How to auto-trim a video based on faces
Instead of manually setting in and out points around every shot of a person, let the app scan your footage and do it for you. Lossless Video Cutter's face-based auto-trim finds every matching segment and adds them to your timeline, so all you have to do is review and export.
4 min read
How it works
The Find Face scan samples frames across your video at regular intervals, detects every face in each sample, and compares them to your reference image using Apple's on-device Vision framework. When a match is found, the surrounding frames are grouped into a segment on the timeline.
The result is a timeline pre-populated with only the shots containing that face. You can then export those segments as a single merged clip or as individual files, without any re-encoding of the video track.
Step-by-step
- Open your video. Use ⌘O or drag the file into the app.
- Pause on a clear frame of the person - or have a reference photo ready. A well-lit, front-facing image gives the best results.
- Open Find Face. Go to Edit → Find Face or click the face icon in the toolbar.
- Set your reference. Click Use Current Frame to crop the face from the paused frame, or Choose Photo to load an image from disk.
- Adjust scan density if needed. A higher scan rate finds shorter appearances at the cost of a longer scan. The default works well for most footage.
- Start the scan. Click Scan and watch segments appear on the timeline as matches are found.
- Review and clean up. Scrub through each segment to confirm it's a genuine match. Delete false positives by clicking the segment and pressing Delete.
- Export. Press ⌘E for a merged file, or use the export menu to write each segment as its own clip.
Difference between merged and separate export
Merged export (⌘E)
All matched segments are concatenated into one file in timeline order. Good for a highlight reel or sizzle reel.
Separate files
Each segment becomes its own clip, named sequentially. Useful when you need individual shots for further editing in another tool.
Why the export stays lossless
Lossless Video Cutter copies the original compressed video packets directly from the source file into the output. It never decodes video to pixels and re-encodes it, so there is no quality loss compared to the source, and export is much faster than re-encoding.
The only caveat is that cut points must align with keyframes in the source. The app handles this automatically - it snaps segment boundaries to the nearest keyframe and shows you the actual cut point in the preview so you know exactly what you'll get.
Try it now
Find Face is a Pro feature
Download free, then start a 7-day trial to unlock face-based auto-trim and all other Pro smart tools.