Timeline reference

Structure

A timeline has three units.

• Track: a layer of video, audio, or subtitles. Upper tracks render on top.
• Clip: one rectangle on a track, with start/end times, source path, and transition info.
• Keyframe: a property value at a specific time inside a clip (position, scale, opacity, volume).

Add a track

1. Click the + button on the left of the timeline and pick video / audio / subtitle.
2. Drag to reorder. Higher rows render in front during compositing.
3. Use the ☰ menu on each row for solo / mute / lock toggles.

Clip operations

• Move: drag the body of the clip
• Trim: drag the edge handles (start/end time)
• Split: hover the playhead and press S, or right-click → Split
• Delete: select then Delete
• Duplicate: Ctrl/⌘ + D

Multi-select and group move

Drag in empty space to box-select. The clips inside move and delete together.

Zoom and snap

• Mouse wheel — zoom in/out around the playhead
• Magnet (snap) icon — auto-align to clip edges, playhead, markers
• Home / End — jump to the start or end of the timeline

Keyframe animation

Select a clip and change a property in the right inspector — a keyframe is recorded at the current playhead. Values between keyframes interpolate using the chosen curve.

• Linear — constant speed
• Ease In / Out — slow start or end
• Hold — keep the value until the next keyframe

Edit the JSON directly

Open ~/.bom/timelines/<project>.json in any editor. FileSystemWatcher reloads the editor as soon as you save.

{
  "version": 1,
  "tracks": [
    {
      "type": "video",
      "clips": [
        { "source": "intro.mp4", "in": 0, "out": 3.0, "start": 0 }
      ]
    }
  ]
}

Backups & recovery

Every 5 minutes the timeline is auto-backed-up to ~/.bom/timelines/.backup/. Copy a backup over the live file to restore.