QuickTime Frame Reordering Explained

[ This article was first published in the July, 2009, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]

Jonathan Bewley asks:

When exporting in H.264 DV, is Frame Reordering recommended? I frankly don’t understand what this feature does.

Larry replies: In general, leave this on. It reduces file size while maintaining quality.

In researching this, I read this on Apple’s website:

Some more advanced compressors use “frame reordering” to more efficiently represent movie data. Frame reordering is the concept of allowing frames to be decompressed in a different order than their display order. For almost all cases, leave this box checked for H.264 encoding. The only time you would uncheck this box is if you are creating an H.264 movie that needs to be played back by an application that does not understand frame reordering, i.e., an application that does not yet use the new Frame Reordering APIs of QuickTime 7 or if someone asks you to create your content with “B-frames turned off.” If your audience will play back your movie with QuickTime 7 Player, you should leave the box checked.