[pulseaudio-discuss] [RFC PATCH 0/2] HDMI IEC61937 + HBR passthrough support

[Alexander E. Patrakov]

2017-08-29 3:49 GMT+05:00 Pierre-Louis Bossart
<pierre-louis.bossart at linux.intel.com>:
> HDMI passthrough needs some love. What works with ALSA is plain
> broken with PulseAudio (no audio or random noise). Only the AC3
> format seems to work, EAC3 is broken and HBR formats are not
> supported yet.
>
> Fix EAC3 issues where the AES non-audio bit is not set when opening
> the alsa-sink. The fix is to force a suspend/resume when an actual
> sink-input is connected. This is far from optimal since we suspend/resume
> twice (once for rate, once on entering passthrough) but the state
> machine is obviously quite racy.
>
> Add definitions for Dolby TrueHD and DTSHD. This needs additional
> work since ALSA will only enable the HBR passthrough mode with
> 8 channels and 192kHz. For now the ALSA sinks are only configured to
> support 2 channels for passthrough and we'd need to switch between 2
> and 8 channels depending on the format. I don't quite understand how
> the profiles are managed and could use some help here.

Your work invalidates the comment added in this commit:

https://cgit.freedesktop.org/pulseaudio/pulseaudio/commit/?id=04737989ec537e01d63c155807a5d19b0ec5b294

I think that, if you don't undo this commit, at least a better message
what exactly works is needed. I.e. how to test, given that the HDMI
sink does not have the formats set.

-- 
Alexander E. Patrakov