Bug#763885: isrcsubmit: documenting the Recommends

[Johannes Dewender]

I am the upstream maintainer. Maybe I can help a bit for the context.

> I like Recommends & Suggests to have some blurb attached, so I can
> decide for/against installing the package referenced. For example, I
> still don't know if or how good isrcsubmit works without cdrdao.

Isrcsubmit works completely fine without cdrdao (uses only libdiscid then).

ISRCs are normally stored in the subchannel data of the disc. This is
where libdiscid searches for ISRCs. ISRCs can also be stored in CD-TEXT.
CDrDAO searches also there.
Most CDs that have ISRCs in CD-TEXT also have them in the subchannel data.

There are very rare cases where cdrdao finds ISRCs in CD-TEXT. The
designated place for ISRCs is the subchannel data though and libdiscid
finds them there. CDs having ISRCs in CD-TEXT normally have them in the
subchannel as well.

So if you want to make sure you are not missing any ISRCs, install
cdrdao (it is preferred when installed).
You rarely miss ISRCs even when not using cdrdao. I personally don't
have a release in my collection that wouldn't work with plain libdiscid.

Note that releases that are not on major labels often don't have any
ISRCs, neither in subchannel nor in CD-TEXT. That is especially true for
older releases. Current "alternative" labels also tend to add ISRCs to
discs now.

Related issues:
http://tickets.musicbrainz.org/browse/LIB-25
(request for CD-Text support in libdiscid)
https://github.com/JonnyJD/musicbrainz-isrcsubmit/issues/17
(example of "CD-Text-only" release in comments)

A short note for the Recommends could read:
CDRDAO: read ISRCs in CD-Text