Author Topic: (Request for Discussion) SMPTE Support  (Read 2009 times)

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
(Request for Discussion) SMPTE Support
« on: April 09, 2014, 08:29:50 PM »
Hi guys,

Here's a hot topic to discuss regarding a possible SMPTE support for the SSLMixed Computer.

This is something I would really like to see discussed by the community because there are a few different ways we can do this and at the same time there are so many different workflows to attend to. l know it's almost an utopia, but since this is a community project I didn't want to left no one behind, and make an effort to consider and include all possible workflow scenarios into the SSLMixed Computer design.

With this out of the way I'm firing the theme of discussion, SMPTE support.

We are designing the SSL Mixed computer to support automation, and because the console doesn't work by itself, time synchronizing with other devices (including DAW) for time reference is paramount.

The computer is being designed to be totally autonomous without the need of a PC (your DAW computer) to work properly, although it's will be possible to also work with it. 

We are currently planing in supporting 2 main workflows:

1) Computer Autonomous:

- This is for those purists who only use tape, but still want to have total computer support (automation, recall, etc.)

2) Computer + DAW:

- This will enable to link the computer to the DAW, both in transport, time reference, and maybe in future more control of the console inside the DAW.

For scenario 1 we need to be able to provide Time Reference, since the SSLMixed Computer will be the master.

For scenario 2 we need to be able to lock Time Reference, since the SSLMixed COmputer will be the slave to the DAW.

To be able to achieve this we are planing on equipping the computer with a SMPTE IN and SMPTE OUT (with XLR M/F connectors), since from what we've seen so far SMPTE is still the standard time reference standard and that offers the most accurate and stable signal. But for the scenario 2 to work you'll need a device such as AVID SYNC I/O to output SMPTE reference.

EDIT: Just to make things totally correct, instead of using a SYNC I/O, one can also use a pre recorded SMPTE track in the DAW and output it into the SMPTE IN of the SSLMixed computer.

There are other alternatives like MIDI TIME CODE (MTC) or even MTC over USB. But what we are afraid is that the signal would not be as much stable due to nowadays operating systems that introduces natural latency due to things such as multi-tasking, non real-time kernel, no DSP CPU. But this instability can also be irrelevant to level of precision needed to audio...

We would like to hear your opinions regarding this topic and please discuss so we can find the best possible solution.

Cheers,

Artur 
« Last Edit: April 10, 2014, 11:40:55 AM by Artur D'Assumpção »

marcmozart

  • Sr. Member
  • ****
  • Posts: 480
  • Karma: +28/-0
    • Frankfurt/Germany
    • Mozart & Friends
Re: (Request for Discussion) SMPTE Support
« Reply #1 on: April 09, 2014, 11:05:27 PM »
See if you can get Werner (the creator of "The Konnektor") involved.

My first reaction would be - don't make a Sync I/O necessary! It should hook up to the DAW the easiest possible way. Personally, I think even an audio SMPTE track in the DAW is an easy solution, but probably best to get USB MIDI working.
1992 SSL 4048 G-Series
Mix Engineer Blog
http://www.mixedbymarcmozart.com

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #2 on: April 10, 2014, 11:39:14 AM »
Hi,

Actually I was not being totally correct. One can also use also a SYNC track inside the DAW , and you won't need the SYNC I/O, exactly like The Konnektor.

For SMPTE syncing we would have and XLR IN and XLR OUT.

What I want to discuss here is the use of SMPTE vs other syncing methods.

Cheers,

Artur

marcmozart

  • Sr. Member
  • ****
  • Posts: 480
  • Karma: +28/-0
    • Frankfurt/Germany
    • Mozart & Friends
Re: (Request for Discussion) SMPTE Support
« Reply #3 on: April 10, 2014, 12:01:50 PM »
Correct me if I'm wrong, but the Mix Computer as a SMPTE Master is not a good idea as any DAW synced externally needs a (high quality) Wordclock as master, so there's no point to include XLR Out.
1992 SSL 4048 G-Series
Mix Engineer Blog
http://www.mixedbymarcmozart.com

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #4 on: April 10, 2014, 01:56:12 PM »
Marc,

You didn't read what I wrote! :D

The idea is to enable an autonomous computer that can work with or without a DAW. On the later case it would only with a tape machine, like the original one did. Without a DAW you need to generate SMPTE to be master for the tape machine.

...unless we decide this is pointless these days, and we just forget totally the workflow of the computer without a DAW. :D

This is why we are having this discussion after all! :D

Cheers,

Artur

waltzingbear

  • Sr. Member
  • ****
  • Posts: 253
  • Karma: +10/-0
    • Portland, Oregon
    • Waltzing Bear Audio
Re: (Request for Discussion) SMPTE Support
« Reply #5 on: April 10, 2014, 04:33:04 PM »
when dealing with SMPTE and sync always assume that you'll need In and Out as there will be some weird situation that crops up that makes you do something you would never want to do if you had a choice.

Alan
Alan Garren
Waltzing Bear Audio

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #6 on: April 10, 2014, 05:32:37 PM »
Do you guys think the SMPTE is still the go to for time syncing these days?

