I think that this is a misunderstanding. The audio renderer is a piece of software that runs on your HTPC. According to this page in the Wiki, the audio renderer does this:but the Yamaha AV Receiver still does the audio rendering.
This audio renderer combats video playback related issues that almost all (without ReClock) Windows-based media players suffer from. It also provides WASAPI exclusive mode access to audio hardware so that the operating system mixer is not part of the audio pipeline.
Your Yamaha receiver will extract the audio from the datastream, so that it can perform the D-to-A conversion and send the output to the loudspeakers. The data forwarded to the TV may or may not contain audio (I suspect that it would contain audio, since then it is a simple "pass through").But I am no expert in these matters, so I am happy to be corrected.
-- from CyberSimian in the UK