Simultaneous I2S (external DAC) and HDMI


#1

Sorry if that was asked before.

I plan to buy DAC module which attaches via I2S interface to RPI2. The only thing that stopping me would be if it’s not possible to play sound simultaneously over HDMI and external DAC in the same time via kodi. I saw similar questions being asked, but no one explicitly said it is doable.

What I got so far searching around is:

So to try to answer the question to myself, it looks like the only way would be to buy the following addon board:
http://www.audiophonics.fr/fr/raspberry-pi/st-600-module-hat-hdmi-vers-spdif-rca-stereo-51-1080p-p-10249.html
which would allow to solve my exact needs in “passthrough” mode. Am I right?


#2

HDMI + I2S audio is not supported.

A HDMI/optical splitter may do what you want:


#3

Hi Popcornmix,

at the moment it’s possible for Kodi to simultaneously stream audio to HDMI and PWM (poor theoretical SNR of 66dB). Any chance to enable rerouting audio stream to I2S bus instead to PWM in software?

I’m asking because the solution you offered is definately not an audiophile DAC and wouldn’t bring any benefits to existing possibility to dual routing audio in Kodi (hdmi+analogue).


#4

No. HDMI and PWM audio are both driven by the firmware, so duplicating the output to both is feasible.
I2S is driven by the arm from the kernel. That is a very different problem to solve.


#5

Hi All,

What about this device from Audiophonics:
https://www.audiophonics.fr/fr/lecteurs-reseau-audio-raspdac/raspdigi-lte-lvds-v2-lecteur-reseau-i2s-lvds-hdmi-reclocker-allo-kali-format-audio-gd-p-13064.html

It holds the original hdmi port from the Pi + a second one for I2S hdmi out.

Do you know or think it would work with OSMC ?
Outputting video to the original hdmi and sound to the i2s hdmi?