Enable FEC decoding

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

@@ -7,7 +7,7 @@ namespace Discord.Audio
         protected IntPtr _ptr;
 
         /// <summary> Gets the bit rate of this converter. </summary>
-        public const int BitsPerSample = 16;
+        public const int BitsPerSample = sizeof(short) * 8;
         /// <summary> Gets the bytes per sample. </summary>
         public const int SampleSize = (BitsPerSample / 8) * MaxChannels;
         /// <summary> Gets the maximum amount of channels this encoder supports. </summary>

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

@@ -32,11 +32,11 @@ namespace Discord.Audio
             int result = 0;
             fixed (byte* inPtr = input)
             fixed (byte* outPtr = output)
-                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, (output.Length - outputOffset) / SampleSize, 0); //TODO: Enable FEC
+                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, (output.Length - outputOffset) / SampleSize, 1);
 
             if (result < 0)
                 throw new Exception($"Opus Error: {(OpusError)result}");
-            return result * 4;
+            return result * SampleSize;
         }
 
         protected override void Dispose(bool disposing)

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

@@ -12,7 +12,7 @@ namespace Discord.Audio.Streams
         private readonly byte[] _buffer;
         private readonly OpusDecoder _decoder;
 
-        public OpusDecodeStream(AudioStream next, int channels = OpusConverter.MaxChannels, int bufferSize = 5760 * 4)
+        public OpusDecodeStream(AudioStream next, int channels = OpusConverter.MaxChannels, int bufferSize = 5760 * 2 * sizeof(short))
         {
             _next = next;
             _buffer = new byte[bufferSize];