Teradek 150/450 setup really lagging, please assist.

[michael zaletel]

We just purchased a Teradek 150/450 setup in order to wireless stream EPIC HD-SDI out to an HDMI decoder connected to a large flat panel that will be hung in the air in our booth at MacWorld. Perhaps we are doing something wrong. We are using a NETGEAR N900 Dual-Band Gigabit Router with nothing else on the WiFi network. The feed coming into the LCD is completely unusable. It's choppy, low frame rate and lags (high-latency) would never lip sync with live audio. Are we making some common mistake in setting this up either on the EPIC side or the 150 or 450 side?

Please assist,

Michael Zaletel

 

[Andy Jarosz]

I've heard these have a ~one second latency inherently.

 

[Curtis Abbott]

Make sure they are on the latest firmware. There was recently a bug that caused this. I believe it was corrected on the latest firmware. Also, are you having this issue if you use a computer to iOS device to view the stream?

 

[michael zaletel]

One second latency would be a no-go for live wireless because live mic audio would be way off. We were under the impression from Teradek's website that it had like 20 milliseconds latency. We just received these from Teradek yesterday and they have the latest firmware.

-Michael

 

[Conrad Hunziker]

You'll never get under a second with the teradek - theres just too much going on between the encoding to h264, broadcast, then decoding. You really wanted the camwave then a hdsdi->HDMI adapter. Or probably a lot cheaper - a cable.

 

[michael zaletel]

Or probably a lot cheaper - a cable.

Quote of my day.

 

[Larry McKee]

Optitek's HDMI wireless system has no noticeable latency.

 

[Nicol Verheem]

Hi Michael

Short answer: Something is wrong, what you describe is definitely not normal behavior. Hopefully it's a configuration issue. Please e-mail support@teradek.com, we'll go through some steps and test with you and have your units performing well soon. Curtis is right we did have some bugs slip out over the holidays. My apologies if that's the case here. We have a very dedicated support team, and e-mail is the best way since it's a mailing list and you reach 10 of us at once.

Longer answer: The Teradek encodes to H.264 in about 60ms (2 frames). Even a healthy network will add about another frame of delay. So the minimum latency is around 100ms (3 frames), but this has some risk, so the decoder typically has to add some more buffering (to smooth out e.g. late frames and make sure sync is good). Note we're talking about only 3 more frames of delay here, not 20 frames. So in most cases 7 or 8 frames total end to end latency (200-300ms, or 1/5-1/3 second) has good video quality, perfect sync, works with multiple decoders, iPads, and can handle a reasonable amount of RF interference. This is our recommended setup, and most people can use this quite effectively. For example we assisted a complicated steadicam shot on "Gangster Squad" where the steadicam operator started in a street scene on a crane 30 feet up, came down, walked through traffic, then through a crowded sidewalk, into a building up a flight of stairs over a landing down a flight of stairs onto a crowded dance floor, where the camera danced around a bit before settling on the conversation between the actors. More than 200ft of movement, outside to inside, up and down, and many, many extras around the crew, about a 2 minute shot every time. We did it 25+ times over a 6hr period. We had 2 oscar winning gurus looking at the 150/250's output on the Director's monitor all night long. These guys would not stand for crappy out of sync video. After we set it up, they didn't complain once - it only burped a few times all night and the sync was good. The delay bothered no one once they realized it was normal. These were stock units, with a stock Apple Airport Extreme. It might take some playing around with settings, but your units should be capable of the same results. And note the audio should always sync - we have lots of units out in TV news applications too - they air every night on prime time news on many news channels all over the country. Out of sync audio would never fly.

Please note the Teradek Cube will never be a zero delay system, but in return for the ~1/4 sec delay it has many other benefits like streaming to iPads, laptops, over the internet etc. and doing instant dailies.

I hope this helped. Feel free to contact me with any further questions.

Cheers
Nicol