Speed Ramp — effect skill for cuts & pacing

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Change playback speed within a shot (fast into a moment, slow on it, fast out) to stress the beat.

What it does

Built on Beat Freeze Cut by HeyGen (HyperFrames), Apache-2.0. The write-up and recipes below are varg's.

Motion races, suddenly drops into slow motion on the key moment, then snaps back to speed.

When: Sport, action, product hero shots, music edits; shoot at 60/120 fps for clean slow parts.

Watch out: Slowing 24/30 fps footage below ~0.5× stutters; ramps on talking heads distort speech.

Timing: Ramp transitions of 4–8 frames between speeds; slow section 0.3–0.5×

Also called: time ramp, speed curve, velocity ramp, ramping

In FFmpeg

FFmpeg has no speed curve; approximate with constant-speed segments (1× → 2× → 0.5×):

ffmpeg -i in.mp4 -filter_complex \
"[0:v]split=3[s1][s2][s3];[0:a]asplit=3[t1][t2][t3];\
 [s1]trim=0:2,setpts=PTS-STARTPTS[v1];[t1]atrim=0:2,asetpts=PTS-STARTPTS[a1];\
 [s2]trim=2:4,setpts=(PTS-STARTPTS)/2[v2];[t2]atrim=2:4,asetpts=PTS-STARTPTS,atempo=2[a2];\
 [s3]trim=4:5,setpts=(PTS-STARTPTS)*2[v3];[t3]atrim=4:5,asetpts=PTS-STARTPTS,atempo=0.5[a3];\
 [v1][a1][v2][a2][v3][a3]concat=n=3:v=1:a=1[v][a]" -map "[v]" -map "[a]" -r 30 out.mp4

atempo accepts 0.5–100; chain it for more. Add minterpolate=fps=60 for smoother slow motion.

In HyperFrames

A rate lane in data-automation (0.1–10, log-scale interpolation):

<video src="clip.mp4" data-start="0" data-duration="4" data-track-index="0"
  data-automation='{"version":1,"lanes":[{"target":"rate","points":[{"t":0,"v":1},{"t":2,"v":4},{"t":4,"v":0.5}]}]}'></video>

In Remotion

playbackRate cannot be interpolated directly. Accumulate the rate per frame and pass it as trimBefore, as in Remotion's accelerated-video snippet (each frame wraps the video in <Sequence from={frame}>).

In CapCut

Select clip → Speed → Curve → a preset (Montage, Hero, Bullet, Jump Cut, Flash In, Flash Out) or Custom and drag the points.

Ready-made components

Where this comes from

Use when

Not for

Install

Example output

https://s3.varg.ai/how-to/previews/58326a2880d1/take-speed-ramp.mp4 — ramp between two shots, with the timeline strip of the edit. Footage: WING IT! (2023), Blender Studio | studio.blender.org, CC BY 4.0; WING IT! (2023), Blender Studio | studio.blender.org, CC BY 4.0. (credit: Rendered by varg · WING IT! (2023))

More cuts & pacing skills

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