beetbox
POPM (popularity meter) tag support
POPM seems to be the standard tag used for ratings across many music apps. This PR adds support for this tag.
Closes https://github.com/beetbox/mediafile/issues/23
Hi @jmbannon sorry for a little late reply. Basically I think it's about time this tag gets integrated in mediafile. Great!
maybe you can put as much context into the PR description as possible, for documentation purposes. I'm actually not sure if this repo has it's own changelog and how it's documented, so my only idea is to put as much as possible in the PR's description. I know you linked to the issue, but maybe copy over everything that is really relevant/true/worth knowing about his change. Which programs use this tag (eg Traktor I read, what else?), link to the docs on id3.org and so on.
And then there is something @Wolkenarchitect mentioned which I don't entirely understand: https://github.com/beetbox/mediafile/issues/23#issuecomment-571804333 Is that relevant? AFAIS you implemented a basic tag that is a an integer? Is that enough?
Ah, found it, there actually is a changelog: https://mediafile.readthedocs.io/en/latest/#changelog and this is the source: https://github.com/beetbox/mediafile/edit/master/docs/index.rst
But it seems like @sampsyo did additions to that log in the past when pushing out a release. So not sure if you should add to it within this PR
Collecting some info about this tag and how other taggers/software implement it:
Basically the POPM tag looks like this:
emailaddress: "value", rating: int 0-255 ,count: int
- there can be more than one POPM tag in a file.
- count is optional
mp3tag
- https://docs.mp3tag.de/mapping/#popularimeter
- https://community.mp3tag.de/t/ratings-in-mp3tag-where-stored-how-to-display-1-5-star-values/64303/8
- https://community.mp3tag.de/t/popularimeter-tag/2826
puddletag
- https://docs.puddletag.net/source/id3.html#field-popularimeter-frame-popm
exiftool
- https://exiftool.org/forum/index.php?topic=4699.msg22670#msg22670 FIXME changelog?
windows explorer
- https://www.mediamonkey.com/forum/viewtopic.php?p=450818&hilit=popm#p450818
mediamonkey
- mp3tag supports the slightly different mediamonkey implementation as well: https://docs.mp3tag.de/mapping/#rating-mm -> shouldn't bother us in mediafile.
translating scales
there seems to be discrepancies bertween translation of the 0-255 rating value to other scales in different tools, but that shouldn't bother the implementation of the actual POPM tag, it's simply 0-255 integer:
- https://www.mediamonkey.com/forum/viewtopic.php?p=450821#p450821
issuecomment @wolkenarchitect
- https://github.com/beetbox/mediafile/issues/23#issuecomment-571804333
- http://id3.org/id3v2.3.0#Popularimeter (Attention: This website is not reachable often from my experience, but it is still existing. I could access it a couple of days ago.)
- archive.org id3v3 alternative link: https://ia804507.us.archive.org/17/items/id3v2.3.0/id3v2.3.0.html
- definition copied from the id3.org (textfile):
4.18. Popularimeter
The purpose of this frame is to specify how good an audio file is.
Many interesting applications could be found to this frame such as a
playlist that features better audiofiles more often than others or it
could be used to profile a person's taste and find other 'good' files
by comparing people's profiles. The frame is very simple. It contains
the email address to the user, one rating byte and a four byte play
counter, intended to be increased with one for every time the file is
played. The email is a terminated string. The rating is 1-255 where
1 is worst and 255 is best. 0 is unknown. If no personal counter is
wanted it may be omitted. When the counter reaches all one's, one
byte is inserted in front of the counter thus making the counter
eight bits bigger in the same away as the play counter ("PCNT").
There may be more than one "POPM" frame in each tag, but only one
with the same email address.
Email to user $00
Rating $xx
Counter $xx xx xx xx (xx ...)
maybe that's offtopic, MP4 in mutagen's implementation
has a rtng aka rating tag that is just an integer:
- https://mutagen.readthedocs.io/en/latest/api/mp4.html#mutagen.mp4.MP4Tags