This is a bit different though. Why not output PCM over your HDMI ?
... because I enjoy listening surround sounds, if the sound source holds several channels.
My digital AV receiver (amplifier) processes stereo PCM, AC3 and DTS encoded sounds through S/PDIF connection - and nothing else (like multichannel PCM, E-AC3, DTS-HD, or HDMI connection). In this configuration, where the PC audio ouput is directly transmitted to the AV receiver, it is the responsability of the PC audio filters to convert the sounds to the compatible encodings, with 5.1 channels in case of a surround sound source.
As I said, I can also use another configuration, where the main screen of the PC is a TV set connected through an HDMI cable. In this case, the audio is output through the HDMI link to the TV set, which transfer it to the amplifier through a S/PDIF connection. This work well for stereo PCM and AC3 streams. Currently, it seems that sending E-AC3 streams through HDMI output nothing, that surprises me because I'm sure the TV is able to convert external (HDMI) E-AC3 streams to AC3 (or extract it as additional audio stream of HDMI ?). It may be a matter of content protection (HDCP), a bug of initialisation protocol or a limitation of additional audio streams - I have no tools nor knowledge to go further. Doesn't work also for simple DTS streams.
You might wish to know my equipment :
- MPC-HC with ffdshow audio (64 bits)
Realtek High Definition Audio chip (embedded on motherboard)
Sapphire Radeon HD6450 graphic card (with ATI HDMI audio)
Sony KDL-46W5500 TV set
Surround Sound Receiver NAD T761
Tuner Enregistreur TNT HD AKIRA (HDMI-connected to the TV set, sending E-AC3 streams correctly converted to AC3 5.1 by the TV)
... it goes without saying that the TV set converts the broadcasted E-AC3 sound to AC3 over S/PDIF connection.
HDMI seems messy, isn't it ?