beat-sync-video · Beat-Synced Video
Beat-synced short-video maker: detects the beat of background music with librosa, then hard-cuts between images or clips exactly on the beats, with zoom or white-flash effects — producing rhythmic "beat-drop" style short videos.
Feed it a music file and a set of assets: cut frequency is adjustable (default every 2 beats), assets auto-loop when there are fewer than beat segments; the output matches the music length by default, with a duration cap for platform limits.
Example invocation: "Make a 15-second vertical beat-sync video from this song and these photos."
Full brief
Positioning
beat-sync-video is a beat-synced short-video generator: beat detection decides where frames switch, not fixed durations. It makes one kind of video — the "beat-drop" edit — not general-purpose editing.
Core capabilities
- Beat detection: librosa
beat_trackdetects beats (onset strength + dynamic programming), reporting BPM and beat timestamps; degrades to evenly spaced cuts with a note when the music has no clear beat. - Beat hard-cuts: frames switch exactly on beat points (deliberately no transitions, which would blur the rhythmic impact), cutting every N beats as configured.
- Beat effects: zoom push-in (default) / flash white-flash / none for a clean hard cut.
- Asset looping: fewer assets than beat segments? They auto-loop. Directories can be fed in bulk, ordered by filename.
- Build report: segment count, total duration, detected BPM, effect used.
Workflow
- Detect beats (print BPM and beat points, decide cut frequency)
- Build the video (assets, frame size, beats-per-cut, effect)
- Outputs land in
outputs/<theme>/: final video + report
Inputs & outputs
| Input | Notes |
|---|---|
| Background music | Required — drives the beat cuts; stronger rhythm works better |
| Assets | Required — an ordered set of images and/or short clips, or a directory |
| Frame size | Required — horizontal/vertical/resolution, must be user-confirmed, never defaulted |
| Cut frequency | Optional — cuts every N beats (default 2) |
| Effect | Optional — zoom / flash / none |
| Duration cap | Optional, e.g. 15s for short-video platforms |
Output: beat-synced *.mp4 + build report (segments, duration, BPM, effect).
Boundaries with adjacent skills
| Skill | Lane |
|---|---|
| beat-sync-video (this) | Cut points decided by music beats; hard cuts with effects |
| slideshow-video | Fixed per-image duration with soft transitions (album video) |
| auto-short-video | One-shot topic → AI images + dubbing final-video pipeline |
Fit
- Beat-drop edits for music, trend, or sports accounts
- Turning a handful of photos into a rhythm-driven short fast
- Beat-aligned promo intro segments
Before you start
- Prepare the music file and assets; rhythmically clear music works best.
- Frame size must be explicitly confirmed before building (horizontal/vertical/resolution).
- Local script processing, no third-party API cost; librosa and dependencies are installed on first use.
beat-sync-video is part of the Aiglade Skill library. Invoke it from the Aiglade chat box in plain language.