xref: /expo/docs/pages/versions/unversioned/sdk/av.mdx (revision 53eb0d93)

---
title: AV
description: A universal library that provides separate APIs for Audio and Video playback.
sourceCodeUrl: 'https://github.com/expo/expo/tree/main/packages/expo-av'
packageName: 'expo-av'
iconUrl: '/static/images/packages/expo-av.png'
---

import { APIInstallSection } from '~/components/plugins/InstallSection';
import APISection from '~/components/plugins/APISection';
import PlatformsSection from '~/components/plugins/PlatformsSection';
import {
  ConfigReactNative,
  ConfigPluginExample,
  ConfigPluginProperties,
} from '~/components/plugins/ConfigSection';
import { AndroidPermissions, IOSPermissions } from '~/components/plugins/permissions';

The [`Audio.Sound`](audio.mdx) objects and [`Video`](video.mdx) components share a unified imperative API for media playback.

Note that for `Video`, all of the operations are also available via props on the component. However, we recommend using this imperative playback API for most applications where finer control over the state of the video playback is needed.

Try the [playlist example app](http://expo.dev/@community/playlist) (source code is [on GitHub](https://github.com/expo/playlist-example)) to see an example usage of the playback API for both `Audio.Sound` and `Video`.

<PlatformsSection android emulator ios simulator web />

## Installation

<APIInstallSection />

## Configuration in app.json/app.config.js

You can configure `expo-av` using its built-in [config plugin](/config-plugins/introduction/) if you use config plugins in your project ([EAS Build](/build/introduction) or `npx expo run:[android|ios]`). The plugin allows you to configure various properties that cannot be set at runtime and require building a new app binary to take effect.

<ConfigPluginExample>

```json app.json
{
  "expo": {
    "plugins": [
      [
        "expo-av",
        {
          "microphonePermission": "Allow $(PRODUCT_NAME) to access your microphone."
        }
      ]
    ]
  }
}
```

</ConfigPluginExample>

<ConfigPluginProperties
  properties={[
    {
      name: 'microphonePermission',
      platform: 'ios',
      description:
        'A string to set the [`NSMicrophoneUsageDescription`](#permission-nsmicrophoneusagedescription) permission message.',
      default: '"Allow $(PRODUCT_NAME) to access your microphone"',
    },
  ]}
/>

<ConfigReactNative>

Learn how to configure the native projects in the [installation instructions in the `expo-av` repository](https://github.com/expo/expo/tree/main/packages/expo-av#installation-in-bare-react-native-projects).

</ConfigReactNative>

## Usage

On this page, we reference operations on `playbackObject`s. Here is an example of obtaining access to the reference for both sound and video:

### Example: `Audio.Sound`

```javascript
await Audio.setAudioModeAsync({ playsInSilentModeIOS: true });

const playbackObject = new Audio.Sound();
// OR
const { sound: playbackObject } = await Audio.Sound.createAsync(
  { uri: 'http://foo/bar.mp3' },
  { shouldPlay: true }
);
...
```

See the [audio documentation](audio.mdx) for further information on `Audio.Sound.createAsync()`.

### Example: `Video`

```javascript
...
_handleVideoRef = component => {
  const playbackObject = component;
  ...
}

...

render() {
  return (
    ...
      <Video
        ref={this._handleVideoRef}
        ...
      />
    ...
  )
}
...
```

See the [video documentation](video.mdx) for further information.

### Example: `setOnPlaybackStatusUpdate()`

```javascript
_onPlaybackStatusUpdate = playbackStatus => {
  if (!playbackStatus.isLoaded) {
    // Update your UI for the unloaded state
    if (playbackStatus.error) {
      console.log(`Encountered a fatal error during playback: ${playbackStatus.error}`);
      // Send Expo team the error on Slack or the forums so we can help you debug!
    }
  } else {
    // Update your UI for the loaded state

    if (playbackStatus.isPlaying) {
      // Update your UI for the playing state
    } else {
      // Update your UI for the paused state
    }

    if (playbackStatus.isBuffering) {
      // Update your UI for the buffering state
    }

    if (playbackStatus.didJustFinish && !playbackStatus.isLooping) {
      // The player has just finished playing and will stop. Maybe you want to play something else?
    }

    ... // etc
  }
};

... // Load the playbackObject and obtain the reference.
playbackObject.setOnPlaybackStatusUpdate(this._onPlaybackStatusUpdate);
...
```

### Example: Loop media exactly 20 times

```javascript
const N = 20;
...

_onPlaybackStatusUpdate = (playbackStatus) => {
  if (playbackStatus.didJustFinish) {
    if (this.state.numberOfLoops == N - 1) {
      playbackObject.setIsLooping(false);
    }
    this.setState({ numberOfLoops: this.state.numberOfLoops + 1 });
  }
};

...
this.setState({ numberOfLoops: 0 });
... // Load the playbackObject and obtain the reference.
playbackObject.setOnPlaybackStatusUpdate(this._onPlaybackStatusUpdate);
playbackObject.setIsLooping(true);
...
```

## What is seek tolerance and why would I want to use it [iOS only]

When asked to seek an A/V item, native player in iOS sometimes may seek to a slightly different time. This technique, mentioned in [Apple documentation](https://developer.apple.com/documentation/avfoundation/avplayer/1387741-seek#discussion), is used to shorten the time of the `seekTo` call (the player may decide to play immediately from a different time than requested, instead of decoding the exact requested part and playing it with the decoding delay).

If precision is important, you can specify the tolerance with which the player will seek. However, this will result in an increased delay.

## API

```js
import { Audio, Video } from 'expo-av';
```

<APISection packageName="expo-av" apiName="AV" />

## Permissions

### Android

You must add the following permissions to your **app.json** inside the [`expo.android.permissions`](/versions/latest/config/app/#permissions) array.

<AndroidPermissions permissions={['RECORD_AUDIO']} />

### iOS

The following usage description keys are used by this library:

<IOSPermissions permissions={['NSMicrophoneUsageDescription']} />