Release type guessing logic fails on releases with 7-8 tracks

[chaban-mb]

Written with and analyzed by AI

The fnGuessReleaseType function in mbimport.js contains a logical gap for releases containing exactly 7 or 8 tracks.

perhaps_EP checks for <= 6 tracks, while perhaps_album checks for > 8 tracks. As a result, a release with 8 tracks and a duration over 30 minutes sets perhaps_album to false.

Because of this, the condition if (perhaps_album && duration_mn > 30) evaluates to false, and the function returns an empty string "" instead of "album".

Additionally, explicit string tokens in the release title (like "EP" or "Single") should ideally override strict duration rules.

Example release where type detection fails:
https://volumo.com/album/8721466924472-train-dreams-ep

[arsinclair]

We don't have a script to support volumo.com, isn't it?

[chaban-mb]

Not yet. I'm working on something:
https://github.com/chaban-mb/userscripts/blob/volumo-importer/feat/add-volumo-importer/src/Volumo%20MusicBrainz%20Importer.user.js

Based on murdos libraries but with own buttons, lookup and caching. (Actually nothing is cached persistently, just in memory)

Since I couldn't find a public API documentation I had to reverse-engineer and have to deduce exactly how the fields are filled. Most importantly I don't know yet how to best handle the different dates.
Generally it seems quite similar to Beatport except that releases seem to often appear later instead of sooner (Beatport has many releases available in advance)
However Volumo also has exclusives that are not available elsewhere. So it would be a valuable provider.

This release for example is an exclusive and is dated 29 May 2026 but the original date is displayed as 26 June 2026:
https://volumo.com/album/5054289829871-feel-the-beat-ep

See also:
https://community.metabrainz.org/t/stop-importing-wrong-release-dates-from-streaming-sites/814960/18?u=chaban

[arsinclair]

Thank you, yes I initially failed to see the connection between userscripts here and Volumo.

It makes sense, I'll take a look at this bug.

Thank you for sharing the amazing work for the Volumo provider. If you ever decide to integrate your userscripts in this repo, you're most welcome. Just let me or Murdos know.

[arsinclair]

It is extremely hard to come up with a correct decision tree that would accomodate all cases. It seems the LP/EP/Single are very loosely defined and followed, and they're more of a marketing term nowadays than an actual distinctor.

There are releases, which are marketed as albums: however they have 9-10 tracks shorter than 2 minutes each.
There are releases (especially in ambient music) that only have a single track which is over an hour long.
There are singles, which have 8-10 tracks, all remixes of a one particular track.

And the list goes on.

I'm not sure we can build something robust here. I'm looking into the algorithm to see if existing gaps can be closed though.

Additionally, explicit string tokens in the release title (like "EP" or "Single") should ideally override strict duration rules.

I agree.

[arsinclair]

@chaban-mb can you take a look at the changes in #953 and let me know what you think.