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Video

Machinima screen capture on the Mac

by Ian on January 22, 2008

in Mac, Second Life, Video

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 1280×720 (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.

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iMovie ‘08

August 30, 2007

It’s been broadly well received, with the very notable and vociferous exception of iMovie ‘08 which has suffered from the severe disapprobation of the commentariat (thanks to Alastair Campbell for that term, by the way). iMovie power users everywhere are up in arms about all the stuff that is missing or different, compared with iMovie ‘06, the previous version.You see, the thing is this. Apple ditched the whole way of thinking and working that underpinned the previous version. Someone at Apple decided, correctly in my opinion, that iMovie ‘06 was too hard to use for your average non-technical user. They decided to change the direction of iMovie to cater for this kind of user – which arguably is who the iLife apps should be targeted at.Apple’s aim, therefore, was to make it very quick and easy to import a movie from your camera and edit it. Having done this, it they wanted it to be very easy to publish the movie so that people can watch it…. There’s more than enough bloat already in the world of software.I expect things like iDVD publishing to be added incrementally over time, as non chargeable updates to iMovie ‘08. I don’t expect to see timelines, timecode, audio track editing and other complicated stuff coming back…. It was too hard for consumers to use, and too limited for the prosumers.For the machinima that I’ve been involved with, I used (read: battled) iMovie ‘06 for a while, but subsequently upgraded to Final Cut Express, and have never looked back.

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Buying HD video cameras…

August 19, 2007

One minute I had this normal life, and the next I was spending hours and hours doing screen capture from Second Life and trying to edit it, and on tight deadlines too!In a considerable hurry, I suddenly had to understand a whole lot of things about video – not least because the Apple video editing products I used (iMovie 6 and later Final Cut Express HD v3.5) only edit video formats…. So I learned about video, and I learned how to edit video.Given all this new experience, plus motivation generated by the imminent advent of the next Smith, I have decided to buy another video camera…. These are the Panasonic HDC-SD1, which records video in AVCHD format to flash memory, and the Canon HV20, which records video in HDV format to tape. They both produce 1080i video, although the Canon has a 24p option that produces 1080p output at 24fps for a more film-like effect.I should say, at this point, that while I’ve looked all over the Internet, the side that has generated the most credibility with me on this whole topic has been camcorderinfo.com…. However, recording to hard disk or flash memory has now become a very practical alternative and the manufacturers are starting to push a new HD format called AVCHD, developed by Sony and Panasonic.AVCHD is much less widely supported in editing tools – iMovie ‘08 and Final Cut Studio 2 support it, but (importantly to me) Final Cut Express doesn’t as yet. To compound the problems, there’s some doubt about AVCHD support on PowerPC Macs – Final Cut Studio definitely doesn’t support it on PowerPC, but I can’t find any hard info about iMovie ‘08. At any rate, such support for AVCHD as exists was introduced following the recent refreshes of Final Cut Studio and iMovie – it’s my uninformed guess that a refresh of Final Cut Express is in the pipeline. For the interim, there’s a $30 tool called Voltaic which will convert the AVCHD into Apple Intermediate Codec for editing in FCE.AVCHD is based on H.264 compression and while it supports bitrates of up to 24Mbps, the HDC-SD1 can only output up to 13Mbps…. As H.264 is a far more modern and advanced compression algorithm, one might expect better results from it, but it turns out that in the comparison done by the folks at camcorderinfo.com, the Canon outperforms the Panasonic on picture quality maybe due to the lower 13Mbps bitrate cap.

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