Subtitles incorrectly forced?

[defagos]

An SRF user reported the following issue:

Habe mich schon mal via Twitter gemeldet - bei mir läuft seit dem letzten iOS Update das Streaming via AirPlay überhaupt nicht mehr.
Wenn ich eine Sendung anwähle, spielt sie sauber und in voller Auflösung ab. Dann nach ca. 2-3 Minuten geht die Bildqualität massiv zurück, man erkennt kaum mehr Gesichter.
So kann es dann eine Weile weitergehen, oder es stoppt komplett. Abschiessen der App hilft nicht, danach lässt sich der Playback für diese Sendung gar nicht mehr starten - passiert einfach nichts,
Eine neue Sendung läuft dann wieder, aber wie oben.
Mein Setup: iPhone XS Max, aktuelles iOS -> AppleTV 4K, ebenfalls aktuell. AppleTV hängt an Ethernet.
Beispiel Sendungen wo das bei mir passiert:
Mini Schwiiz, dini Schwiiz, Stadt Bern - Tag 1
Mini Schwiiz, dini Schwiiz, Solothrun - Tag 4
Übrigens, bei mir wird auch immer der Untertitel angezeigt, obwohl ausgeschaltet. Wenn ich nochmals auf “Aus” clicke, verschwindet er aber.

I could not reproduce the AirPlay quality issues (for which we have no real control). For subtitles, @ahmedgoumri provided us with the following reproducible scenario:

• Make sure in setting that subtitles are turned off
• Start Play SRF App and play a video with subtitles (here: Kassensturz from editorial tipps)
  show subtitle settings (Subtitles turned offI
• Activate AirPlay. at first try, no subtitles shown on AirPlay 4K device.
• Stop and Play same video again. Subtitles are displayed on AirPlay device. Settings still the same (Subtitles turned off)
• Any further video on Airplay is displayed with subtitles .

At first I could not reproduce this issue with these instructions either. This might depend on device settings, though, and needs further investigation.

Here are a video capture of the issue, as well as the device language and accessibility settings:

Issue type

Incorrect behavior

Description of the problem

Environment information

• Library version: 3.0.0
• iOS version: Any
• Device: Physical

Reproducibility

To be determined.

[defagos]

I could find out what forces subtitles when using AirPlay. It is the Apple TV itself which saves the last choice made on it in the top pane displayed during playback (swipe down with Apple Remote), and restores it.

At least this is what I could verify with my Apple TV running tvOS 13. I cannot remember which was the behavior on tvOS 12, maybe this is something that changed with tvOS 13.

Here is how to reproduce and understand this behavior (for simplicity I only use Off and German subtitles settings; the Automatic setting depends on device settings and device / content languages):

1. Open Play SRF on a mobile device and pick a content with subtitles (e.g. 10vor10). Set subtitles to Off.
2. Play the content and enable AirPlay from the player.
3. On the TV receiver, open the subtitles settings pane at the top, and choose Off.
4. Close and reopen the content on the mobile device. Subtitles are still off.
5. On the TV receiver, now choose German subtitles.
6. Close and reopen the content on the mobile device. German subtitles are automatically displayed (a choice reflected on the mobile, where the subtitles icon is highlighted).
7. On the TV receiver, select Off again.
8. Close and reopen the content on the mobile device. Subtitles are now off.

It remains to be determined whether this is an iOS 13 change, by reproducing the above steps with a tvOS 12 receiver. If this is a change, we can either recognize it as such (after all, it can make sense to have the same accessibility settings we have on iOS saved on tvOS as well). Otherwise we can file a bug report for a regression.

In the meantime, the workaround is of course to use the Apple remote to disable subtitles on the receiver.

[defagos]

We could / should probably document subtitle expected behavior better with proper use cases. This would make it far easier to test this feature for regressions in the future.

In the meantime, I might have spotted two minor issues on our side:

• When using AirPlay, Automatic is disabled on the mobile device but can be tapped anyway.
• With the subtitles window open on mobile, the subtitle choice is not correctly updated when changing subtitles on the TV.

[defagos]

Here is my proposal to solve this issue:

• Study AVPlayerViewController behavior carefully.
• Document use cases.
• If possible and meaningful, try to explain the current behavior in the tracks selection popover

[defagos]

This is a bug on our side. Though the Apple TV receiver saves the last used language as well, it influences the default language on a casting device.

I opened a dedicated issue for SRG Media Player.

[defagos]

Fixed, will be available in version 3.0.0.