LG C9 + Arc + UB820 / Multichannel PCM for DTS Blu-Ray discs

@Chetiya Glad you got it working with the Arcana. I experience the same video input drop on my Panasonic TV for a few seconds too. You’ll get used to it over time.

Thanks for confirming. Yeah it’s a minor gripe, doesn’t impact the actual viewing experience. 
 

I've got cases open with Panasonic and LG around this issue but only getting generic responses thus far. I’m not holding my breath!

I wanted to share some new experiments. All of this is preliminary!!!!

I just received the hardware to make adjustments to the DR HDMI 4K EDID custom units. I went with both the Bluetooth module ($49) and a USB cable (only $10). At this point, I am all about the experimenting so caution continues to be thrown to the wind.

Reminder, I have the Panasonic 820, the LG C9 55” and the Sonos Arc + Sub + Surrounds (2). All units are on current firmware releases. Symptom: Inability to send multichannel sound from DTS tracks (converted at the Panasonic) through to the Arc. Dolby formats and 2.0 tracks all work fine. I want to retain Dolby Vision and HDR format compatibility for 4K discs.

With DR HDMI 4K in the signal pathway, I can fix the audio problem, but I lose Dolby Vision. With the HD Arcana, everything works fine although I am using the device in an odd format vs its intended use. 

My thesis is this: 

I would like to use the EDID output from the LG but edit it to fix whatever issue is causing it to not output MC PCM audio. I prefer to use the LG EDID because all other aspects seem to be working (video formats, color gamma, Dolby audio). 

Using the DR HDMI 4K, I copied the EDID from the LG to the SINK setting. I then transferred that file via the HDFury iOS app (via the bluetooth dongle) to my iPad. That was then moved to my PC (via cable) and imported into the Advantiv EEditGold program. I also saved the HD Full Audio EDID profile that produced the correct audio (but was missing the Dolby Vision ability) for comparison. 

Looking at the two files, I focused on the audio sections. I do not want to touch video because it works in the original profile.

Here I found two differences. They both seem to be necessary, but I need to keep playing to know how much has to match.

First, the audio formats on the LG EDID are missing the 1 bit audio. This is SACD so it seems odd this is needed, but I added it back in and adjusted the listed order to match the working EDID.

Second, and I believe at the heart of the matter, the LG EDID does NOT include the speaker table. This section tells the player which speaker locations are available for output. I added this block (see image) and enabled the same channels. 

I exported the new EDID block to a .BIN file and reversed the pathway back to the DR HDMI 4K, using a custom slot. 

Voila! This change enabled both desired states - at least with my limited testing. Dolby Vision working for those UHD discs. HDR for my 1 4k disc that only has that instead of Dolby Vision. Dolby Atmos still working all the way to the Arc. And LPCM 7.1 audio output (from 5.1 or 7.1 tracks) Upsampling from 1080 images to 4K working. 24 fps, 30 fps and 60 fps all working.

More to follow as I want to really nail down the minimal fixes to make this work. 

Again, for ease of use, the Arcana is the way to go. For those brave to follow this, it is possible to get there with a DR HDMI 4K and a likely a $10 USB cable (although I still need try that exact path). 

More testing tomorrow.

That’s fantastic work Laird! I think modifying the TVs EDID to allow it to support a legitimate format makes sense. No idea who is at fault here based on your findings, I’m not sure there are universal standards that aren’t being adhered to or if it’s a vendor by vendor implementation. 
 

Have you got a case open with LG and / or Panasonic where you can update them with your findings? 
 

Also, it might be helpful if you could upload the fixed EDID file somewhere, it would probably help people as they’d only need to copy it their Dr HDMI without having to do any editing. 
 

At this point I’m happy with my Arcana so probably won’t be doing this, although if I can’t find a buyer for my DR HDMI I may try it and sell the Arcana instead as it’s an in demand product. 

Thanks, @Chetiya

I do plan to open a case although I know others on this thread have one going. But I am going to do so when I really can pinpoint the issue. My ideal is to find the absolute minimum number of bytes to change. 

In terms of uploading a file, I do plan to do that with caution. First, I need to remove my serial number. Second, I want to be sure I have figured it out reliably. Also, this will really only work for a C9 model TV. If someone wants to send me a CX EDID, I am happy to send back a few variants to try. Also, I think the EDID file also is aware of the screen size (55” in my case). So, that too might be a factor with using my EDID vs doing the editing. But anyway, I am happy to share for those willing to experiment. I make no warranties or guarantees!

Again, more to follow when I get back to playing around again. I am having fun with this and I am hopeful if I (or others) can truly figure out the problem, LG or Panasonic (or even Sonos) can adjust on their end.

