transcode file format changed from ts to mp4

[blue212121]

hello, i just updated jellyfin from version 10.8.11 to 10.9.11 and this fixed an issue for me where when i wanted to play hevc encoded video from jellyfin-web from my phone (pixel 7a), it displayed the "this client isnt compatible with the media...." error message... now the update did fix this issue, but somewhere along the lines the transcoded video file extension and format changed from .ts to .mp4

i tried to look at the release history but could not pinpoint when this change occured between the two versions, and also dont know if there is any way to change it back?

[TheDreadPirate]

This setting has always been present, but it was disabled by default in 10.8. It is enabled by default in 10.9

On the CLIENT, click on your profile icon and click "Playback". There is a setting called "Prefer fMP4" that should be enabled right now.

Also, any particular reason you WANT ts over mp4?

[blue212121]

right, i tried unsetting this flag, but when watching from my phone it would still remux/transcode to mp4... when i got home yesterday i tried from a pc with a i5-6500t, turns out, jellyfin will transcode to ts when watching from this device hevc->h.264, aac lc->aac lc (i dont know why, but it says in the logs or the playback info that the audio was not compatible, yet it converts to the same format the file already has?)

the reason behind wanting ts over mp4 is (and this very well could be outdated/incorrect information) when i was working as a movie theater projectionist, when we got movies with mp4 format, a lot of them had compression artifacts in them, which ruined the watching experience
using .ts or .m2ts file format, there were no artifacts present, yet the file size could still be the same (so compression was still in use), since then i am trying to stay away from mp4 as much as possible, but again since then it could be that mp4 no longer produces compression artifacts, as this was ~10 years ago or so

[gnattu]

mpegts and mp4 are just containers and will not affect the video quality, the actual codec used inside the container will. For HLS, fmp4 is actually a superior choice because it enables the use of advanced codecs like hevc and av1 which will improve perceptual quality at the same bitrate.

[blue212121]

right so the file formats themselves basically just carry the data, and no matter what that container is, the codecs used could be at fault... unfortunately back then i didnt even know what ffmpeg or ffprobe is, but now i wish i could go back and compare the codecs used for those files thanks for the help guys, i think i will stick with whatever jellyfin decides to use, and not try to change it, since my original problem was solved with the update

[TheDreadPirate]

Regarding your question about AAC to AAC transcoding, it is possible that the channel count was the issue. It may have downmixed 7.1, or whatever it was, to stereo.