# Remotion Rule: Get Audio Duration

> Remotion skill rule: Getting the duration of an audio file in seconds with Mediabunny. Part of the official Remotion Agent Skill for programmatic video in React.

## Install

Save the content below to `.claude/skills/` or append to your `CLAUDE.md`:

## Quick Use

```bash
npx skills add remotion-dev/skills
```

This rule activates automatically when working with get audio duration in a Remotion project.

---

## Intro

Getting the duration of an audio file in seconds with Mediabunny. Part of the [Remotion AI Skill](https://tokrepo.com/en/workflows/57997ead-c8fa-409c-916f-28bbc0adc8d9) — the official Agent Skill for programmatic video creation in React.

**Best for**: Developers using Remotion for get audio duration
**Works with**: Claude Code, OpenAI Codex, Cursor

---

## Rule Content

# Getting audio duration with Mediabunny

Mediabunny can extract the duration of an audio file. It works in browser, Node.js, and Bun environments.

## Getting audio duration

```tsx title="get-audio-duration.ts"
import { Input, ALL_FORMATS, UrlSource } from "mediabunny";

export const getAudioDuration = async (src: string) => {
  const input = new Input({
    formats: ALL_FORMATS,
    source: new UrlSource(src, {
      getRetryDelay: () => null,
    }),
  });

  const durationInSeconds = await input.computeDuration();
  return durationInSeconds;
};
```

## Usage

```tsx
const duration = await getAudioDuration("https://remotion.media/audio.mp3");
console.log(duration); // e.g. 180.5 (seconds)
```

## Using with staticFile in Remotion

Make sure to wrap the file path in `staticFile()`:

```tsx
import { staticFile } from "remotion";

const duration = await getAudioDuration(staticFile("audio.mp3"));
```

## In Node.js and Bun

Use `FileSource` instead of `UrlSource`:

```tsx
import { Input, ALL_FORMATS, FileSource } from "mediabunny";

const input = new Input({
  formats: ALL_FORMATS,
  source: new FileSource(file), // File object from input or drag-drop
});
```

---

## Source & Thanks

> Created by [Remotion](https://github.com/remotion-dev). Licensed under MIT.
> [remotion-dev/skills](https://github.com/remotion-dev/skills) — Rule: `get-audio-duration`

Part of the [Remotion AI Skill](https://tokrepo.com/en/workflows/57997ead-c8fa-409c-916f-28bbc0adc8d9) collection on TokRepo.

---
Source: https://tokrepo.com/en/workflows/c14c3bd1-b513-4d4e-9194-0379445fe785
Author: Skill Factory