Channel Order Confusion

[ric982]

Hi,
I've bring up a Protools Studio / Dolby Atmos Productions Suite / Dante Virtual Sound Card / MTRX Studio / 9.1.4 setup.

Protools 2022.10, DAPS 3.7.3, Monterey 12.6

- I created a session using the Dolby ATMOS Renderer Audio Bridge Stereo Template. So the 7.1.2 bed is in SMPTE order (L/R/C/Lfe/Ls/Rs/Lrs/Rrs/Lts/Rts) like the renderer expects. I've got a stereo object that I can pan and see that the panning is hitting the correct channels to the Dolby ATMOS Renderer and I can see it being sent through DVS to the MTRX Studio and the Monitoring outputs are behaving as expected (all good so far).

- Similiar to what Alan Sallaback described in Protools Expert "Using The Dolby Atmos Audio Bridge - An Alternative Workflow - Free Expert Tutorial Part 3", I set up a 5.1 Loudness re-render in the DAB, sent it out Dante channels 17-22 (in SMPTE order), wrapped back to Dante channels 17-22 in the MTRX Studio, and brought in DVS channels 17-22 through a Source-Nexus plug-in to a 5.1 aux track to allow Loudness measurement with visLM.

For testing, I panned both L/R channels of a stereo source object to the same point and then locked the symmetries so that it is a pannable Mono source. If I pan the object around the room, I can see the 5.1 re-render has the expected channels hit and I can see in visLM that it is registering signal in the peak detection in the correct channels. I also see the track meters are correctly showing the channels in Protools film channel order.

What I'm confused about is that in Alan Salaback's video, he did SMPTE to Film reordering of channels in his 5.1 wrap back in his audio interface. I'm not doing that and it's working correctly. It seems that Protools is treating the input in SMPTE order.

Is there some setting somewhere that the template sets up that is causing Protools to handle this as described?

[gives]

Originally Posted by ric982

Hi,
I've bring up a Protools Studio / Dolby Atmos Productions Suite / Dante Virtual Sound Card / MTRX Studio / 9.1.4 setup.

Protools 2022.10, DAPS 3.7.3, Monterey 12.6

- I created a session using the Dolby ATMOS Renderer Audio Bridge Stereo Template. So the 7.1.2 bed is in SMPTE order (L/R/C/Lfe/Ls/Rs/Lrs/Rrs/Lts/Rts) like the renderer expects. I've got a stereo object that I can pan and see that the panning is hitting the correct channels to the Dolby ATMOS Renderer and I can see it being sent through DVS to the MTRX Studio and the Monitoring outputs are behaving as expected (all good so far).

- Similiar to what Alan Sallaback described in Protools Expert "Using The Dolby Atmos Audio Bridge - An Alternative Workflow - Free Expert Tutorial Part 3", I set up a 5.1 Loudness re-render in the DAB, sent it out Dante channels 17-22 (in SMPTE order), wrapped back to Dante channels 17-22 in the MTRX Studio, and brought in DVS channels 17-22 through a Source-Nexus plug-in to a 5.1 aux track to allow Loudness measurement with visLM.

For testing, I panned both L/R channels of a stereo source object to the same point and then locked the symmetries so that it is a pannable Mono source. If I pan the object around the room, I can see the 5.1 re-render has the expected channels hit and I can see in visLM that it is registering signal in the peak detection in the correct channels. I also see the track meters are correctly showing the channels in Protools film channel order.

What I'm confused about is that in Alan Salaback's video, he did SMPTE to Film reordering of channels in his 5.1 wrap back in his audio interface. I'm not doing that and it's working correctly. It seems that Protools is treating the input in SMPTE order.

Is there some setting somewhere that the template sets up that is causing Protools to handle this as described?

Not that I am aware of, but not sure where this is being delivered to. Looks like you are having to do a ton of routing for the setup you have there, is that right. Just trying to understand your process. I just had surgery a few days ago so I can't really do much to help right now. I think on it though. Maybe after the drugs wear off a bit-:). G

[LDS]

I have been experiencing a few strange things with channel order over the last few days. Mostly spotting 5.1 ambiences to the timeline. SMPTE order files would appear in SMPTE order on the timeline, but still try and playback in film order with C & R switched and one of the surround channels going through LFE. Moving it to six mono tracks to manually reorder them has also been a bit hit and miss, as they have often be reverting back to SMPTE order.

