To start using the API you need to initialize the `YoutubeExplode` class (which will create a new http client), and get (for example) the video id of the video you'd want to retrieve information, which usually is the `v` parameter.
```dart
var id = YoutubeExplode.parseVideoId('https://www.youtube.com/watch?v=OpQFFLBMEPI'); // Returns `OpQFFLBMEPI`
var yt = YoutubeExplode();
```
## Get video metadata
The [Video][Video] class contains info about the video such as the video title, the duration or the search keywords.
```dart
var video = yt.getVideo(id); // Returns a Video instance.
```
## Get video mediaStream
The [MediaStreamsInfoSet][MediaStreamsInfoSet] contains the audio, video and muxed streams of the video. Each of the streams provides an url which can be used to download a video with a get request (See [example][VidExample]).
```dart
var mediaStreams = yt.getVideoMediaStream();
var muxed = mediaStreams.muxed; // List of `MuxedStreamInfo` sorted by video quality.
var audio = mediaStreams.audio; // List of `AudioStreamInfo` sorted by bitrate.
var video = mediaStreams.video; // List of `VideoSteamInfo` sorted by video quality.
var videoDetails = mediaStreams.videoDetails; //Returns a `Video` instance. Used to avoid calling `yt.getVideo`.
```
Be aware, the muxed streams don't hold the best quality, to achieve so, you'd need to merge the audio and video streams.
## Closed Captions
To get the video closed caption it is need to query before the caption track infos, which can be used to retrieve the closed caption.
```dart
var trackInfos = await yt.getVideoClosedCaptionTrackInfos(id); // Get the caption track infos
if (trackInfos.isEmpty) {
// No caption is available.
return;
}
var enTrack = trackInfos.firstWhere(
(e) => e.language.code == 'en'); // Find the english caption track.
if (enTrack == null) {
// The english track doesn't exist.
return;
}
var captionTrack = await yt.getClosedCaptionTrack(enTrack); // Get the english closed caption track
var captions = captionTrack.captions; // List of ClosedCaption
captions.first; // Get the first displayed caption.
captions.getByTime(7); // Get the caption displayed at the 7th second.
```
## Cleanup
You need to close `YoutubeExplode`'s http client when done otherwise this could halt the dart process.
```dart
yt.close();
```
---
Check the [api doc][API] for additional information.
