Text-Tracks not parsed on iOS

Bug

Subtitles listed in textTracks are null when utilizing version 6.0.0-alpha.1. This issue does not exist on the latest stable release 5.2.0.

Platform

Tested on iPhone 12 Simulator

Environment info

Library version: 6.0.0-alpha.1

Steps To Reproduce

Fetch the available textTracks from data provided via the onLoad-Event.

Video sample

https://bitmovin-a.akamaihd.net/content/sintel/hls/playlist.m3u8

[jemise111]

We’re facing this issue too (on 6.0.0-alpha3) but I believe the cause is different.

We’re passing a .m3u8 source with a selectedTextTrack. It looks like setSelectedTextTrack is called immediately because the prop is set. This calls RCTPlayerOperations.setMediaSelectionTrackForCharacteristic which relies on _player to not be nil… but during the initial render it is nil since it is not instantiated until this line (which intentionally has a built in delay and some setup code first).

And so it is crashing on this line because group is nil.

This ^ crash also lines up with the stack trace provided by @awinograd.

We were able to fix this by simply adding a guard against group being nil.

static func setMediaSelectionTrackForCharacteristic(player:AVPlayer?, characteristic:AVMediaCharacteristic, criteria:SelectedTrackCriteria?) {
    let type = criteria?.type
    let group:AVMediaSelectionGroup! = player?.currentItem?.asset.mediaSelectionGroup(forMediaCharacteristic: characteristic)
    var mediaOption:AVMediaSelectionOption!

    guard group != nil else { return }  // <======= HERE

    if (type == "disabled") {
        // Do nothing. We want to ensure option is nil
    } else if (type == "language") || (type == "title") {
    ....
    ....
    ....

And I believe this fix might be a good one since setSelectedTextTrack is called again immediately after _player is instantiated (via applyModifiers). If anyone has more insight and agrees I’m happy to put up a PR

[alexejh]

The main issue is that we pass a custom class array in a react native event. I had not time yet to make a PR, but could successfully test it with this line change.