dmap-ng is an improved version of the original dmap gem, rewritten from the ground up with a more detailed test suite and has awesome features like a DSL and supports a more extensive part of the DMAP protocol.
DMAP stands for Digital Media Access Protocol which is the data serialisation format used in the DAAP protocol mainly used in iTunes for media sharing and remote control.
You should care if you want to write anything that interacts with iTunes/DAAP-compatible media server or a DAAP client.
I wanted to write a gem that emulates an iTunes DJ server so the Remote.app on the iPhone/iTouch/iPad can interface with any app that has voting, so it was my Railscamp 7 project. I wrote this gem over the two days at Railscamp, using the tag list from jphasting's dmap gem but writing everything from scratch. It has enough tag support to get the Remote.app to show arbitrary data with the gem I'll upload once it's in a decent state named 'deejay'.
Real easy. Check this out:
This is a aply (playlists) entry.
playlists = DMAP.parse("aply\000\000\001\nmstt\000\000\000\004\000\000\000\310muty\000\000\000\001\000mtco\000\000\000\004\000\000\000\002mrco\000\000\000\004\000\000\000\002mlcl\000\000\000\325mlit\000\000\000_miid\000\000\000\004\000\000(Fmper\000\000\000\b\000\000\000\000\000\000\000{minm\000\000\000\005MusicaeSP\000\000\000\001\001mpco\000\000\000\004\000\000\000\000aePS\000\000\000\001\006meds\000\000\000\004\000\000\000\000mimc\000\000\000\004\000\000\000\002mlit\000\000\000fmiid\000\000\000\004\000\000()mper\000\000\000\b\000\000\000\000\000\000\004\322minm\000\000\000\tiTunes DJmpco\000\000\000\004\000\000\000\000aePS\000\000\000\001\002meds\000\000\000\004\000\000\000\000ceJI\000\000\000\004\000\000(,mimc\000\000\000\004\000\000\000\022")
would return:
aply[266]:
mstt[4]: 200
muty[1]: 0
mtco[4]: 2
mrco[4]: 2
mlcl[213]:
mlit[95]:
miid[4]: 10310
mper[8]: 123
minm[5]: "Music"
aeSP[1]: true
mpco[4]: 0
aePS[1]: 6
meds[4]: 0
mimc[4]: 2
mlit[102]:
miid[4]: 10281
mper[8]: 1234
minm[9]: "iTunes DJ"
mpco[4]: 0
aePS[1]: 2
meds[4]: 0
ceJI[4]: 10284
mimc[4]: 18
Which is a DMAP::Tag object. You can access individual tags like this:
playlists.mstt # => 200
playlists.mlcl[1].minm # => "iTunes DJ"
To build a DMAP structure, you do this:
DMAP.build do
mlit do # dmap.listingitem
mikd 2 # dmap.itemkind
asal "Aquarium" # daap.songalbum
asar "Naomi" # daap.songartist
miid 3123 # dmap.itemid
minm "Relax She Said" # dmap.itemname
mper 9013529250002063060 # dmap.persistentid
mcti 10386 # dmap.containeritemid
aeHV 0 # com.apple.itunes.has-video
asai 9013529250002063588 # daap.songalbumid
ceJV 2 # com.apple.itunes.jukebox-vote
ceJC 1 # com.apple.itunes.jukebox-client-vote
end
end
There is also a #to_dsl method on DMAP::Tag that returns a copy-pasta-able ruby code that goes inside the DMAP.build block.
puts playlists.to_dsl
which gives you this:
aply do # daap.databaseplaylists
mstt 200 # dmap.status
muty 0 # dmap.updatetype
mtco 2 # dmap.specifiedtotalcount
mrco 2 # dmap.returnedcount
mlcl do # dmap.listing
mlit do # dmap.listingitem
miid 10310 # dmap.itemid
mper 123 # dmap.persistentid
minm "Music" # dmap.itemname
aeSP true # com.apple.itunes.smart-playlist
mpco 0 # dmap.parentcontainerid
aePS 6 # com.apple.itunes.special-playlist
meds 0 # dmap.editcommandssupported
mimc 2 # dmap.itemcount
end
mlit do # dmap.listingitem
miid 10281 # dmap.itemid
mper 1234 # dmap.persistentid
minm "iTunes DJ" # dmap.itemname
mpco 0 # dmap.parentcontainerid
aePS 2 # com.apple.itunes.special-playlist
meds 0 # dmap.editcommandssupported
ceJI 10284 # com.apple.itunes.jukebox-current
mimc 18 # dmap.itemcount
end
end
end
As you can see, it also puts in the tag definition at the end because I got tired of having to look up what a tag actually was.
Also, there is a dmap executable that lets you pipe DMAP data to it and it'll give you a DMAP::Tag#inspect output. Example usage:
$ curl A "Remote/1.3.3" -H "Special-Client: 2" "http://localhost:3689/server-info" | dmap
msrv[316]: dmap.serverinforesponse
mstt[4]: 200 - dmap.status
mpro[4]: [0, 2, 0, 6] - dmap.protocolversion
apro[4]: [0, 3, 0, 8] - daap.protocolversion
aeSV[4]: [0, 3, 0, 1] - com.apple.itunes.music-sharing-version
aeFP[1]: 1 - com.apple.itunes.req-fplay
ated[2]: 3 - daap.supportsextradata
msed[1]: 0 - unknown_msed
msml[48]: unknown_msml
msma[8]: <censored until I know what this does>
msma[8]: <censored until I know what this does>
msma[8]: <censored until I know what this does>
ceWM[3]: "sup" - com.apple.itunes.welcome-message
ceVO[1]: 1 - com.apple.itunes.unknown-voting
minm[18]: "chendo\342\200\231s Library" - dmap.itemname
mslr[1]: 1 - dmap.loginrequired
mstm[4]: 1800 - dmap.timeoutinterval
msal[1]: 1 - dmap.supportsautologout
msas[1]: 3 - dmap.authenticationschemes
msup[1]: 1 - dmap.supportsupdate
mspi[1]: 1 - dmap.supportspersistentids
msex[1]: 1 - dmap.supportsextensions
msbr[1]: 1 - dmap.supportsbrowse
msqy[1]: 1 - dmap.supportsquery
msix[1]: 1 - dmap.supportsindex
msrs[1]: 1 - dmap.supportsresolve
msdc[4]: 1 - dmap.databasescount
mstc[4]: 1271654695 - dmap.utctime
msto[4]: 36000 - dmap.utcoffset
Or if you've saved the bytes to a file with Wireshark or something:
$ dmap file.dump
$ cat file.dump | dmap
$ dmap < file.dump
Send me an email with a pcap dump of the entire process and I'll see what I can do.
- Fork the project.
- Make your feature addition or bug fix.
- Add tests for it. This is important so I don't break it in a future version unintentionally.
- Commit, do not mess with rakefile, version, or history. (if you want to have your own version, that is fine but bump version in a commit by itself I can ignore when I pull)
- Send me a pull request. Bonus points for topic branches.
Copyright (c) 2010 Jack "chendo" Chen. See LICENSE for details.