QT "Single Field" Property?

[promoter]

What does enabling the "Single Field" property of a .MOV in QuickTime Player do? It's in the Get Movie Properties->Video Track->High Quality settings.

I know the "High Quality" checkbox improves the quality of playback in QuickTime Player, but I haven't found any information on the "Single Field" property. Why would I use it? Does this have anything to do with interlacing?

[promoter]

OK, from the links below it appears that "Single Field" is an option like High Quality that provides higher-quality playback in QuickTime Player:

http://developer.apple.com/techpubs/quicktime/qtdevdocs/REF/whatsnewqt5/Max.36.htm
http://developer.apple.com/qa/qtmcc/qtmcc12.html
http://developer.apple.com/quicktime/icefloe/dispatch011.html

A sentence in the last paragraph of the last link above reads, "A movie's hints are a run time property. Therefore a movie's hints are not saved with a movie. Similarly, they are not transferred when a movie is copied in an editing operation." So, it sounds like this doesn't have any effect on the quality of the .MOV file. I wonder why, then, after I set the "High Quality" property, I am prompted to save the .MOV as if I'd made a change?

[Cornucopia]

promoter-

I could be wrong, but I believe what Apple is really trying to say is that the HighQuality flag is NOT saved with the Video encoding. It is saved with the movie. If you just copy a movie from drive to drive, the flag WILL be retained. If you Re-Edit, or do some other modification of the movie, that's when you could lose the HQ flag.

Also,
the SingleField flag is used to reduce the load on a CPU when doing decompression (i.e. it may still be encoded with both interlaced fields), and also be more visually appealling when viewing interlaced material that is paused or in still mode.

Thanks for those links (and their relatives)-they could come in handy.

Scott

[promoter]

Cornucopia:

Thanks for expounding on the "Single Field" flag. Aside from the links I provided, I could find no other information on this property. My brief futzing confirms that you're right, setting the "Single Field" flag does in fact affect the .MOV.

Setting the "Single Field" flag on a short .MOV clip eliminated a problem I had <http://www.vcdhelp.com/forum/viewtopic.php?t=112614> with .MOVs exported from iMovie using the "For iDVD" option (DV - NTSC, 720 x 480, 29.97 fps, 48kHz audio). Setting the "High Quality" bit in QT Player, it appeared that only every other horizontal line was updated during playback. Setting the "Single Field" bit eliminated this effect. When I set both flags, saved the .MOV, and used ffmpegX 0.0.4d to create an MPEG2, the MPEG2 didn't show the interlaced effect. The effect appeared if I didn't set the "Single Field" bit, whether or not the "High Quality" bit was set.