You can find more details about and discuss this release on the official forums.
As always, please ensure you stop your Jellyfin server and take a full backup of your metadata/configs before upgrading!
Jellyfin Server 12.2
📈 General Changes
Replace custom item display preferences in one transaction [PR #18266], by @martimarkov
Use hvc1 for Dolby Vision profile 8 [PR #18300], by @theopeuchlestrade
Make the OwnerId and ExtraType/OwnerId indexes partial so extras lookups keep using them [PR #18276], by @Shadowghost
Enhance internal search provider for multiple scripts [PR #18223], by @excelsior-dev
Dispose the database context in DeleteTrickplayDataAsync [PR #18269], by @martimarkov
Fix orphan ItemValues cleanup after deletion [PR #17892], by @nintwentydo
Fix off-by-one in the optimistic locking retry backoff [PR #18268], by @martimarkov
Upgrade ATL to 7.18.0 to fix malformed FLAC hangs [PR #18224], by @ScottishTapWater
Fix EPUB metadata and covers not loading on Windows [PR #18283], by @chino
Refuse to start a set-up server whose database is missing or empty [PR #18264], by @martimarkov
Compare local image dates with a one second tolerance [PR #18278], by @Shadowghost
Only propagate a changed rating to children that follow it [PR #18280], by @Shadowghost
Recognize numbered sample and trailer files as extras [PR #18255], by @HaraldNordgren
Recompute the parental rating score whenever an item is saved [PR #18279], by @Shadowghost
Compare person names without regard to case in the letter range filters [PR #18265], by @martimarkov
Fix video quality at low bitrates when reducing bit depth [PR #18261], by @nyanmisaka
Update episode season name after editing the season name [PR #18253], by @theguymadmax
Fix segment cleaner deleting segments ahead of playback when remuxing MKV [PR #18186], by @klizas
Fix user preferences when renaming libraries [PR #18236], by @z0rimo
Fix item display preferences item [PR #18259], by @martimarkov
Use XmlReader in encoder preset migration tests [PR #18237], by @maghuro
Don't advance rewatch Next Up past a barely started episode [PR #18202], by @Shadowghost
Keep an item's user data rows in agreement [PR #18001], by @Shadowghost
Stop rebuilding the inherited-tag set per row, and count only the people /Persons can return [PR #18093], by @Shadowghost
Never treat unresolvable libraries as grounds for deletion [PR #18102], by @Shadowghost
Don't let a failed shutdown cancel an in-process restart [PR #18063], by @Shadowghost
Match artist creation lookups using CleanName [PR #18005], by @orut34iop
Serve graphical subtitles as raw files with range support [PR #18168], by @Shadowghost
Use MusicBrainz artist name first [PR #18192], by @juxuanu
Skip statistics on an empty library and refresh them after every scan [PR #18196], by @Shadowghost
Check media directory write permission before generating trickplays [PR #18161], by @thedreaddpirate
Reconcile missing episodes by episode, not by number [PR #18090], by @Shadowghost
Apply stereo downmix filter consistently to progressive audio transcodes [PR #18195], by @Shadowghost
Fix transcoding settings migration failure caused by null EncoderPreset [PR #18059], by @scr4bble
Fix more rating systems [PR #18057], by @Shadowghost
Fix ChangeOwnerIdToGuid migration performance [PR #18073], by @Shadowghost
Retry MusicBrainz requests when the server is busy [PR #18095], by @Shadowghost
Fix playlist views [PR #18104], by @Shadowghost
Scope the music library cover image to that library's artists [PR #18148], by @Shadowghost
Read the image region when determining TMDb image language in TmdbUtils [PR #18150], by @mateusbandeiraa
Ignore Sample subfolders when resolving movie folders [PR #17964], by @panko
Don't apply the allowed tags filter to by-name items [PR #18138], by @Shadowghost
Only regenerate extra names that were generated by the scan [PR #18139], by @Shadowghost
Skip optimistic expressions when parsing series names [PR #18061], by @panko
Decode HTML entities in OMDb responses [PR #18096], by @Shadowghost
Fix the item type name of BaseItemKind.Channel [PR #18132], by @martimarkov
Log chapter image extraction once per video [PR #18107], by @Jellyfrog
update tw.json (rating) [PR #18134], by @allexjuang
Fix typo when parsing codec_tag_string [PR #18164], by @nyanmisaka
Fix test concurrency [PR #18058], by @Shadowghost
Fix formatting issue in PlayCommandQueueTests [PR #18079], by @theguymadmax
Jellyfin Web 12.2
🔒 Security
Fix track titles and external urls not being escaped [PR #8533], by @thornbill
🌟 Highlights
Disable the still watching prompt by default [PR #8592], by @thornbill
🏗️ Enhancements
Update the mixed library icon [PR #8591], by @thornbill
Remove 40 char search restriction [PR #8412], by @enter-a-random-username
Move reset filters button and add alphabet support [PR #8568], by @thornbill
Exposes subtitle save path setting regardless if fetcher is installed [PR #8521], by @thedreaddpirate
Fix blurhash to image transition [PR #8526], by @heyhippari
📈 General Changes
Fix backdrop removal race condition [PR #8573], by @thornbill
Hide playlist move options from users without edit access [PR #8570], by @gokulbits
Fix embedded VobSub subtitles not rendering [PR #8564], by @moontwister
Fix live tv program badges being hidden on details page [PR #8553], by @thornbill
Fix navigation with multiple gamepads [PR #8522], by @dmitrylyzo
Fix metadata manager using mixed themes [PR #8550], by @thornbill
Drop OPUS in MP4, TS and HLS-TS on Tizen [PR #8519], by @dmitrylyzo
Fix Samsung Browser detection [PR #8493], by @MBR-0001
Fix photos autoplaying [PR #8487], by @theguymadmax
Clear query cache on user language change [PR #8494], by @thornbill
