Get this effect
Switch to Code in your Claude Desktop App
Install the skill (once)
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Install the Recharm video effects skill: download https://recharm-growth-staging.s3.us-east-2.amazonaws.com/website/downloads/recharm-video-effects.zip and unzip it into ~/.claude/skillsAsk for the effect
Make a before/after slider from before.mp4 and after.mp4 How fast the divider swings: 1.3 Half the divider's width, in pixels: 3
Several videos, several effects, one ask
Put your clips in the folder, mention them with @, and ask for everything at once. Claude runs one tested script after another on each clip, then joins them.
Add a before/after slider to @clip1.mp4, put a sale badge on @clip2.mp4, give @clip3.mp4 a VHS look, then join all three with crossfades.
Settings you can change
Ask Claude to change any of these, or edit them at the top of the command.
| Setting | Default | What it does |
|---|---|---|
SPEED | 1.3 | How fast the divider swings. |
LINE | 3 | Half the divider's width, in pixels. |
Without the skill
Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.
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Make a before/after slider from before.mp4 and after.mp4: a 6-pixel white vertical divider swings back and forth between 10% and 90% of the width (position 0.5+0.4*cos(1.3*t)), with before.mp4 shown left of the divider and after.mp4 right of it. Use after.mp4's audio. Use ffmpeg and save it as output.mp4.Run it without Claude
This is the exact command we tested. Save it as before-after-slider.sh and run:
sh before-after-slider.sh before.mp4 after.mp4 output.mp4Show the command
#!/bin/sh
# Before/after slider: a white divider sweeps across the frame, with "before" on its left and "after" on its right.
# Usage: sh before-after-slider.sh before.mp4 after.mp4 output.mp4 (both clips the same size)
set -e
BEFORE="$1"; AFTER="$2"; OUT="$3"
SPEED=1.3 # how fast the divider swings back and forth
LINE=3 # half the divider's width, in pixels
# P is the divider's position (0 = left edge, 1 = right edge); it swings between 0.1 and 0.9
P="(0.5+0.4*cos(T*$SPEED))"
ffmpeg -y -i "$BEFORE" -i "$AFTER" -filter_complex "\
[0:v]format=gbrp[b];[1:v]format=gbrp[a];\
[b][a]blend=all_expr='if(lt(abs(X-W*$P),$LINE),255,if(lt(X,W*$P),A,B))',format=yuv420p[v]" \
-map "[v]" -map "1:a?" -c:v libx264 -crf 18 -c:a copy "$OUT"
