Fixed several audio stream issues

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

@@ -1,43 +1,19 @@
 using System;
-using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 
 namespace Discord.Audio
 {
-    public abstract class AudioInStream : Stream
+    public abstract class AudioInStream : AudioStream
     {
-        public override bool CanRead => true;
-        public override bool CanSeek => false;
-        public override bool CanWrite => true;
         public abstract int AvailableFrames { get; }
 
+        public override bool CanRead => true;
+        public override bool CanWrite => true;        
+
         public abstract Task<RTPFrame> ReadFrameAsync(CancellationToken cancelToken);
         public abstract bool TryReadFrame(CancellationToken cancelToken, out RTPFrame frame);
 
-        public RTPFrame ReadFrame()
-        {
-            return ReadFrameAsync(CancellationToken.None).GetAwaiter().GetResult();
-        }
-        public override int Read(byte[] buffer, int offset, int count)
-        {
-            return ReadAsync(buffer, offset, count, CancellationToken.None).GetAwaiter().GetResult();
-        }
-        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(); }
+        public override Task FlushAsync(CancellationToken cancelToken) { throw new NotSupportedException(); }
     }
 }