How to lazy load media source for a playlist in ExoPlayer?

[Cubxity]

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I would like to lazily load media sources for a playlist. When the user clicks previous/next, then I will call the API to retrieve the streaming URI for the previous/next video in the playlist.
For example:

• I play video Add support for parsing senc boxes. #4
• I click the previous button
• The app fetches streaming URI from the server
• The app creates the media source
• video Investigate adding HLS support. #3 is being played

[marcbaechinger]

If you are using the ConcatenatingMediaSource you can choose to have the child media source lazily prepared by passing the useLazyInitialization flag accordingly to the constructor.

I'm not quite sure what your use case is. It may be the above is not enough. You may also want to look into the ResolvingDataSource which allows you to wait with setting up the end point on a data source level.

[Cubxity]

Are there any examples regarding this feature?

[Cubxity]

Also, ResolvingDataSource only resolves the DataSpec lazily not the MediaSource itself.

[marcbaechinger]

Can you explain you r use case a little bit? If resolving data source is not sufficient, I reckon that the type of the MediaSource can change between being added to the playlist and starting to play? So you don't know whether it is an adaptive stream (eg. DASH/HSL) or a progressive stream?

Like in your steps above the type of MediaSource is not known until step "The app created the media source"?

[Cubxity]

So basically I only have basic data about each media in the playlist. F.ex id, title, thumbnails, etc. I don't know anything about the type of the stream until the streaming data is loaded. I would like to load the streaming data lazily upon previous/next.

[marcbaechinger]

In this case I don't think there is something which helps you out of the box.

You can look into creating your own MediaSource which acts as a facade and when prepare() is called, fetches the uri, detects what type of media source is required and creates it internally. If you go down that route I recommend looking into CompositeMediaSource which is an abstract implementation which might be helpful for implementing what you want. You can check subclasses of CompositeMediaSource like the ClippingMediaSource just to learn about how to use the CompositeMediaSource.

Of course you can also only just rely on the MediaSource interface.

[Cubxity]

Thanks for the info. Do you know what apps like YouTube, Spotify does?

[marcbaechinger]

I don't think they have such a requirement because they know beforehand what type of media source to use. They just populate a playlist with a MediaSource of a certain type and a uri.

[marcbaechinger]

Closing due to inactivity. Please reopen if required.