Roku setup

[kushakhan]

Hi all, I set up the stick and have it connected to my local plex server. When I play videos that are mp4, for some reason on the playback info on the stick it says mkv as well as saying partial transcode (throttled) which I'm assuming is the issue I'm seeing where the movie is stuttering/buffering. When I play the same video from my galaxy s10 phone for example on the mobile plex app, it shows mp4 properly and plays relatively smoothly. On the plex media server itself, I can see the mobile app showing as Direct Play for both audio and video while from the Roku stick it shows Direct Stream and Audio transcode. The movie itself is HVEC Main 10 and the audio is AAC 5.1. Is all this just telling me that Roku stick doesn't natively support those codecs and thats why its transcoding?

[Emissary35]

I set up my Streaming Stick 4K with everything on direct play in the Plex app settings and everything plays fine. Works for mp4 and mkv and h264 and h65 codec with no buffering or stuttering. Get it off the transcoding setting if you don't need it because it ruins the playback experience.

[renojim]

AAC 5.1 is not supported on (some/many/all?) Roku devices, so it's transcoding and packaging it in MKV.  Whether you can force it to direct play will depend on all the equipment involved.

You can read this for some not so helpful information on supported codecs:
https://support.roku.com/article/208754908