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djozy
05-25-2007, 08:55 AM
If i want to use external tbc's how do i disable the internals?

ScorpioProd
05-25-2007, 12:50 PM
Capture from Main In instead of Program Out and you bypass the internals.

djozy
05-25-2007, 03:10 PM
Im talking about live switching not editing.

ScorpioProd
05-25-2007, 04:00 PM
Well, then you can't.

By definition, the internal TBC/frame synchronizer is always on for that use, to let you switch unsynced live sources.

But honestly, why would you want to disable the internal TBC just cause you have an external one?

djozy
05-26-2007, 01:02 AM
It's very simple.
With the internal TBC i have an annoying delay in cuts.
Internal tbc is a feature, why do i have to use it?
There are a few annoying things in the vt that are really simple to change
but newtek doing nothing about that and its too bad that i will have to sell the system because of these simple things.

another thing is "scrubbing in one field" which i requested before:
in the DDR window there is a small preview window at the bottom, and when i click and drag i can 'scrub' or 'jog' the video, but it is all shaky because it's scrubbing frames and not files.
so the scrubbing is useless!
in the most simple externals DDRs you have that option, why not in a 10000$ system?

ScorpioProd
05-26-2007, 01:39 AM
Ah, OK, valid reason.

The genlock card option for VT should be able to minimize the delay you mention.

But hopefully someone with one of the genlock cards can comment on the improvment.

rbartlett
05-26-2007, 07:42 AM
I believe that if you already have your sources sync'd together then you can expect latency through VT of only two or three fields' duration by what you'd measure on the pgm-out port. If your sources are not sync'd then you might need to suffer an extra frame or a further three fields through-delay. From what I've read only. A search here would confirm my recollection of all this.

Switching could be an issue if your PC isn't set up optimally hardware or software wise. Is selecting by function-key/mouse any different to the RS-8?

The genlock function of the VT (add-on for older hardware, VTPro has it onboard) is to sync VT's output/s to the house/facility. Using that along with your sync sources might optimise your overall system performance.

Lastly, Djozy- how are you cutting between sources? Are you putting the new source up on preview and then switching to it?

bbeanan
05-26-2007, 08:54 AM
even an external TBC will add a frame or two of delay... heck a simple video amp will even add between 1/2 - 1 frame of delay.

Don't go a sell a VT system when it most likely is only a part of the problem. Most installs I have see where a VT is being used are done on a budget thus cheaper gear is bought. That cheaper gear all adds a delay, which when added together it is a big deal.

djozy
05-29-2007, 03:27 AM
When i cut between program and preview theres no delay at all.
only when i'm cuting on program row which is popular.
when i use a simple switcher with no internal tbc's and if everything is genlocked, the cuttings are perfect. why cant i do the same with VT?

billmi
05-29-2007, 07:20 AM
When i cut between program and preview theres no delay at all.
only when i'm cuting on program row which is popular.
when i use a simple switcher with no internal tbc's and if everything is genlocked, the cuttings are perfect. why cant i do the same with VT?

Because the VT is not a simple switcher.

The a simple switcher is just combining analog signals that are already in synch. The VT is converting the signals to digital data streams and prepping them for DVE, scaling and other realtime processing. Even if all you are going to do is a simple switch, it still has to flow through that same process - that's just how it works. And box capable of doing DVEs is going to add delay, whether you use the fancy effects or do simple cuts.

vanderwielen
05-29-2007, 07:35 PM
FYI: analog DA's add no delay.

bbeanan
05-29-2007, 10:03 PM
FYI: analog DA's add no delay.

FYI: Yes they do... everything does even the wire the signals are traveling down... granted most of the time it is un-noticable. Heck it has even been proven that data going down fibre will get a slight delay.

bbeanan
05-29-2007, 10:23 PM
Here you go:
From Miranda website...
The VEA-101i is an analog video distribution amplifier with 6 outputs providing equalization and differential input.

PROCESSING PERFORMANCE
PROCESSING DELAY (NO EQ.): 5 ns

Jim_C
05-29-2007, 10:36 PM
Yea, not taking sides or causing wars, but Brett's right. All we use in some set ups between a camera and a couple of monitors is a VAC brick and you can see a really slight delay.

But it really is splitting hairs and NO ONE in the general non -vid public would notice.

rbartlett
05-30-2007, 12:29 AM
To see a 5ns delay is so fantastic to be fantasy. A distribution amp ought to introduce less than a lines worth of delay but 5ns is in pixel timing territory.

Field or frame based (or multiples thereof) TBCs that have internal framers would be noticable - granted.

It is important to note that djozy is attempting to switch between inputs on main using just the main selection buttons / "buttons". This is likely to introduce either delay or tearing in the VT live switching solution.

