHeader(seq++, timestamp, false);
                                         await _next.WriteAsync(_silenceFrame, 0, _silenceFrame.Length).ConfigureAwait(false);
-                                    else
+                                    }
+                                    else if (_isSpeaking)
+                                    {
                                         await _client.ApiClient.SendSetSpeaking(false).ConfigureAwait(false);
+                                        _isSpeaking = false;
+                                    }
                                     nextTick += _ticksPerFrame;
+                                    timestamp += OpusEncoder.FrameSamplesPerChannel;
                                 }
 #if DEBUG
-                                var _ = _logger.DebugAsync($"Buffer underrun");
+                                var _ = _logger?.DebugAsync($"Buffer underrun");
 #endif
                             }
                         }
@@ -125,19 +146,16 @@ namespace Discord.Audio.Streams
             if (!_bufferPool.TryDequeue(out buffer))
             {
 #if DEBUG
-                var _ = _logger.DebugAsync($"Buffer overflow"); //Should never happen because of the queueLock
+                var _ = _logger?.DebugAsync($"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");
+                var _ = _logger?.DebugAsync($"Preloaded");
 #endif
                 _isPreloaded = true;
             }
@@ -161,10 +179,5 @@ namespace Discord.Audio.Streams
             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/InputStream.cs

@@ -14,6 +14,7 @@ namespace Discord.Audio.Streams
         private SemaphoreSlim _signal;
         private ushort _nextSeq;
         private uint _nextTimestamp;
+        private bool _nextMissed;
         private bool _hasHeader;
         private bool _isDisposed;
 
@@ -60,13 +61,14 @@ namespace Discord.Audio.Streams
             return frame;
         }
 
-        public void WriteHeader(ushort seq, uint timestamp)
+        public override void WriteHeader(ushort seq, uint timestamp, bool missed)
         {
             if (_hasHeader)
                 throw new InvalidOperationException("Header received with no payload");
             _hasHeader = true;
             _nextSeq = seq;
             _nextTimestamp = timestamp;
+            _nextMissed = missed;
         }
         public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancelToken)
         {
@@ -79,16 +81,17 @@ namespace Discord.Audio.Streams
             }
             if (!_hasHeader)
                 throw new InvalidOperationException("Received payload without an RTP header");
+            _hasHeader = false;
             byte[] payload = new byte[count];
             Buffer.BlockCopy(buffer, offset, payload, 0, count);
 
             _frames.Enqueue(new RTPFrame(
                 sequence: _nextSeq,
                 timestamp: _nextTimestamp,
+                missed: _nextMissed,
                 payload: payload
             ));
             _signal.Release();
-            _hasHeader = false;
             return Task.Delay(0);
         }
 

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

@@ -1,4 +1,5 @@
-using System.Threading;
+using System;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Discord.Audio.Streams
@@ -11,6 +12,8 @@ namespace Discord.Audio.Streams
         private readonly AudioStream _next;
         private readonly OpusDecoder _decoder;
         private readonly byte[] _buffer;
+        private bool _nextMissed;
+        private bool _hasHeader;
 
         public OpusDecodeStream(AudioStream next)
         {
@@ -19,10 +22,35 @@ namespace Discord.Audio.Streams
             _decoder = new OpusDecoder();
         }
 
+        public override void WriteHeader(ushort seq, uint timestamp, bool missed)
+        {
+            if (_hasHeader)
+                throw new InvalidOperationException("Header received with no payload");
+            _nextMissed = missed;
+            _hasHeader = true;
+            _next.WriteHeader(seq, timestamp, missed);
+        }
         public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
-            count = _decoder.DecodeFrame(buffer, offset, count, _buffer, 0);
+            if (!_hasHeader)
-            await _next.WriteAsync(_buffer, 0, count, cancellationToken).ConfigureAwait(false);
+                throw new InvalidOperationException("Received payload without an RTP header");
+            _hasHeader = false;
+
+            if (!_nextMissed)
+            {
+                count = _decoder.DecodeFrame(buffer, offset, count, _buffer, 0, false);
+                await _next.WriteAsync(_buffer, 0, count, cancellationToken).ConfigureAwait(false);
+            }
+            else if (count > 0)
+            {
+                count = _decoder.DecodeFrame(buffer, offset, count, _buffer, 0, true);            
+                await _next.WriteAsync(_buffer, 0, count, cancellationToken).ConfigureAwait(false);
+            }
+            else
+            {
+                count = _decoder.DecodeFrame(null, 0, 0, _buffer, 0, true);            
+                await _next.WriteAsync(_buffer, 0, count, cancellationToken).ConfigureAwait(false);
+            }
         }
 
         public override async Task FlushAsync(CancellationToken cancelToken)

