---
title: "How to add a directional blur with Claude (tested prompt and ffmpeg command)"
description: "At one second the whole frame smears sideways into flat horizontal streaks, the bottle and backdrop alike, then snaps back sharp at four seconds. Install one skill and ask Claude Code, or run the ffmpeg command we tested yourself."
url: https://www.recharm.com/effects/directional-blur
---

# How to add a directional blur with Claude

At one second the whole frame smears sideways into flat horizontal streaks, the bottle and backdrop alike, then snaps back sharp at four seconds.

Made by the command on this page, from our own test clip.

## Get this effect

1. ### Switch to Code in your [Claude Desktop App](https://claude.com/download)

2. ### Install the skill (once)

   ```
   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/skills
   ```

3. ### Ask for the effect

   ```
   Add a directional blur to input.mp4
   Second the blur starts fading in: 1.0
   Second the blur starts fading back out: 4.0
   ```

## 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 directional blur 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                                                                  |
| -------- | ------- | ----------------------------------------------------------------------------- |
| `START`  | `1.0`   | Second the blur starts fading in. Before it the video is untouched.           |
| `END`    | `4.0`   | Second the blur starts fading back out.                                       |
| `RAMP`   | `0.3`   | Seconds to fade the blur in and out.                                          |
| `ANGLE`  | `0`     | Direction of the smear in degrees. 0 is horizontal, 90 vertical, 45 diagonal. |
| `RADIUS` | `20`    | Length of the smear in pixels. Higher makes longer streaks.                   |

## Without the skill

Don’t want to install the skill? Paste this prompt into Claude Code and Claude writes the command itself.

```
In input.mp4, add a horizontal directional blur from 1.0 to 4.0 seconds; before 1.0s and after 4.3s the video must be untouched. Make a blurred copy with ffmpeg's dblur filter at angle 0 (a horizontal smear) and radius 20, the same blur on every pixel whether or not it moves, and overlay it on the original with its opacity fading from 0 to 1 between 1.0s and 1.3s, staying at 1 until 4.0s and fading back to 0 by 4.3s. Keep the size (540x960), 30fps, 6 seconds and the audio. Use ffmpeg, encode H.264 yuv420p and save it as output.mp4.
```

## Run it without Claude

This is the exact command we tested. Save it as `directional-blur.sh` and run:

```
sh directional-blur.sh input.mp4 output.mp4
```

```
#!/bin/sh
# Directional blur: from 1s to 4s the whole picture smears sideways in one fixed direction, then snaps back sharp.
# Usage: sh directional-blur.sh input.mp4 output.mp4  (needs only ffmpeg)
set -e
IN="$1"; OUT="$2"
START=1.0    # second the blur starts fading in (before it the video is untouched)
END=4.0      # second it starts fading back out
RAMP=0.3     # seconds to fade the blur in and out
ANGLE=0      # direction of the smear in degrees (0 = horizontal, 90 = vertical)
RADIUS=20    # length of the smear in pixels

# blur a copy along ANGLE, then lay it over the original with its opacity ramped up at START and down at END
ffmpeg -y -i "$IN" -filter_complex "\
[0:v]fps=30,format=yuv420p,split[sharp][src];\
[src]dblur=angle=$ANGLE:radius=$RADIUS,format=yuva420p,\
fade=in:st=$START:d=$RAMP:alpha=1,fade=out:st=$END:d=$RAMP:alpha=1[blur];\
[sharp][blur]overlay=format=auto,format=yuv420p[v]" \
  -map "[v]" -map 0:a -c:v libx264 -crf 18 -pix_fmt yuv420p -c:a copy "$OUT"
```

## More motion and camera

- [2.5D parallax photo **2.5D parallax photo**](https://www.recharm.com/effects/2-5d-parallax-photo)
- [Back-and-forth loop **Back-and-forth loop**](https://www.recharm.com/effects/back-and-forth-loop)
- [Background blur **Background blur**](https://www.recharm.com/effects/background-blur)
- [Bullet time **Bullet time**](https://www.recharm.com/effects/bullet-time)
- [Cinemagraph **Cinemagraph**](https://www.recharm.com/effects/cinemagraph)

## Find 3x _winning ads_

Recharm cuts your ad footage into tagged, searchable clips: hooks, testimonials, product shots. Find the shots that win, add the effect with Claude, and ship 3x more ad edits.

[Start 14-day free trial](https://www.recharm.com/get-started)