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Latency issue for live event projection with Livestream HD31?
I’m doing a multicamera event and projecting the feed to large screens IN THE SAME ROOM as the event (singers and speakers). I’m running 3 cameras (JVC GY-HM700) through a Livestream HD31 switcher (running Studio) using HD-SDI connections (HDMI is also available). There is a delay to the projection that appears to be from the switcher and is at least a quarter of a second (about 10 frames). This delay between image and live audio (not going through unit) is unacceptable, especially with close ups. Anyone know of any solution? Are there preferred settings within the HD31 that I can make to minimize this latency?
Thanks
AnthonyAnthony Popolo
Sunnyside Entertainment -
7 Replies
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Clarification:
I may have mis-used the word “latency”. I know it is generally applied to AUDIO, but my issue is with the VIDEO delay. The audio is live through a PA system so there is no delay in the audio delivery. ThanksAnthony Popolo
Sunnyside Entertainment -
“Latency” is still meaningful for video delay, too.
Some delay accumulating in the system should be expected. Every digital device in the chain that processes frames is going to add a minimum of 1 frame of delay, and some will add 2. (This can include scalers, projectors, and distribution, too!) I’m not familiar with your switcher, but the manual might specify how many frames of delay it adds in processing.
It’s normal to add some audio delay to compensate for the video delay to preserve lip sync on-screen, but obviously this can pose a challenge in smaller rooms.
What else do you have in your system’s engineering?
Walter Soyka
Designer & Mad Scientist at Keen Live [link]
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
@keenlive | RenderBreak [blog] | Profile [LinkedIn] -
You might just have to look at a dedicated switcher for screens. The unit you are using is deigned for streaming (It’s really a PC with input cards), not designed for live production with iMag.
Most basic switchers will usually give you about a frame of delay. Look at Sony , Panasonic or Ross if you are just switching cameras. Even a cheaper Roland mixer would do it.
Vince Becquiot
San Francisco Bay Area
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Thanks guys. I ran a test and it looks like the delay is on the input side of the switcher (almost a quarter of a second)! That was not even taking into consideration syncing other cameras or the output through projector. So yeah, it looks like this unit really isn’t designed for live-live. I will check out the others you recommended. Thanks!
AAnthony Popolo
Sunnyside Entertainment -
Depending where you live, you should be able to rent it. I can vouch for the ease of use of the Edirol (Roland) as well as the Panasonic.
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I am familiar with Livestream for sending video out on the web, and there can be up to a 10 second delay between real-time and the stream. I suspect the Livestream switcher is not intended for a live I-MAG application
Mike Cohen
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Thanks. I’ve been back and forth with the Livestream guys and they finally came to the conclusion that this unit might not be best for IMAG. :/
I’ve gotten the latency down to about 7 frames (30p environment), which is close to a quarter second. Not acceptable for IMAG. Thanks for your confirmation.
AnthonyAnthony Popolo
Sunnyside Entertainment
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