The approach to recommend is to switch in two stages via preview. Assuming direction is given to the operator on the switcher in those steps rather than switch-box cuts from the sources. I don't suppose this workflow suits everyone in every part of the world but it is in sympathy with how VT was designed.

Alexxi has posted this little snippet in the past that has been pursued and might work out in this case too:


"Yes, itīs already said, without perfect alignement with genlock, that switching happens during the blanking pulse, there is no way to make it happen.

But maybe this could help:
In VT4/ Drivers folder is the newtekrtme.cfg file
opening this file with a texteditor you can see several adjustements for tweakings.
you can increase the "switdelay" and the number of frames for syncing before switching.
This should help. The disadvantage is the odd feeling of switching, because after pressing the pgm button, real switching needs more time."



The risk is swapping the delay issue for a noticable glitch by not "going-to" the take via preview.

From what I've learned, two stage switching is a North American phenomenon but it is what VT was designed to take advantage of. The SX-SDI may have the edge over the SX8 /SX84 in this regard but I would think this would only come if you have a common sync policy throughout a studio and a good SDI on-camera implementation.

Otherwise, to state the obvious, switch with the mixer that works without delay and Y-cable VT into the scheme as a backup in case this cheap mixer fails in service. The VT could still provide switching services and all the rest of the good stuff a VT can do but it would be a blend based on an alternate workflow - ie switching without preview oriented direction.

vanderwielen
05-30-2007, 06:54 AM
bbeanan:

i'll give you the 5 nano-seconds, but your comment of a DA adding 1/2-1 frames of delay was incorrect. also, the delay in wire, coax and fiber is the speed of light times a dielectric coefficient which is typically a fraction nearing 1. (insignificant) I just didnt want a novice getting paranoid about adding simple DAs thinking such delays would be realized.

CreatvGnius
05-30-2007, 07:42 AM
If i want to use external tbc's how do i disable the internals?

Hi, "djozy" -- I do not believe VT[4]'s TBC is a separate module at all -- one which you can access, so as to "switch off" and/or "switch on".

When employing an external TBC, you'd simply go ahead and attach that, while VT's frame-synchronization and other TBC functions continue to work their magic. :)

I suppose you possess more than one external TBC, and you intend to use one for each incoming video stream that's input to the SX-84 is this correct?

If so, many users have reported the value of adding this "additional" TBC functionality to their systems, especially so as to provide increased stability of the video output from old videotape and/or old VTRs (videotape recorders) -- before ingesting video via VT's Capture module.

So go ahead, hook up that TBC; you'll be cool (but you'd be cooler still, if you have hardware control of it, on the fly -- during capture. Do you have that capability?)

By the way, your "signature" indicates your NewTek switcher module's model number incorrectly, doesn't it? :o

CreatvGnius
05-30-2007, 07:55 AM
Because the VT is not a simple switcher.

[A] simple switcher is just combining analog signals that are already in synch. The VT is converting the signals to digital data streams and prepping them for DVE, scaling and other realtime processing. Even if all you are going to do is a simple switch, it still has to flow through that same process - that's just how it works. [Any] box capable of doing DVEs is going to add delay, whether you use the fancy effects or do simple cuts.

I believe "djozy" has somehow left off from his reasoning, the fact that VT is indeed a sophisticated digital switcher. You've aptly identified this in your post, Billmi. What's more, your last comment, about "any digital effects box...causing a [digital] delay" -- a.k.a. "latency" -- is most appropriate. :thumbsup:

CreatvGnius
05-30-2007, 07:58 AM
FYI: analog DA's add no delay.

Ooooooh [Cringing]! I hope no science professor is teaching *that* at Purdue University.:thumbsdow

CreatvGnius
05-30-2007, 08:03 AM
Ah, OK, valid reason.

The genlock card option for VT should be able to minimize the delay you mention...

Naw, Eugene. That genlock feature built into the VT[4] Pro (and sold as an optional daughtercard for the VT[2] and VT[3]) isn't for that purpose at all, TTBOMK. Instead, it allows a VT to be "slaved" -- that is, synchronized to a common sync source, along with a studio's other gear.

CreatvGnius
05-30-2007, 08:07 AM
even an external TBC will add a frame or two of delay... heck a simple video amp will even add between 1/2 - 1 frame of delay.

Don't go a sell a VT system when it most likely is only a part of the problem. Most installs I have see where a VT is being used are done on a budget thus cheaper gear is bought. That cheaper gear all adds a delay, which when added together it is a big deal.

Very, very salient point, there, bbeanan. Selling the VT won't really solve the issue at all: What'll djozy do then: invest more money in gear that will yet add "delay"?

