[arch-general] HDMI audio input - HDMI microphone

[Neven Sajko]

> Sounds like a standard thing. I'm not aware of your restrictions but I would
> actually suggest looking into some pre-made Texas Instruments ADC/DAC->USB ICs
> which are widely in use in existing products.

Well, my MEMS microphones are actually themselves digital (PDM) so I
do not need an ADC. I will look into existing USB ICs, but I do not
think I will use them as this is a learning exercise (I think I will
solve PDM->USB with either a microcontroller or an FPGA).

> USB is sufficient, for LPCM (assuming 16bit stereo 48kHz) requires 1.47Mbit/s
> whereas USB2.0 is already 480Mbit/s.
> HDMI generally only carries audio from a video source (PC) to a monitor, it
> can optionally carry audio back through ARC (Audio Return Channel), which is
> used by TVs that are connected to a HDMI receiver (those fancy 5.1, 7.1
> amplifiers that switch HDMI), adding the ability to route TV audio back to the
> receiver even though the receiver generally only sends video to the TV over
> this cable.

Thanks a bunch :) .

So the conclusion is that HDMI supports this ARC thing, but the
graphics cards do not. Well, then I will use USB.

Thanks again,
Nsajko