02:29 <la-s> do people here know how to get HDMI sound working on the odroid n2 (S922X)?

02:54 <chewitt> la-s audio support is upstream for a while, what kernel are you using?

02:54 <chewitt> it normally requires some userspace bits too

02:55 <la-s> <chewitt "Las audio support is upstream fo"> 5.7rc6

02:55 <chewitt> see https://github.com/chewitt/alsa-lib/commits/amlogic

02:55 <la-s> What bits?

02:55 <la-s> thanks

02:56 <la-s> I'll try compiling my alsa with this

02:56 <chewitt> and mixer settings: https://github.com/chewitt/LibreELEC.tv/blob/amlogic-master/packages/audio/alsa-utils/scripts/soundconfig#L131-L136

02:59 <la-s> chewitt: how do I apply the mixer settings?

03:00 <chewitt> in a conventional distro you should be able to add the conf and add an alias (or rename AMLOGIC-HDMI in the conf to G12B-ODROID-N2 so it matches the card name in device-tree) without needing to patch anything

03:00 <chewitt> I use patches as that's how the LibreELEC build-system kind of works

03:01 <chewitt> the mixer settings can be set with "amixer"

03:06 <chewitt> can I ask, what distro or app are you working on? .. I noticed the Q&A over HDMI things

03:06 <la-s> chewitt: using NixOS

03:07 <la-s> thanks for the bit about the configuration

03:09 <la-s> Packages are immutable, and I don't think there is any easy way to add the configuration without needing to patch anything, and in any case, patching it is easier.

03:09 <la-s> I just added an override for the alsaLib package to use your repo as the source

03:12 <chewitt> audio support is still a bit work-in-progress, so that repo may be rebased

03:12 <la-s> BTW, how well does hardware accelerated decoding actually work?

03:13 <chewitt> that's a hard to answer question

03:13 <la-s> I haven't found any easy way to test it (or get it to work) but was wondering if it worked mostly fine with some patches or something

03:13 <chewitt> until last ~September it was all working rather well

03:14 <chewitt> then the kernel APIs firmed up and the vdec was reworked for compliance

03:14 <chewitt> h264, vp9 now pass compliance tests

03:15 <chewitt> but player apps like ffmpeg, gstreamer, mpv need varying levels of rework to match

03:15 <chewitt> like everything else in the V4L2 world, there is no prior art and everything inches forwards slowly

03:16 <chewitt> and HEVC is missing

03:16 <chewitt> N2 has enough CPU to software decode anything at 1080p, but 4K needs hardware decode

03:16 <la-s> Thanks!

03:16 <chewitt> and since most 4K material is HEVC, there's a double challenge

03:17 <la-s> Yeah, I can at most decode 1080p @ 30 FPS

03:18 <chewitt> fixing the current issues probably needs changes to the API, the vdec, and the player app

03:19 <chewitt> the "herding cats" issue is .. getting all the players into the same room at the same time for a fix party

03:19 <chewitt> I have been trying to do that, with limited success, since last Sept

03:20 <chewitt> s/limited/little

03:21 <chewitt> it's _very_ frustrating

03:23 <la-s> chewitt: is there any documentation for the userspace/kernel APIs for hardware decoding used by meson?

03:24 <chewitt> in the kernel I guess

03:24 <chewitt> I don't personally code, so it's not something I've gone looking for to read :)

03:24 <la-s> thanks

03:25 <la-s> Wonder how hard it would be to add support to mpv

03:26 <chewitt> IIRC there is already some support, but probably needs updating since the APIs firmed up