# Extract audio from video with Typescript and ffmpeg

![](https://i.imgur.com/z0OFsjk.png)

To extract audio from a video file in a TypeScript project, you can leverage the `fluent-ffmpeg` library, which is a wrapper around the FFmpeg command-line tool. FFmpeg must be installed on your system for `fluent-ffmpeg` to work. Here's how you can accomplish this task:

### Step 1: Install FFmpeg

Ensure FFmpeg is installed on your system. You can download it from [FFmpeg's official website](https://ffmpeg.org/download.html) or install it via a package manager if you're using Linux or macOS.

### Step 2: Install `fluent-ffmpeg`

If you haven't already, add `fluent-ffmpeg` to your project by running:

```shell
npm install fluent-ffmpeg
```

### Step 3: TypeScript Code to Extract Audio

Here's a simple TypeScript script that uses `fluent-ffmpeg` to extract audio from a video file and save it as an MP3 file. Ensure you have a `tsconfig.json` configured with `ESNext`, `CommonJS`, and strict typing.

```typescript
import ffmpeg from 'fluent-ffmpeg';

/**
 * Extracts audio from a video file and saves it as an MP3 file.
 * @param videoFilePath - The path to the video file.
 * @param outputAudioPath - The path where the extracted audio file should be saved.
 */
function extractAudioFromVideo(videoFilePath: string, outputAudioPath: string): Promise<void> {
    return new Promise((resolve, reject) => {
        ffmpeg(videoFilePath)
            .outputFormat('mp3') // Set the output format to mp3
            .on('end', () => {
                console.log(`Extraction completed: ${outputAudioPath}`);
                resolve();
            })
            .on('error', (err) => {
                console.error(`Error extracting audio: ${err.message}`);
                reject(err);
            })
            .save(outputAudioPath); // Specify the output file path
    });
}

// Example usage
const videoFilePath = 'path/to/your/video.mp4';
const outputAudioPath = 'path/to/output/audio.mp3';

extractAudioFromVideo(videoFilePath, outputAudioPath)
    .then(() => console.log('Audio extraction successful.'))
    .catch((err) => console.error(err));

```

**Important Notes:**

* **FFmpeg Dependency:** This script assumes FFmpeg is correctly installed and accessible in your system's PATH. If you encounter any issues, verify your FFmpeg installation.
* **Type Definitions:** If TypeScript cannot find the type definitions for `fluent-ffmpeg`, you may need to install them using `npm install @types/fluent-ffmpeg --save-dev`, assuming they are available, or use a `// @ts-ignore` directive above the import if necessary.
* **Error Handling:** The script uses Promises for asynchronous execution and error handling. Customize the error handling logic based on your application's requirements.

By following these steps, you should be able to extract audio from video files within your TypeScript project efficiently and effectively.