[Libcdio-devel] Re: mmc_get_disc_erasable proposition + questions

[Thomas Schmitt]

Hi,

> If in some
> cases a sbc routine does the same thing as a spc routine that's okay and can
> easily be handled.

The standards are coordinated.
For our purposes SBC covers only
  1Bh START/STOP UNIT
SPC is used in libburn in form of
  12h INQUIRY
  5Ah MODE SENSE
  55h MODE SELECT
  03h REQUEST SENSE
  00h TEST UNIT READY

A special case is
  1Eh PREVENT/ALLOW MEDIA REMOVAL
where MMC-5 says:
  "[SPC-3] describes a PREVENT ALLOW MEDIUM
   REMOVAL command; however, the [SPC-3]
   description does not apply to MM devices.
  "
So we should only obey the MMC prescriptions
and ignore SPC here.

No double functions to expect.


> I think you will have to help doing the
> READ DISC STRUCTURE part. 

Sure. Give me the framework.
The problem is that you have to pull logics from
the OS drivers into the generic part.


> In many respects, I am just moderating here as I
> really don't have any specific need for any of this. ;-)

There is some need in libcdio for catching up
with those media. TOC is flatly wrong.


>  I don't feel comfortable
> violating an existing standard such as say the Philips Red book

This standard simply does not apply to DVD
and BD. The newer standards would apply to CD,
but in that aspect i vote for keeping old CD
functionality unchanged.
The newer media are near enough to CD to be
covered by libcdio. You just have to open it
a bit for their new concepts.
Vice versa a libdvdio would have a huge
intersection of features with libcdio.

> Both users and application writers need to be aware and transparent about
> the fact that an extension on a standard format is getting used.

They would be aware by the fact that the new
TOC call has to be used by the application
on the first hand. Old call = old result.

The performance of cd-info with DVD TOCs is
awful enough so that any user will be happy
with breaking its habits on DVD.

The media recognizer would only be confusing
by telling new yet unkown media types.
Any caller should have a default case for
such unknown replies.


Have a nice day :)

Thomas