Audio fingerprinting and metadatacorrection with Python

Alastair Porter

November 21, 2011

Me

Background in Computer ScienceMasters McGill Music TechOnline

http://github.com/alastair (20/28 music; 11 in python)http://twitter.com/alastairporter

Python as a go-to language

Quick for prototypingUse the same code in a production releaseVery handy for API access (thin wrapper around urllib2)

Music and Metadata

Music and Metadata

The problem:People are really bad at naming musicInconsistent over releases

The solution:CrowdsourcingGet info from as many trusted sources as possibleMake renaming take no effort

MusicBrainz

Amazon

Amazon (Coverart)

Last.fm

Last.fm (Genre tags)

MusicBrainz

albumidentify

http://github.com/albumidentify/albumidentify

MP3, FLAC, Ogg, CDs

Identification strategy

If there’s a CD TOC, use that (musicbrainz lookup)If no match, use audio fingerprintingIf no match, do a text lookup (artist/album)

Fingerprinting

Converts an audio signal to a short sequence of numbersSmaller to compare than an entire filePerceptual features rather than byte comparison (workswith different encodings)

Identification strategy

Fingerprinting gives us a set of candidate tracksA track could be on many albums (original release, best of,mix album)Keep a list of what tracks we have for each albumOnce we fill all the slots for an album, success!

Metadata strategy

Text information from MusicbrainzGenre from last.fmImage from Amazon (or folder.jpg)Musicbrainz tells us where these are (don’t need to search)Save in every file (Text is cheap)

Writing it all out

Custom MP3/ID3 writerOgg meta tagsFLAC meta tagsName files

Artist/Artist - Year - Album/01 - Artist - Track

Replaygain!Be a good citizen: Submit fingerprints to musicbrainz

What’s next

New version of musicbrainzNew fingerprinterMore metadataMore metadata

Thanks

More information:

MusicBrainz: http://musicbrainz.orgalbumidentify:http://github.com/albumidentify/albumidentify

More fingerprinting: http://acoustid.org,http://echoprint.me

Last.fm