I've research other options but I think they are very limitative and can give you really weird timing problems, like standard MTC or even MTC over USB.

Specially if you resort to MTC and then you have to covert it to SMPTE then hell breaks loose.


waltzingbear

  • Sr. Member
  • ****
  • Posts: 253
  • Karma: +10/-0
    • Portland, Oregon
    • Waltzing Bear Audio
Re: (Request for Discussion) SMPTE Support
« Reply #7 on: April 11, 2014, 05:19:45 PM »
resolved SMPTE is still the only lingua franca for syncing everything together. Even there some ingenuity may be needed :-{  and that relies on a lot of old gear that hasn't been made in years, but fortunately was well made to begin with (Timeline) . Then again, neither has a multitrack tape deck been made in decades.


A quick refresher:

Resolved- making sure everything is running at the same speed. In the old days, that was blackburst video. Today it is often word clock. We can also get video derived from work clock today (my preference)

Sync- everything happening at the same time. SMPTE LTC is a time stamp that provides only the information of the time of the event, it does not provide the information needed to make sure it is at the same speed.

Today, computer generated LTC is often very good at having the correct time resolution, but it is not guaranteed. Running wild will often work for shorter length events (several minutes), but is not sample or frame accurate.

Of course running wild is the natural state of audio engineers and is best enjoyed with beverage of choice!

Cheers,
Alan
Alan Garren
Waltzing Bear Audio

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #8 on: April 11, 2014, 07:36:16 PM »
Thanks Alan!

You always provide awesome and deep info! ;)

So you're of the opinion we should still maintain the support for SMPTE IN (slaving) and OUT (master)?

Cheers,

Artur

 

waltzingbear

  • Sr. Member
  • ****
  • Posts: 253
  • Karma: +10/-0
    • Portland, Oregon
    • Waltzing Bear Audio
Re: (Request for Discussion) SMPTE Support
« Reply #9 on: April 12, 2014, 07:49:01 PM »
in my experience working with SSL automation, SMPTE LTC was used as slave on the desk. The timing accuracy needed on fade changes pales in comparison with locking the decks together, either video or analog or digital.

the LTC out was really only used as a source of LTC to stripe tape.

Alan
Alan Garren
Waltzing Bear Audio

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #10 on: April 13, 2014, 09:54:46 AM »
Hi Alan,

So you were using other equipment to provide the SMPTE signal and the console would slave to it? I'm curious what did you used as SMPTE master?

Cheers,

Artur

waltzingbear

  • Sr. Member
  • ****
  • Posts: 253
  • Karma: +10/-0
    • Portland, Oregon
    • Waltzing Bear Audio
Re: (Request for Discussion) SMPTE Support
« Reply #11 on: April 13, 2014, 07:52:28 PM »
the Tape Deck! what computer?

source of LTC to stripe the project could be SSL or TimeLine.

In today's world with a mixed mode project, my preference is to use a master oscillator providing word clock to the computer and having video derived from the word clock (Brainstorm, I think Rosendahl, and a few other master clocks). One could also use WC from the master AD with the master osc locked to it.

there are many ways one could skin the cat.

Alan
« Last Edit: April 13, 2014, 07:54:39 PM by waltzingbear »
Alan Garren
Waltzing Bear Audio

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #12 on: April 14, 2014, 12:30:45 AM »
Alan,

So it still makes sense to keep SMPTE IN and OUT support so the new computer can slave or be master of SMPTE.

The master SMPTE feature is only for those users that don't use a PC in their workflow and still want to rely on tape. Which should be a minority these days! :D

Cheers,

Artur

mikelleroy

  • Newbie
  • *
  • Posts: 22
  • Karma: +1/-0
    • Amsterdam Holland
    • Studio Le Roy
Re: (Request for Discussion) SMPTE Support
« Reply #13 on: October 16, 2014, 05:39:32 PM »
Hi,
i have striped LTC on track of 2" recorder or use SMPTE output from Digidesign Sync I/O.
On both Tape-sessions and ProTools-sessions i just feed the console-automation with this LTC only, never have to think about nothing,
always works.
I dont use Transport of the SSL.
Best,
Mikel

Artur D'Assumpção

  • Moderator
  • Hero Member
  • *****
  • Posts: 663
  • Karma: +22/-0
  • Sintra, Portugal
Re: (Request for Discussion) SMPTE Support
« Reply #14 on: October 17, 2014, 03:59:01 PM »
Hi,

Thanks for the input. So I think the MIDI will be more than enough, since you can still use whatever workflow you've been using but this time you use your DAW to generate the lock sync via Midi Time Code.

As I imagine most of these days one will use the following sync workflow:

- DAW is master
     - generates SMPTE/LTC to any outboard that only knows this format (with AVID you can use SYNC I/O or SYNC HD for this)
     - generates Midi Time Code for all the others that are synced via MIDI

For these I believe MIDI will suffice and will accommodate all scenarios. To add SMPTE/LTC support would impose more costs to the solution in hardware and development time.

CHeers,

Artur