Re: "Patch" libdvdread.

Mon Aug 19 2002, Olaf Beck wrote:
> Hello Folks,
> 
> As some of you know I currently hacking a DVD Creation/Authoring
> framework (dvd-create.sf.net). My present task is to make a
> ifoedit/create library (libifoedit - yes lame name :). Anyways is
> will depend on dvdread to read ifo structures and then convert them
> to editable once that I can manipulate with libifoedit.
>
> The case is that dvdread doesn't export the whole ifo structure some
> small parts are missing. It's offset tables ...

Do you really want them?  I gues they only matter if you want to make
minimal non-intrusive edits.  The are just the offsets to were the
info is stored.  When you layout the suff in the IFO file you createt
just make up new offsets that will work for the data you generate.

> and the time map in the VTS IFO that I main issues

I've actually just implemented this, see current cvs
(http://cvs.berlios.de/cgi-bin/viewcvs.cgi/ogle/libdvdread/)

> although I have also bumped into some incorrect things. 
> Anyhow I have attached a patch for ifo_types.h that will "export" all
> I need for ifoedit.
>
The audio extensions stuff wasn't exactly a clean addition.
Where is that information derived from?   Having a bunch of pointers
in the ifo_handle_t instead of at the end of the vmgi_mat_t and 
vtsi_mat_t was to share the common ones (and it looked a bit cleaner).

The TMAPT changes clash with my implementation, and
again do you really need the extra offsets?

> My question is if you as dvdread developer are happy with my
> additions to the structure, may be you have questions, suggestions,
> or want to alter it a bit etc. After the structure is sorted out I
> will go a head and implement the changes to libdvdread but I think
> it was a good idea to start with the types so we are on the same
> line so to say rather than me sending in a bigger patch in one
> chunk.
> 
Very good plan.
Depending on how you look at it, you now have to redo some work with
fixing the ifo_types.h again for my TMAPT changes, on the other hand
I've already written the ifo_read / ifo_print changes.

> PS: I'm working on the VMG_TXTDT_MG structure but there are many
> black holes that need to be filled in before it's ready - any hints
> or more docs regards to it is very welcomed.

Have a look at the documentation on microsofts developer pages for there
DVD player api.  It seems to be very close to the on disc format.

We have a few (two or three) DVDs that have TXTDT if you need more examples.

-- 
Håkan Hjort