Optionls for multichannel (hdmi) input for computer-based DSP?


2019-11-17 6:08 pm
Options for multichannel (hdmi) input for computer-based DSP?

Hi all,

I recently got interested in DSP for room correction. I am looking for an affordable solution to have an active subwoofer crossover and some other filters (ideally FIR) for a 3.1 setup. As far as I understand, as long as I have multichannel source material available on a computer (even something like a Raspberry Pi), I should be able to preprocess the sound system-wide and output the resulting four channels to my AVR via HDMI.

Now ideally, I would like to be able to also process other sources that usually have an HDMI output while avoiding any unnecessary AD and DA conversion. For stereo input signals, I think the least painful solution would be to get an SPDIF input interface and an HDMI audio extractor to pipe everything to the Pi). But what about multi-channel? Do any of you know of a good way to extract the digital audio signal (say for the sake of simplicity multi-channel PCM) from an HDMI source and make it available for further processing? My dream device would be a low-cost board that interfaces with the GPIO pins of a Raspberry Pi and registers as a multi-channel audio input device. Is anybody aware of such a thing? I know there are people here with a lot of electronics knowledge, would anybody interested in building something like this :D?

Alternatively, I guess I could use an hdmi capture card, but I’m concerned with the performance requirements since those need to handle the video as well. Besides, they seem rather pricey. Does anybody have experience with the latency caused by using one of those for dsp purposes?

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