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View Full Version : Latency and lip-syncing with TriCasters on LIVE Shows / Events



wavefx
02-07-2014, 03:41 AM
I know Iím on thin ice here and expect to get shot down but here I go...

Letís say Iím on a big show and the Tricaster is going to another switcher before it hits the projector, letís also say that the sound guy has delayed the sound the best he can before the presenters hear echoís of their own voice. All the cabling is SDI, everything is 1080i and the sync looks good at the Tricaster. Then letís say the end result on the screens is so bad its better just to show a holding logo.

We then tried an old old switcher (blow the dust off) Panasonic MX50 with component cables and the output was fine/acceptable

Why? - Does anyone have any tips or advice about how best to route a TriCaster through another switcher

Is there a preferred project profile, setup, output

Fire


(TriCaster 450 Extreme)

kanep
02-07-2014, 08:02 AM
It isn't fair to compare the performance of the ENTIRE system when one configuration is running HD through the TriCaster but only SD running through the MX50. Less information going into the projector can mean that it can process the signal faster and lower the latency. And when working with latency the entire system needs to be analyzed, not just the switcher.

Additionally, an interlace signal is a poor choice when trying to do IMAG. Not that it can't work, but staying progressive generally is better. Almost all display technology these days are native progressive display and additional processing needs to happen when an interlace signal it sent to it.

If possible, try to use 720p format in the TriCaster, this format runs at a higher frame rate, so the perceived latency can be lower. This isn't always the case, you need to see what the other equipment wants to run at, so if the projector is native 1080p, then you might be better off working in that session format.

When you said that 'sync looks good at the Tricaster' but then it was poor on the projector, leads me to believe that the issue really doesn't have much to do with the TriCaster at all. But that the projector in use is adding most of the delay. You need to find out what kind of projector, what native resolution does it display? As an example, I was demoing a Tricaster at a client location and connected it to the client's television monitor via HDMI and we saw over a half of second image delay caused just by sending a 1080i signal to it, once I switched to progressive video this same TV's delay drop to an unnoticeable latency amount.

Also features like keystone adjustment on the projector can add latency and the latency can vary when the projector is trying to keystone correct HD or SD video.

Just something else to be aware of, if you happened to be using a Tricaster 8000, there are HDMI and VGAs outputs where you can set the exact resolution, so if the projector works at 1440x900, then you could display that and it will be fastest signal to display.

I'm not saying that there aren't switchers with lower latency than TriCaster. But TriCaster latency is in no way unusable for IMAG work. If you have seen our booths at BVE, NAB and IBC shows last year, we had IMAG going on for the main stage demos and the sync was spot on. Everything was running through a TriCaster.

As for sending the output to TriCaster into another switcher, what was the model of the other switcher?