Attempt to implement rtcp receiver reports; Attempt to implement fec;…

… minor improvements here and there

examples/HelloWorld/src/Program.cs

@@ -4,6 +4,7 @@
 using System.IO;
 using System.Threading.Tasks;
 using DSharpPlus.VoiceLink.Enums;
+using DSharpPlus.VoiceLink.VoiceEncrypters;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
 using Serilog;

src/DSharpPlus.VoiceLink/DSharpPlus.VoiceLink.csproj

@@ -16,7 +16,6 @@
   </PropertyGroup>
   <ItemGroup>
     <None Include="../../LICENSE" Pack="true" PackagePath="" />
-    <ProjectReference Include="../../libs/DSharpPlus/DSharpPlus/DSharpPlus.csproj" />
     <PackageReference Include="Geralt" Version="3.0.1" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.0" />
     <PackageReference Include="System.IO.Pipelines" Version="8.0.0" />
@@ -26,4 +25,7 @@
     <PackageReference Include="Serilog.Sinks.Console" Version="5.0.1" />
     <PackageReference Include="Serilog.Sinks.File" Version="5.0.0" />
   </ItemGroup>
-</Project>
+  <ItemGroup>
+    <ProjectReference Include="..\..\libs\DSharpPlus\DSharpPlus\DSharpPlus.csproj" />
+  </ItemGroup>
+</Project>

src/DSharpPlus.VoiceLink/Opus/OpusDecoder.cs

@@ -31,15 +31,22 @@ public unsafe void Init(OpusSampleRate sampleRate, int channels)
             }
         }
 
-        /// <inheritdoc cref="OpusNativeMethods.Decode(OpusDecoder*, byte*, int, short*, int, int)"/>
-        public unsafe int Decode(ReadOnlySpan<byte> data, ref Span<short> pcm, int frameSize, bool decodeFec)
+        /// <inheritdoc cref="OpusNativeMethods.Decode(OpusDecoder*, byte*, int, byte*, int, int)"/>
+        public unsafe int Decode(ReadOnlySpan<byte> data, Span<byte> pcm, bool decodeFec)
         {
             int decodedLength;
             fixed (OpusDecoder* pinned = &this)
             fixed (byte* dataPointer = data)
-            fixed (short* pcmPointer = pcm)
+            fixed (byte* pcmPointer = pcm)
             {
-                decodedLength = OpusNativeMethods.Decode(pinned, dataPointer, data.Length, pcmPointer, frameSize, decodeFec ? 1 : 0);
+                decodedLength = OpusNativeMethods.Decode(
+                    pinned,
+                    dataPointer,
+                    data.Length,
+                    pcmPointer,
+                    OpusNativeMethods.PacketGetNbFrames(dataPointer, data.Length),
+                    decodeFec ? 1 : 0
+                );
             }
 
             // Less than zero means an error occurred
@@ -48,16 +55,17 @@ public unsafe int Decode(ReadOnlySpan<byte> data, ref Span<short> pcm, int frame
                 throw new OpusException((OpusErrorCode)decodedLength);
             }
 
-            return decodedLength * sizeof(short) * 2; // Multiplied by the sample size, which is size of short times the number of channels
+            // Multiplied by the sample size, which is size of short times the number of channels
+            return decodedLength * sizeof(short) * 2;
         }
 
         /// <inheritdoc cref="OpusNativeMethods.DecodeFloat(OpusDecoder*, byte*, int, float*, int, int)"/>
-        public unsafe int DecodeFloat(ReadOnlySpan<byte> data, ref Span<float> pcm, int frameSize, bool decodeFec)
+        public unsafe int DecodeFloat(ReadOnlySpan<byte> data, Span<byte> pcm, int frameSize, bool decodeFec)
         {
             int decodedLength;
             fixed (OpusDecoder* pinned = &this)
             fixed (byte* dataPointer = data)
-            fixed (float* pcmPointer = pcm)
+            fixed (byte* pcmPointer = pcm)
             {
                 decodedLength = OpusNativeMethods.DecodeFloat(pinned, dataPointer, data.Length, pcmPointer, frameSize, decodeFec ? 1 : 0);
             }

src/DSharpPlus.VoiceLink/Opus/OpusException.cs

@@ -31,7 +31,7 @@ public sealed class OpusException : Exception
             OpusErrorCode.Unimplemented => "Error -5: Invalid/unsupported request number.",
             OpusErrorCode.InvalidState => "Error -6: An encoder or decoder structure is invalid or already freed.",
             OpusErrorCode.AllocFail => "Error -7: Memory allocation has failed.",
-            _ => "Unknown error."
+            _ => $"Error {(int)errorCode}: Unknown error."
         };
     }
 }