CreatvGnius
05-30-2007, 08:15 AM
...another thing is "scrubbing in one field" which i requested before:
in the DDR window there is a small preview window at the bottom, and when i click and drag i can 'scrub' or 'jog' the video, but it is all shaky because it's scrubbing frames and not [fields].
so the scrubbing is useless!
in the most simple externals DDRs you have that option, why not in a 10000$ system?

Wow! VT[4]Pro, SX-84 and RS-8 sells for 10K US$ overseas?

While the notion that DDR scrubbing is "useless" if the image within its preview window is shaky might be a bit of a stretch -- I would have imagined that within VT[4]'s PREFERENCES, we have the capability to eliminate juddering (instability) on "PAUSE", within the DDR -- and that selfsame feature might also effectively resolve the issue you spoke of here, djozy. Am I not correct? (Anybody?)

CreatvGnius
05-30-2007, 08:27 AM
bbeanan:

i'll give you the 5 nano-seconds, but your comment of a DA adding 1/2-1 frames of delay was incorrect. also, the delay in wire, coax and fiber is the speed of light times a dielectric coefficient which is typically a fraction nearing 1. (insignificant) I just didnt want a novice getting paranoid about adding simple DAs thinking such delays would be realized.

Touche' :thumbsup:
PeterG

bbeanan
05-30-2007, 08:55 AM
What I was trying to point out and I have run into this is you take your Camera that runs down a 500' snake to a CCU, then to a Preview monitor for shading, then it goes into a DA with one leg heading to the switcher where in the non-vt world it goes into a preview monitor and loops out to the switcher, from the switcher it goes out to CG system bla bla bla
In the end EVERY 5ns delay addition (and the Miranda equipment is top of the line stuff) adds up. Sure if you look at any one item yes you can laugh at it and say it's just 5 ns...
and I if you go out to radio crap and buy a $5 analog da you can see a delay being added.
Here is my problem most VT system that are being used for live production are there due to budget. Yes it is a great system and I manage 8 VT systems myself but the reaility is, the VT system is a "cheap" solution. What ends up happening is people think wow my main part of the system (the VT)was only $10k, why should I spend $1k on a high quaility processing equipment, if the cheaper product is better in the case of VT does not mean the other items can be looping into that catagory.

man this is turning into a rant....

and yet I continue...

This is also a reason why there are not many third part additions to the VT. Sure there are a few of us whom have come up with great additions to the system but when the average VT user sees a price over $100 they say it is to expensive.
Well I just deleted the next 2 paragraphs as this is getting to long and off topic...

bbeanan
05-30-2007, 09:05 AM
Very, very salient point, there, bbeanan. Selling the VT won't really solve the issue at all: What'll djozy do then: invest more money in gear that will yet add "delay"?

Yes he will have to spend some time and money to track down what parts of his system are causing the delay then chart it all out and prioritize the list as to what he can lose or replace with better. He may find out that (and this is a common issue now days) that he used cheap baluns to move the video around via CAT5 and there would be your problem (heck even the expensive baluns add to much delay when used with a VT)

Here is the test you need to do... in a DDR play the TimeCode file which you can download from Newtek with overlay on. Then play it though your system, with one of your cameras as the source. Then using another camera not connected to the system shoot both the VT Program screen (computer monitor) and the audience screen.
Then you can measure your delay of your whole system. then work back from there....

rbartlett
05-30-2007, 11:05 AM
System thru delay is one thing. Latency between pressing between inputs on main and seeing the switch occur is another type of delay altogether.

The more active the device is, the more likely it will delay by a big unit of measurement like a line, field or frame. The more passive it is, (like a balun, impedance match, even a wired delay line) the more nanosecond oriented the insertion will be. I don't think this is where our original poster is coming from.

He says he is happy when he switches between sources via going-to preview first. Button/action latency is then at a level where he feels that VT is acting like hardware. When he presses between inputs on main, his concern is that some action might be missed in the wait he suffers while the switch takes place.


This isn't distribution-amp, ADC-DAC, framer, filter or hundreds to thousands of nanoseconds of delay. Unless I've missed the original intent while I've been adding my two-penneth over what might be different between VT and other types of switchers/routers/mixers/TBC-amps etc.

djozy
05-30-2007, 11:11 AM
Wow! VT[4]Pro, SX-84 and RS-8 sells for 10K US$ overseas?

While the notion that DDR scrubbing is "useless" if the image within its preview window is shaky might be a bit of a stretch -- I would have imagined that within VT[4]'s PREFERENCES, we have the capability to eliminate juddering (instability) on "PAUSE", within the DDR -- and that selfsame feature might also effectively resolve the issue you spoke of here, djozy. Am I not correct? (Anybody?)

