Picard Last.fm.ng Plugin

About

Picard Last.fm.ng is not exactly a rewrite of the other popular last.fm plugins for MusicBrainz Picard. It was developed as an alternative and with slightly different design goals.

Initial motivation was more flexible configuration and more predictable outcomes. It also used the Last.fm API v2.0 from the start.

It might work for you as a drop-in replacement and a lot is possible with simple configuration changes, but there are as many naming and tagging schemes as there are music lovers.

Thanks go out to contributors of the original and plus last.fm plugins! They were invaluable as a starting point.

Features

• Last.fm API v2.0 support
• uses both Picard API calls for per-album and per-track last.fm-tags
• special "albumgrouping" and "albumgenre" variables for consistent per-album tagging and naming
• comprehensive, ini-file based configuration
• save tags as multiple tags or combined to a string
• ignore featured artists when looking up last.fm-tags

Please see the "How it works" section for a better understanding on what the plugin does.

FAQ

It's ok to ask questions using github issues, but please check if your question was already answered before. They are usually labeled with "faq":

https://github.com/fdemmer/Picard-Last.fm.ng-Plugin/issues?utf8=%E2%9C%93&q=is%3Aissue+label%3Afaq+

Install

1. Download the latest release from the github releases page.

2. Extract the "lastfmng" directory in the archive to your user's plugin directory.

   To find it use the "Open plugin folder" button in the "Plugins" section of Picard's "Options" dialog:

   Depending on your setup it could be:

   • Windows: %APPDATA%\MusicBrainz\Picard\plugins
   • Linux/MacOS: ~/.config/MusicBrainz/Picard/plugins

3. Start or restart Picard to load the plugin and enable it in the "Plugins" section of Picard's "Options" dialog.

---

NOTE

Do not just put all the files contained inside the "lastfmng" directory there, put the whole directory there!

e.g.: ~/.config/MusicBrainz/Picard/plugins/lastfmng/...

---

Updating

It is recommended to back up your config.ini and delete the existing "lastfmng" directory before extracting a new version to the "plugins" directory.

Then copy the configuration file back in place.

Sorry for the inconvenience.

Configuration

The plugin does not provide a configuration dialog, but is easy to configure using ini-files.

The provided defaults.ini contains all available settings.

To customize settings create a new empty file called config.ini with only the settings you want to change. There is no need to copy the defaults! If a config.ini file is found, it will be loaded after defaults.ini overwriting the default settings with yours.

Make sure you save the files in UTF-8 encoding!

Naming rules

This plugin is supposed to be used with the following naming rules:

$rreplace(%subdirectory%/$if2(%albumgrouping%,Unknown)/$if2(%albumartist%,%artist%) - $if($if2(%originalyear%,%originaldate%,%date%),$left($if2(%originalyear%,%originaldate%,%date%),4),0000) - $replace(%album%,...,…)/$replace(%album%,...,…) - $if($ne(1,%totaldiscs%),%discnumber%,)$num(%tracknumber%,2) - %artist% - %title%,[*|:"<>?],~)

It builds a basic directory structure using the %subdirectory% and %albumgrouping% variables. The %albumgrouping% is configured to only one last.fm-tag by default and guaranteed to be consistent per album.

Set this script, to generate the %subdirectory%:

$set(subdirectory,Archive Albums)
$if($in(%releasetype%,soundtrack),
    $set(subdirectory,Archive Soundtracks)
    $set(genre,Soundtrack)
)
$if($in(%releasetype%,compilation),
    $if($eq(%albumartist%,Various Artists),
        $set(subdirectory,Archive Compilations))
)

It puts all albums, that look like soundtracks or compilations in a different top-level directory, than "normal" albums. Also, it adds a tag called "Soundtrack" to the "genre" metatag of all tracks that are soundtracks.

Last.fm API

The plugin should work out of the box with the shipped API key.

However, please use your own Last.fm API key and set it using lastfm_key. You don't need to change lastfm_host or lastfm_port, but by setting lastfm_port to 443 https will be used.

If you want you can put the Last.fm related settings in an extra file called lastfm.ini.

How it works

The basic concept is this:

1. Download last.fm-tags for the album, the artist of the album (if there is one) or each artist of each track and each track. A "last.fm-tag" is just words users have assigned; it can be anything like "my favourite", "heard last night", "sucks" or terms we are more interested in like "classic", "80s" or "death metal".
2. This step filters and separate all the last.fm-tags into categories (like "grouping", "genre", "mood", "country", ...)
3. Then sort the last.fm-tag by popularity in each category. Last.fm provides a numeric popularity score for each tag.
4. Assign the most popular last.fm-tag in each category to a variable, that can be used in a script, naming rule or by Picard directly to assign to a metatag of a file (e.g. the "genre" id3 tag).

Step 1

Last.fm provides "tags" for artists, albums and tracks.

This plugin is triggered via two Picard plugin API calls:

• register_track_metadata_processor
• register_album_metadata_processor

So the collection of last.fm-tags also happens in two steps: once for the album and for each track.

