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View Full Version : Time Delay with Program Out???



timayates
03-09-2003, 03:40 PM
Ok yet another problem with the Toaster 2.

I did a live three camera shoot today and we had overall probably a half second delay on the program out to the large screen. The guy leading the songs on the big screen and clapping was completely off tempo from the actual sounds the audience was hearing?

What can I do to fix this?

Tim

Jim Capillo
03-09-2003, 05:27 PM
Are your cameras genlocked (together and to the T2)? I believe that once all the equipment is timed together the delay is minimal.

timayates
03-09-2003, 05:32 PM
I was told by the guys at Newtek that all I would have to do was plug the cameras into the VT2. They are not genlocked together. I am running two Sony DSR-300's in the stands, and one Canon GL2 on the floor being mobile.

I was under the impression that the toaster 2 time synced all of the inputs before it sent to program out.

??

Tim

Faraz
03-09-2003, 05:42 PM
The Toaster doesn't need genlock but then your video and audio will be delayed by 3-4 frames. If you have genlock running thorugh your camera then it should knock off another frame. bringing it down to 3 frames.
I haven't tried this but someone told me if you get the genlock card it knocks off another frame. Bringing it down to 2 frames.

Keith Gandy
03-09-2003, 11:45 PM
There is another frame delay caused by most projection units. This will only compound the delay present from the VT2. With our tests, we are actually 0.27 seconds delayed from the VT2 processed video signal, but .... the projector adds another couple of frames delay to our signal delay. Yes, our congregation also has adjusted to this also.

Faraz
03-10-2003, 07:26 AM
Something like 12-14 frames!

That can't be right....

Keith Gandy
03-10-2003, 07:34 AM
What can't be right? Our experience is that projection does result in a delay of about 6-7 frames. We are running PAL format. 25 fps / 0.27 seconds (what we delay our audio signal so that it is syncronized externally with the delayed vt2 video signal) results in roughly 6 frame delay. The projector kicks in its own delay. I don't think it is around 12-14 frames total, but in our case it is definitely more than 2-3.

Faraz
03-10-2003, 07:40 AM
Sorry-
I didn't understand. I thought just the Toaster was giving you 12-14 frames of delay. If you use DLP projectors the delay sould be a lot less.

mgrusin
03-10-2003, 11:10 AM
Are you using firewire input for any of your cameras? I've heard there's a substantial delay there.

-MG

Keith Gandy
03-10-2003, 11:28 AM
To whom were you posing the question? As for us, we are using DXC and BVP equipment - no firewire stuff. Lately we have not been genlocking the stuff - we saw no need with the bob. We can and my try again, should that cut down on the frame delay.

mgrusin
03-10-2003, 11:43 AM
Sorry, that was directed at the original poster, timayates. He hadn't mentioned using firewire inputs, but I've heard there's a substantial delay there, so I thought I'd mention it as a possible cause.

BTW, external genlocks will add an additional frame or two of delay; don't add them if you don't need them. Under most circumstances the BOB should be all the genlock you need.

edit: also BTW, another poster mentions that they delay their PA audio to match the delay in video. A solution for your live productions?

-MG

Keith Gandy
03-10-2003, 12:43 PM
Yes, we do delay our audio for tape recording and closed circuit overflow rooms.

If we would take any signal into the sx-8 that would cause a loop problem, because we sent to sx-8 to the audio mixer that serves the amps for the entire auditorium. The reason for this is that we want to send the audio side of any clip from the vt2. If we would feed the entire signal into the sx-8 so that we could broadcast live to the internet, then that signal would be sent back to the amps. Not a great solution for the long run, but it works right now.

Eric Pratt
03-10-2003, 12:59 PM
Now, I'm not exactly advocating this but....
The newtekrtme.cfg file in the drivers folder has a setting called switdelay near the top which by default is set to one. If you are not using FX you can try setting this to 0 to knock off some more time (essentially the DVE needs a whole frame to work with before it can DVE the video. ie in a DVE that inverts the video it needs the last line read into memory before it can write the first line).

disclaimer: play with these files at your own risk. Don't be a dummy, make backups :)

Faraz
03-11-2003, 08:47 PM
I played around with that file. You can do all sorts of things, did the delay thing. Additionally there is some cool stuff with the chroma keyer....

timayates
03-11-2003, 10:38 PM
Ok, help me understand here. To genlock my two Sony DSR-300 before the reach that BOB what is needed? Do I just need sync the two cameras together? Or is there another piece of equipment needed to do this?

