Re: The Magnetic Timeline What's The Paradigm?

[David Lawrence] " I'm primarily interested in what AV foundation, i.e. an object data model means for FCP UI in broader terms. "
Hi
This is, I think, the $64,000 question.

[Michael Aranyshev] "CoreData and AVFoundation are parts of the system, so they are sort of "free"."

Apple have nailed their colours to the mast, and bet the crown jewels on their new (iOS-derived) core technologies. For better for worse... ;-)

[Andrew Richards] "AVFoundation is Apple's new framework for dealing with time-based media. ...It does four basic things: read media, play media, assemble media, and export media."

QuickTime has allowed media to be 'assembled' within a .mov file, in a manner very similar to Michael Gissing's layered single track methodology - lots of tracks (video, audio, timecode, chapter points, text overlays etc). But its been a very clunky technology.

[Michael Gissing] "I see no reason why AV foundation versus quicktime should make any difference to how a GUI displays something as basic as a timeline."

Apple has totally transformed the old QT legacy concepts with their new foundation - this is what they say about how AV Foundation is used to assemble media:
Editing
AV Foundation uses compositions to create new assets from existing pieces of media (typically, one or more video and audio tracks). You use a mutable composition to add and remove tracks, and adjust their temporal orderings. You can also set the relative volumes and ramping of audio tracks; and set the opacity, and opacity ramps, of video tracks. A composition is an assemblage of pieces of media held in memory. When you export a composition using an export session, it's collapsed to a file.

It seems to me that the section I've emphasised is an excellent description of a basic FCP X timeline.

This being so:-
i) There is no 'Project' as such to define a timeline - its description is all being recorded by the OS and CoreData.
ii) FCP X is just a GUI and a toolkit to build and modify these AV Foundation 'mutable compositions'.

[Michael Gissing] "In audio DAWs (good ones like Fairlight) you can stack clips on top of each other on a track. So your other edits are safe underneath. You always hear the top layer."

That in itself is a complex methodology in a 2D interface, as you have to visually represent the hidden layers in some meaningful way. If you shift the axis of your 'viewpoint' by 90º then the tracks are all visible again - all layed out side-by-side or above and below...

FCP 1-7's Project-based data structure made a traditional timeline an excellent GUI paradigm.
The very different essence of an AV Foundation mutable composition I think requires as different a control GUI,
as say an aeroplane does compared to a car. Joy stick compared to a steering wheel ;-)

As to the linearity of time. Musical notation has traditionally had to deal with the progress of time in a flexible way - how fast do the pages of a pianist's sheet music have to be turned during a Chopin Prelude for the fast and slow movements. The old NLE timeline paradigm is very inflexible in this respect