Question about CD album thumbnail behaviour

I keep my music in a Music// folder structure and I have CD album thumbnails enabled. Each album folder contains a Folder.jpg file and I know I can force the CD thumbnail using a coverart.jpg file but I haven't done so yet. Most of the folders contain enough music files to trigger the CD thumbnail automatically, but I'm curious about the exact logic controlling the display.


  • One folder contains a single MP3, a Folder.jpg and a hidden AlbumArtSmall.jpg generated by Windows, and understandably shows as a standard folder.
  • Another folder contains two MP3s, a folder.jpg and a hidden AlbumArtSmall.jpg, and shows as a CD
  • Another folder contains two MP3s, a folder.jpg and three hidden .jpgs (AlbumArtSmall and two AlbumArt_{xxxx}_Large|Small.jpg files). This folder shows as a standard folder

Does the folder just have to have more music files than other files before it shows as a CD? Are hidden non-music files counted? Are Windows' hidden thumbnail files counted?

I’m not sure the exact rules are defined to that level of detail. Just copy folder.jpg to coverart.jpg if it doesn’t work automatically.

Note that in the Opus 13 beta these rules are configurable, but the defaults are:

  • One of the specific files (coverart.jpg, coverart.png or cover.jpg) is present, or
  • Shell folder type set to "Music", or
  • At least 2 out of the first 5 files in the folder must be in the Music filetype group (ignoring .bin, .cue and .log files)

Opus 12 was probably similar as the Opus 13 defaults were based on its hard-coded behaviour.

Ah, that's a useful one. Thanks.