Hey,
question to everyone with a hardware RMU/renderer.
Can you be sure that the .atmos is perfectly sync to picture?

The ReRenders have a certain delay, what about the master?

You can export an ADM WAV file and bring that back into Pro Tools. It takes a bit.

I have been testing this using the local renderer and have found that the printed DAFP/ADM wav have a latency of 1190 samples (roughly half a frame).

We are getting around this by moving the session back by 1190 samples prior to DAFP creation.

It has been a while since I have done this with the hardware RMU. We usually just use it for live QC or mixing.

Randall

Dolby's hardware RMU has a feature that allows you to zoom in and adjust the sync.

Thanks Randall. That's exactly what I did. In my case, the delay was 170-ish milliseconds.
The Re-Renders have another 10ms on top of that.
Correcting the Re-Renders is of course easy, it's the DAFP that's a pain..
Would be easier if you could edit and then re-export ADM WAVs out of PT.

Another option might be trimming of the master file with the Atmos Conversion Tool.

This is a still a super clunky workflow. I hope all of this gets better with the hardware renderer.

Interesting. Do you know if this is possible just with the theatrical RMU or also with the HT renderer?

Don't know. I have theatrical RMU only.

Any chance you are still on version 1.7.2 of the RMU software? 170 ms is about what we had on v1.7.2, but the latency went way down to about 45ms when we switched to v3.0.2 (which is what we are on now.) We are in the middle of QC/mastering of an ATMOS series, when it finishes we will upgrade to 3.3.

To check for latency, I sent the syncheck test files through the RMU and recorded the output. After moving the audio early to compensate, all of the rerenders and ADMs are in sync (Based on the 2-pop).

It is frustrating. There are a number of things that I would like to see implemented into the HT RMU, and I have been in contact with Dolby about them - the latency being one of them. Exporting an ADM or DAFP from a Pro Tools session directly is another.

Randall

Nope, we're on 3.0.2 as well.

And sending the SyncCheck files through the Renderer is exactly what I did as well.

I agree with all your points. Another one for me would be to be able to sync the record arming of the Renderer to PT (or via Eucon) so you can punch into an DAFP and live-recorded re-renders at the same time. Plus that a selection in PT gets automatically sent as in/out points to the renderer.

You bring up an enormously important and at the same time enormously neglected-by-developers/hardware-manufacturers issue of modern/digital times: A/V sync.
With the introduction of digital in our world, the opportunities became endless, but at the same time there's one big word that every step of the way is a pain in the b***: LATENCY...it's bloody everywhere: production-postproduction-consumption.
I type this while listening/watching to the Dolby Atmos mix of the Roger Waters' film/concert (great mix btw), where I had to start by finding the A/V sync offset for this particular playback on a Samsung 4K TV with Atmos playback over 7.1.4 I can change this offset in the BluRay player and/or in the Marantz home theater pre-amp I'm using. If I watch the same film via projection, I have to adapt the sync again. If I take other Blu-Ray content I have to re-check. If I change to my DVD player, I have to adapt sync again...and so on...

I'm putting a lot of 360 spatial audio content on Youtube nowadays. If I play the same 360 YT video on an Oculus Go, a GearVR/GalaxyS7 or desktop browser, the A/V sync is 3 times different (with the Oculus Go being the worst)...

