Archive for October, 2012

Live Stream Capture Setup October 2012

Side-by side camera and slide.

I’ve been building a capture setup to live stream usergroup technical presentations including a direct feed of the presenter’s laptop to produce readable code examples at 720p. Here is the hardware so far

On the software side I think XSplit is really awesome. Once you get the video input working I can simultaneously record locally at a high bitrate and upload to ustream at a lower bitrate. When things are working they work great.

When things aren’t working however, they tend to fail in a handful of ways. This capture card has HDMI in and out, which works well unless the projector doesn’t have a HDMI input. HDMI to DVI cables have worked reliably (they are just pin adapters, nothing really to go wrong), but converting HDMI to VGA can be problematic. Though in practice, if I have that problem, I usually have it worse than that.

I tried to capture as much as I could at the last code camp at USC. I had problems seeing the video from the presenters with macs. One had a retina MacBook Pro, and another just a normal MacBook Pro. I have the mini-displayport to HDMI adapter which works fine when connected directly to a supported projector, but when I tried capturing those two laptops I just saw an HDCP error and the video output (going through monoprice HDMI to VGA adapter as required by the projection setup) wasn’t showing anything either. I think the answer to this is to bring my own projector, but I’ll have to buy a newer mac to find out. My “late 2007” macbook works fine with my capture setup.

This setup does work with the 1366×768 required for windows 8 metro applications. I’ve recorded two presentations about windows 8 and the presenters didn’t change any settings so they sent out 1920×1080. It worked great. Well, it was downscaled to 1280×720 as I’ve configured XSplit but still the text is quite readable.

I need to find some way to get better audio out of the microphone. Last weekend I had it connected to the mic port on my desktop and it worked okay with the Gain cranked up, a bunch of background noise (I’ll try to upload a sample) and it was quiet. I think this can be solved with a compressor or more professional external audio input device that can better amplify.

Well, or putting a wireless microphone on the speaker directly. I like the shotgun mic because I don’t have to bother the presenter much though, and it can catch some room sound if questions are asked.

If you have suggestions for better software though that would be awesome to hear. My “live to tape” setup with XSplit lets me switch real-time, but I’m kind of stuck with the choices I made live after the fact. Thankfully I’m lazy and that works, but if I want to post-process the audio or video, such as trim out a break in the middle of the talk, or adjust the audio noise and levels, I probably need to be taking a different approach.

I also need to find a better way to get set up quickly and such. The desktop on a hand-truck and camera on a tripod works pretty well, but I can’t set everything up in just 5 minutes, even if the cables are already plugged in.


View of code overlaid with video from presenter.

Capture computer on crate with hand truck. Tripod has camera and microphone.



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