Beets Extended Metadata Plugin

This is a plugin for the music management tool beets.
This plugin adds Extended Metadata capabilities to beets. It extends the beets query syntax, allowing you to query songs based on Extended Metadata and also allows you to write, update and view Extended Metadata based on queries.

Setup

Install the plugin

pip beets-extended-metadata

Configure the plugin

Edit your beets configuration file and add the following section:

extendedmetadata:
    query_prefix: 'x'
    input_field: 'comments'

Also add extendedmetadata to the plugins section.

The query_prefix defines a prefix that you need to add to the parts of your queries which should look into Extended Metadata instead of the normal metadata.

The input_field is the name of the audio tag, according to this audio file fields list, that contains your Extended Metadata string. As default, the comments field will be used. Depending on what field you choose some software, including beets, will not be able to handle or persist it. I recommend using the comments field, since most software out there will be able to work with this field and having any other information in this field is usually unnecessary.

Limitations

The query syntax as well as the emd sub-command syntax have some limitations regarding the characters you can use for tag names / tag values.

Tag Name Limitations:
A tag name may only contain letters and numbers (including unicode letters) as well as hyphens, underscores and spaces.

Tag Value Limitations:
A tag value may contain any character except for commas, also it cannot start with a colon. This limitation is necessary because colons and commas are special characters that cannot be escaped in any way without breaking the query/command syntax.

Writing Queries

Assumptions:

• You configured x as the query prefix and comments as the input field.
• Your library contains songs with Extended Metadata strings in the comments field.
• You imported the songs into your beets library after writing the metadata to the files.

Examples

Note: All queries are case-insensitive. If you have a value Abc it will match the query value abc. If you want to query case-sensitive, use regex queries.

Searching for all russian songs

This assumes you have a custom tag language containing the language of the song.

beet list x:language:russian

Here you can see how you can reference a custom tag from your Extended Metadata. You start a query part with your query prefix x, followed by a colon. After that the syntax is the same as with normal beets queries, but it will reference tag names and values from the Extended Metadata instead.

Searching for all songs that use synthesizer v

This assumes you have a custom tag vocal_synth containing the vocal synthesizer used in the song.

beet list x:vocal_synth:"syntheszer v"

You can query for values containing spaces by enclosing them in parentheses or quotes. This is just the way a shell works and is not done by this plugin.

Searching for all songs that are either japanese or chinese

This assumes you have a custom tag language containing the language of the song.

beet list x:language:japanese,chinese

By passing multiple values, separated by commas, you can query files that match one of the provided values

Searching for all rock variant songs

This assumes you have a custom tag genre containing the genre of the song.

beet list x:genre::.+rock

Here you can see how you can use regex to make your queries more flexible. Just like with beets you can specify that your query value is regex by using the double colon :: instead of a single colon.

Searching for all songs in japanese that to not come from japan from the last 3 years

This assumes you have a custom tag language containing the language of the song and a custom tag origin containing the origin country.

beet list x:.language:japanese x:.origin:'!japan' year:2010..2020

In this example you can see how to easily combine Extended Metadata queries with normal audio field queries. It also shows how to negate query values. If you prefix the query tag value with ! it will mean not equals / not contains.

Managing Extended Metadata

The query capabilities work as long as the Extended Metadata has been written to the files according to the Extended Metadata documentation. This means it is not required to use this plugin to write the Extended Metadata to your files.

The plugin provides an emd subcommand to write, update and show Extended Metadata based on beets queries. The sub command requires a beets query that matches the items you want to apply options to, and a list of options that define what you want to do. To get an overview of all options you can use the --help option:

$ beet emd --help
Usage: beet emd <query> [options]

