Add duration for PlaybackState.

[addie9000]

Is your feature request related to a problem? Please describe.
If the source duration is not known before playing, can not set the seek bar.

Describe the solution you'd like
Player could know the duration after loading the source, so if PlaybackState has the duration, it's good enough.

[ryanheise]

Forgive me if I misunderstand the question, but the only seek bar in audio_service is the one shown in the Android notification and the iOS control center for the currently playing media item, and it uses the duration in the MediaItem object. The MediaItem class has a duration field. The duration isn't a property of playback state, it's a property of the media itself. This is based on the design of the underlying native APIs.

You can provide additional seek bars in your Flutter UI, but they can operate based on the same principle, obtaining the duration from the media item rather than the playback state.

It is the responsibility of your code to update the duration in a new MediaItem object once it is known, and this can be done with the copyWith method.

[Iamsdt]

I am working with this library. But I don't have the duration of the media file, during MediaItem creation. Is there any way to get the duration of current track from UI side.

[DGempler]

@ryanheise For me, the problem has been due to MediaItem being a const. In my own app I use a forked version of this plugin (and just_audio) where I remove the const declaration on MediaItem and set the duration as a non-final prop. I can then do this in my BackgroundAudioTask implementation:

final duration = await _audioPlayer.setUrl(mediaItem.id);
mediaItem.duration = duration?.inMilliseconds;
AudioServiceBackground.setMediaItem(mediaItem);

I see that a duration stream has been added to the just_audio player recently, but due to the way the example for this plugin was at the time I started using it 😄, and lack of time to try something different, this is how I've been able to get and set duration before I call setMediaItem. I suppose a handler could be set up on the duration stream that then calls setMediaItem once setUrl streams it. Is that your recommendation, or did you have something else in mind for media with dynamic durations?

[ryanheise]

This can be done with the copyWith method.

E.g.

mediaItem = mediaItem.copyWith(duration: newDuration);

Because media items are immutable, this pattern is similar to the way theme data works.

[addie9000]

@ryanheise Thank you for detailed explanation! I totally understood and confirmed the MediaItem way works for my problem. Please close the issue and PR.

@Iamsdt You have to set the duration after you determine it by actual player.
Example with just_audio is shown by @DGempler #229 (comment)

[DGempler]

This can be done with the copyWith method.

E.g.

mediaItem = mediaItem.copyWith(duration: newDuration);

Because media items are immutable, this pattern is similar to the way theme data works.

@ryanheise makes total sense, thank you sir!

[github-actions]

This issue has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs, or use StackOverflow if you need help with audio_service.