5 imag and latency, Imag and latency – NewTek TriCaster 40 User Manual

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NewTek’s 3Play instant replay system can send output directly to TriCaster’s Switcher across a network,
freeing up analog video inputs for other purposes.

Some antivirus software can interfere with certain iVGA PRO features. In such cases, try disabling your
protection briefly. If the problem goes away, consider using a different anti-malware product.

If iVGA PRO’s connection to TriCaster seems intermittent, make sure only one network path exists
between the two systems, to prevent the PC from switching back and forth between connections.

Some systems deliberately restrict access to system sound (for DRM reasons), preventing the system
‘Stereo Mix’ from appearing as an audio source option for iVGA PRO. Several workarounds exist; as a
starting point, try an Internet search for terms like “audio loopback software”.

7.4.5 IMAG AND LATENCY

“IMAG” is a compression of the expression “image magnification.” Typically in modern IMAG applications, video
cameras supply live imagery to projection systems, magnifying performers to give audience members in large
venues a better view.

IMAG is a very tricky task at the best of times, one that calls for excellent planning, and where possible, testing.
Those designing an IMAG installation have, not just one, but two inter-related broadcasts to consider –the audio
and video streams.

If audio and video travelled at the same speed, wherever you were seated in the audience, the sound and video
image from the front of the auditorium would reach your ears and your retinas at precisely the same moment.
This is not the case, however. Even in relatively small venues sound reaches those in the rear of the audience
noticeably later than those in the front, while the image arrives effectively instantaneously.

In this context, “latency” refers to the time it takes for the video signal to transit one part of the IMAG path,
from camera lens to final display. It’s desirable to keep video latency to an agreeable minimum – but put away
any notion of ‘zero latency’ as being ideal, since this would result in only those very near the front of the
audience enjoying acceptable lip-sync.

It is common for each device in the production pipeline - even the cameras and monitors - to contribute to the
combined total latency. TriCaster’s portion is well within acceptable standards for devices of this sort – roughly
between 1.5 and 2.5 frames. Here are some points to consider when designing and connecting your system:

If you use Multiview output from the TriCaster to the projector, match the resolution sent from the
TriCaster to the native resolution of the projector.

Try supplying the projector with analog video.

Certain projectors provide a ‘low latency mode’ to disable features of the unit that carry a heavy toll in
latency.

Some cameras include features that add extra latency, such as image stabilization. Disable anything of
that sort that you can.

Latency may be slightly lower for progressive sessions.

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