Streaming My Consciousness

Longtail recently released JW Player 5.0, but it had a bug that prevented it from being used with a Wowza load balance setup. It would catch the redirect and show the first few frames and then start buffering without end.

I just got the new 764 build and am happy to report that it works quite nicely now.

On our live stream page, we have a nifty little javascript counter that lets you know when the next service is.

Leo noticed today that in Internet Explorer, it’s counting down properly, while in Firefox, it’s saying the event is already happening. On a hunch, we changed the target date to 12/31, and it started working properly again.

So, IE’s Javascript is smart enough to figure out that on December 29, the target date of January 3 is likely to be the one next week. Firefox is clinging to the past and assuming that I really meant the January 3 that happened 51 weeks ago.

How is it that the same script can be interpreted so differently within the same language on two different browser platforms? This stuff is supposed to be standard!

Earlier this week, I got an e-mail from Amazon Web Services, with some new goodies being announced.

The first was new pricing for Wowza. While the cost of each instance-hour is going up slightly, the cost of bandwidth is dropping about 15%. This makes me happy.

The second was that Wowza has released version 2. I’ve been working with preview versions of this since last summer with our iPhone streaming. They’ve made some very cool improvements to the product.

Lastly was an item that intrigued me. Amazon has, via Flash Media Server, added RTMP streaming capability to Cloudfront, Amazon’s cloud answer to CDN. Now instead of being able to widely distribute files, you have the capability of setting up a distribution that provides RTMP streaming of any supported video file in an S3 bucket. If you use S3 for on-demand video content, this is big for you. No longer do your viewers have to download the entire file (and run up the bandwidth meter in the process). They can now skip directly to the points they need and only use the bandwidth for stuff they actually watch.

This is potentially very good news for services that serve on-demand content from S3 (such as blip.tv)

It’s not so good news for the folks at Wowza, because I no longer have to spin up a Wowza instance to serve content stored in S3. Luckily for Wowza, the Cloudfront streaming doesn’t do live video.

It’ll be interesting to see how this plays out. As it currently stands, we could replace blip.tv with this functionality, but for the small cost, we get a whole lot of value from Blip.

For the last couple of years, we’ve used LED Christmas lights in our sanctuary. Considering how many we have (hundreds), the electricity savings are probably non-trivial.

All our LED strings in the sanctuary are plugged into either a stage dimmer or, where a dimmer port was unavailable, an Elation UniBar hooked into an RC4 Magic wireless DMX receiver (with the transmitter wired into DMX up in the catwalks). This allows us to control the Christmas lights along with the rest of the theatrical lighting via the Hog. It’s a very nice setup.

The other day, when Frank was running the stream, he saw the Christmas lights were fading in and out in sequence, and called up to the Penalty Box (the plexiglass-wrapped area at the back of house where the lighting operator and worship producer sit) and asked them to quit playing with the lights. As it turns out, they weren’t and the lights were all on. Mysteriously, they were fading in and out in sequence on the wide shot camera. When we looked at them on one of the other remote cameras, everything looked normal.

Then it hit me. I went to the remote control on the wide camera and cranked down the shutter speed, and lo, the lights gradually came together until they were all on. This is what it looked like:

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Most stage dimmers operate by switching the AC cycle on and off via pulse width modulation. LEDs then only show one half of the AC sine wave, making them strobe, effectively reproducing the square-wave pulses that are modulating the dimmers. What We were seeing on the cameras was a beat frequency of the camera’s shutter speed and the strobing of the LEDs. You don’t see this on incandescent lighting because of the thermal persistence of the filaments. But why were the lights cycling at different times? Each one was connected to a different dimmer circuit, and those circuits are spread among the three AC phases coming into the dimmer room (which has a monster 2000-amp breaker).

So, if you’re shooting video of anything that has LED lights in it, make sure your shutter speed is at 1/60, or the lights are going to start acting strangely.