When we are doing Dolby Atmos, A/V sync is as important as ever, only you have to keep 128 channels in sync, which is a challenge in itself depending on the setup. I use a 2 PT HDX2 system setup, with one system as playback and the other to record the 128 Atmos channels + the Dolby Renderer running on that machine. I preferred not to buy a separate Dolby PC for the mastering as that is an unkown to me and PT I know inside out. The recording system is connected to a DAD AX32 with 24 analog outs to the speakers and an extra SSL Delta link 64 MADI interface. The playback system has 2 SSL Delta links and both systems are connected over 128 MADI channels. First issue: PT PB system seems to think with Automatic Delay Compensation that ch1-8 need another offset than ch9-16 (22 samples if I'm not mistaken). Now if you record 128 beeps to the second system, the recording is exactly as wrong as the PT PB system is offsetting. Turning ADC offset off on the PB side, makes everything sync. Why PB PT system thinks it needs to offset is still a mystery to me (although I guess it has to do with Avid's own HD interfaces probably having an offset on ch9-16 and using the reverse-engineered PT connection SSL Delta probably doesn't have this). On the recording side the offset of the DAD and SSL is also different (I know I'm pushing things by using different interfaces, but it's only in a Dolby Atmos situation I really need it). Now when doing Dolby Atmos projects in the past I have always "callibrated" everything with manual offsets, so that all beeps recorded sample accurate.
Then there is the Dolby Atmos recording itself that has, as you mention, its own latency. You gotta love this job :-)
If there is one rule I've always followed through the years of using digital equipment, is to never trust sync or latency and always check every step of the way (with recording beeps and zooming in to the sample level). And to listen if things actually sound ok (first generation Dolby Atmos LtRt re-renders were terrible, I haven't tried since staying with LoRo).
Regarding your request: "Plus that a selection in PT gets automatically sent as in/out points to the renderer" I always set my PT i/o a bit wider than the Dolby renderer punch i/o's to be sure there are no punch issues either side (and then double check a punch by listening of course). I recently had a conversation with Dolby at IBC, where I asked if a punch had an automatic crossfade, but had no definitive answer.
Dolby Atmos and immersive audio (I've mixed a few feature films in Auro-3D as well) is great new territory, but with it come new challenges to get the master right and the theater/consumer playback side as well...

Greetings,

Thierry

You mean you´re using the AVID Atmos Production Suite on the recording PT machine? Or the Mastering Suite?

Do you use that setup only for home theater Atmos mixes or can you do theatrical as well?

Atmos Production Suite on the recording PT machine.

This is only for home theater Atmos. For theatrical you need the Dolby RMU. In this setup I can prep theatrical mixes for Theatrical and finish in a Dolby Atmos mixing stage. For theatrical I go to a big stage anyways.

Greetings,

Thierry

OK, makes sense. When you go to the Atmos mixing stage, do you find that your mixes translate well, assuming that you´re prep mixes are done in a smaller room? Or do you need to change a lot, for instance pans and object positioning? Are you having any issues when reopening your Protools/Atmos sessions on a bigger system?

Can recommend any Atmos stage in Brussels? Thanks

Until now I've only done Home Atmos. For theatrical I'm curious to try it. I've premixed a lot of 5.1 theatrical and 5 Auro-3D films in my room (8x 5,5 x 3,3m) and it translates well to a bigger stage. With big rooms dynamics play different, but you learn to judge that.
For Atmos, the translation of the object panning is something extra to deal with.
However with Dolby Atmos theatrical, there is a fee to pay for each film and with production budgets under constant stress nowadays, it is a price that not everybody is willing to pay.
Logistically the disadvantage of doing Dolby Atmos for feature film is also that you can't do any last minute changes when you leave the bigger stage as the mix needs to be mastered to the RMU.
In Brussels the only bigger mixing stage with Dolby Atmos is Studio l'Equipe AFAIK. I recently mixed a (5.1) film at Posta Amsterdam in their Dolby Atmos stage. I see you are in Portugal, Branko here on Gearslutz has also Dolby Atmos.

Greetings,

Thierry

OK, thanks for sharing your experience. The room I work on is about the same measure of yours. 5.1 and 7.1 translates well in cinemas as well. Regarding Atmos, we can´t do it of course as we can´t get a certification due to our dimensions, let alone the fee that most clients wouldn´t pay of course.I would like to try Auro 3D, but we don´t have the height speaker layer. Apparently they don´t charge a fee or require certification for studios I believe. What´s your experience on that? Do you like it? Apart from what you´ve already mentioned regarding Atmos, sonically, what do you prefer? Thanks.

