Setting the default preferred_media to null is more like previous versions.
This way, as digital becomes more popular, we aren't stuck with a default
configuration that prefers an outdated format.
Saves paranoid and interested users from having to either force all max
recommendations to none or constantly go back to candidate selection
from a recommendation to see if there is another slightly less similar
but more preferred (by the user) candidate.
The new Distance object knows how to perform various types of distance
calculations (expression, equality, number, priority, string).
It will keep track of each individual penalty that has been applied so
that we can utilise that information in the UI and when making decisions
about the recommendation level.
We now display the top 3 penalties (sorted by weight) on the release
list (and "..." if there are more than 3), and we display all penalties
on the album info line and track change line.
The implementation of the `max_rec` setting has been simplified by
removing duplicate validation and instead looking at the penalties that
have been applied to a distance. As a result, we can now configure a
maximum recommendation for any penalty that might be applied.
We have a few new checks when calculating album distance:
`match: preferred: countries` and `match: preferred: media` can each be
set to a list of countries and media in order of your preference. These
are empty by default. A value that matches the first item will have no
penalty, and a value that doesn't match any item will have an unweighted
penalty of 1.0.
If `match: preferred: original_year` is set to "yes", beets will apply
an unweighted penalty of 1.0 for each year of difference between the
release year and the original year.
We now configure individual weights for `mediums` (disctotal), `label`,
`catalognum`, `country` and `albumdisambig` instead of a single generic
`minor` weight. This gives more control, but more importantly separates
and names the applied penalties so that the UI can convey exactly which
fields have contributed to the overall distance penalty.
Likewise, `missing tracks` and `unmatched tracks` are penalised and
displayed in the UI separately, instead of a combined `partial` penalty.
Display non-MusicBrainz source in the disambiguation string, and
"source" in the list of penalties if a release is penalised for being
a non-MusicBrainz.
An earlier change (due to @pedros) added the ability for plugins to define
template fields that work with Albums as well as Items. This enables some
cool new use cases but required that every template field definition check the
type of its arguments. Instead, this iteration on the idea distinguishes
between fields meant for Items and those meant for Albums.
In addition to simplifying the implementation of these functions, this also
enables the creation of album fields with identical names to item fields.
(For example, a user contacted me recently about adding a $bitrate field for
albums, which would be the average bitrate of the items. They can do this now
using a plugin.)
I also changed the docs to stop using the decorator approach to registering
template fields. We're moving toward removing those.
That's 371cc72f2d09 in hg. This makes the patch slightly more general by
reusing our type conversion infrastructure. It also uses "bytes" as a synonym
for "str" that I find a little bit clearer.