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

@@ -1,5 +1,4 @@
-using System.IO;
+using System.Threading;
-using System.Threading;
 using System.Threading.Tasks;
 
 namespace Discord.Audio.Streams
@@ -7,7 +6,6 @@ namespace Discord.Audio.Streams
     ///<summary> Reads the payload from an RTP frame </summary>
     public class RTPReadStream : AudioOutStream
     {
-        private readonly InputStream _queue;
         private readonly AudioStream _next;
         private readonly byte[] _buffer, _nonce;
 
@@ -15,11 +13,8 @@ namespace Discord.Audio.Streams
         public override bool CanSeek => false;
         public override bool CanWrite => true;
 
-        public RTPReadStream(InputStream queue, int bufferSize = 4000)
+        public RTPReadStream(AudioStream next, int bufferSize = 4000)
-            : this(queue, null, bufferSize) { }
-        public RTPReadStream(InputStream queue, AudioStream next, int bufferSize = 4000)
         {
-            _queue = queue;
             _next = next;
             _buffer = new byte[bufferSize];
             _nonce = new byte[24];
@@ -36,11 +31,11 @@ namespace Discord.Audio.Streams
 
             uint timestamp = (uint)((buffer[offset + 4] << 24) |
                 (buffer[offset + 5] << 16) |
-                (buffer[offset + 6] << 16) |
+                (buffer[offset + 6] << 8) |
                 (buffer[offset + 7] << 0));
 
-            _queue.WriteHeader(seq, timestamp);
+            _next.WriteHeader(seq, timestamp, false);
-            await (_next ?? _queue as Stream).WriteAsync(buffer, offset + headerSize, count - headerSize, cancelToken).ConfigureAwait(false);
+            await _next.WriteAsync(buffer, offset + headerSize, count - headerSize, cancelToken).ConfigureAwait(false);
         }
 
         public static bool TryReadSsrc(byte[] buffer, int offset, out uint ssrc)
@@ -58,7 +53,7 @@ namespace Discord.Audio.Streams
 
             ssrc = (uint)((buffer[offset + 8] << 24) |
                 (buffer[offset + 9] << 16) |
-                (buffer[offset + 10] << 16) |
+                (buffer[offset + 10] << 8) |
                 (buffer[offset + 11] << 0));
             return true;
         }

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

@@ -10,7 +10,10 @@ namespace Discord.Audio.Streams
         private readonly AudioStream _next;
         private readonly byte[] _header;
         protected readonly byte[] _buffer;
-        private uint _ssrc, _timestamp = 0;
+        private uint _ssrc;
+        private ushort _nextSeq;
+        private uint _nextTimestamp;
+        private bool _hasHeader;
 
         public RTPWriteStream(AudioStream next, uint ssrc, int bufferSize = 4000)
         {
@@ -26,20 +29,30 @@ namespace Discord.Audio.Streams
             _header[11] = (byte)(_ssrc >> 0);
         }
 
+        public override void WriteHeader(ushort seq, uint timestamp, bool missed)
+        {
+            if (_hasHeader)
+                throw new InvalidOperationException("Header received with no payload");
+            _hasHeader = true;
+            _nextSeq = seq;
+            _nextTimestamp = timestamp;
+        }
         public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
         {
             cancellationToken.ThrowIfCancellationRequested();
 
+            if (!_hasHeader)
+                throw new InvalidOperationException("Received payload without an RTP header");
+            _hasHeader = false;
+
             unchecked
             {
-                if (_header[3]++ == byte.MaxValue)
+                _header[2] = (byte)(_nextSeq >> 8);
-                    _header[2]++;
+                _header[3] = (byte)(_nextSeq >> 0);
-
+                _header[4] = (byte)(_nextTimestamp >> 24);
-                _timestamp += (uint)OpusEncoder.FrameSamples;
+                _header[5] = (byte)(_nextTimestamp >> 16);
-                _header[4] = (byte)(_timestamp >> 24);
+                _header[6] = (byte)(_nextTimestamp >> 8);
-                _header[5] = (byte)(_timestamp >> 16);
+                _header[7] = (byte)(_nextTimestamp >> 0);
-                _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);

src/Discord.Net.WebSocket/DiscordVoiceApiClient.cs

@@ -48,6 +48,8 @@ namespace Discord.Audio
         internal IWebSocketClient WebSocketClient { get; }
         public ConnectionState ConnectionState { get; private set; }
 
+        public ushort UdpPort => _udp.Port;
+
         internal DiscordVoiceAPIClient(ulong guildId, WebSocketProvider webSocketProvider, UdpSocketProvider udpSocketProvider, JsonSerializer serializer = null)
         {
             GuildId = guildId;

src/Discord.Net.WebSocket/Net/DefaultUdpSocket.cs

@@ -19,6 +19,8 @@ namespace Discord.Net.Udp
         private Task _task;
         private bool _isDisposed;
         
+        public ushort Port => (ushort)((_udp?.Client.LocalEndPoint as IPEndPoint)?.Port ?? 0);
+
         public DefaultUdpSocket()
         {
             _lock = new SemaphoreSlim(1, 1);