UltimateSlice
Source Monitor
The Source Monitor previews individual library clips before they are added to the timeline.
Controls
| Element | Description |
|---|---|
| Video display | Shows the current frame of the selected source clip |
| Scrubber bar | Click to seek; In/Out markers shown in green/orange |
| Timecode label | Current position / total duration |
| In/Out timecode bar | Shows the selected range (In → Out) |
| Volume slider | Adjust preview volume for the source clip |
| Play / Pause / Stop | Transport buttons |
Close (✕) |
Deselect current media item and hide the Source Monitor |
Keyboard Shortcuts
| Shortcut | Action |
|---|---|
Space |
Play / Pause |
I |
Set In-point at current position |
O |
Set Out-point at current position |
J |
Shuttle reverse — press repeatedly to increase speed (1×, 2×, 4×) |
K |
Pause / stop shuttle |
L |
Shuttle forward — press repeatedly to increase speed (1×, 2×, 4×) |
← |
Step one frame back |
→ |
Step one frame forward |
, |
Insert at playhead (shift subsequent clips) |
. |
Overwrite at playhead (replace existing material) |
Note: Shuttle shortcuts require the Source Monitor panel to have keyboard focus. Click inside the monitor area first.
Setting In/Out Points
- Play or scrub to the desired start frame.
- Press I (or click Set In) — the green marker moves to the current position.
- Advance to the desired end frame.
- Press O (or click Set Out) — the orange marker moves to the current position.
The selected region is highlighted in the scrubber bar.
Scrubbing
- Click anywhere on the scrubber to jump to that position.
- Click and drag to scrub continuously.
Appending to Timeline
After setting In/Out points, click Append to Timeline to add the marked range to the timeline. The button auto-detects whether the source is audio-only or contains video. If an active track of the matching kind is highlighted in the timeline, the clip is appended there; otherwise it goes to the first track of that kind.
Insert and Overwrite Edits
In addition to Append, the Source Monitor provides two 3-point editing operations:
- ⤵ Insert (or press
,): Places the marked source range at the current playhead position on the timeline. All clips at or after the playhead are shifted right to make room — a ripple insert. - ⏺ Overwrite (or press
.): Places the marked source range at the current playhead position, replacing any existing timeline material in the time range. Overlapping clips are trimmed, split, or removed as needed.
Both operations target the active track (if its kind matches), or fall back to the first matching track. Both support full undo/redo.
Closing the Source Monitor
- Click the ✕ button in the Source Monitor header to close it.
- Closing clears the current media-library selection, hides the panel, stops source playback, and resets source in/out state.
- Select any media item again to reopen and load the Source Monitor.
MCP Automation
select_library_item: selects a media item from the library and loads it into the Source Monitor.source_play: starts playback in the Source Monitor.source_pause: pauses playback in the Source Monitor.set_source_in: sets the source In-point to the current position (equivalent toI).set_source_out: sets the source Out-point to the current position (equivalent toO).