My guess is that the issue is actually Panasonic’s. It may be that Panasonic’s routine to downsample DTS to multichannel PCM requires this mapping to know which channels to pass along and tag and which to fold into their output. This might be to better support Atmos and DTS X positional data in the decode. Again, this is my guess. So, when the Panasonic does not see this info, it moves to a safety mode of 2 channel, since every modern device supports that. As reported on this thread, other players (LG, Sony, Oppo) do not have this issue - they correctly output MC PCM and there is no reason to believe the EDID passed by the LG to those is any different than what the Panasonic sees or I extracted.

I did end up activating additional “supported” frequencies in the EDID audio section, so I want to play around with that and see if changing those alone (without adding the Speaker block) might be the true root of the issue.

(Also, the 1 bit Audio - SACD is definitely not required. I eliminated that last night and everything still works. This is as expected.)

Ok, I’ve played around a bunch more, and I believe the only issue is that the C9 EDID is missing the speaker data. I tried to add various audio format and sound frequencies which are different between the LG EDID and the one that worked for audio but not Dolby Vision. In the file linked below, the only changes are:

1. I added the missing speaker data (see screenshot below)
2. I changed the serial number from my unit to something else (same number of digits). (I doubt this matters to anything.)

This is the file for a C9 55 TV. It may work for other C9 series TVs. I am let sure about B9 or G9. I certainly do not believe it will work for the CX series. (However, I am happy to edit a file for someone if they wish me to try.)

Disclaimer: While I am technical in nature and have been involved in computers and consumer electronics for years, this whole area is new to me. I cannot take any responsibility for the use of this file. I provide it merely for example and experimentation purposed. I do not work for LG, Sonos or Panasonic.

Ok, here is the link: https://www.dropbox.com/s/2986ilhxe5opkus/LG%20C9%2055%20EDID%20Sonos%20Arc%20Speaker%20Data.zip?dl=0

I have a few more experiments to run, but I think I have enough to flag Panasonic that they are failing on this EDID issue and LG for not passing this information from the Sonos.

@Laird M Malamed Thanks for narrowing down what seems to be the issue between the Panasonic player and the LG TVs with the missing speaker data. I don’t think I spent the time to notice the speaker data was different/missing when I was playing around with all this. Unfortunately I’m not able to play around and test this out with my CX setup at the moment, but maybe I’ll be able to confirm the CX has the same problem in a couple weeks or so and also confirm that I’ll be able to fix it by updating the LG output EDID with the missing speaker data (instead of my previous method of taking the existing Dr HDMI profile and adding the missing Dolby Vision info).

Hopefully with this level of detail on the problem, either Panasonic or LG will provide some kind of fix.

I found an error in my shard EDID file above. It is an interesting find because it makes me think that Sonos may be the source of the issues after all. Or how the Sonos and LG talk to one another. 

The error has to do with audio frequency. (Specifically, I have a number of Blu-ray Audio discs. These discs basically have one image - a menu of sorts - and the rest of the disc is Hi-res audio. I like the format (mostly for classical and opera) because I can see the track easily but am not distracted by the image of a conducted concert.)

Today, I happened to put in a disc with DTS-MA 2.0 channel at 192 kHz sample rate. (Confirmed in the status menu that this frequency. I think DTS-MA is somewhat of a container format.) Guess what? The audio could not be rendered by the Sonos. That is not a surprise though - the Sonos is limited to 48 kHz. What surprised me is that even with the Panasonic set to decode DTS to PCM, it did so at the 192 kHz native rate. I looked back at the stock LG EDID, and indeed it shows that 192 kHz (and 96 kHz for that matter) as a supported audio format - which indeed it is for the LG’s internal speakers and playback. I adjusted my EDID on my HDFury DR HDMI 4K and removed the LPCM frequencies  above 48. Presto, the Panasonic correctly output at 48K and the audio played.

Now, what is more interesting is that all of this was with HDMI ARC “Passthrough” audio selected. This is needed to support Dolby Atmos as True HD all the way to the Sonos. When I changed the setting to “Auto” and used the stock LG EDID, the Panasonic output 192 kHz but the Sonos could play it. Why? Because the LG must have been re-encoding it to 48 kHz. Hence, the LG “knows” that the Sonos cannot support the higher frequency - or that is my guess. So, why does the Sonos not broadcast to the LG the speaker configuration data? And why does the LG not pass that along?

So, for those trying this themselves, the needed changes to the EDID are:

1. Add the speaker configuration data
2. Edit the LPCM formats and remove the 192 and 96 kHz options 

I’m a bit of a layman with all this and not sure I understood all of the posts.

To clarify, will those two steps fix the LPCM issue for this setup, without needing an additional switcher?

I’m still hesitant to pay more money for something I should have, so looking for a solution without added gizmos.

Interesting. I wonder if that’s a bug from when they rolled out LPCM support?