4K Remuxing in WebOS

[BionicLlama]

   
When watching certain 4K movies on my LG TV (UA7000), it doesn't transcode, it remuxes. Apparently, while the video and audio streams are compatible, the container isn't... but so far it only seems to be movies showing 4K HEVC Dolby Vision Profile 8.1 (HDR10), while 4K HEVC HDR movies don't seem to have this problem. I may have a a misunderstanding about how things like this are done, but these are movies that are ripped and transcoded to x265 for storage the same way. I don't understand how MKV can be an incompatible container format.

I also have a sneaking suspicion that this remuxing occasionally causes issues with audio sync because the audio tends to be a little delayed and needs a little twitch of the delay slider to reset it, and it's only been on these Dolby Vision-labeled 4Ks.

[Cyril Pasquier]

Yep same issue here on my G26LA on webOS 25 even with DoVi 7.6. My server runs on windows, version 10.11.4.
I tried with plex and evrything works just fine, direct play DoVi and no problem with the subtitles unlike my jellyfin server. So to me it sounds like a problem with the Jellyfin webOS app.

[raulo1985]

When watching certain 4K movies on my LG TV (UA7000), it doesn't transcode, it remuxes. Apparently, while the video and audio streams are compatible, the container isn't... but so far it only seems to be movies showing 4K HEVC Dolby Vision Profile 8.1 (HDR10), while 4K HEVC HDR movies don't seem to have this problem. I may have a a misunderstanding about how things like this are done, but these are movies that are ripped and transcoded to x265 for storage the same way. I don't understand how MKV can be an incompatible container format.

I also have a sneaking suspicion that this remuxing occasionally causes issues with audio sync because the audio tends to be a little delayed and needs a little twitch of the delay slider to reset it, and it's only been on these Dolby Vision-labeled 4Ks.

Some clients have limited support when using MKV container, some of them can't handle it (I'm quite positive the WebOS client is one of them). But since the codecs are compatible, JF remuxes the file to MP4 instead of transcoding (sometimes introducing some delay or sync issues). So, until MKV support is improved on the client side, I always remux my movies to MP4 using FFMPEG to avoid issues (my entire library doesn't have a single MKV file).