renderer: switched audio rendering over to planar buffers

While planar audio cannot be used for playback, it's much easier for processing.
This should lead to cleaner and easier to write code in the future.

app/codec/oiio/oiiodecoder.cpp

@@ -183,9 +183,9 @@ FramePtr OIIODecoder::RetrieveVideo(const rational &timecode, const int& divider
 
   FramePtr frame = Frame::Create();
 
-  frame->set_width(buffer_->spec().width / divider);
-  frame->set_height(buffer_->spec().height / divider);
-  frame->set_format(pix_fmt_);
+  frame->set_video_params(VideoRenderingParams(buffer_->spec().width / divider,
+                                               buffer_->spec().height / divider,
+                                               pix_fmt_));
   frame->allocate();
 
   if (divider == 1) {