Tuesday, February 21, 2012

Webcam for mobile app demos

Demoing an mobile app to a large audience is always a challenge. Most venues don't have a device projector set up, so you are left with static screenshots or canned videos. You can pass the device around after the presentation, but people may or may not end up checking out the coolest features of your app.

After going to a few hackathons, I thought it would be nice to have a portable webcam mount. That way I can show the live video feed on my screen, hook up my laptop to a projector, and do my demos that way. I shared the idea with my husband, who nonchalantly said, "Sure, we can make that".

As luck would have it, my husband works at a video-conferencing startup, so he has tested a lot of webcams. He recommended the Logitech B910, which takes very nice HD video. This webcam also happens to have a folding clip, making it perfect to hang over a ruler.

We went to OSH to get the materials: a thin piece of metal, a metal rod as the stand, and a few wing screws for securing the parts.

We also needed a clipboard as the base, which we procured at Office Max. The great thing about the clipboard is that I can just place my tablet on top, and the weight of the tablet will balance the stand and the webcam.

Next he went to work in his workshop in the garage. He attached a scrap piece of plastic to the metal strip, drilled a hole to hold the metal rod, and made a base for mounting on the clipboard.

Meanwhile I looked into the software for capturing the live video feed from the webcam. Photo Booth almost worked straight out of the box, except one very annoying detail - the image is flipped! I spent hours and hours pouring over the internet looking for a way to unflip the image. I tried editing the Effect.qtz file to no effect. I searched for alternative software, but did not find any that has a large preview with an acceptable frame rate. There was so much cursing that I decided I needed to take a break.

Tonight I searched some more, and finally found the solution: put Flip.qtz in Library/Compositions. I opened Photo Booth, chose the Flip effect, and finally, a straight pass-through preview from my camera!

With that, I hooked up the projector and tried the whole setup.

Laptop and mount connected to the projector

Projected screen

Pretending to demo

Here is a closer view of the mount:

The best part is that I can take it apart, so it's super easy to carry around. I'm definitely taking this to my next hackathon!

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