Ripple, roll, slip and slide

Four operations, and why dragging is none of them

Most self-taught editors have one move: grab the edge of a clip and drag. That single gesture is doing different things depending on where the mouse landed and whether a mode is active, which is why the result is sometimes a gap, sometimes everything shifting, and sometimes a cut that moved when you did not want it to.

There are four named operations. Learn them by name and the timeline stops surprising you.

Ripple

A ripple trim changes the length of one clip and moves everything after it by the same amount. Remove twelve frames from the end of shot 3 and shots 4, 5 and 6 all arrive twelve frames earlier. The overall duration changes.

This is the everyday trim. It is what you want when you are tightening — the six-frame pass from the first lesson is a ripple trim at every cut.

The cost: anything already timed to a position downstream moves out of place. Music cut to picture, a title that lands on a word, a graphic timed to a gesture — all shift. This is the main reason to lock structure before doing timed work.

Roll

A roll trim moves the cut point between two adjacent clips without changing the total duration. Shot 3 gets twelve frames longer and shot 4 gets twelve frames shorter. Nothing downstream moves.

This is the trim for fine-tuning a specific join once the structure is fixed. It is how you find the exact frame a cut on action works on, without disturbing the music you already placed.

Roll requires handles — unused material beyond the current in and out points on both clips. If shot 4 starts at the very first frame of its source file, you cannot roll the cut earlier, because there is nothing there. This is why shooting a few seconds before and after every take matters more than it looks.

Slip

A slip changes which part of a clip is shown without changing where it sits or how long it is. The clip stays in the same place on the timeline, the same number of frames long, but the content inside slides earlier or later.

Use it when the timing of the sequence is right but the moment inside the shot is wrong — the reaction arrives two frames late, the hand enters frame just after your cut. Slip six frames and the content lands where you need it, and nothing else in the timeline moves at all.

Slip is the most under-used trim among beginners and one of the most useful.

Slide

A slide moves a clip earlier or later along the timeline while the clips either side absorb the change — the one before gets longer, the one after gets shorter, or vice versa. The clip's own content and duration are untouched; its position changes.

Use it to reposition a cutaway. You know the insert shot is right and two seconds long; you just want it half a second later. Slide, and the shots around it adjust.

The table you should build in your head

Each operation answers a different question:

• The shot is too long → ripple.
• The join is on the wrong frame, but the rest of the timeline is right → roll.
• The right moment is inside the clip but not where I put it → slip.
• The shot is right, its place is wrong → slide.

Get into the habit of asking which of the four you need before you touch anything. The gesture then becomes obvious.

Where they live

In DaVinci Resolve's edit page, the trim tool is T and the selection tool is A. With the trim tool active, the pointer changes near an edit point: on the outgoing side you get a ripple, in the middle you get a roll, dragging the clip's body gives a slide, and holding the modifier gives a slip. Resolve also has a dedicated Trim Edit Mode where the arrow keys nudge by a frame and shift-arrow by five.

Premiere is B for ripple, N for rolling, Y for slip, U for slide. Kdenlive and Shotcut expose ripple and roll clearly and slip through a modifier drag. The names are consistent across all of them, which is why learning the names beats learning one program's mouse behaviour.

Trim by keyboard, not by pixel

The single habit that changes the quality of your cuts: stop dragging and start nudging. Select an edit point, then use the keys to move it one frame at a time while the timeline loops around the cut.

Resolve's dynamic trim — W to toggle — plays a loop around the selected edit point and lets , and . move it a frame each way while it plays. You feel the cut change rather than looking at numbers. Ten minutes of this on one difficult join teaches more about cutting than an hour of reading.

Two traps

Linked selection. When audio and video are linked, a ripple on the picture ripples the sound with it, which is usually right. When you are building J and L cuts you want them independent. Know where the toggle is — Resolve puts it in the timeline toolbar, and it is the cause of most "my audio went out of sync" reports.

Trimming with no handles. If a clip has been trimmed to the exact bounds of its source, roll and slip do nothing in one direction, and the editor will usually tell you with a small marker on the edge rather than an error message. Look for it before concluding the tool is broken.

Today

Take any three-shot sequence and perform all four operations on it in turn, watching what moves each time. Ten minutes, and the timeline stops being unpredictable.