Get this effect
Switch to Code in your Claude Desktop App
Install the skill (once)
Show the prompt
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
Add a vertical blur background to input.mp4 Output size: 1080, 1920 How blurred the background is: 24
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 vertical blur background 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 |
|---|---|---|
W, H | 1080, 1920 | Output size. |
BLUR | 24 | How blurred the background is. |
In other editors
From each editor’s own help pages, in our words. We haven’t run these ourselves.
Built in: Canvas blur · desktop
- Import the video and drag it onto the timeline.
- Resize the video, then click Video > Canvas.
- Choose Blur (or Color or Pattern) to fill the empty space.
- Adjust the style to match your project.
Source: Change Video Canvas Background Effortlessly (CapCut), checked October 22, 2026.
Built in: Fit with Blur · invideo Studio
- Select the clip on the canvas.
- Click Fit Type at the top.
- Choose Fit with Blur in the left panel to fill the empty area with blur.
- Adjust the clip's placement with the arrow options if needed.
Source: How to edit the fit type of an image or video? | Support (InVideo), checked October 22, 2026.
Without the skill
Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.
Show the prompt
Turn the 16:9 clip input.mp4 into a 1080x1920 vertical video: the original sits in the middle at full width, and the space above and below is filled with a blurred, slightly darkened, zoomed-in copy of the same clip. Keep the audio. Use ffmpeg and save it as output.mp4.Run it without Claude
This is the exact command we tested. Save it as vertical-blur-background.sh and run:
sh vertical-blur-background.sh input.mp4 output.mp4Show the command
#!/bin/sh
# Vertical blur background: fit a 16:9 clip into a 9:16 frame, filling the empty space with a blurred, zoomed copy of itself.
# Usage: sh vertical-blur-background.sh input.mp4 output.mp4
set -e
IN="$1"; OUT="$2"
W=1080; H=1920 # output size (9:16)
BLUR=24 # background blur radius
ffmpeg -y -i "$IN" -filter_complex "\
[0:v]split[a][b];\
[a]scale=$W:$H:force_original_aspect_ratio=increase,crop=$W:$H,boxblur=$BLUR:2,eq=brightness=-0.06[bg];\
[b]scale=$W:-2[fg];\
[bg][fg]overlay=(W-w)/2:(H-h)/2,setsar=1,format=yuv420p[v]" \
-map "[v]" -map "0:a?" -c:v libx264 -crf 18 -c:a copy "$OUT"