• In the per-track call for each track the last.fm-tags for the track's artist and the track itself is fetched from last.fm.

• In the per-album call the last.fm-tags for album title is fetched. To cover both compilations and single artist albums, all artists appearing on any track of the album are looked up. In addition, all last.fm-tags of the tracks are considered again.

  In other words: the tags of each track count towards the tagging of the album.

Data fetched from last.fm is cached to avoid redundant API requests.

Step 2

The plugin uses a fixed list of categories, think of them as buckets where last.fm-tags are put into by "topic":

• grouping
• genre
• mood
• occasion
• category
• country
• city
• decade
• year

Searchlists

For the categories grouping, genre, mood, occasion, category, country and city so called searchlists are used to find valid terms in the downloaded "tags".

Customize the lists in the [searchlist] section of the config file to add or remove valid terms.

Translations of common tag variations are set in the [translations] section. The first value is replaced with the second one.

Make sure you add your translation to the searchlist or it will not be used!

Category configuration

For each category there is a section in the config file.

To disable using a specific category set enabled to False. You will not get any data for that category/metatag then.

If you set the limit to 1 and two "tags" have exactly the same popularity the result will be exactly one, which one however is not clearly defined! There is room for improvement here.

Setting sort to True will sort the "tags" alphabetically after the ones with the highest popularity have been determined. Set this to False to keep the one with the highest popularity in front (from left to right)!

Using titlecase you can switch fixing the case of last.fm-tags off and on. The separator is used to combine more than one toptag into a metatag string and in case not a single toptag was found for a category the value of default_unknown is set.

Step 3

Popularity of a last.fm-tag is based on the score received from last.fm. A higher score indicates a more popular tag. We do not get absolute numbers.

Also, since last.fm tagging is crowd-sourced the quality varies greatly. It is also possible that different artists share the same name, so you might get tags that were actually meant for someone else under that name.

People could have also completely different opinions about genres and simply tag music "wrong".

Nevertheless the plugin works with what it gets.

last.fm-tag score processing

Weight parameters are the multipliers applied to the last.fm-tag's score.

• For per-track tagging the plugin puts an emphasis on variation and detail. The assumption is, that the last.fm-tags put by users on the track are describing the song better, than the tags put on the artist of the track.

  • last.fm-tags of the track itself 80%
  • last.fm-tags of a track's artist are weighed by only 20%

• For per-album tagging the plugin aims for consistency over the artist's body of work.

  • last.fm-tags from all artists on the album are 55%
  • last.fm-tags from all tracks on the album are 30%
  • last.fm-tags of the album itself are weighed only 15%

  Main reason for the low album weight is to get consistency, to be able to use the per-album tagging comfortably in a directory/naming schema -- to keep all albums of an artists grouped together.

  Another anecdotal reasoning for low weight of the album:

  New releases are often tagged very little and more "wrong", than later when more people have tagged the album and the opinions are "evened out". By reducing the weight of the album tag scores, that "wrongfulness" is reduced and covered up by the usually more established, reliable artist tags.

  Note about "all artists on the album":

  When an album features 10 tracks, of which 9 are from the same artist and there is a single guest on the record, the guest artist's score does of course not count the same as the guy singing on 9 tracks!

  In this example the artist tags are already multiplied by 9 for the one guy and ony 1 for the other before going into the weighing process.

  For example: Just because "Disorder" on Slayer's "Soundtrack of the Apocalypse" is featuring Ice-T, you won't get any "hip-hop" in the albumgenre.

  If you know a better example for an "album with unusual guest star" let me know ;)

The weight parameters are not exposed in the configuration files. If you really want to play with those, see settings.py.

Step 4

Finally, the sorted and weighed last.fm-tags are ranked by resulting score in their category-buckets and limited to only the top results(s) (see limit parameter in config.ini).

The result of each category is then put into a variable Picard can use. (see metatag-album and metatag-track in config.ini)

You can change the variable names in the configuration file, but keep in mind, that Picard maps certain variable names to metatags it writes to files:

https://picard.musicbrainz.org/docs/tags/

The metatag_album parameter in config.ini is only available for the categories grouping, genre and mood and is used for the result of the per-album tagging.

Differences to Last.fm.Plus

When using translations, the score of both last.fm-tags are summarized, rather "the greater wins, the lesser is dropped".

Years and decades use a regular expression to find valid values. With decades, both "00s" and "2000s" are valid. This can be easily customized using the LFM_DECADE and LFM_YEAR variables.

There is no "inter tag drop". The "minimum weight" is hardcoded to 1. So last.fm-tags with score 0 are ignored. Usually they would not appear in any of the search lists anyway.

The "year" metatag is disabled for now.

Last.fm.Plus only uses the per-track trigger.

Disclaimer

Even though this code has been in use by many people for years things can go wrong. If they do, please open an issue and maybe we can fix it.

Motivational bitcoin welcome: bc1qe0hs8h7wv200la0tdymlj3rgh0yqe040p2v4c6