I've just bought a new TV which is hooked up to the SPDIF input on my Xonar D2. Some Freeview HD broadcasts use HE-AAC to encode their 5.1 channel audio streams but unfortunately the Xonar doesn't seem to recognise the stream at all and all I get is silence (or noise with validity check disabled). The manual for the TV states that "Dolby Digital Plus, Dolby Digital and HE-AAC multi-channel are output as Dolby Digital Bitstream" so I'm not sure if that means those streams are transcoded to DD Bitstream or they are passed through as-is.

Either way, I'd quite like to get it working. I believe all of the decoding work is done in software, as opposed to the encoding which is hardware based on the Xonar D2. Could this be a problem fixable with software? If I set the SPDIF output on the TV to PCM then it's all dandy, but only in stereo. I have ffdshow installed if that helps.

Any advice appreciated, this appears to be a common issue with Freeview HD at the moment (typically with receivers that don't know what to do with HE-AAC).