whatlastgenre

Improve genre metadata of audio files based on tags from various music sites.

Supported audio files: flac, ogg, mp3, m4a
Supported music sites: Discogs, Last.FM, MusicBrainz, Redacted.ch
Feature Overview
- Gets genre tags for artists and albums from music sites and finds the most eligible ones.
  - Merges similar tags in different writings to ensure consistent naming via aliases and regex
  - Splits tags in various applicable ways
  - Uses a whitelist to avoid bad tags
  - Scores tags while taking personal preferences into account
- Caches all data received from music sites to speedup reruns
- Uses MusicBrainz IDs for searching when available
- Optional: gets release info from redacted (with interactivity if ambiguous)
- Can be used as plugin in other software, currently: beets
- Dry-mode for safe testing
Example output

How it works

It scans through directories for albums and receives genre tags for them and their artists from selected music sites. Equal tags in different writings will be split and/or merged to ensure consistent names and proper scoring. Artist and album tags get handled separately and then merged using configurable score modifiers. The best scored tags will be saved as genre metadata in the corresponding album tracks. All data received from music sites gets cached so that rerunning the script will be super fast. There are several score multipliers to adjust the scoring to your needs and take your personal preferences into account. Please take a look at "Configuration options explained" below for more details.

Tag scoring with counts/weights

lastfm, mbrainz, redacted artist

If counts are supplied for the tags they will get scored by count/topcount, where topcount is the highest count of all tags from a source. So the top tag gets a score of 1.0, a tag having only half of the top tag's count gets a score of 0.5 and so on.

Tag scoring without counts/weights

 discogs, redacted album

Tags supplied without a count will be scored max(1/3, 0.85^(n-1)), where n is the total number of tags supplied by this source. The more tags the lower the score for each tag will be. So if only one tag is supplied, it will get a score of 1.0, two tags will get a score of 0.85 each and so on. The minimum score is 1/3, which applies if there are more than 7 tags supplied.

Tag merging of artist and album tags

After all tags have been gathered the scores of album and artist tags will be scaled and then merged together taking the artist score modifier option into account. This enables that multiple albums from one artist get more equal tags by giving tags found by artist searches advantage over tags found by album searches. See artist score option below.

Tag scoring for various artist albums without any specific album artist

If there is no specific album artist for a various artist album every track artist can get used for searching. Tags for artists that appear multiple times in that album get counted multiple times. See various score option below.

Multiple value metadata and old ID3 versions

Mutagen's ID3 API is primary targeted at id3v2.4, so by default any id3 tags will be upgraded to 2.4 and saving a file will make it 2.4 as well. See mutagen doc for details. However, if you don't want to use v2.4 tags you can use the id3v23sep config option explained below.

Release info tagging and interactivity

releasetype, year, label, catalog, edition, media

Releaseinfo can be tagged for snatched torrents (make sure to enable 'Snatched torrents indicator' in your redacted profile settings). Although prefiltering tries to minimize needed user input, some might be required in ambiguous cases while tagging releaseinfo. -r implies interactivity, -n disables interactivity. Be aware that -r saves the original release year into the date metadata field.

Installation

You'll need Python. It should work with 2.7 and 3.x.

Install the dependencies with your package manager, on Debian based distros run this as root:

apt-get install python-mutagen python-requests

Alternatively, install the dependencies using python-pip: pip install mutagen requests
Clone the repository or download and unzip the source package
Run it without install by using ./whatlastgenre from the directory you cloned/extracted to
Install it by running python setup.py install as root in that directory

Optional dependencies

configparser is required for py27.
rauth is required for Discogs. If you want to use Discogs, install rauth with pip like above and activate discogs in the config file (see below).
requests-cache can additionally cache the raw queries from requests if installed. This is mainly a developers feature.

Configuration

A configuration file with default values will be created at ~/.whatlastgenre/config on first run.

Example configuration file

[wlg]
sources = discogs, lastfm, redacted
whitelist =
tagsfile =
id3v23sep =
[genres]
love = trip-rock
hate = alternative, electronic, indie, pop, rock
[scores]
artist = 1.33
various = 0.66
splitup = 0.33
minimum = 0.10
src_discogs = 1.00
src_lastfm = 0.66
src_mbrainz = 0.66
src_redacted = 1.50
[discogs]
token =
secret =
[redacted]
username =
password =
session =

Configuration options explained

whatlastgenre (wlg) section

sources option

Source	Artist	Album	Auth	...
discogs	0	1	1	fixed list of genres and styles
lastfm	1	1	0	many personal tags from users
mbrainz	1	1	0	home of mbids (overstrained)
redacted	1	1	1	well-kept tags from community

whitelist/tagsfile option

Path to your custom whitelist and tagsfile. Use shipped whitelist/tagsfile if empty (default). Instead of setting the path here, you can also put the files in your config directory and they should get recognized (see debug log).

