Dolby Atmos in Dolby MAT
A Dolby MAT encoder resides in a Blu-ray player to pack the variable bit-rate Dolby TrueHD bitstreams for transmission over the fixed bit-rate HDMI. A Dolby MAT decoder is concurrently employed in the Dolby TrueHD decoder in the sound bar to unpack the Dolby TrueHD bitstreams. With the introduction of Dolby Atmos, we have expanded the Dolby MAT technology to support encoding and decoding of Dolby Atmos metadata incorporated in lossless pulse-code modulation (PCM) audio.
A key benefit of Dolby MAT 2.0 is that Dolby Atmos object-based audio can be live encoded and transmitted from a source device with limited latency and processing complexity. Among the likely sources are broadcast set-top boxes and game consoles. The Dolby MAT 2.0 decoder in the Dolby Atmos enabled sound bar outputs the object-based audio and its metadata for further processing inside the device. The Dolby MAT 2.0 container is scalable and leverages the full potential of the HDMI audio pipeline.
Disney+ didn't support Atmos at release either, it does now. I'd assume it's nothing to do with technicalities.So why is any additional support required if the Apple app is simply using DD+ in order to facilitate Atmos? All the TV would need to do it bitstream the associated DD+ encoded audio that is inclusive of the Atmos metadata. It appears that Apple are having to rework their app in ordr to allow it to access DD+ inclusive of the Atmos metadata in order for the TV to then be able to output it.
Things like this should have been addressed by Apple prior to their initial launch of the app. It isn't rocket science and needs no research or development to make it work. The same is true of Netflix and the way in which they made Atmos available to some TV apps and not others. What is the issue that causes this to be such a difficult thing to implement? I've devices that predate Atmos that have no issue bitstreaming DD+ inclusive of Atmos metadata. Surely anyone developing a streaming service and app would or should be making this possible from day one even if not actually carrying such audio yet? Similar issues are apparent with the BBC's iPlayer which cannot even handle anything more than 2 channel stereo and would require the developers to scrap its current app build and rebuild it from scratch as well as rethink ythe entire iPlayer service's infrastructure in order for users to get access to DD 5.1.
Are all these developers living in a bubble on another planet and why are they being what appears to be purposefully difficult?
The fact that LG and Apple are making it possible to gain access to Atmos via the app shouldn't even be a news item, the feature should have been included to start with. Apple provided access to Atmos encoded content via their service prior to the app being launched on the LG platform so why only address the ability to access it so late in the day?
My C9 does pass atmos from Apple TV over arc. I’ve got my ATV4k plugged straight into the tv and I get no issues with atmos over arc to my Samsung hw-n950 soundbar.So why is any additional support required if the Apple app is simply using DD+ in order to facilitate Atmos? All the TV would need to do it bitstream the associated DD+ encoded audio that is inclusive of the Atmos metadata. It appears that Apple are having to rework their app in ordr to allow it to access DD+ inclusive of the Atmos metadata in order for the TV to then be able to output it.
Things like this should have been addressed by Apple prior to their initial launch of the app. It isn't rocket science and needs no research or development to make it work. The same is true of Netflix and the way in which they made Atmos available to some TV apps and not others. What is the issue that causes this to be such a difficult thing to implement? I've devices that predate Atmos that have no issue bitstreaming DD+ inclusive of Atmos metadata. Surely anyone developing a streaming service and app would or should be making this possible from day one even if not actually carrying such audio yet? Similar issues are apparent with the BBC's iPlayer which cannot even handle anything more than 2 channel stereo and would require the developers to scrap its current app build and rebuild it from scratch as well as rethink ythe entire iPlayer service's infrastructure in order for users to get access to DD 5.1.
Are all these developers living in a bubble on another planet and why are they being what appears to be purposefully difficult?
The fact that LG and Apple are making it possible to gain access to Atmos via the app shouldn't even be a news item, the feature should have been included to start with. Apple provided access to Atmos encoded content via their service prior to the app being launched on the LG platform so why only address the ability to access it so late in the day?
My C9 does pass atmos from Apple TV over arc. I’ve got my ATV4k plugged straight into the tv and I get no issues with atmos over arc to my Samsung hw-n950 soundbar.
Is there a list of the actual LG TV models that will be getting the ATV+ app?
