Effects: silence, loops, speed and freeze

Tools → Effects. Five separate jobs share this panel, and they all operate on a source between Effects In (source seconds) and Effects Out (source seconds).

Cutting the silence out

Detect Gaps finds the quiet stretches. Auto-cut threshold (dB) is how quiet counts as silence, and Minimum gap (seconds) is how long a gap must be before it is worth removing.

The detected gaps are drawn on the source timeline, and you go through them one at a time with Accept Cut and Reject Cut. Nothing is removed until you accept it.

Review them rather than accepting everything. Automatic silence removal is very good at cutting the pause before somebody says the important thing.

Start with a threshold around -40 dB and a minimum gap of half a second, and adjust from what it proposes. A noisy room needs a higher threshold because its silence is not very silent.

Finding a loop point

Find Loop Points compares the start of the selection against its end and reports the candidates, closest match first.

On audio it snaps to a nearby zero crossing so the loop does not click. This is how you make a music bed or a background plate repeat without a visible or audible seam.

Changing speed

Playback speed (x). Above 1 is faster, below is slower.

Audio pitch decides whether the sound rises and falls with the speed. Leave correction on for speech, which is what keeps a voice sounding like itself. Turning it off is occasionally what you want for effect, and it is audible on music long before it is audible on speech.

Hold duration before speed change (seconds) plays at normal speed for a moment before the change begins, which stops a speed ramp from feeling abrupt.

Slowing footage below about half speed looks like a slideshow unless it was shot at a high frame rate, because there are no frames in between to show. See Frames, time, and why the numbers are strange.

Freezing a frame

Freeze source time (seconds) picks the frame to hold.

A freeze carries no sound. If the audio has to continue under it, it has to come from somewhere else.

Watermarks

Choose Watermark Image takes a file and places it on the output.

Small, low opacity, in a corner no platform interface covers. If it distracts it is too big, and if it is easy to crop off it is in the wrong corner.

Checking before the full run

Render 10-second Preview produces a short pass at real settings so you can see what you are about to commit to. Use it before a long render rather than after.

Cancel Analysis stops a detection that is taking longer than it is worth.

Output

Effects video format and the output folder. The job runs in the queue.