I really have no idea what is going on. Messing with the default path and channel order settings in the I/O window has made it a bit more predicable, but it still hasn't been the same experience as older versions of Pro Tools.

[ric982]

Originally Posted by gives

Not that I am aware of, but not sure where this is being delivered to. Looks like you are having to do a ton of routing for the setup you have there, is that right. Just trying to understand your process. I just had surgery a few days ago so I can't really do much to help right now. I think on it though. Maybe after the drugs wear off a bit-:). G

So basically, I'm just trying to set up a loudness measurement on a 5.1 re-render. With Protools using the Dolby Audio Bridge to Dobly renderer on the same machine, you get 130 audio channels out from Protools to DAR but no return channels (DAB is one way and Protools has its inputs tied to DAB). To get the 5.1 re-render back to protools, you need to send it out the DAR's output device and then route it back into the system so that you can feed it back into protools to a loudness plugin through some side channel mechanism.

In this case the DAR 5.1 SMPTE output has been send out through DVS to MTRX Studio and wrapped back on the same channels to the DVS in 5.1 SMPTE order. From there I'm using Source-Nexus to get it back into to protools. Source-Nexus maps a 5.1 input as 6 successive channels from DVS to the 6 channels in the Aux track it's sitting in. So as I've got it, it should be SMPTE 5.1 all the way through the path. I originally tried flpping the channel order in DVS to film order and ended up with C and R swapped and the LFE and one of the surrond sides swapped. I did this originally because that's what Alan Sallaback said he needed to do. I would have expected that it should be needed because the track meter is in Film order and I would assume it would want it's input to be in that order. I'm really not sure if it's Protools or Source-Nexus that is handling the order correction - but I'm guessing it's not Source-Nexus - the plugin doesn't appear to have that functionality.


I shut everything down last night. I'll report back if there's any change this morning when I look at it again. Last night it looks like it was working fine - I just don't understand why it didn't need the remapping in the wrap back.

[gives]

Originally Posted by ric982

So basically, I'm just trying to set up a loudness measurement on a 5.1 re-render. With Protools using the Dolby Audio Bridge to Dobly renderer on the same machine, you get 130 audio channels out from Protools to DAR but no return channels (DAB is one way and Protools has its inputs tied to DAB). To get the 5.1 re-render back to protools, you need to send it out the DAR's output device and then route it back into the system so that you can feed it back into protools to a loudness plugin through some side channel mechanism.

In this case the DAR 5.1 SMPTE output has been send out through DVS to MTRX Studio and wrapped back on the same channels to the DVS in 5.1 SMPTE order. From there I'm using Source-Nexus to get it back into to protools. Source-Nexus maps a 5.1 input as 6 successive channels from DVS to the 6 channels in the Aux track it's sitting in. So as I've got it, it should be SMPTE 5.1 all the way through the path. I originally tried flpping the channel order in DVS to film order and ended up with C and R swapped and the LFE and one of the surrond sides swapped. I did this originally because that's what Alan Sallaback said he needed to do. I would have expected that it should be needed because the track meter is in Film order and I would assume it would want it's input to be in that order. I'm really not sure if it's Protools or Source-Nexus that is handling the order correction - but I'm guessing it's not Source-Nexus - the plugin doesn't appear to have that functionality.


I shut everything down last night. I'll report back if there's any change this morning when I look at it again. Last night it looks like it was working fine - I just don't understand why it didn't need the remapping in the wrap back.

Copy that. Sometimes this stuff just has a gremlin and then it's gone. I had some issues right after I did my migration from my 10 year old Mac Pro Trash Can to the Mac Studio ULTRA about two weeks ago, but it seems to be working now.
G

[ric982]

OK - so combing through the Pro Tools Reference manual....

When you create a session, there is a field in the "New Session Windows" labeled "I/O Settings" and you can select things like "5.1 Fim Mix", "SMPTE/ITU". I think it says this setting affects the "default" I/O setup which I will speculate affects channel order defaults. Since I created this session from the dolby template, my guest is it set this setting to "SMPTE/ITU" and that that setting is causing any new I/O paths or busses to default to SMPTE order. I didn't find this setting anywhere else that I looked on the pull downs so it's probably only specified at session creation.

In the track I was confused about, there's no input (because the Source-Nexus plug-in is providing the inputs) and the output is assigned to a mono bus I defined called "Null" to sorta flag that this track shouldn't be feed anywhere because it might cause a feedback loop. So there is no "bus" to see for the 5.1 signal in the I/O setup. But, I'm assuming that the channel order internal to the track must have defaulted to SMPTE. As always, the meter is in film order.

