Is audio delay relative to video possible?

[mikeyp]

Hi.

I'm involved in a local community cinema. I'm investigating whether SCS would be suitable for our needs. What I do is pretty simple. Cueing up slides and music before a show as people enter, trailers etc. before the film, the main feature, then back to slides etc. at the end. In the demo I've been able to replicate all but one important function we rely on in VLC, which is that we need a 200ms audio delay for lip sync with the projector. This video only delay is caused by our HDMI over CAT6A sender so is unavoidable. Can this be done in SCS?

Thank you

[PhilVale]

If I've needed delay I've usually done it in the amp.

BUT have you explored putting a VST2 plugin onto the audio output device for the video? There's lots of free ones on Plug In Boutique but I don't know which ones work with SCS. Search VST in the help file for how to do it or just press VST on the menu bar and "experiment".

Might be worth a try.

Lets see what the experts come back and suggest.

[mikeyp]

That was my first route of exploration but unfortunately the Behringer XR18 doesn't do that.

If it helps, we're using Windows 8 channel USB Audio output to L/R Main and 3x Aux Out to make up 5.1 audio. It works very well providing I can get the required 200ms audio delay.

Thank you. I'll have a look at the VST plugins later and also await further input from others.

[Mike Daniell]

We could add this feature to SCS as the video playback library we use has a function to set an audio delay time. We will investigate this.

[PhilVale]

So if you're using an X18 there are a few FX delays built into the mixer. I have an X18 but never actually experimented with these as I do any delay in the amp, which in a pure world is probably the right place to do it. But we don't always live in a pure world!!!!

All the X18 delays look to be DELAY+(something). But it also looks like you should be able to adjust them to turn off/down the (something) bit to make it just a delay.

[dee99]

I have an X32 and the delay effect does not have any fine granularity to be able to set up for Audio video sync.
However according to the internet the X18 has delays on the Aux outputs, if this is so you could use those.

[mikeyp]

We could add this feature to SCS as the video playback library we use has a function to set an audio delay time. We will investigate this.

Thank you. If this is possible to do, it would break down a barrier of entry for me.

So if you're using an X18 there are a few FX delays built into the mixer. I have an X18 but never actually experimented with these as I do any delay in the amp, which in a pure world is probably the right place to do it. But we don't always live in a pure world!!!!

All the X18 delays look to be DELAY+(something). But it also looks like you should be able to adjust them to turn off/down the (something) bit to make it just a delay.

I was given to understand there wasn't a delay built into the XR18 and even if there is, surely it's only a L/R effect, not applying to the other 3 channels outputting to AUX1,2,3? I can look into that but don't think it is my answer.

I have an X32 and the delay effect does not have any fine granularity to be able to set up for Audio video sync.
However according to the internet the X18 has delays on the Aux outputs, if this is so you could use those.

Do you mean X18? That's a different unit. We have the XR18. I haven't found a way to put a delay on aux outputs but would LOVE to be corrected!

[Mike Daniell]

I have access to an XR18 although I haven't used it for a while. The manual doesn't list delay apart from numerous mentions in effects. A quick Google search reveals that delay is a frequently requested feature for the XR18. Maybe the suggestion from 'Allegedly_Sound_Dave' in this Reddit posting may help: https://www.reddit.com/r/livesound/comm ... _no_delay/.

[mikeyp]

I have access to an XR18 although I haven't used it for a while. The manual doesn't list delay apart from numerous mentions in effects. A quick Google search reveals that delay is a frequently requested feature for the XR18. Maybe the suggestion from 'Allegedly_Sound_Dave' in this Reddit posting may help: https://www.reddit.com/r/livesound/comm ... _no_delay/.

I will give it a go next time I get into the venue and can try it out but the question is whether I can apply the effect to all 5 channels, as mentioned before, L, R, the bus/aux outputs. I just fear the number of posts online of people who have said it can't be done. I'm frustrated now about not being able to get in to try it. I'm reliant on other people to book the venue and give me access.

[PhilVale]

So an XR18 is very similar to an X18 (in my mind the R stands for Rack but don't know if that's true). There are some differences like the XR18 uses all XLR connections while the X18 has balanced jacks, but they use the same firmware files.

https://www.sweetwater.com/sweetcare/ar ... onachannel

Talks about inserting fx in an X18 BUT it doesn't talk about where the insert sits in the chanel path. My understanding was that it could be configured via Sends page, but it's not obvious how.

(I have to say Berhinger documentation is usually fairly poor but they do have some good how to video's.)

There is of course a lash up you could do:

Put an FX on the chanel, route it to ONLY L/R, then run a patch cable from the L/R output back to another chanel and route that chanel ONLY to the aux's taking say Aux 1 & 2 to your L/R amp, 3&4 and 5&6 to somewhere else. Bit Heath Robinson, but I don't see why it wouldn't work. Still assumes you can reduce the FX from DELAY+(SOMETHING) to just DELAY and that you don't want to use L/R for anything else.

Failing that an external FX unit but that may be more cost than it's worth given Mike says he can do it in software.

[mikeyp]

I was having a look at the software given what you've described and I'm hoping to use the "stereo delay" effect. That however is just theory and worlds apart from actually trying it in person.

It would be ideal to apply it to *everything* there rather than just in one application. That said, the other issue is we share the unit with the drama group. A 200ms delay would confuse them something rotten if they forgot to take it off!

[PhilVale]

So if others are using the desk for other situations you could look at scenes. So a scene for you (with your delay in) and a scene for your other users.

If you interface to your X18 via USB you can then send Midi commands to swap scenes. (I'm pretty sure). So when you fire up SCS then have a cue set to automaticall in your cue file that fire when the cue file is loaded that automatically fires a midi command to load your scene, or have it on a Hot Key. Similarly before you close down SCS have a last cue which fires a command to load a default scene.

If you use something like a StreamDeck and Companion then you can also have a key on that which will load the required scene.

Just some further thoughts to play with.

[mikeyp]

Ok. Finally got in today. You're right. I was able to setup 3 stereo delays on the XR18, channels 11,12 for my FR and FL, and Bus 1-4 for C, Sub, SL and SR. That resolves the issue permanently and for all software. Thank you for pushing me in the right direction. Now to investigate SCS for our purposes. Thank you and have a good day!

[PhilVale]

Glad to have helped even if in a small way Mike.

[PaulsTV]

I implemented a simple solution recently, 8 sync video streams and a separate 5.1 audio stream - also sync - 30 minute long films individually into 8 projectors and surround sound audio system - perfect sync retained over 8 hours of repeating the sequence.

I took 6 channel optical out of the server into a variable optical delay - this compensates for different projectors/monitors delay characteristics. Delay up to 350 ms - and costs 60 pounds sterling UK -

I've used one for years, reliable and remembers your set up.

its here:
https://www.js-technology.com/store/ind ... er=product

Paul