So I figured something out today.
I add and remove podcasts in iTunes all the time. And every so often, iTunes loses track of, er, tracks. This usually shows up in a smart playlist, where a podcast episode exists in iTunes’s database, but there’s no corresponding MP3 file on disk. You can’t manually delete entries from smart playlists; and if I’ve deleted the podcast, then I can’t even go back to the podcast list to delete the bogus episode. Nor does it show up in the “Music” list, since it’s a podcast episode.
What I finally figured out is that if you change the Media type from “Podcast” to “Music”, that’ll move the episode to the Music list, where you can delete it.
You can change the media type with “Get info” (⌘-I) → Options → “Media Kind”.
Unfortunately, if the file is missing, iTunes won’t let you edit the media kind. So first you need to associate the podcast episode with an MP3 file. The easiest way is to copy an existing MP3 file to /tmp/foo.mp3 or some such. Then, when you ⌘-I and iTunes says no such file and “Do you want to locate it?”, say yes, and point it at /tmp/foo.mp3. Then you can edit the media kind, and delete the file from the Music list.
MacOS plist XML files are evil; even more so than regular XML. For instance, my iTunes library file consists mostly of entries like:
<key>Composer</key><string>Paul McCartney/John Lennon</string>
<key>Album</key><string>Sgt. Pepper's Lonely Hearts Club Band</string>
You’ll notice that there’s no connection between a key and its value, other than proximity. There’s no real indication that these are fields in a data record, and unlike most XML files, you have to consider the position of each element compared to its neighbors. It’s almost as if someone took a file of the form
Track_ID = 5436
Name = "Getting Better"
Artist = "The Beatles"
Coposer = "Paul McCartney/John Lennon"
and, when told to convert it to XML in the name of buzzword-compliance, did a simple and quarter-assed search and replace.
But of course, what was fucked up by (lossless) text substitution can be unfucked by text substitution. And what’s the buzzword-compliant tool for doing text substitution on XML, even crappy XML? XSLT, of course. The template language that combines the power of sed with the terseness of COBOL.
So I hacked up an XSLT template to convert my iTunes library into a file that can be required in a Perl script. Feel free to use it in good or ill health. If you spring it on unsuspecting developers, please send me a photo of their reaction.
One thing you can do in iTunes is to give songs a rating from 1 to 5 stars. It also has an option to play highly-rated songs more often during shuffle play, but frankly, I can’t be bothered to go through my collection rating songs by hand. And besides, the metadata that iTunes stores for each song includes things like the number of times it was played, the last time it was played, the number of times it was skipped, the last time it was skipped, and the time when it was added to the library. It seems that from this, it should be possible to figure out what I like and what I don’t like. Specifically, it should be possible to write an AppleScript script that goes through the library and computes ratings.
Continue reading “Calculating My Tastes”
Every so often, I’ll update the MP3 file for a given song. For instance, if I record an LP to MP3, then buy and rip the CD, I’ll just update the MP3 file on the back end and tell iTunes to reread it (with open -a itunes /path/to/file.mp3, for those who care).
Unfortunately, when I do this, I’ve noticed that iTunes plays the new file properly, while the iPod tends to hang a few seconds befor the end of the song, or, in more extreme cases, reset itself.
Continue reading “Truncated Songs on iPod”