id3v23sep option

By (mutagen) default all id3 v2.3 tags will be upgraded to v2.4. Since v2.3 can't store multiple value metadata you need to set a separator if you intend to use old v2.3 tags (not recommended). Setting this to a non-empty value (for example ,) will downgrade all id3 tags to v2.3 and store all genres in one tag separated by id3v23sep instead of using v2.4 tags that can have multiple values. Empty by default. You should upgrade your other software to support id3v24 instead of using this.

genres section

love and hate options

List of tags that get a multiplier bonus of 2.0 and 0.5 respectively. Should be considered as "soft white-/blacklist" where you can in-/decrease the occurrence of specific tags that you don't like or that are too inaccurate for you without fully banning them.

scores section

artist option

Score multiplier to give tags found by albumartist searches advantage over tags from album searches. The tags get stored separately at first but then put together while taking this multiplier into account. This enables that multiple albums from one artist get more equal tags.

<artist tags> * <artist score> + <album tags>

Default 1.33

= 0.0 disable artist queries
< 1.0 prefer album tags
= 1.0 handle them equally
> 1.0 prefer artist tags

various option

Score multiplier similar to the artist option, but this one applies to various artists releases if there is no albumartist and all the track artists get used for searching. This will make queries for va-albums without an albumartist take significantly longer, but yields more results. For example: a 5 track va-album with 3 tracks from artist A and 2 tracks from artist B will get tags like this:

(3 * <artist A tags> + 2 * <artist B tags>) * <various score> + <album tags>

Default 0.66

= 0.0 disable various artist queries
< 1.0 prefer album tags
= 1.0 handle them equally
> 1.0 prefer various artist tags

splitup option

Score multiplier for modifying the score of a tag that got split up by space. This enables you to decide whether to keep, lessen or ignore the 'base' tags.

Default 0.33

= 0.0 forget about the base tags
< 1.0 reduce score of base tags
= 1.0 leave score unmodified

minimum option

Minimum score for final filtering.

Default 0.10

= 0.0 no minimum score
= 1.0 same effect as --tag-limit 1

src_* options

Every source has its own score multiplier, so music sites that generally provide higher quality tags can be given advantage over sources that often provide bad, inaccurate or personal tags. Increase if you trust the tags from a source, lower if the source provides many inaccurate or personal tags. If you don't want tags from a specific source remove it from the sources list option.

Default 1.0, see sources option above.

dataprovider related sections

discogs token and secret options

Authentication information for discogs, will be set interactively.

redacted username, password and session options

You can optionally store your username and/or password here. If you don't store them, you will be asked interactively every time the automatically stored session cookie expired (or does not exist yet).

Usage

usage: whatlastgenre [-h] [-v] [-n] [-u] [-l N] [-r] [-d] path [path ...]

positional arguments:
  path                 path(s) to scan for albums

optional arguments:
  -h, --help           show this help message and exit
  -v, --verbose        verbose output (-vv for debug) (default: 0)
  -n, --dry            don't save metadata (default: False)
  -u, --update-cache   force cache update (default: False)
  -l N, --tag-limit N  max. number of genre tags (default: 4)
  -r, --release        get release info from redacted (default: False)
  -d, --difflib        enable difflib matching (slow) (default: False)

If you want to tag releasetypes -r, you should do a dry-run beforehand to fill the cache and then be able to choose the right results without much waiting time in between.

Remove the cache file to reset the cache or use -u to force cache updates.

whatlastgenre doesn't correct any other tags. If your music files are badly or not tagged it won't work well at all.

Examples

Do a verbose dry-run on your albums in /media/music changing nothing:

whatlastgenre -vn /media/music

Tag up to 3 genre tags for all albums in /media/music and /home/user/music:

whatlastgenre -l 3 /media/music /home/user/music

Tag releaseinfo and up to 4 genre tags for all albums in /media/music:

whatlastgenre -r /media/music

Plugins

whatlastgenre can be used in other software via plugins.

At the moment there is a plugin for beets.

See README files in the plugin directory for details.

Help / Debug

Errors / Bugs / Crashes

If you encounter any strange errors (especially after updating to a later version), please delete the cache file and try again with an empty cache before reporting it (do a backup first in case it doesn't solve the issue).

Mediaplayers and file modification times

Since file modification times are preserved, some players don't realize the changed genre metadata automatically and might require some manual steps, e.g.:

mpd: needs rescan instead of normal update to get the mpd database updated.

Debug tag handling / Improve tag results

In order to debug tag handling to improve the whitelist and tagsfile, you can do a debug dry run and save the output to a logfile (adjust path):

whatlastgenre -nvv /media/music > /tmp/wlg.log

Then search the logfile for specific lines:

grep ^tag /tmp/wlg.log | sort | uniq -c | sort -r | less

Use the results to add missing whitelist entries, aliases or replaces.

Feel free to share your improvements to the data/*.txt files or send me your logfile so i can use it for debugging myself.

Another way to find possible aliases is using the difflib -d argument.

Please report any bugs and errors, i would like to fix them :)

Thanks to everyone who made suggestions and reported problems <3

murphieslaw23 / whatlastgenre