[Soul_]

No, Dolby Access uses EAC3. That can only use 192 khz, that is the one. ATV, AFAIK, uses MAT, but I did not test that myself, and as LG C9 got that info removed, I will not be able to say for sure.

There is no PCM Atmos. There is LPCM like Dolby MAT 2.0, EAC3 Atmos (that is ONLY 192 kHz) and TrueHD. I know nothing about that last mode, but AFAIK, TrueHD can be encapuslated inside Dolby MAT 2.0.

This first picture uses EAC3 192 kHz from Dolby Access. Folby MAT looks differently.

View attachment 3112557 View attachment 3112557

Thank you. That helps.

 

[avernar]

TrueHD can be encapuslated inside Dolby MAT 2.0.

Yes, but it might also just be sent in the original MAT format for backwards compatibility. MAT was originally created to transport variable rate TrueHD frames over a fixed rate HDMI connection.

 

[DannyzR]

So I couldn't stop thinking about this issue that you are facing, and I recalled something today. Long time ago in 2015, I had horrible audio stuttering issues over HDMI on my 980ti going to my Samsung TV, and it would only happen in Hitman 1 (and even in Hitman it would only happen over HDMI), and all other games were fine. And I had tried everything trick in the book, and almost gave up. But there was one little thing that saved my bacon, BCLK frequency locking.

My ASUS board was auto OCing and moving the BCLK around. The moment I fixed my BCLK to 100 with PLL and other settings at 100Mhz, audio over HDMI magically stopped stuttering. I am still using the same settings where I am forcing all BCLK related clocks manually at 100Mhz, and PLL is set to support lower frequencies as well. Maybe this is why I am not facing this Atmos issue as well.

Try it and see if this helps you.

If this fixes, I have a theory on why this fixes. It has to do with how LipSync signalling on eARC works.

edit: If you want I can post a screenshot of my BIOS settings.

This was actually one of the first things I played around with. I have my BCLK set to 100MHz. But the other thing I was looking into was VDDG and VDDP voltages. As on a ryzen system I have my memory overclocked to 3600MHz which meant overclocking the infinity fabric. This can be quite stressful on the system and some people mentioned this was causing audio issues for them it the voltages are set to low. Despite raising voltages and even just trying stock (no XMP enabled) the problem still occurs.

 

[Soul_]

This was actually one of the first things I played around with. I have my BCLK set to 100MHz. But the other thing I was looking into was VDDG and VDDP voltages. As on a ryzen system I have my memory overclocked to 3600MHz which meant overclocking the infinity fabric. This can be quite stressful on the system and some people mentioned this was causing audio issues for them it the voltages are set to low. Despite raising voltages and even just trying stock (no XMP enabled) the problem still occurs.

Hi Danny, Looks like you have your ducks in a row there. I am going to upgrade to Ryzen next year possibly (currently running 4790k), I hope I don't face this issue then, it would drive me up the wall (getting PTSD flashbacks of my issue on Hitman 1 HDMI audio).

Either way, I thought I would share if that helps, but looks like there is something more to it. Someone mentioned this being an nVidia audio driver issue, which could be true. I feel like your audio drifting without eARC and clipping with eARC could be related. Audio drifts due to some timing issue, eARC tries to catch it when it drifts (due to its auto lipsync feature), which results in clipping due to how nVidia manages audio via HDMI. Just a wild speculation.

 

[Balthazar Lin]

Yes, but it might also just be sent in the original MAT format for backwards compatibility. MAT was originally created to transport variable rate TrueHD frames over a fixed rate HDMI connection.

What I meant is (as you can see in EDID) there is MAT 2.0, EAC3, LPCM, TrueHD, DTS, that are all supported AND different! The point here is that TrueHD can be sent in TrueHD mode, but it can also be decoded and send through MAT 2.0 or it can be not decoded and send through MAT 2.0. In the last case Atmos is preserved for sure, that is what LAVFilters use.

There is some info in January 2021 CTA-861-H standard and in that IEC. I can look later.

BTW, very interesting what Dolby Access on LG C9 itself uses.

 

[DannyzR]

Hi Danny, Looks like you have your ducks in a row there. I am going to upgrade to Ryzen next year possibly (currently running 4790k), I hope I don't face this issue then, it would drive me up the wall (getting PTSD flashbacks of my issue on Hitman 1 HDMI audio).

Either way, I thought I would share if that helps, but looks like there is something more to it. Someone mentioned this being an nVidia audio driver issue, which could be true. I feel like your audio drifting without eARC and clipping with eARC could be related. Audio drifts due to some timing issue, eARC tries to catch it when it drifts (due to its auto lipsync feature), which results in clipping due to how nVidia manages audio via HDMI. Just a wild speculation.

The audio drifting occured because I had my eARC digital output set to "auto" instead of "pass through". After setting it to pass through, the audio delay was eliminated but then that's when the audio popping/crackling/distortion started.

 

[samuel.c.casilla]

A brief warning regarding v05.00.25:
The version seems to cause problems in PC mode with the PS5 (black screen). I therefore assume that LG will not release this version before the problem is fixed, which may take a while.

I will add this info in the original post.

Update on this. Just checked PC mode is fine now on PS5 with test firmware V05.00.30

Sent from my LM-G820 using Tapatalk

 

[Soul_]

The audio drifting occured because I had my eARC digital output set to "auto" instead of "pass through". After setting it to pass through, the audio delay was eliminated but then that's when the audio popping/crackling/distortion started.

