.PRPROJ File Format – Items, sequences and keyframes

Time

Every time is an integer count of ticks, 254,016,000,000 ticks a second, the unit of Premiere’s scripting Time object. The number divides evenly by all the common frame rates and audio sample rates. A frame rate is stored as ticks per frame in a FrameRate element: 10,584,000,000 for 24 frames a second, 10,160,640,000 for 25, 8,467,200,000 for 30 and 8,475,667,200 for 29.97. The time −91,445,760,000,000,000 (minus 100 hours) marks the single stored value of a parameter that is not keyframed.

Project items

A bin’s children are the references in ProjectItemContainer/Items/Item. Every item has ProjectItem/Name and ProjectItem/Node with an ID and a Properties bag (the colour label is Column.PropertyText.Label there).

A clip item’s MasterClip leads to its media:

1. ClipProjectItem/MasterClip → master clip.
2. Clips/Clip → one clip per stream (a video clip and audio clips).
3. Clip/Source → a media source object, whose OriginalDuration is the length in ticks.
4. MediaSource/Media → the Media object, whose FilePath is the path of the file. Generators such as black video and adjustment layers store a number there instead of a path.

A sequence’s clip item has SequenceSource/Sequence in its source, an ObjectURef to the Sequence object. A start-time override is Media/AlternateStart with UseAlternateStart.

Sequences and tracks

A Sequence lists its track groups in TrackGroups/TrackGroup; each pair’s Second refers to the group object.

A group’s tracks are the references in TrackGroup/Tracks/Track. In a track, ClipTrack/Track/ID and ClipTrack/Track/Index give its identity and position, ClipTrack/ClipItems/TrackItems/TrackItem lists its clips and ClipTrack/TransitionItems/TrackItems/TrackItem its transitions.

Track items

Markers, on clips and sequences, are reached through MarkerOwner/Markers and then Markers/Marker, each pair’s Second referring to a marker object.

Components and parameters

A component chain holds the effects applied to a clip. Premiere stores only the components that differ from their defaults; the fixed Motion and Opacity effects are created when the project is opened unless they were changed. Each parameter is an object such as VideoComponentParam with these leaves:

Value encodings

Keyframe entries

A scalar entry has eight comma-separated fields:

A 2D point entry has fourteen fields: the same eight with x:y as the value, then a constant pair, then the four spatial handles (in x, in y, out x, out y).

Example: 0,0.,0,0,0,0.16666666666666666,50,0.16666666666666666;254016000000,50.,0,0,50,0.16666666666666666,0,0.16666666666666666; is a linear ramp from 0 at 0 seconds to 50 at 1 second, a slope of 50 a second.

Blend modes

A clip’s blend mode is stored twice in its Opacity effect, in two popup parameters both named Blend Mode: parameter 3 holds the menu position (0 to 31, with 2, 8, 14, 22 and 27 unused because they are separators in the menu) and parameter 2 the value the scripting interfaces use (0 to 27).

Caption formats

A caption track’s format is stored as Format (low word) and SubFormat (high word); both are left out for subtitles.

Not publicly known

Hundreds of other classes (render and export settings, Lumetri, audio mixer state, multicam, Essential Graphics templates, team project data) have no public description. Their element names are readable, but their meaning and their changes between versions are undocumented.