Re: [Libcdio-devel] Miscellaneous questions, primarily on design

[Leon Merten Lohse]

Hi,

On 21.03.20 21:41, Samuel May wrote:

> Thomas Schmitt wrote:
> > > * What about changing the language of a block?  I know libcdio isn't
> > > primarily a disc-authoring library, though with cdtext_set(..) and
> > > cdio_get_cdtext_raw(..) it can definitely be used constructively
> >
> > Indeed ? Does it burn audio CDs ?
>
> I was maybe a bit over-generous in that description -- I mainly meant
> that if someone wanted to use libcdio as an over-qualified CDTEXT binary
> editor, they for the most part could.  (Though see my next response to
> Rocky below.)

I believe there is a slight misunderstanding here.

libcdio parses the raw CDTEXT and stores it in an internal data 
structure. The raw CDTEXT can either be read from an audio CD or from a 
"raw CDTEXT dump".

The inverse (packing the internal data structure into raw CDTEXT) is not 
implemented, as far as I remember. So I would say libcdio is very far 
from being a CDTEXT binary editor.
IMHO Thomas' libburnia is a much better option here.

cdio_get_cdtext_raw dumps the raw CDTEXT from the current audio CD and 
has nothing to do with the CDTEXT parser.

cdtext_set is merely the "setter" for the internal data structure and 
should not be called from outside the library. I believe it is mainly 
exposed because at some point there was the idea to move the CDTEXT 
parser into an external library (which was later given up due to mutual 
dependencies).

Multi-language support was added at a much later stage so there was not 
so much freedom in the API, it needed to be backwards compatible, and 
not so many people were interested in it at the time. (To my knowledge) 
only very expensive mastering software even supported it then and I 
could not find any examples in the wild.
(Arguably the API could still have been designed better.)

> Ah, right.  Do one thing but do it well.  I'm going to blame this on
> getting distracted by the presence of cdtext_set(..) -- there's no way
> to set the genre code either.  I'm guessing that cdtext_set(..) is in
> there primarily because it's needed for cdtext_data_init(..), and there
> wasn't much reason /not/ to add it to the interface?  Thanks for pulling
> me back to the proper scope!

Exactly.

Best regards
Leon