If you already have a library mixed with x264 and x265, Sonarr struggles to "upgrade" them because it sees both as 1080p. To force upgrades:
Set the to 0 (this ensures Sonarr will still grab x264 files if no x265 version exists). Click Save . Advanced Tweaks: Avoiding Low-Quality Scrapes
: Not all devices support x265 natively, which might affect playback on certain devices. Ensure your playback devices support x265 or consider transcoding options. sonarr prefer x265
Sonarr doesn't know if an x265 file was made by a skilled encoder or a script-kitty who nuked the quality to save 50MB. Low-quality x265 releases are notorious for introducing "banding" in skies and "blocking" in dark scenes. x264, being older, has more standardized, high-quality release groups.
Some release groups don't include "x265" in the filename. Sonarr may incorrectly tag these as "HDTV" or standard quality, causing it to ignore them. If you already have a library mixed with
Most modern streaming devices (Apple TV 4K, Nvidia Shield, Roku Streaming Stick+, and modern Smart TVs) natively decode x265. If your clients support it, your media server will use almost zero CPU to play the file.
While x264 is excellent for 1080p, it is highly inefficient for 4K UHD content. The x265 codec was built from the ground up to handle high resolutions, 10-bit color depth, and High Dynamic Range (HDR) metadata seamlessly. The Catch: Hardware Compatibility and Transcoding Advanced Tweaks: Avoiding Low-Quality Scrapes : Not all
Paste the following Regular Expression (RegEx) into the text box: \b([hx].?265|hevc)\b Use code with caution. Click . Step 2: Update Your Quality Profiles Navigate to Settings > Profiles .
This ensures we are targeting standard encoding formats, not strictly 4K (which is naturally HEVC but handled differently).