So I guess I'll say this answers my confusion.

[its2loud]

Originally Posted by ric982

OK - so combing through the Pro Tools Reference manual....

When you create a session, there is a field in the "New Session Windows" labeled "I/O Settings" and you can select things like "5.1 Fim Mix", "SMPTE/ITU". I think it says this setting affects the "default" I/O setup which I will speculate affects channel order defaults. Since I created this session from the dolby template, my guest is it set this setting to "SMPTE/ITU" and that that setting is causing any new I/O paths or busses to default to SMPTE order. I didn't find this setting anywhere else that I looked on the pull downs so it's probably only specified at session creation.

In the track I was confused about, there's no input (because the Source-Nexus plug-in is providing the inputs) and the output is assigned to a mono bus I defined called "Null" to sorta flag that this track shouldn't be feed anywhere because it might cause a feedback loop. So there is no "bus" to see for the 5.1 signal in the I/O setup. But, I'm assuming that the channel order internal to the track must have defaulted to SMPTE. As always, the meter is in film order.

So I guess I'll say this answers my confusion.

Track order in Pro Tools is always going to be Film order. Regardless of the IO assignment. If recording in a 5.1 signal, you map your inputs according to incoming channel order but the audio recorded on the track will be film order.

Again, same with output. The order on the track is Film order but the Output routing can be something different depending on your speakers setup.

Now, to make matters even more confusing, I believe if you export audio from the track, that order will be SMPTE but if you just take the recorded file directly from the Audio Files folder, that order is FILM. This was the case versions ago and I honestly do not know if it has changed.

I remember using Salaback’s method a while back and scratching my head at this very same thing when bringing back in a 5.1 signal. I would take a look at your metering plug-in. I believe Vis-LM and Insight both can change the order

[ric982]

Originally Posted by its2loud

Track order in Pro Tools is always going to be Film order. Regardless of the IO assignment. If recording in a 5.1 signal, you map your inputs according to incoming channel order but the audio recorded on the track will be film order.

Again, same with output. The order on the track is Film order but the Output routing can be something different depending on your speakers setup.

Now, to make matters even more confusing, I believe if you export audio from the track, that order will be SMPTE but if you just take the recorded file directly from the Audio Files folder, that order is FILM. This was the case versions ago and I honestly do not know if it has changed.

I remember using Salaback’s method a while back and scratching my head at this very same thing when bringing back in a 5.1 signal. I would take a look at your metering plug-in. I believe Vis-LM and Insight both can change the order

Thanks. That's all helpful information and I'm glad I'm not alone in my "confusion".

You are correct that visLM has channel order settings.

By default in a 5.1 channel in ProTools, visLM shows that the channel order is "AUTO" and displays its channels in film order. I tested selecting FILM which did not change the displayed order. I switched to ITC and it did changed the order to SMPTE order. In playback AUTO/FILM have the correct channel assignments. ITC is not correct in Protools.

So my explaination of ProTools behavior is that:
1) My original 5.1 Input was sent in SMPTE order.
2) My I/O definition specified SMPTE order for outputs.
3) Because my I/O definition is SMPTE order, Protools re-ordered the 5.1 input channels to covert the SMPTE order to film order as used internally to protools.
4) I didn't need to override the channel ordering in DVS because protools is doing the re-ordering based on my SMPTE I/O definition.
5) The protools track metering and its presentation of channels to my visLM plugin is in film order.
6) visLM wisely chose Film order for it's AUTO setting in Protools.

There appears to be quite a number of other posts on AVID DUC that come up if you google "5.1 Channel Order". Somehow I didn't find them when I searched for channel order on the forum. The ones I've checked seem to agree with the above and also talk more about exporting channel order (Film order seems to be the prevailing answer for Protools) and ways you can possibly re-order on the way to importing to something that wants SMPTE. One post says there is metadata describing the order in the export data and perhaps an intelligent importer would know to re-order if necessary. I'm not sure these older posts had the option to specify SMPTE in the I/O definition or not, and whether this would effect the behavior of export/import ordering processing - perhaps an investigation for some other day when I get there.

Thanks again for the help.

[ric982]

Opps - one correction:

The 5.1 channel order posts - Its2Loud is all over them - and again in this thread:

The channel order in protools wav file exports is SMPTE
(I said Film above - wrong).