When you do Auto, TV starts to convert all audio to PCM before it sends to Audio device, atleast in my case. And once in while in Auto mode, sporadically it will only transmit only 2 channels to sound device, and rest of the audio will just go missing, even though EDID is negotiated at multichannel, so I don't recommend using 'Auto' mode at all.

Easy way to check it is, run Dolby Atmos Multichannel check, and all sound that is supposed to come from behind you, or from sides will just not come out of the speakers when using Auto mode. This is how for the first time I realised that something is not right, and switching to passthrough fixed it for me.

 

[HiFi4Vision]

As always, appreciate your work. Thank you

Great work, thanks.

You work is quite invaluable.

Thank you all for the kind words, I appreciate it.

Is there a changelog for 05.00.30? I'm assuming the changelog would be the same as 05.00.25.

No, there's no official changelog for v05.00.30 (since it's not officially available) and yes, the difference between v05.00.25 and v05.00.30 is minimal, if that's what you want to know.

Is it some way that you could get permission to edit first few posts? I feel like all of your key messages should be stickied somehow.

I don't think that's possible.
I thought about creating a separate thread, but the 2019 generation is imo now just too old for that and it would mean too much effort for me.

Update on this. Just checked PC mode is fine now on PS5 with test firmware V05.00.30

Thanks for letting us know!
I was not able to identify a change in v05.00.30 that could fix this problem. As mentioned, v05.00.25 and v05.00.30 have almost no difference.

Having said that: I probably won't write a separate post about the changes in v05.00.30 until I'm aware of significant changes.

 

[Balthazar Lin]

Dolby Vision Gaming now works on LG C9 and Xbox Series X! Nuts!

Xbox Series X: Dolby Vision Gaming für Insider freigeschaltet

Im Xbox Insider Programm wurde Dolby Vision Gaming freigeschaltet.

www.xboxdynasty.de

 

[TechNerd666]

Heads up if anyone has AI Picture enabled.
I enabled it for about a week and I was noticing a slight lip-sync issue on Apple TV. It was a very minor delay so some may not even notice.
I saw no noticeable improvement from the feature so I’ll go back to keeping it off.

 

[PatrickDotStar]

Dolby Vision Gaming now works on LG C9 and Xbox Series X! Nuts!

Enabling Dolby Vision will probably restrict the refresh rate to 60Hz but I guess we have to wait until this feature will be available for all of us.

 

[fenster3000]

Enabling Dolby Vision will probably restrict the refresh rate to 60Hz but I guess we have to wait until this feature will be available for all of us.

This is not the case on LG TVs.
You can use [email protected]@DV just fine.

 

[HiFi4Vision]

This is not the case on LG TVs.
You can use [email protected]@DV just fine.

Dolby Vision normally works with 12-bit. If this bit depth is used on the Xbox for DV, then it would either have to use only 60Hz or use chroma subsampling like 4:2:2 at [email protected] because of its 40Gbps HDMI 2.1 limitation.
The same applies to LG's 2020/21 OLED TVs with their 40Gbps limited HDMI 2.1 ports.

 

[avernar]

This is not the case on LG TVs.
You can use [email protected]@DV just fine.

Currently the Xbox is limited to 60Hz DV.

https://twitter.com/i/web/status/1373329812517978117

 

[HiFi4Vision]

Currently the Xbox is limited to 60Hz DV.

It might be a coincidence, but [email protected] 12-bit 4:2:2 is just under the bandwidth limit of HDMI 2.0 at 17.8Gbps.
It is possible that DV simply does not work with HDMI 2.1 (FRL) on the Xbox Series X, but only in HDMI 2.0 mode.

Of course, this is just a guess on my part, but the numbers would support it.

 

[avernar]

It might be a coincidence, but [email protected] 12-bit 4:2:2 is just under the bandwidth limit of HDMI 2.0 at 17.8Gbps.
It is possible that DV simply does not work with HDMI 2.1 (FRL) on the Xbox Series X, but only in HDMI 2.0 mode.

Of course, this is just a guess on my part, but the numbers would support it.

FRL is just a packetizer that encapsulates the three 3 TMDS channels. So anything that can be sent using TMDS can be sent using FRL. I believe Vincent said that the Xbox DV is player led so it's not using the proprietary DV transport but just a standard HDMI signal.

But it could very well be that the FRL packetizer in Xbox is broken and is messing with the data islands in the TMDS channels before encoding them and corrupting the DV metadata.

The Xbox is also weird in that it won't use FRL for 4K 60Hz to allow RGB 10/12 bit output.

 

[Balthazar Lin]

This is not the case on LG TVs.
You can use [email protected]@DV just fine.

Where? I though EDID flag clearly says that Dolby Vision is limited to 60 fps. Also I was confirmed it work also on C8, so C9 must work. 🤔

 

[avernar]

I though EDID flag clearly says that Dolby Vision is limited to 60 fps.

It's not saying it's limited to 60Hz but that it can do 60Hz. There is no 120Hz flag in version 1 of that block and in version 2 they got rid of the 60Hz flag.

 

[MrGrimble]

Hi,
Just got the Anthem 740 and I'm trying to solve an issue that I have with eARC. Just for background, I have an HTPC that's connected via the PC MODE on the C9.
So eARC works fine on TV apps but the second that I exit one of the TV apps, the audio signal reverts back to the HTPC and does not stick with eARC.
I don't think that it's an AVR issue, as I also had the same issue in which my Apple tv always "hijacked" the main input. Now that my Apple tv is not connected, the HTPC does the same to eARC.