---
title: "How to add cinematic bars with Claude (tested prompt and ffmpeg command)"
description: "Black bars slide down from the top and up from the bottom, trimming the wide shot to a thin 2.39:1 movie-screen strip. Install one skill and ask Claude Code, or run the ffmpeg command we tested yourself."
url: https://www.recharm.com/effects/cinematic-bars
---

# How to add cinematic bars with Claude

Black bars slide down from the top and up from the bottom, trimming the wide shot to a thin 2.39:1 movie-screen strip.

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 cinematic bars to input.mp4
   Shape of the picture left between the bars: 2.39
   Second the bars start sliding in: 0.5
   ```

## 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 cinematic bars 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                                                                                              |
| ------- | ------- | --------------------------------------------------------------------------------------------------------- |
| `RATIO` | `2.39`  | Shape of the picture left between the bars. 2.39 is the widescreen cinema shape; 1.85 gives thinner bars. |
| `START` | `0.5`   | Second the bars start sliding in.                                                                         |
| `SLIDE` | `0.5`   | Seconds the bars take to reach full size. 0 makes them cut in.                                            |

## Without the skill

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

```
Add cinematic letterbox bars to input.mp4 (960x540). Two solid black (#000000) bars, each the full width and 69 pixels tall, slide in over the picture: the top one down from the top edge and the bottom one up from the bottom edge, both moving linearly from 0.5 to 1.0 seconds, then staying put to the end so the picture between them is 960x402 (2.39:1), centered vertically. Before 0.5 seconds the frame is untouched. Don't scale or move the picture itself; the bars just cover the top and bottom 69 pixels. Keep the size, 30fps, 6 second length and audio. Use ffmpeg and save it as output.mp4.
```

## Run it without Claude

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

```
sh cinematic-bars.sh input.mp4 output.mp4
```

```
#!/bin/sh
# Cinematic bars: black bars slide in from the top and bottom edges to crop the shot to a 2.39:1 widescreen frame.
# Usage: sh cinematic-bars.sh input.mp4 output.mp4  (needs only ffmpeg)
set -e
IN="$1"; OUT="$2"
RATIO=2.39   # shape of the picture left between the bars (2.39 is the widescreen cinema shape)
START=0.5    # second the bars start sliding in
SLIDE=0.5    # seconds the bars take to reach full size

W=$(ffprobe -v error -select_streams v:0 -show_entries stream=width -of csv=p=0 "$IN")
H=$(ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=p=0 "$IN")
BAR=$(awk "BEGIN { print int(($H - $W / $RATIO) / 2 + 0.5) }")   # height of each bar in pixels
GROW="$BAR*clip((t-$START)/$SLIDE,0,1)"   # how much of each bar is on screen at time t

ffmpeg -y -i "$IN" -f lavfi -i "color=black:s=${W}x${BAR}:r=30" -filter_complex \
  "[0:v]fps=30[v];[v][1:v]overlay=y='$GROW-$BAR':shortest=1[top];[top][1:v]overlay=y='H-$GROW':shortest=1" \
  -c:v libx264 -crf 18 -pix_fmt yuv420p -c:a copy "$OUT"
```

## More layouts and reframing

- [Background replacement **Background replacement**](https://www.recharm.com/effects/background-replacement)
- [Binocular view **Binocular view**](https://www.recharm.com/effects/binocular-view)
- [Blur region **Blur region**](https://www.recharm.com/effects/blur-region)
- [Comic panel layout **Comic panel layout**](https://www.recharm.com/effects/comic-panel-layout)
- [Corner pin **Corner pin**](https://www.recharm.com/effects/corner-pin)

## 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)