And no I'm not using firewire with the cameras.

Tim

Keith Gandy
03-12-2003, 12:57 AM
Tim, to genlock anything together a sync generator, known also as black burst, is used. I don't know if it is would help you to have that unit - I don't know if you can externally genlock other units to the toaster. There is no need to genlock cameras/vtr units going into the toaster - toaster does that itself. I can't see the advantage at present.

timayates
03-12-2003, 08:25 AM
I have now heard that I may have up to a 6 frame delay even with all of the tools? what is noticable to the human eye? How can newtek sell this as a "live" switcher, or is it like a Clinton, "What is the meaing of is is?" type thing. "What is the meaning of "live" is live now or is live then?"

eh?

Keith Gandy
03-12-2003, 08:37 AM
Just for fodder: I saw a small segment from Entertainment Tonight where the moderator was standing in front of a video wall, which was a shot of the moderator standing in front of the video wall. The wall signal was delayed from the live shot and the director did not allow the shot to stagnate - otherwise the viewer would definitely catch on pretty quick.

And to think, they are definitely using something a little pricier than our toaster!

SBowie
03-12-2003, 08:46 AM
Originally posted by timayates
I have now heard that I may have up to a 6 frame delay even with all of the tools? what is noticable to the human eye? How can newtek sell this as a "live" switcher, or is it like a Clinton, "What is the meaing of is is?" type thing. "What is the meaning of "live" is live now or is live then?"

eh? I'm not sure how you're arriving at that figure. I have it on the highest (human) authority that at the moment, the minimum achievable delay through the entire Toaster system (with all equipment genlocked) is 2 frames, or just a hair under that. With non-genlocked equipment, probably 3-4.

This seems VERY good for most practical purpose to me. If it's not good enough for your application, you need to look elsewhere. I don't think Newtek can fairly be held to account for latency introduced elswhere in the system, such as by projection equipment, etc.

Keith Gandy
03-12-2003, 08:51 AM
Steve,

earlier in this thread it was suggested to stay away from genlocking the equipment. You suggest doing such.

Question: Which suggestion is the more accurate?
Question: Does it make a difference if the VT2 is running without the genlock option?

SBowie
03-12-2003, 09:12 AM
Originally posted by Keith Gandy

earlier in this thread it was suggested to stay away from genlocking the equipment. You suggest doing such.

Question: Which suggestion is the more accurate?
Question: Does it make a difference if the VT2 is running without the genlock option? In an editing situation, clearly as someone else pointed out, it matters not a whit.

As far as interfacing with live studio equipment, my understanding is that genlocking can help reduce latency, but I haven't experimented to see to what degree this might be so. Nevertheless, I am paraphrasing (but not loosely) unimpeachable sources. Still, even without genlocking you should be looking at 3-4 frames. In many settings, this would be acceptable.

Fireknight2k
08-12-2004, 09:13 PM
Thought I would through my two cents in. We have the same proplem. We come out of the bob to a smartfade (line doubler) then into the projector and we are getting about 6 to 7 frames delay. Totally sucks. Newtek is obviously aware of the problem and should post some info about the problem on the site. Who cares if you saw a delay at another function and they seemed okay with it. The point is that obviousely it is a problem that is being noticed by people and instead of makeing excuses or showing people examples of where it's been done and it's okay is lame at the least. It would be nice if Newtek would but more effort into trying to come up with a solution rather then excuses to me. Because in the end try it tell an audiance that "sorry that's just the way it is" isn't going to cut it. For all of newtek's hipe you would think they would be more concerned about it.

If I for one had none about this issue before hand I would have probably gone with higher end system. Because I ahve used anolog switchers with the same bells and whistles as toaster without haveing this kind of delay, which means it is possible.

But hey, that's just me.

Jim_C
08-12-2004, 09:28 PM
2 frames from the Toaster, 2 frames from the doubler, 2 frames from the projector.

Seems about right.

Not Newteks fault.

Buy an audio delay unit. the screen will be off from the live but it will be in sync with itself.