Video trimming & consolidating
Play just the part of a video you want. Trims are non-destructive source windows by default, with a one-way consolidate tool for when you're ready to shrink the master itself.
Source windows: trims without touching the file
Every video and audio clip can carry a source window: an in-point and an out-point into the master file. The clip plays only that slice: playback cues up at the in-point and stops at the out-point. The master file on disk is never modified and never re-encoded; the window is just timing data stored with the action, so you can widen, narrow, or clear it at any time with zero quality cost.
Both the Chapter Studio preview and the player on Vision Pro honor the window, so what you scrub on the Mac is exactly what plays on the headset, down to the frame where the clip cues in and where it ends.
The fastest way to set a window is before the clip exists: mark In and Out in the Source Previewer and place the take with its range already carried. The edges below are for refining a clip that's already down.
Trim or slip: the edge model
A media clip's edges do one of two jobs, and the words matter:
- Trim changes the clip's length: the left edge moves when playback starts and slips the in-point with it; the right edge sets the out-point where playback stops.
- Slip changes which frames the clip shows without moving either edge: the beat stays where it is on the timeline while the content reframes under it — the classic film-editing slip.
Pick the edge mode in the clip's Video Properties… sheet (the Edge Edit: Trim | Slip control), and hold ⌥ during any edge drag to momentarily use the other mode. The Clip menu also offers Slip Source Back and Slip Source Forward in one-second nudges. Plain body drags still just move the clip in time; see editing clips.
Longer than the media: loop or hold
Stretch a clip past the end of its source and Chapter Studio asks a fair question: what should the extra time show? The Clip ▸ Past End of Source submenu gives two answers. Loop Selected Range repeats the windowed slice, and the bar draws dashed divisions at each repeat. Hold Last Frame freezes the final frame, and the bar draws a hatched tail with a bright line at the exact moment the content ran out. Either way, the timeline tells you the truth about what's playing, and the clip's right edge keeps a gentle detent at the true end of the media so "exactly as long as the file" is always easy to hit.
Tip. On Chapter Vision, select a video clip and switch its mode chip to Trim. The left handle becomes the slip and the right handle the out-point, mirroring the Mac's edge modes.
Consolidating: shrinking the master
Source windows are perfect while you're iterating, but a two-minute master trimmed down to a ten-second window still ships two minutes of video in your chapter bundle. When the edit has settled, Consolidate — Overwrite Master File… makes the trim physical:
The windows are rebased. Every clip in the chapter that plays the same master, across all segments, has its source window recalculated against the new, shorter file, so every clip keeps playing exactly the frames it played before.
The file is trimmed with a passthrough export. The video is cut, not re-encoded: no generation loss, no quality change, and it's fast.
The master is replaced atomically. The new file swaps in as a single operation, so there's never a moment where the chapter points at a half-written video.
Content fingerprints refresh. The chapter's asset records are updated so a connected Vision Pro re-fetches the new file immediately, so the headset never plays stale frames from a cached copy of the old master.
You'll find the command in two places in Chapter Studio (the video clip's right-click menu and the clip inspector), and on Chapter Vision in the selected clip's trim card or by long-pressing the clip, where it appears as Crop to Clip Length…. Either way it's only offered when the clip actually has a source window to make physical.
Watch out. Consolidating is destructive: the media outside the window is permanently discarded from the master file, and every clip sharing that file is affected. If you might want the discarded footage later, keep a copy of the original video outside the project before cropping.
Choosing between the two
| Source window (edge trim) | Consolidate | |
|---|---|---|
| Reversible | Yes, adjust or clear any time | No, discarded media is gone |
| Master file | Untouched | Physically shortened |
| Quality | Unchanged | Unchanged (passthrough, no re-encode) |
| Bundle size | Full master ships | Only the kept slice ships |
| Best for | Iterating on an edit | Final cleanup before sharing or shipping a chapter |
A good rhythm: trim non-destructively while the story is still moving, then
consolidate the masters as a last pass. Your .chapterscript bundle gets
lighter, loads faster over live sync, and plays
identically.