Support partial stream downloads

[blueslabs]

This is just a question. Trying to see if it is possible to do prefetch with DASH. Basically we want to preload the cache with a couple of seconds of data before a video is played.

Is DashChunkSource the one we should look into? Can we use it directly and have it fill some data to the CacheDataSource?

[thomasbreitbach]

You want to delay the start? setPlayWhenReady(boolean playWhenReady); could be a good starting point.

[lzyang187]

Hello, I want to know how to cache while playing mp3? thx a lot! @blueslabs

[erdemguven]

For downloading DASH streams, please see: https://medium.com/google-exoplayer/downloading-adaptive-streams-37191f9776e

Currently it isn't possible to download partially. Let's use this issue to track the implementation of this feature.

[giladna]

@tonihei I would also suggest supporting scenario where app will want to download part of the stream but from specific position and not only from the start and give the duration that is requested to download as a parameter

[ojw28]

Note: We will want any solution to work for both download (we keep a record of it, and retain the downloaded data until the app tells us not to) and pre-caching (fire-and-forget from the application). Gaps we have currently:

1. Partial downloads (all format types)
2. Fire-and-forget caching (adaptive format types; CacheWriter already solves this for progressive types).

[VeraUvads]

Hello The thread is 4 years old, is there any chance that someday this task will be implemented? Cause it really necessary feature