src/DSharpPlus.VoiceLink/Opus/OpusNativeMethods.Decoder.cs

@@ -43,11 +43,11 @@ internal static partial class OpusNativeMethods
         /// <param name="decodeFec">Flag (0 or 1) to request that any in-band forward error correction data be decoded. If no such data is available, the frame is decoded as if it were lost.</param>
         /// <returns>Number of decoded samples or an <see cref="OpusErrorCode"/></returns>
         [LibraryImport("opus", EntryPoint = "opus_decode")]
-        public static unsafe partial int Decode(OpusDecoder* decoder, byte* data, int length, short* pcm, int frameSize, int decodeFec);
+        public static unsafe partial int Decode(OpusDecoder* decoder, byte* data, int length, byte* pcm, int frameSize, int decodeFec);
 
         /// <inheritdoc cref="Decode(OpusDecoder*, byte*, int, byte*, int, int)"/>
         [LibraryImport("opus", EntryPoint = "opus_decode_float")]
-        public static unsafe partial int DecodeFloat(OpusDecoder* decoder, byte* data, int length, float* pcm, int frameSize, int decodeFec);
+        public static unsafe partial int DecodeFloat(OpusDecoder* decoder, byte* data, int length, byte* pcm, int frameSize, int decodeFec);
 
         /// <summary>
         /// Perform a CTL function on an Opus decoder.

src/DSharpPlus.VoiceLink/Rtp/RtcpHeader.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Buffers.Binary;
+
+namespace DSharpPlus.VoiceLink.Rtp
+{
+    public readonly record struct RtcpHeader
+    {
+        /// <summary>
+        /// Gets the version of the RTCP header.
+        /// </summary>
+        public int Version { get; init; }
+
+        /// <summary>
+        /// Gets whether the RTCP header has padding.
+        /// </summary>
+        public int Padding { get; init; }
+
+        /// <summary>
+        /// Gets the report count of the RTCP header.
+        /// </summary>
+        public int ReportCount { get; init; }
+
+        /// <summary>
+        /// Gets the packet type of the RTCP header.
+        /// </summary>
+        public int PacketType { get; init; }
+
+        /// <summary>
+        /// Gets the length of the RTCP header.
+        /// </summary>
+        public int Length { get; init; }
+
+        /// <summary>
+        /// Gets the SSRC of the RTCP header.
+        /// </summary>
+        public uint Ssrc { get; init; }
+
+        public RtcpHeader(ReadOnlySpan<byte> data)
+        {
+            if (data.Length < 8)
+            {
+                throw new ArgumentException("The source buffer must have a minimum of 8 bytes for it to be a RTCP header.", nameof(data));
+            }
+            else if (data[1] != 201)
+            {
+                throw new ArgumentException("The source buffer must contain a RTCP receiver report.", nameof(data));
+            }
+
+            Version = data[0] >> 6;
+            Padding = (data[0] >> 5) & 0b00000001;
+            ReportCount = data[0] & 0b00011111;
+            PacketType = data[1];
+            Length = BinaryPrimitives.ReadUInt16BigEndian(data[2..4]);
+            Ssrc = BinaryPrimitives.ReadUInt32BigEndian(data[4..8]);
+        }
+    }
+}

src/DSharpPlus.VoiceLink/Rtp/RtcpReceiverReportPacket.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+
+namespace DSharpPlus.VoiceLink.Rtp
+{
+    public readonly record struct RtcpReceiverReportPacket
+    {
+        /// <summary>
+        /// Gets the header of the RTCP packet.
+        /// </summary>
+        public RtcpHeader Header { get; init; }
+
+        /// <summary>
+        /// Gets the report blocks of the RTCP packet.
+        /// </summary>
+        public IReadOnlyList<RtcpReportBlock> ReportBlocks { get; init; }
+
+        public RtcpReceiverReportPacket(RtcpHeader header, ReadOnlySpan<byte> data)
+        {
+            List<RtcpReportBlock> reportBlocks = new(header.ReportCount);
+            for (int i = 0; i < header.ReportCount; i++)
+            {
+                reportBlocks.Add(new RtcpReportBlock(data));
+                data = data[24..];
+            }
+
+            Header = header;
+            ReportBlocks = reportBlocks;
+        }
+    }
+}

