From: Ken Bloom <kbloom@...>
Date: 2007-08-27T04:40:05+09:00
Subject: Re: [SOLUTION][QUIZ] ID3 Tags (#136)

On Sun, 26 Aug 2007 09:16:32 -0500, Ken Bloom wrote:

> class NoID3Error < StandardError
> end
> 
> class ID3
>   Genres=" Blues
>     Classic Rock
>     Country
>     Dance
>     Disco
>     Funk
>     Grunge
>     Hip-Hop
>     Jazz
>     Metal
>     New Age
>     Oldies
>     Other
>     Pop
>     R&B
>     Rap
>     Reggae
>     Rock
>     Techno
>     Industrial
>     Alternative
>     Ska
>     Death Metal
>     Pranks
>     Soundtrack
>     Euro-Techno
>     Ambient
>     Trip-Hop
>     Vocal
>     Jazz+Funk
>     Fusion
>     Trance
>     Classical
>     Instrumental
>     Acid
>     House
>     Game
>     Sound Clip
>     Gospel
>     Noise
>     AlternRock
>     Bass
>     Soul
>     Punk
>     Space
>     Meditative
>     Instrumental Pop
>     Instrumental Rock
>     Ethnic
>     Gothic
>     Darkwave
>     Techno-Industrial
>     Electronic
>     Pop-Folk
>     Eurodance
>     Dream
>     Southern Rock
>     Comedy
>     Cult
>     Gangsta
>     Top 40
>     Christian Rap
>     Pop/Funk
>     Jungle
>     Native American
>     Cabaret
>     New Wave
>     Psychadelic
>     Rave
>     Showtunes
>     Trailer
>     Lo-Fi
>     Tribal
>     Acid Punk
>     Acid Jazz
>     Polka
>     Retro
>     Musical
>     Rock & Roll
>     Hard Rock
>     Folk
>     Folk-Rock
>     National Folk
>     Swing
>     Fast Fusion
>     Bebob
>     Latin
>     Revival
>     Celtic
>     Bluegrass
>     Avantgarde
>     Gothic Rock
>     Progressive Rock
>     Psychedelic Rock
>     Symphonic Rock
>     Slow Rock
>     Big Band
>     Chorus
>     Easy Listening
>     Acoustic
>     Humour
>     Speech
>     Chanson
>     Opera
>     Chamber Music
>     Sonata
>     Symphony
>     Booty Bass
>     Primus
>     Porn Groove
>     Satire
>     Slow Jam
>     Club
>     Tango
>     Samba
>     Folklore
>     Ballad
>     Power Ballad
>     Rhythmic Soul
>     Freestyle
>     Duet
>     Punk Rock
>     Drum Solo
>     A capella
>     Euro-House
>     Dance Hall".split("\n").map{|x| x.gsub(/^\s+/,'')}
> 
>   attr_accessor :title, :artist, :album, :year, :comment, :genre, :track
>   def genre_name
>     Genres[@genre]
>   end
> 
>   def initialize(filename)
>     rawdata=open(filename) do |f|
>       f.seek(f.lstat.size-128)
>       f.read
>     end
>     tag,@title,@artist,@album,@year,@comment,@genre=rawdata.unpack
>     "A3A30A30A30A4A30c" if rawdata[3+30+30+30+4+28]==0
>       @track=rawdata[3+30+30+30+4+29]
>       @track=nil if @track==0
>     end
>     if tag!="TAG"
>       raise NoID3Error
>     end
>   end
> end

Apparently unpack('A30') doesn't work quite the way I thought --
it only shortens the string if the string ends in null characters.
If there are nulls in the middle, then those and the characters after
them are preserved.

--Ken

-- 
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu/~kbloom1/