Inputting audio signal to a PC

Question

I want to have my TV and PC connected to the same sound system which is a "custom" surround 4.0. I currently have wired 2 speakers to the line out of my integrated PC sound card and 2 speakers to the line in and configured it for surround. The TV is connected to the PC through HDMI.

This works, but I want to add a media center box (Raspberry Pi) to the TV (through HDMI) and use the surround instead of the integrated speakers in the TV. So my idea is to add a sound card with optical in like Karaoke Reverb CMI8768 connect it to the TV through SPDIF and connect the speakers as before.

My concerns are:

1. Is it going to work
2. Is it going to require manual configuration each time I want to switch the audio input signal between the PC and the TV.

My motherboard is ASRock H61M-U3S3 (it doesn't have SPDIF) so I need the sound card.

Answer 1

If I understand your intended configuration right, you mean to attempt to pass audio through your PC. Unfortunately, this is not something usually supported by the OS by default.

You'll likely need a sort of virtual patch cord system, software that allows you to route audio from one device to another (such as JACK Audio Connection Kit). Some possible issues: This would require that your PC is on at the times you want to pass audio through. Audio quality may suffer as the incoming sound is literally recorded on one device and played back on another and real-time, high quality digital audio recording can eat a good chunk of CPU capacity. There would be a bit of lag introduced, milliseconds worth but it can be noticeable in some situations. Some audio cards (especially the low end ones) cannot do playback and recording of different streams simultaneously (though they can often do "monitoring", allowing you to listen to a stream as it's recorded).

Another option is to use an external hardware mixer/router. These are common in the music industry but they can get pricey and I'm not able to find one that supports SPDIF.