src/DSharpPlus.VoiceLink/Rtp/RtcpReportBlock.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Buffers.Binary;
+
+namespace DSharpPlus.VoiceLink.Rtp
+{
+    public readonly record struct RtcpReportBlock
+    {
+        public ushort SynchronizationSource { get; }
+        public ushort FractionLost { get; }
+        public uint CumulativePacketsLost { get; }
+        public uint ExtendedHighestSequenceNumberReceived { get; }
+        public uint InterarrivalJitter { get; }
+        public uint LastSenderReport { get; }
+        public uint DelaySinceLastSenderReport { get; }
+
+        public RtcpReportBlock(ReadOnlySpan<byte> data)
+        {
+            SynchronizationSource = BinaryPrimitives.ReadUInt16BigEndian(data);
+            FractionLost = data[2];
+            CumulativePacketsLost = BinaryPrimitives.ReadUInt32BigEndian(data[3..]);
+            ExtendedHighestSequenceNumberReceived = BinaryPrimitives.ReadUInt32BigEndian(data[7..]);
+            InterarrivalJitter = BinaryPrimitives.ReadUInt32BigEndian(data[11..]);
+            LastSenderReport = BinaryPrimitives.ReadUInt32BigEndian(data[15..]);
+            DelaySinceLastSenderReport = BinaryPrimitives.ReadUInt32BigEndian(data[19..]);
+        }
+    }
+}

src/DSharpPlus.VoiceLink/Rtp/RtcpUtilities.cs

@@ -0,0 +1,28 @@
+using System;
+
+namespace DSharpPlus.VoiceLink.Rtp
+{
+    public static class RtcpUtilities
+    {
+        /// <summary>
+        /// Determines if the given buffer contains a valid RTCP header.
+        /// </summary>
+        /// <param name="source">The data to reference.</param>
+        /// <returns>Whether the data contains a valid RTCP header.</returns>
+        public static bool IsRtcpReceiverReport(ReadOnlySpan<byte> source) => source.Length >= 8 && source[1] == 201;
+
+        public static RtcpHeader DecodeHeader(ReadOnlySpan<byte> source)
+        {
+            if (source.Length < 8)
+            {
+                throw new ArgumentException("The source buffer must have a minimum of 8 bytes for it to be a RTCP header.", nameof(source));
+            }
+            else if (source[1] != 201)
+            {
+                throw new ArgumentException("The source buffer must contain a RTCP receiver report.", nameof(source));
+            }
+
+            return new RtcpHeader(source);
+        }
+    }
+}

src/DSharpPlus.VoiceLink/Rtp/RtpHeader.cs

@@ -1,9 +1,29 @@
 namespace DSharpPlus.VoiceLink.Rtp
 {
-    public readonly struct RtpHeader
+    public readonly record struct RtpHeader
     {
+        public byte FirstMetadata { get; init; }
+        public byte SecondMetadata { get; init; }
         public ushort Sequence { get; init; }
         public uint Timestamp { get; init; }
         public uint Ssrc { get; init; }
+
+        // The version is the first two bits of the first byte.
+        public byte Version => (byte)(FirstMetadata & 0b11000000);
+
+        // The padding bit is the third bit of the first byte.
+        public bool HasPadding => (FirstMetadata & 0b00100000) != 0;
+
+        // The extension bit is the fourth bit of the first byte.
+        public bool HasExtension => (FirstMetadata & 0b00010000) != 0;
+
+        // The CSRC count is the last four bits of the first byte.
+        public byte CsrcCount => (byte)((FirstMetadata & 0b00001111) >> 4);
+
+        // The marker bit is the first bit of the second byte.
+        public bool HasMarker => (SecondMetadata & 0b10000000) != 0;
+
+        // The payload type is the last seven bits of the second byte.
+        public byte PayloadType => (byte)(SecondMetadata & 0b01111111);
     }
 }

src/DSharpPlus.VoiceLink/Rtp/RtpUtilities.cs

@@ -11,6 +11,7 @@ public static class RtpUtilities
         public const byte VersionWithExtension = 0x90;
         public const byte Version = 0x80;
         public const byte PayloadType = 0x78;
+        public static readonly byte[] RtpExtensionOneByte = [190, 222];
 
