Pasp
Clap
Tapt
- Pasp
'pasp' means "pixel aspect ratio". A movie's aspect ratio obtains as its media sample size x pixel aspect ratio.
For example an NTSC DV movie has media sample size 720x480. To arrive at the desired 4:3 aspect ratio we need a pixel aspect ratio of 8:9.
Common values are 4:3 (for 1080i HDV), 59:54 for PAL DV and 10:11 for (clipped) NTSC DV.
Square pixel translates to 1:1 (or no pasp). Non-square pixel media is called "anamorphic".- Clap
'clap' means "clean aperture".
Actually the 'clap' extension only encodes a clean rectangle inside the movie frame.
The "clean aperture" in QuickTime-speak includes any anamorphic scaling.- Tapt
'tapt' means "track apertures". These are three rectangles to be used as the track dimensions depending on the aperture mode the movie is in.
"Encoded pixels" are the raw media dimensions.
"Production" includes anamorphic scaling.
"Clean" (the default for movie display) realizes both clipping and scaling.
Usually the 'tapt' atom is generated based on 'clap' and 'pasp', but you can have a 'tapt' atom in the absence of 'pasp' and 'clap'.
In theory 'tapt' may overrule 'clap' and/or 'pasp' but this isn't recommended.
Also beware that removing a 'clap' extension doesn't guarantee that a default zero clip is used for the clean aperture mode (even if a 'tapt' is present and clean dimensions equal production dimensions). The standard clipping for the compressed format may be used instead! For formats like DVCProHD it is better to set the 'clap' explicitly to 0 if you want no clipping in clean aperture mode.
Note that this application doesn't change the movie aperture mode that you can set and save with QT Player Pro 7 (the 'apmd' movie user data as viewed in Dumpster).
When judging the result of processing with Extensifier be aware of the movie aperture mode. In the absence of an 'apmd' the movie is opened in clean aperture mode.