FireTV Stick Fails Playback when Transcoding Video if Subtitles are Enabled

[boimouseorange]

Describe the bug

Hi There,

I am wondering if anything is in the works for this issue. If I am running the Jellyfin App on my FireTV Stick 4k Max, I find that getting a video to transocde works just fine (which is exactly what I want), the problem is when I enable subtitles. The video will fail to playback if subtitles are enabled. Additionally, if I watch a video with subtitles enabled without transcoding, then everything is fine. Then if I force the video to transcode, the subtitles are automatically disabled and the video is played fine until I try to reenable the subtitles (which then the playback fails again).

I checked if this was the case on my computer within Brave Browser and it was totally okay to play subtitles while transcoding a video (this leads me to believe it may have something to do with how the FireTV Jellyfin app handles subtitles.

P.S. The raw (embedded) subtitle files I have been testing with are simple subrip files (.srt).

Android TV App Version: 0.18.2
Jellyfin Server Version: 10.10.3

Logs

No response

Application version

0.18.2

Where did you install the app from?

Amazon Appstore

Device information

Amazon Firestick 4K

Android version

Fire OS

Jellyfin server version

10.10.3

[boimouseorange]

Okay, so I did some more digging and troubleshooting with some ideas I got from the Jellyfin forums. I am now confident that it is a problem with the subtitle parser. I say that because I attempted to play a video that had no subtitles embedded in it but the subs were in the same directory so that Jellyfin could still use them. That played just fine with subtitles while transcoding. Though, the second I re-embedded those subs, the playback failed.

I have all my media in .m4v files in order to ensure compatibility for all my devices but I never tested this with other file formats to see if that was another problem.

UPDATE: I tested this with an MKV file and the subtitle parsing worked perfectly while transcoding. It seems that Jellyfin on AndroidTV doesn't like .m4v files because of the way that subtitles or remuxed into the file. This is especially frustrating because all of my media is in .m4v format to ensure compatibility for all my devices.