SMPTE offset

[Peter]

Hi all,

Normally the video will be cued from the lighting desk but for 2 instances, we'll need to sync multi channel audio files to the video. Perhaps after rehearsals we can write a multi channel QT, but for the moment we need to be flexible.

Will there always be a delay when cueing the video from another mac with QLab when we have smpte in active and sync to smpte on in the layer?

When there is, will we need to program the inframe in the same layer in the previous memory on the desk?

Could this also be done the other way around? Meaning, the video will start from a cue in the memorie, at the same time the lighting desk will send a program change to the Qlab mac to play the multi channel files. But will all of this be in sync? And what about a delay before the Qlab system responds?

Thanks,

Peter

[OlliR]

Hi Peter,

when using sync to smtpe or sync to midi the inframe and outframe values act a little different comapred to other playback modes.
they act as an offset to the incomming timecode - so you can compensate for any delay that may occur on your signal chain...
The good thing abou an offset is that you can still adjust it while it is playing back.
I keep forgetting it but I believe that the inframe is the positive offset (i.e. Inframe = 1 Timecode 0:0:0.0 results in playback of frame 1 / Inframe =25 Timecode 0:0:0.0 > Frame 25

The Outframe is the negative offset.

Catalyst will only read minutes second and frames of the timecode and ignore the hour value (max offset can be 43.7 minutes...)

Hope this is a little help...

[Peter]

Hi all,

Need a little help.

First i've made 2 QT's, one with sound, one with video.

Then i've connected the headphone (works : tested with a speaker) out from a G5. Tha audio G5 goes to analoge input 1-2 on the motu on the catalyst mac. In the system prefs sound i see the meter moving.

On this mac i've activated the sound hud which sees the motu input channels. I've smpte on (blue light is on and i see 00:00:00:00) in the catalyst control window and on layer 1 i have the movie with sync to smpte L (also tried R) but nothing happens.

Any idees?

Thanks,

Peter

[Semillion]

LTC can only come in through the line in on the mac itself and not through Firewire or USB.

That's why you're not able to read the timecode.

One way is to run a line balance box in reverse to get your balanced LTC into the Mac.

Hope that helps.

S

[Peter]

That's what i did first but nothing happened, mini jack to mini jack

[Peter]

Hi guys,

It was kind of stupid, i didnt have a smpte audio file on it. So now we tested a bunch of things :

1. Qlab with QT multichannel audio and smpte included (all seperate outputs), output from the ssl alpha link to mini jack mac input and to the input on a motu 828 mkii : works (the motu did only work when we plugged into the mic/git on the front)

2. Same as 1 but with a seperate smpte file in QLab. Qlab is sample accurate, so when we put the multichannel files and a seperate smpte file in a group and triggered this it seems to work well.

All files were 10' long.

We still need to test mini jack out and motu out from the QLab mac and with longer files.

Ciao