Options:
  -h, --help            show this help message and exit
  -y, --yes             automatically confirms yes/no prompts that require
                        user input
  -u UPDATE_EXPRESSION, --update=UPDATE_EXPRESSION
                        update or move a tag value. Example: "tag1:v1/tag1:v2"
                        or "tag1:v1/tag2:v1" or "tag1:v1/tag2:v2".
  -r RENAME_EXPRESSION, --rename=RENAME_EXPRESSION
                        rename a tag. Example: "tag1/tag2".
  -a ADD_EXPRESSION, --add=ADD_EXPRESSION
                        add a tag value. Example: "tag1:v1" or
                        "tag1:v1,v2,v3".
  -c COPY_EXPRESSION, --copy=COPY_EXPRESSION
                        copy a tag value from/to extended metadata or normal
                        metadata. Tags prefixed with . refer to tags of normal
                        metadata. Examples: "tag1/tag2", ".artist/tag2",
                        "tag1/.artist", ".artist/.album_artist"
  -d DELETE_EXPRESSION, --delete=DELETE_EXPRESSION
                        delete a tag value or tag. Example: "tag1" or
                        "tag1:v1".
  -s, --show            show the extended meta data of the items

The query argument can be passed to the emd command in the same way you pass it to the list command. The options are optional, but you have to set at least one option. All non-flag options are repeatable. By repeating an option you can apply multiple actions of the same type.

Examples

Show Extended Metadata of matching files

beet emd artist:ギガP album:'No title' -s

With the show option the Extended Metadata of each matching file will be printed to the screen. The Extended Metadata will be shown in its json format. You can also combine this option with any other options, in which case the shown Extended Metadata represents the resulting Extended Metadata after all other option have been applied.

Add tags for a specific artist

beet emd artist:REOL -a language:japanese -a origin:japan

Here you can see how to add new tag values to the Extended Metadata of the file. You can add multiple tags by repeating the add option.

Remove a tag from all files

beet emd '' -d genre

You can match all files by simply passing an empty string to the query option. This deletes the genre tag from all files, regardless of its value.

Remove a tag value for certain audio formats

beet emd path::*\.flac -d tag:uncompressed

Here we do not delete the entire tag but only a certain value of the tag. You can use a path query to apply the changes to certain directories or, in this case, certain audio formats by using regex.

Rename a tag in all files

beet emd '' -r singer/vocals

With the rename option you can rename a tag by passing the old- and the new tag name separated by /.

Update a tag value

beet emd x:origin:germany -u category:good/category:favorite

With the update option you can change a tag value. The syntax is the same as with the rename option but it also includes a tag value.

Move a tag value in all files

beet emd '' -u tag:metal/genre:metal

By defining different tag names ins the old- and new value expression you can move a value from one tag to another.

Move and update a tag value in all files

beet emd '' -u tag:'thrash metal'/genre:metal

By defining different tags and values in both the old- and new tag value expression you can move and change a tag value at the same time.

Copy a value from normal metadata to extended metadata in all files

beet emd '' -c .comments/lyrics

In a copy expression your can use normal metadata tags as source or destination for a copy operation by prefixing the tag name with a dot. In this example the value from the normal metadata tag comments will be copied to an EMD tag lyrics. When the destination tag does not exist it will be created, if it does exist the value will be appended to existing values.

Hint: When adding EMD to a file for the first time you can use this to back up existing tag values from the tag that will be used to store the EMD.

Everything combined

beet emd x:origin:germany,austria x:language:'!german' -a tag:western,lederhosen -a category:good -d circle -u circle:'hyper hyper'/tag:hyper -r category/rating -c .artist:artist -s

This adds the values western and lederhosen to the tag tag, adds good to the tag category, deletes the tag circle, moves the value hyper hyper from tag circle to the tag tag and changes it to hyper, renames the tag origin to country, copies the value from the normal tag artist to the emd tag artist and prints the resulting Extended Metadata to the screen for all songs from germany or austria that are not german.

Here we delete and rename tags that are also referenced in add and update operations. In general this works, but it is important to be aware of the order in which the options are applied:

1. Update
2. Rename
3. Add
4. Copy
5. Delete
6. Show

So in this example we rename category to rating before we add the value good to the tag category. So we basically add a tag with the old name after renaming it. This is probably not what we want. In this example we could easily fix this by simply using the new tag name for adding the value.