rbcdio

Version

:include:VERSION

Overview

rbcdio is a Ruby interface to the CD Input and Control library (libcdio). You can get the source from rubyforge rubyforge.org/projects/rbcdio/ or at the same place as libcdio:

ftp://ftp.gnu.org:/pub/gnu/libcdio

The rbcdio (and libcdio) libraries encapsulate CD-ROM reading and control. Ruby programs wishing to be oblivious of the OS- and device-dependent properties of a CD-ROM can use this library.

Requirements

I’ve tested rbcdio on Ruby 1.8.4 - 1.8.7 and 1.9.x You’ll need a C compiler so the extension can be compiled when it is installed. You’ll also need libcdio (www.gnu.org/software/libcdio) and it’s header files installed.

One weirdness I’ve seen in running “gem install” is that on some OS’s like Solaris, gem assume the GNU “install” program goes by the name “ginstall”. (I’ve read a report that on cygwin this was the case too: www.cygwin.com/ml/cygwin/2005-10/msg00259.html )

What’s here

libcdio is rather large and yet may still grow a bit. (UDF support in libcdio may be on the horizon.)

What is in rbcdio is incomplete; over time it may grow to completion depending on various factors: e.g. interest, whether others help out.

Sections of libcdio that are currently missing are the (SCSI) MMC commands, and the cdparanoia library. Of the audio controls, I put in those things that didn’t require any thought. The ISO 9660 library is pretty complete, except file “stat” information which is at present is pretty minimal.

That said, what’s in there is very usable. It contains probably more access capabilities than what most media players that don’t issue MMC directly need.

The encapsulation by SWIG is done in two parts. The lower-level Ruby interface is called rubycdio and is generated by SWIG.

The more object-oriented module is cdio; it is a Ruby class that uses rubycdio. Although rubycdio is perfectly usable on its own, it is expected that cdio is what most people will use. As rubycdio more closely models the C interface, it is conceivable (if unlikely) that diehard libcdio C users who are very familiar with that interface could prefer that. Ditto for the Ruby class iso9660 the lower-level C extension rubyiso9660.

It might be possible to change the SWIG in such a way to combine these pieces. However there are the problems. First, I’m not that much of a SWIG expert. Second it looks as though the resulting SWIG code would be more complex. Note that SWIG seems to create a module while what is in lib are classes. Third the separation makes translation very straight forward to understand and maintain: first get what’s in C into Ruby as a one-to-one translation. Then we implement some nice abstraction off of that. The abstraction can be modified without having to redo the underlying translation. (But the reverse is generally not true: usually changes to the C-to-python translation, rubycdio, do result in small, but obvious and straightforward changes to the abstraction layer cdio.)

There is much to be done - if you see something missing and want to help out, please do so!

Standalone documentation is missing although many of the methods, classes and functions have some document strings. See also the programs in the example directory.