Still sounds great to my ears.Your C9 can passthrough DD+ inclusive of Atmos metadata (or indeed TrueHD inc. Atmos metadata if using eARC), but cannot passthrough the Multichannel PCM associated with Dolby MAT the Apple TV uses to convey Atmos metadata. Conventional ARC is restricted to no more than just 2 channels of PCM data and the current implimentation of eARC onboard LG TVs is also unable to convey multichannel PCM. The Apple TV cannot bitstream DD+ or Atmos and LG TVs cannot passthrough multichannel PCM needed to facilitate Dolby MAT. AS things currently stand. you'd need a direct HDMI connection from the ATV to your AV receiver (or soundbar) if wanting to access Atmos encoded audio from the ATV. LG have said that they will be addressing the eARC multichannel LPCM issue sometime later this year though, but you will never ever be able to stream multichannel PCM via conventional ARC.
Still sounds great to my ears.
Dolby Atmos shows on my soundbar. Sounds like atmos to me.It ain't Atmos (Dolby MAT encoded multicahannel PCM) though if sourceing the audio via an external ATV and then passing it through the TV and out via either ARC, optical or even eARC. The latter of those three will/should however eventually become a possiblity if and when LG get around to rectifying their implimentaion of eARC and giving it the ability to convey multichannel PCM. You'd still need an external AV receiver or soundbar that is also eARC compliant though.
The fact of the matter is that if you are using Dolby MAT as a means by which to convey Atmos metadata then the source is outputting multichannel PCM to your TV and then downmixing it to just 2 channel PCM prior to it being output to your soundbar. What you are experiencing is either stereo PCM or stereo PCM being upmixed by the soundbar.
It ain't Atmos (Dolby MAT encoded multicahannel PCM) though if sourceing the audio via an external ATV and then passing it through the TV and out via either ARC, optical or even eARC. The latter of those three will/should however eventually become a possiblity if and when LG get around to rectifying their implimentaion of eARC and giving it the ability to convey multichannel PCM. You'd still need an external AV receiver or soundbar that is also eARC compliant though.
The fact of the matter is that if you are using Dolby MAT as a means by which to convey Atmos metadata then the source is outputting multichannel PCM to your TV and then downmixing it to just 2 channel PCM prior to it being output to your soundbar. What you are experiencing is either stereo PCM or stereo PCM being upmixed by the soundbar.
Dolby Atmos shows on my soundbar. Sounds like atmos to me.
I also found that my Sony AF9 can output Atmos from ATV out over ARC (nb with eARC disabled). I think what’s happening is this: the Apple TV sends Dolby Mat Atmos to the TV, and then the TV converts it to DD+ Atmos to output over ARC.
Note that this only became possible after a very recent update to my TV, which gave it the ability to process Atmos for the built-in speakers. Before this update the Apple TV would only pass Atmos when the TV was operating in eARC mode.
Also just briefly to another of your points - if you enable the developer HUD on an ATV 4K you can see that when playing Atmos content it is decoding a DD+ Atmos stream from Apples content servers (eac3). So it seems straight forward enough that Apple simply choose to share these eac3 streams with the likes of the LG app.
The TV has no ability to encode multichannel PCM as DD+ and then package Atmos metadata with that DD+ encoded audio.
The Apple TV outputs all Atmos audio as multichannel PCM inclusive of the Atmos metadata and doesn't bitstream DD+ or TrueHD inclusive of Atmos metadata.
It is a well known fact that the Apple TV uses Dolby MAT and that ARC is restricted to no more than just 2 channels of PCM data. AS I've already said, you'd need LG update their mosr recent eARC enabled TVs so that they'd pass multichannel PCM via eARC in order to be able to passthrough multichannel PCM and or the Dolby MAT signal as output via an Apple TV when configured to output Atmos.
Very true mate, you do NOT need eARC for Atmos via Netflix or ATV100% I get Atmos out over ARC from an Apple TV, when eARC is set to off on a Sony AF9. And @antsims seem to report the same for an LG C9.
I agree this means it must be coming out as DD+ Atmos - but as I say - how this is happening I don’t know. But I assure you it is happening.
Edit: And to re-iterate - this was not the case before an update last week which added onboard Atmos decoding to the Sony AF9. Notably the C9 also has onboard Atmos decoding for it’s built in speakers.
Edit: And to re-iterate - this was not the case before an update last week which added onboard Atmos decoding to the Sony AF9. Notably the C9 also has onboard Atmos decoding for it’s built in speakers.