Issues with Additional Audio Tracks in Subler Not Showing on Apple TV

[david-vh-developer]

Hi, everyone!

I’m working on enhancing movie files by adding second (and sometimes third) audio language tracks, but I’m running into an issue with Apple TV playback and how Subler handles the audio tracks.

What I'm Doing:

• I’m adding audio files (".ac3" or ".eac3") directly into Subler’s main window.
• The muxed files play fine on Apple TV, and audio is synced — no issues there.

Problems I'm Encountering:

1. Apple TV Doesn’t Show Added Audio Tracks During Playback

• On Apple TV, I can’t switch audio tracks during playback — only the original track appears in the language list.
• The added tracks do work, but to access them I have to go into Settings > Language and change the default track manually.
• However, when I drag a movie file that already includes the additional audio track into Subler, everything works as expected — all tracks are selectable during playback.
• This suggests that how the track is added in Subler affects visibility in tvOS.

2. Audio Format Mislabeling in Subler

• When I add an ".eac3" file (e.g., with 8 channels), Subler labels it as "AC3, 6ch" instead of "E-AC3, 8ch".
• But if I drag a movie file that already has the track embedded, Subler displays the correct format.
• This can be confusing — I’ve confirmed the audio file itself is correct using MediaInfo, so it seems like a display or metadata issue in Subler.

What I’m Looking For:

• Has anyone else experienced this behavior with Apple TV and Subler?
• Is there a better or more consistent way to add audio tracks to ensure full compatibility with Apple TV's in-player language selector?
• Are there any tools or workflows you’d recommend for handling this more reliably?

Thanks in advance for any insight or tips!

[david-vh-developer]

After a lot of trial and error, I found a clunky workaround.

I open the video file in MKVToolNix and add the audio track there. Then, I run the file through Subler to create a version that works on Apple TV.

The good news is that I can choose the audio track while watching on Apple TV.

Still, it would be great if Subler alone could handle the whole process.

[galad87]

Hard to say without having the new file to diff.

[david-vh-developer]

Thank you for the response!

Happy to share whatever would be helpful. Would it make sense to provide:

• The original file (before adding the audio)?
• The version after adding the track manually in Subler (where the issue appears)?
• The working version created with the MKVToolNix + Subler workaround?
• MediaInfo reports for each?

Let me know what you'd like to see or compare, and in what format — I’m happy to put together a test set.

[david-vh-developer]

Is Subler capable of modifying a language file's metadata so that the Apple TV Computer app can detect extra language tracks and enable switching between them during playback?

[galad87]

Check how the alternate groups are set, all the audio tracks should be in one, and all the subtitles tracks in another one. Check the media characteristics tags too.

Yes you can change the tracks language.

[david-vh-developer]

Restating the issue I'm running into:

• On Apple TV, I’m unable to switch audio tracks during playback — only the original track shows up in the language list.
• The additional audio tracks do work, but to access them, I have to go into Settings > Language and manually change the default audio language.

I’ve tried your suggestions, and so far none have worked.

To help replicate the issue, I’ve created six 2-minute audio/video samples:

https://pixeldrain.com/u/kWZjVWmX

Here’s what’s included:

1. The original movie clip and its second audio channel.
2. Re-encoded versions of the original audio track using FFmpeg (.ac3 and .eac3).
3. Two muxes made with Subler — one using the .ac3 file, the other with the .eac3 file.

It seems like there’s some missing or incorrect metadata (possibly atom-level) in the original and re-encoded .ac3 audio files.

Ideally, I’d love to fix this directly within Subler, instead of extracting, re-encoding, and re-muxing the second audio track for all ~200 of my movies. That would save a ton of time!

[galad87]

The two files have the track set to a different languages, tries to match the track metadata first.

[david-vh-developer]

Yes, the file "3. Not Working ac3.mp4" had its Spanish audio track incorrectly labelled as English. Even after correcting it to the proper language, the option still doesn't appear as selectable during playback.

[galad87]

What version of macOS are you using?

[david-vh-developer]

Good morning,

I am currently using Sequoia version 15.4.1. I recently upgraded to a new Mac, but this issue also occurred on Monterey 12.76.

After further testing, I believe the problem may be related to the Computer app on Apple TV.

Here is another download file:

https://pixeldrain.com/u/S5a7wK7M

It contains two English audio tracks: the first is E-AC3, and the second is AC3. The AC3 audio track is not selectable during playback. However, if you mux the provided E-AC3 English audio file (found in Archive 2) into the movie, it becomes visible and selectable.