This morning I booted up and logged in as normal. My machine is configured to start a whole host of helper applications and a few applications I always fire up in the morning, but this morning the machine booted, I logged in, but no applications started. No helpers, no main applications, nada.

A bit of investigation revealed that a file (~/Library/Preferences/com.apple.loginitems.plist) had been cleared during yesterday’s boot. Why? I have no idea, but it had.

Fortunately I run TimeMachine and the file was easily recovered from yesterday. This saved me from having to remember all the utilities that I start, so good save TimeMachine. Once restored my login behaved as it should and all was once again right with the world.

This all leaves the mystery of why yesterday’s login decided to clear the file, which is frustrating.

I’m in the process of developing a lot of video demonstrations. To do this I am using SnapzProX on Mac OS X to capture screen video at HDV720p25, which provides 25fps at 1280×720 resolution, ideal for my purpose. These screen capture videos are then assembled with titles, voice over, music, etc. into the final product using Final Cut Pro (with some Motion work thrown in for good measure). The final video is then rendered to various formats using Compressor and the excellent CRAM library of Compressor settings.

This workflow works very well but for one step. When loading SnapzProX capture (SnapzProX claims to be writing Apple HDV720p25) into a Final Cut project with an HDV720p25 timeline the video is chopped off early. The problem, it turns out, is caused by the way SnapzProX records video. The framerate in the video is recorded using a variable rate and is not properly encoded as 25fps when written out, despite the codec being set to HDV720p25. Long story short, the captured video is complete (plays back fine in Quicktime) but Final Cut is more picky and always reads the framerate as 10fps (the default constant framerate used by SnapzProX) even though the actually recorded video may have a variable frame rate. Confused? So was I.

The solution, it turned out, was to re-encode the SnapzProX produced video using Compressor set to produce HDV720p25 video. This additional step corrects the framerate information in the video (making the video slightly larger as a conseqence). With this corrected encoding Final Cut is satsfied and all is right with the world again.