Machinima screen capture on the Mac

I've been working on another machinima project.

For over a year now, I've been doing these things on and off. I've learned a lot, mostly by being incredibly frustrated for extended periods of time.

Throughout all of this time, I have used Snapz Pro X to capture the movie clips from Second Life, or whatever other virtual world platform I was using. This product is indispensable, and yet it has provided me with some of my most miserable moments. You see, Snapz has a dangerous propensity to lose all the data that you just captured with it.

The main reason is that it is simultaneously inflexible and intolerant when it comes to disk space. Inflexible because it contains no options allowing the user to save output to any drive except the boot drive. Snapz creates a temporary capture file as it is going along, and then it encodes this into the final output format. This process requires up to twice as much disk space as either of these files require on their own. Intolerant, because if you run out of space on your primary disk, Snapz bins all your work. That's it. Bye bye. See you later.

So I decided to try an alternative piece of capture software called iShowU.

In many ways, this software seemed to be the answer to my prayers. It offers useful and easily configurable profiles for capture. The save file is produced immediately after capture finishes - no hanging around. Finally, it only uses one lot of disk space. If there's 1Gb left on the disk you can stop capture, and know that saving your work will require no further space. Oh, and joy of joys - you can configure where the final output is sent, and where the temporary files are kept.

After joyously using this for a brief period, I noticed that Second Life was running unusually slowly while I was capturing it. An investigation revealed, perhaps obviously, that some of the benefit of iShowU was coming at a cost. So I did a quick and dirty test.

A quick look at Activity Monitor while capturing reveals that Snapz uses about 2.5% of a CPU on my MacBook Pro to capture at 1280x720 (it's a 2.33GHz Core 2 Duo).

Activity Monitor Screenshot of Snapz Pro X

The same test for iShowU reveals that it is using more than an entire CPU for its capture at the same resolution and target frame rate.

Activity Monitor Screenshot showing iShowU

When it is capturing, Snapz Pro is obviously writing its output into a file with very little compression. All the CPU requirement comes afterwards for the encoding. iShowU achieves its greater convenience by doing the processing at capture time, but of course that has a major impact on the application being captured. This is probably tolerable for capturing Safari or Mail or other less demanding applications, but not for Second Life, or games.

So I guess I'm going to end up putting up with Snapz and its idiosyncrasies for a while yet. I'm just going to cross my fingers for the provision of additional preferences so that I can tell it where to put its files.