How to switch between HDMI and Headphone

[RandomRouter]

Originally Posted by AlbanRampon

It depends on the product and how the manufacturer has configured the chip.

You mean the chip of the soundcard in the connected computer?

Originally Posted by AlbanRampon

Windows hasn't allowed to play the same content simultaneously to several devices, so they are all playing by default.

I didn't get it. How do they play all by default if it's not allowed by Windows to play on several devices?

Would it be possible under Linux (if the soundcard is able to handle it)?

Sorry for my stupid questions. I just want to get behind this concept