No fee with Auro-3D indeed and no certification. I like it a lot and the side heights are a more interesting speaker position (you're more sensitive to it) than the ceiling (which Auro also have, but it's a mono voice-of-god channel). Interestingly, I recently saw a picture of a new Dolby Atmos installation in Blackbird studios, where they moved the ceiling channels outward:
https://www.audiomediainternational....c-mixing-room/
In my hometheater I have a router and when playing Dolby Atmos, I can switch the ceiling channels to play over the Auro height channels and that can be more interesting at times.
That said, in the cinema world out there, there are not too many Auro-3D installations and unfortunately not much content is coming out lately, while at the same time the Dolby Atmos train really got rolling.

Greetings,

Thierry

Hi Thierry, thanks for sharing your experience on Auro. I always find weird that formats that demand fees, certifications and heavy investments in gear etc., are the ones that ultimately prevail. Not that I have anything against Atmos of course, but in a way, it´s all about business and marketing power I guess. Then you go to cinema rooms and it´s a jungle, apparently there´s no compliance needed, which is odd, considering the demands that Dolby asks you to have at studio level.

The picture of "Blackbird Studios" is for Dolby Atmos Music mixing.

Having recently installed "Dolby Atmos Home Theater " in my room that has
"Dolby Atmos Theatrical " my experience has been very positive on how Theatrical Atmos and Home Theater Atmos translates to each other.
The clients were very happy.
As for Auro, I was the 3rd place in the world to install it but I haven't mixed anything in Auro for the last 4 years. Auro is more focused on Home Theater and Music upmixing and cars.

Something that might account for the uptick in ATMOS home theater mixing vs the other immersive sound formats is that ATMOS is currently the only immersive format that can be broadcast, either OTT or linear.

Randall

MPEG-H is another immersive broadcast format that exists since 2016, although it's currently only used in Korea:
https://www.mpegh.com/en/home/
I talked to Fraunhofer at last IBC and the system is interesting. Thing is as long as nobody in Europe or the US (or anywhere else outside Korea :-) is using it, then it isn't really an option or interesting to work with the format (a bit of chicken and egg situation)
Auro was developing CX for this use, but I don't think it is used anywhere in the world.
SMPTE, ITU, AES have been talking about standardisation and exchange between immersive formats for quite some time now, for example:
https://www.itu.int/dms_pubrec/itu-r...7-I!!PDF-E.pdf
https://www.smpte.org/sites/default/...sa-Handout.pdf
Dolby Atmos is now widely used and the most popular immersive forma, also for streaming.
Dolby's latest v3.3 can export to IMF IAB, more info:
https://developer.dolby.com/globalas...guidelines.pdf

Greetings,

Thierry

Hi Marti, the intent for Blackbird is indeed Dolby Atmos music mixing, which is where the Auro-3D speaker setup really works great (especially with native recordings). My favourite Auro-3D disc is Magnifcat, a great composition and performance, recorded by Morten Lindberg (L2 label). Here's a link where you can also see the mic setup.
https://www.youtube.com/watch?v=Ym4sH9VaHbU

I'm curious how you have done your Home Theater Atmos setup. I've visited your studio and heard your Meyer system in Auro-3D some years ago (thanks again for that) and it's great. Do you use a more near field setup when mixing for Dolby Atmos Home Theater? And do have lower hanging ceiling channels then as well? (which seems to me physically hard/difficult to set up).

Greetings,

Thierry

I recently mixed a live-concert in Atmos. It was interesting how the ceiling speakers really could emphasize the atmosphere of the stadium.
So for music concerts it's great, I am not so sure for 'album music'.

As for HT an theatrical in the same room, Arri in Munich have that with a completely separate mid-field Neumann setup in addition to their JBL theatrical system in that room.
In their case the HT surround and ceiling setup is permanent, the LCR plus the screen can be lowered from under the ceiling.

Was that the Andreas Gabalier concert by any chance?
Just asking since I recorded that and it was for Red Bull.