Fixed a few audio constants

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

@@ -12,8 +12,8 @@ namespace Discord.Audio
 
         public const int SampleBytes = sizeof(short) * Channels;
 
-        public const int FrameSamples = SamplingRate / 1000 * FrameMillis;
         public const int FrameSamplesPerChannel = SamplingRate / 1000 * FrameMillis;
+        public const int FrameSamples = FrameSamplesPerChannel * Channels;
         public const int FrameBytes = FrameSamples * SampleBytes;
         
         protected bool _isDisposed = false;

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

@@ -25,9 +25,9 @@ namespace Discord.Audio
             int result = 0;
             fixed (byte* inPtr = input)
             fixed (byte* outPtr = output)
-                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, FrameBytes / SampleBytes, 1);
+                result = Decode(_ptr, inPtr + inputOffset, inputCount, outPtr + outputOffset, FrameSamplesPerChannel, 1);
             CheckError(result);
-            return FrameBytes;
+            return result * SampleBytes;
         }
 
         protected override void Dispose(bool disposing)