HLS content playback on Safari does not use UITextDisplayer

[Qingkui9]

Have you read the FAQ and checked for duplicate open issues?
Yes.

What version of Shaka Player are you using?
The one from master branch.

Please ask your question
It seems like the HLS content playback on Safari doesn't pick up the UITextDisplayer. It is alway using its own shadow dom text track container. Is this the correct behavior or did I miss anything?

[joeyparrish]

Native HLS playback on Safari includes native text rendering, I believe. I don't think we have any control over that, as the subtitles/captions are fetched by Apple below the level of JavaScript. We don't have any access to that data unless we are in control of playback, as we are when we use MediaSource on desktop Safari or other platforms. But MediaSource isn't an option for us on iOS or when FairPlay is used on desktop.

Sorry for the confusion!

[avelad]

I think there is a way to implement this. Taking the cuechange event, you could map activeCues to a Cue understood by the ShakaPlayer and use the UITextDisplayer.

Note: for this you would also have to disable native rendering via css.
Note2: right now Safari supports PiP with subtitles and this would be lost.

[TheModMaker]

In my testing, native HLS doesn't populate the activeCues field.

[avelad]

I just tested again with Safari 13.1 in macOS 10.15.4 and activeCues only is available with showing mode

[TheModMaker]

I tested in Safari 13.0.5, so it may be a new feature. So we can have this be an enhancement for the future.

[avelad]

I attach a screenshot with what I see and with the code that I have tried:

@TheModMaker If you make the same change as me, do you see the same result?

In Safari you can modify the css cue style with

video::-webkit-media-text-track-container {
    // Style the container
}

video::-webkit-media-text-track-background {
    // Style the text background
}

video::-webkit-media-text-track-display {
    // Style the text itself
}

With this you can disable CSS rendering and use activeCues as you like.

[TheModMaker]

Sorry, I naively just picked the first TextTrack element. After finding the active one, I see the activeCues contains the correct cues.

[bidisha15hotstar]

Still exists for me.

[joeyparrish]

PRs are always welcome! The team at Google doesn't have the bandwidth to resolve all feature requests, but the beauty of open source is that you don't have to wait on anyone else.

[bidisha15hotstar]

@joeyparrish , the active cue is empty when we switch to english to arabic to english.

[avelad]

Is there anyone still interested in this? Thanks!

[shaka-bot]

Closing due to inactivity. If this is still an issue for you or if you have further questions, the OP can ask shaka-bot to reopen it by including @shaka-bot reopen in a comment.

[avelad]

@tykus160 will work on it