So where does one find id3tag.h? (Again, silly n00b question)
It’s part of libid3tag.
Taking this a bit further, can the mt-daapd.sh script be modified to do script execs to spawn off the corresponding transcoder? This would mean one less process per transcode, and every little bit helps on the slug. (I’ll try to do this as well, provided I get around to making the build work)
Yeah, you could, but it would make it a lot less flexible at the expense of one process (and processes are cheap on linux — plus, you already probably have a couple busyboxes running, so you’re sharing whatever pages are shareable anyway). I’d consider it to be not worth it.
I like the idea of putting the parameters in environment variables instead of $1, $2… I’m thinking all the HTTP headers are useful to the transcoding script, including accepted deflaters (gzip) etc.
Yup. Source IP, song ID, any number of other pieces of info.