My son's new [MP3] player is able to display some sound information such as title, artist etc. I wondered how this info is coded in the MP3 file. A short research led me to http://www.dv.co.yu/mpgscript/mpeghdr.htm . A simple 128 byte trailer is appended to the MP3 file. The following program can read, edit and (re)write this trailer. Have fun tagging your MP3s. '''[US]''' [AK] - Can something similar be done for Ogg/Vorbis files ? [US] - Made a slight change in the binary scan/format lines, now it's exactly ID3v1.1 format. This is also used by some Ogg/Vorbis en-/decoders. It should be possible to use this program unchanged for both MP3 and Ogg/Vorbis. (ID3v2 is a different cup of tea) [NEM] - Added variable to keep track of where you last looked for files. Makes my life a little easier. '''EE''' - Note: I've encountered a number of files claiming to be mp3 files that had a huge pile of junk at the *beginning* of the file. This junk contained an extended amount of file identification data, sometimes even including an embedded thumbnail of an album cover image. Some of my mp3 players would complain about "junk at beginning of file", but not all. in particular, xmms would display the band-name and song-name from that data if present, although the "delete ID3 tag" function in xmms wouldn't delete that header junk. Unfortunately, I don't know the format of the junk blob, or how to recognize its start and end, and music starting point.. [US] - This is probably ID3v2, AFAIK XML based. '''miriam''' - See http://www.id3.org/ for full specifications of the ID3v2 tag. It is quite a lot more complex than ID3v1 but much more flexible. Being at the head of the file it is picked up at the beginning of a streaming file. It can contain descriptions longer than 30 characters. Fields can contain anything, even images if desired. It is an expandable set of chunks like IFF files or PNG files where a reader program can skip parts it doesn't understand. The downside of course is the complexity. ---- #! /usr/local/bin/tclsh8.3 package require msgcat namespace import msgcat::* if {[info exists ::env(HOME)]} { set initial_dir $::env(HOME) } else { set initial_dir [pwd] } # # Read tag (if there is one) # proc rd_tag {} { global title artist album year comment track genre hastag fnam set fd [open $fnam r] fconfigure $fd -encoding binary -translation binary if {[catch {seek $fd -128 end}]} { too_short .m.file entryconfigure [mc Schreiben] -state disabled return } set tag [read $fd] close $fd binary scan $tag A3 id if {[string equal $id TAG]} { set hastag 1 set genre 12 binary scan $tag A3A30A30A30A4A28ccc id title artist album year comment zero track genre } else { set hastag 0 set title "" set artist "" set album "" set year "" set comment "" set track 0 set genre 12 } .f3.lbgen selection clear 0 end .f3.lbgen selection set $genre .f3.lbgen see $genre } # # Choose a file to read # proc rd_file {} { global fnam initial_dir set ftypes {{MP3 .mp3} {All *}} set fnam [tk_getOpenFile -filetypes $ftypes -defaultextension .mp3 \ -initialdir $initial_dir] if {[string length $fnam]} { set initial_dir [file dirname $fnam] .m.file entryconfigure [mc Schreiben] -state normal rd_tag } else { .m.file entryconfigure [mc Schreiben] -state disabled } } # # Write (back) tag to file # proc wr_file {} { global title artist album year comment track hastag fnam set genre [.f3.lbgen curselection] set tag [binary format a3a30a30a30a4a28ccc TAG $title $artist $album $year $comment 0 [string trimleft $track 0] $genre] set fd [open $fnam a] fconfigure $fd -encoding binary -translation binary if {$hastag} { seek $fd -128 end } puts -nonewline $fd $tag close $fd } # # seek fails, file too short # proc too_short {} { global fnam tk_messageBox -type ok -icon warning \ -message "[mc \"Die Datei\"] $fnam [mc \"ist keine MP3-Datei.\"]" } # # Message catalogs: # # Deutsch mcset de Lesen mcset de Schreiben mcset de Datei mcset de Ende mcset de Titel mcset de Interpret mcset de Album mcset de Kommentar mcset de Jahr mcset de Track mcset de Genre mcset de "Die Datei" mcset de "ist keine MP3-Datei." # English mcset en Lesen Read mcset en Schreiben Write mcset en Datei File mcset en Ende Exit mcset en Titel Title mcset en Interpret Artist mcset en Album mcset en Kommentar Comment mcset en Jahr Year mcset en Track mcset en Genre mcset en "Die Datei" "The file" mcset en "ist keine MP3-Datei." "is not an MP3 file." # Add your preferred language here # # Build GUI # menu .m -type menubar . configure -menu .m .m add cascade -label [mc Datei] -menu .m.file menu .m.file -tearoff 0 .m.file add command -label [mc Lesen] -command rd_file .m.file add command -label [mc Schreiben] -command wr_file .m.file add separator .m.file add command -label [mc Ende] -command {destroy .} frame .f1 frame .f2 frame .f3 label .f1.lfil -text [mc Datei]: entry .f1.efil -textvariable fnam -width 30 label .f1.ltit -text [mc Titel]: entry .f1.etit -textvariable title -width 30 label .f1.lart -text [mc Interpret]: entry .f1.eart -textvariable artist -width 30 label .f1.lalb -text [mc Album]: entry .f1.ealb -textvariable album -width 30 label .f1.lcom -text [mc Kommentar]: entry .f1.ecom -textvariable comment -width 30 label .f2.lyea -text [mc Jahr]: entry .f2.eyea -textvariable year -width 4 label .f2.ltrk -text [mc Track]: entry .f2.etrk -textvariable track -width 2 label .f3.lgen -text [mc Genre]: listbox .f3.lbgen -listvar lgenre -width 40 -height 5 \ -yscrollcommand {.f3.sbgen set} \ -exportselection 0 scrollbar .f3.sbgen -orient vert -command {.f3.lbgen yview} pack .f1 .f2 .f3 -padx 1m -pady 1m grid .f1.lfil -row 0 -column 0 -sticky e grid .f1.efil -row 0 -column 1 grid .f1.ltit -row 1 -column 0 -sticky e grid .f1.etit -row 1 -column 1 grid .f1.lart -row 2 -column 0 -sticky e grid .f1.eart -row 2 -column 1 grid .f1.lalb -row 3 -column 0 -sticky e grid .f1.ealb -row 3 -column 1 grid .f1.lcom -row 4 -column 0 -sticky e grid .f1.ecom -row 4 -column 1 pack .f2.lyea .f2.eyea .f2.ltrk .f2.etrk -side left pack .f3.lgen pack .f3.lbgen .f3.sbgen -side left -fill y .m.file entryconfigure [mc Schreiben] -state disabled # # Some variables # set hastag 0 set fnam "" set lgenre { 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 Brass} Primus {Porn Groove} Satire {Slow Jam} Club Tango Samba Folklore Ballad {Power Ballad} {Rhytmic Soul} Freestyle Duet {Punk Rock} {Drum Solo} {A Capela} Euro-House {Dance Hall} } # # Set defaults # .f3.lbgen selection clear 0 end .f3.lbgen selection set 12 .f3.lbgen see 12 ---- [Category Application] - [Category Sound] - [Category Multimedia] - [Category Music] - [Category File] ----