Originally Posted by Callsign_Vega
Guys, my receiver doesn't support HDR pass-through. So I have a question:
If I output 4K 60 Hz HDR signal + Atmos sound out from my PC's Titan-Xp video card HDMI 2.0 port, directly into the C7, can I then use the HDMI ARC port on the C7 to pass Atmos to my receiver?
Originally Posted by adamadamadam
In theory, if your AVR supports atmos over ARC - not many do . In practice, I'm not sure if LG has even activated this feature yet. I can't get ARC to work at all so far
HDMI-ARC currently only supports DD and DD+ streams, the latter of which can technically contain more than 5.1 channels but I've never seen it implemented. Both codecs are lossy, unlike TrueHD, DTS-HD and Atmos (update: Atmos comes in lossy flavour DD+, as well as lossless TrueHD). There isn't any solid reason why ARC wouldn't support the lossless codecs (particularly if the one connection doen'st have an upstream video content), but the HDMI org just didn't implement it that way when they did up the HDMI 1.4 spec.
The next version of HDMI, which is 2.1, will have something called "eARC" which is clearly intended to mean support for the object-based codecs like Atmos (which will include TrueHD and DTS-HD as well). HDMI's FAQ says that "some" impementations of HDMI 2.0x (like our TV) will be firmware upgradable to 2.1. So this is likely a "future support" potential, assuming HDMI 2.1 becomes official before the 2018 models are announced.
[Update -> I've added to post 1782 of this thread with more up to date / accurate info about the future prospect of TrueHD over ARC]
In short, no, the B7/C7 won't passthrough Atmos or other lossless codecs through ARC. (I've already tried using a PS4). I hope it comes, since my receiver also does not support HDR, but I'm expecting to upgrade it to a Yamaha Aventage soon.
Originally Posted by poisson
My use case is slightly different, in that I have locally stored videos which have TrueHD or Atmos 7.1 audio tracks, and I'm trying to play them with the TV's DLNA client. They can't even play the audio track, and report an error that the video contains no audio. I was hoping this would work, to passthrough the audio to my receiver. I don't have an ARC capable receiver yet, but it doesn't look like it would matter, so I'll stick with what I have now and continue to use Optical out of the TV.
Sounds like HMDI-ARC doesn't currently support outputting this audio either, so I'm limited unless I want to go to a 4K receiver and run everything through that. I was hoping to go direct to the TV so that I could dial in my adjustments for each input, and send audio out with 1 cable, but it just doesn't look like that's going to be an option.
I agree it seems the LG DLNA client won't decode, process, or stream the lossless codecs, which is unfortunate for your scenario. However, you might have a different source in your setup that would recognize and pass it to your receiver. (A Blu-Ray player, game console, or streaming box, maybe). That would mean using the the secondary device for your client, though. In the worst case, you might try an inexpensive PC or android box.
I would be surprised if your receiver doen't support ARC though. If it has "tv" as a selectable input, it should. You might need to enable its HDMI-CEC feature, which every company seems to label differently. (Ex, LG calls it SIMPLINK). It is a moot point in your current setup though, unfortunately, since ARC won't currently do the lossless codecs anyway, and the client seems not to either.