encoder: write audio in segments

I'll be honest, this probably makes no noticeable difference at all. It should be faster and more efficient, but whether that translates into any tangible improvement is yet to be seen.

app/codec/oiio/oiioencoder.cpp

@@ -62,9 +62,10 @@ bool OIIOEncoder::WriteFrame(FramePtr frame, rational time)
   return true;
 }
 
-void OIIOEncoder::WriteAudio(AudioParams pcm_info, QIODevice *file)
+bool OIIOEncoder::WriteAudio(SampleBufferPtr audio)
 {
   // Do nothing
+  return false;
 }
 
 void OIIOEncoder::Close()