No, you're not correct. this option in PREFERENCES is helping ONLY on PAUSE.
it doesn't change anything in scrubbing.
when i use VT for replay there are times when i need to show the replay back and forth manually so the judges will see the fault.
Well, i can't do that.

djozy
05-30-2007, 11:20 AM
What I was trying to point out and I have run into this is you take your Camera that runs down a 500' snake to a CCU, then to a Preview monitor for shading, then it goes into a DA with one leg heading to the switcher where in the non-vt world it goes into a preview monitor and loops out to the switcher, from the switcher it goes out to CG system bla bla bla
In the end EVERY 5ns delay addition (and the Miranda equipment is top of the line stuff) adds up. Sure if you look at any one item yes you can laugh at it and say it's just 5 ns...
and I if you go out to radio crap and buy a $5 analog da you can see a delay being added.
Here is my problem most VT system that are being used for live production are there due to budget. Yes it is a great system and I manage 8 VT systems myself but the reaility is, the VT system is a "cheap" solution. What ends up happening is people think wow my main part of the system (the VT)was only $10k, why should I spend $1k on a high quaility processing equipment, if the cheaper product is better in the case of VT does not mean the other items can be looping into that catagory.

man this is turning into a rant....

and yet I continue...

This is also a reason why there are not many third part additions to the VT. Sure there are a few of us whom have come up with great additions to the system but when the average VT user sees a price over $100 they say it is to expensive.
Well I just deleted the next 2 paragraphs as this is getting to long and off topic...


Well...
I have an OB truck that worth at least A 1,000,000$ with a least 700,000$ equipment inside so don't tell me about cheep equipment.

I bought the VT for a test drive and i was impressed, but there are simple annoying thing that can be solved by a simple software tweaking.
so thats all I'm asking.

The big advantage of the VT over all other systems is it's flexibility and the ability to change it and make it self suitable, which you can't do in 150,000$ switcher.

Jim_C
05-30-2007, 12:14 PM
when i use VT for replay there are times when i need to show the replay back and forth manually so the judges will see the fault.
Well, i can't do that.

Have you tried using a small VT-Edit interface with the defielding filter on it?

Throw your clip on the timeline and you can use the shuttle knob just as you would a ddr.

bbeanan
05-30-2007, 12:39 PM
Well...
I have an OB truck that worth at least A 1,000,000$ with a least 700,000$ equipment inside so don't tell me about cheep equipment.

I bought the VT for a test drive and i was impressed, but there are simple annoying thing that can be solved by a simple software tweaking.
so thats all I'm asking.

The big advantage of the VT over all other systems is it's flexibility and the ability to change it and make it self suitable, which you can't do in 150,000$ switcher.


Sorry I didn't know your exact set-up which I would now assume you do have good equipment and even techs for it that can track down the problem.
Now if I understand the problem it is with doing hard bump switches... your best bet again what I have done in the past is route your cameras into an old analog switcher then into the VT. That way you can bump switch your cameras as needed and when you need FX you can use the VT. When I did this I actually split each camera via a 6 way DA right off of the CCU.
Out 1 To the VT
Out 2 to the analog switcher (I think it was a JVC)
Out 3 to the Director preview monitor
Out 4 to the analog switcher Position preview
Out 5 to the VT Switcher Position for preview
Out 6 to a Vectorscope Waveform

then I took the out of the analog into the VT. For the awards part of the show I swtiched all cameras on the VT... during the music breaks we switched via the analog switcher so he could bang away. The nice thing is it gave me a break when needed.... Another time did the same set-up but added in a Folsum 1604 into the mix as we had 3 screens all with different content... Us techs could see the slight delay but was not to bad

djozy
05-30-2007, 12:40 PM
Have you tried using a small VT-Edit interface with the defielding filter on it?

Throw your clip on the timeline and you can use the shuttle knob just as you would a ddr.

Thanks, the problem is that the replay should be instant and it takes time to do this

bbeanan
05-30-2007, 12:58 PM
Thanks, the problem is that the replay should be instant and it takes time to do this

I think Young Monkey has a instant replay plug in for the VT which may be a good solution...
check it out here:
http://www.youngmonkey.ca/hands/restaurant/plugins/InstantReplay/index.html

Jim_C
05-30-2007, 01:02 PM
Thanks, the problem is that the replay should be instant and it takes time to do this


I've never done it, but you can record straight to the VT-Edit timeline. Maybe an option if it happens to drop the file in the right place re: the deinterlace filter.

djozy
05-30-2007, 01:49 PM
I think Young Monkey has a instant replay plug in for the VT which may be a good solution...
check it out here:
http://www.youngmonkey.ca/hands/restaurant/plugins/InstantReplay/index.html

the plugin i have is really good, just the scrubbing problem.