Originally Posted by Wertzius
the LG 2017 TVs support Atmos over Arc, but LG uses a proprietary way because it is not defined by the HDMI Org as you said. So only the LG SJ9 recognises it, with luck other receivers.
Yes this makes sense, HDMI 2.1 isn't official but the companies know enough about it they could make their own implementations without the licensing. I highly suspect full 2.1 support (or at least eARC support) will come via firmware update.
Originally Posted by Wjboshart
Atmos over arc works on the c7. Quite a number of titles I have from vudu support atmos and it works just fine
Originally Posted by jrref
This is interesting because the Sony A1E passes "lossy" Atmos over HDMI ARC. When I play the Dolby Atmos trailers on VuDu, it plays in Dolby Atmos on my Marantz 7009. I would think the C7 would do the same.
Interesting - does the receiver recognize it as Atmos, or is it a multichannel DD+ stream?
Thanks for the link, lots of good info there. So far as I understand DD+ is still a lossy codec, just with support for a wider number of channels and higher bitrates (less compression, better sound quality possible, still lossy).
Atmos decoders, for the most part, would be implemented with the ability to downmix the stream into something the connected receiver can decode - typically dolby TrueHD for those of us with non-Atmos receivers (I think this is actually a requirement for blu-ray players). It makes sense to me the B7 would have that ability using ARC (at least in the future), but I'm intrigued by the users reporting native Atmos passthrough. I've not managed to passthrough TrueHD streams (they get downmixed to 5.1 DD+), but it makes sense they included the Atmos functionality so they could brand this as an "atmos" TV line. IMO, not much point to atmos unless you have 7+ channels including elevation... but then I have a bunch of high end speakers so I'm biased against anybody's soundbar claiming the same effect
At any rate, I would expect a firmware update to enable lossless audio passthrough in its current formats at some point. If it already does Atmos, that's great for those of us with Atmos sources and receivers. Its not a big step from there to support TrueHD and DTS-HD. Here's hopin'
Turns out there are flavours of Atmos. The object metadata can be embedded into a DD+ stream using DD+ based audio (lossy codec). But you can also get TrueHD-based Atmos, where the audio codec used is the lossless one with much higher AQ. You can pass DD+ based Atmos over HDMI-ARC and this LG TV evidently supports this (7.1 channels or object-based lossy audio to 5.1.4, etc). But HDMI-ARC does not support passthrough of TrueHD over ARC (just doesn't have the bandwidth). This is the promise of eARC in the HDMI 2.1 spec.
At this point I won't hold my breath that LG's SoC will be firmware up-gradable for eARC, since this evidently uses the ethernet wires on the HDMI cable and unless they built that functionality in ahead of time, we're probably out of luck (but maybe not, since the drafts of 2.1 would have been available).
So everybody go out and buy expensive new AV receivers to go with your expensive new TV =)