         /// <summary>
         /// Determines if the given buffer contains a valid RTP header.
@@ -67,6 +68,8 @@ public static RtpHeader DecodeHeader(ReadOnlySpan<byte> source)
 
             return new RtpHeader()
             {
+                FirstMetadata = source[0],
+                SecondMetadata = source[1],
                 Sequence = BinaryPrimitives.ReadUInt16BigEndian(source[2..4]),
                 Timestamp = BinaryPrimitives.ReadUInt32BigEndian(source[4..8]),
                 Ssrc = BinaryPrimitives.ReadUInt32BigEndian(source[8..12])

src/DSharpPlus.VoiceLink/VoiceEncrypters/IVoiceEncrypter.cs

@@ -10,7 +10,8 @@ public interface IVoiceEncrypter
 
         int GetEncryptedSize(int length);
         int GetDecryptedSize(int length);
-        bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target);
-        bool Decrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target);
+        bool TryEncryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target);
+        bool TryDecryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target);
+        bool TryDecryptReportPacket(ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target) => false;
     }
 }

src/DSharpPlus.VoiceLink/VoiceEncrypters/XSalsa20Poly1305.cs

@@ -15,7 +15,7 @@ public sealed record XSalsa20Poly1305 : IVoiceEncrypter
         public int GetEncryptedSize(int length) => length + SodiumXSalsa20Poly1305.MacSize;
         public int GetDecryptedSize(int length) => length - SodiumXSalsa20Poly1305.MacSize;
 
-        public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryEncryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {
@@ -35,10 +35,10 @@ public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOn
             target[..12].CopyTo(nonce);
 
             // Encrypt the data
-            return SodiumXSalsa20Poly1305.Encrypt(data, key, nonce, target[24..]) == 0;
+            return SodiumXSalsa20Poly1305.Encrypt(data, key, nonce, target[12..]) == 0;
         }
 
-        public bool Decrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryDecryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {

src/DSharpPlus.VoiceLink/VoiceEncrypters/XSalsa20Poly1305Lite.cs

@@ -23,7 +23,7 @@ public sealed record XSalsa20Poly1305Lite : IVoiceEncrypter
         public int GetEncryptedSize(int length) => length + SodiumXSalsa20Poly1305.MacSize;
         public int GetDecryptedSize(int length) => length - SodiumXSalsa20Poly1305.MacSize;
 
-        public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryEncryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {
@@ -47,7 +47,7 @@ public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOn
             return SodiumXSalsa20Poly1305.Encrypt(data, key, nonce, target[16..]) == 0;
         }
 
-        public bool Decrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryDecryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {

src/DSharpPlus.VoiceLink/VoiceEncrypters/XSalsa20Poly1305Suffix.cs

@@ -16,7 +16,7 @@ public sealed record XSalsa20Poly1305Suffix : IVoiceEncrypter
         public int GetEncryptedSize(int length) => length + SodiumXSalsa20Poly1305.MacSize;
         public int GetDecryptedSize(int length) => length - SodiumXSalsa20Poly1305.MacSize;
 
-        public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryEncryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {
@@ -40,7 +40,7 @@ public bool Encrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOn
             return SodiumXSalsa20Poly1305.Encrypt(data, key, nonce, target[36..]) == 0;
         }
 
-        public bool Decrypt(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
+        public bool TryDecryptOpusPacket(VoiceLinkUser voiceLinkUser, ReadOnlySpan<byte> data, ReadOnlySpan<byte> key, Span<byte> target)
         {
             if (data.Length < SodiumXSalsa20Poly1305.MacSize)
             {

src/DSharpPlus.VoiceLink/VoiceLinkConfiguration.cs

@@ -1,6 +1,4 @@
 using System;
-using System.Net;
-using DSharpPlus.Net.WebSocket;
 using DSharpPlus.VoiceLink.VoiceEncrypters;
 using Microsoft.Extensions.DependencyInjection;
 
@@ -11,15 +9,6 @@ public sealed record VoiceLinkConfiguration
         public IServiceCollection ServiceCollection { get; set; } = new ServiceCollection();
         internal IServiceProvider ServiceProvider => _serviceProvider ??= ServiceCollection.BuildServiceProvider();
         private IServiceProvider? _serviceProvider;
-
-        public IWebProxy? Proxy { get; set; }
-        public WebSocketClientFactoryDelegate WebSocketClientFactory
-        {
-            internal get => _webSocketClientFactory;
-            set => _webSocketClientFactory = value is null ? throw new ArgumentNullException(nameof(value)) : value;
-        }
-        private WebSocketClientFactoryDelegate _webSocketClientFactory = WebSocketClient.CreateNew;
-
         public int MaxHeartbeatQueueSize { get; set; } = 5;
         public IVoiceEncrypter VoiceEncrypter { get; set; } = new XSalsa20Poly1305();
     }