Saturday, May 28, 2005

Making DVDs without pro apps revisited

In a previous post I learned the hard way that making compilation DVDs with Final Cut from source movies has the unwanted time/disk space baggage of reprocessing, and FC's highly finicky nature about the KHz of the clips. I also learned that QT Pro does a jim-dandy job of snipping out commercials and saving short reference movies for iDVD.

Which brings me to the next challenge. By default iDVD considers separate movie clips dropped into it as, well, separate. Click one and it plays, but at the end it returns to the main menu instead of continuing to the next, the way you'd expect chapters to play on a theatrical DVD. And there's no "play all" option.

In order for iDVD to consider clips as being linear chunks of a sequence, they have to be linear chunks in a sequence when dropped into iDVD. If iDVD doesn't see chapter markers in a file dropped into it, it considers them self-contained, unsubdividable sequences.

If you don't have Final Cut, you've got two options for making chapter markers. Prior to iMovie HD, you had to have QT Pro, a text editor, an understanding of QT's caption markup language, and the patience of a saint. And enough time and disk space to export a separate, self-contained movie of the original movies put together in order. It's time consuming and may crash at the 98% complete point. Oh, and there's a pretty good chance iDVD won't recognize the chapter titles if anything's amiss. Suddenly FC's razorblade icon starts suggesting its other popular connotation.

iMovie HD offers a simpler solution. As before, edit your source clips in QT Pro, save reference movies, and then open a new iMovie project. Drop the reference movies into iMovie's timeline in your preferred order, then click the iDVD button. A list window appears; click each movie clip then click "Add Chapter." Then click "Create iDVD Project" and iMovie does the dirty work for you, silently building a chaptered reference movie and dropping it into a new iDVD project. Main menu title screen with "Play All/Select Chapter" options, and a second page with the default chapter metaphor (e.g. freezeframes of the chapter beginning).

As a test I did this reusing the clips from the last DVD project I built. The first three movie clips came in lickety split... ...then the fourth sprung the dreaded "Importing Files" dropdown, with an import time longer than the clip. I cancelled it and tried the fifth clip. Same result. Why? Is there some "honeymoon" limit of roughly 60 minutes before imports go to hell? I doubt it.

As it so happens the first three clips were 20-minute reference movies saved from original 32-minute movies. The fourth and fifth were 20-minute reference movies saved from the same original 62-minute movie. I suspect iMovie's import speed is proportional to the number of edits from the source movie. Interestingly enough, after import the aspect ratio on the two clips is squashed with black TV-safe margins above and below.

We'll see how the final movies come out. If this technique works I have a vastly improved workflow for my MST3K conversion process.

Unusual note: I was testing how well the H.264 codec performs when I noticed shit-awful levels of flicker. At first I was inclined to blame the codec itself, but when getting info on the samples I saw they had fps rates of 11 and 14 instead of the 29.97 AlchemyTV was told to capture. The clearly visible frame overlap in freeze frames proves it.

So, the question of the day is what's changing the framerate?