format_parser M4A format support

Edit to add: here is a link to a M4A sample file I made that I'm releasing here under an MIT license if someone wants to take this on.

Jan 21 '18 13:01 bermannoah

Can be integrated into the MOOV parser, we need a file from the iTunes Store for this (with permission from the artist and the artist must be an independent)

Jan 21 '18 16:01 julik

I created an M4A that can be used - link to download - was taking a look at this issue but I'm not sure if I'll get to polish it off soon so thought I'd put it here as well if a passerby is interested. :)

Jan 22 '18 08:01 bermannoah

@bermannoah any chance we could get a hand at that file once more?

May 23 '18 23:05 julik

Whoops. ~Here's~ an updated link.

May 24 '18 08:05 bermannoah

That's an MP4. We were talking about an M4A from iTunes Store no?

May 24 '18 21:05 julik

Which browser did you download it with? 😭 Chrome does something naughty to the file on download. Safari should get you an m4a.

May 24 '18 21:05 bermannoah

.mp4 is actually the same as an .m4a but a different file extension so all good. But when I load it into iTunes I do not see any metadata. Is there supposed to be any?

May 24 '18 21:05 julik

Ah! I can add some. Try this. If there's iTunes specific metadata that I can't generate myself then we're back where we started. Maybe someone at WT or on ams.rb is a tracks-on-itunes-haver?

May 24 '18 21:05 bermannoah