Re: libdvdread, ifo_types.h and VIDEO_TS.IFO

Mon May 08 2006, Russ Turner wrote:
> I am writing an application that will automatically and reliably (!)
> determine the title of a commercial DVD.  Some DVD's provide enough
> information in a separate disc.id file, but others do not.  The
> "Provider ID:" field in VIDEO_TS.IFO sometimes has helpful data.  But
> in other cases, while there is useful information in the VIDEO_TS.IFO 
> file, it is not in "Provider ID" or the other data that is defined in 
> ifo_types.h and reported by libdvdread (ifo_dump).  The Sony movie 
> "Radio" is an example of such a DVD.  The name of the movie and the 
> studio can befound in VIDEO_TS.IFO with grep or cat, but is not reported 
> by libdvdread.
> 
> Are there additional IFO types that I can add to the header file and the
> libdvdread programs that will capture this additional IFO information?
> 

Yes, if you get the title name when doing a grep on the .IFO file the
dvd probably implements Text Data. This is not completely implemented
in libdvdread. There were very few dvds with text data before so we didn't
have anything to test with. I haven't checked lately if more dvds are using
it.

There will be many dvds where you won't be able to extract the title name
automatically from. Are you going to add those titles in a separate database
or just ignore them?
If you are planning to use a separate db you should
use the disc_id function in libdvdread to identify the dvd.
It md5sums the first 10 ifo files on a disc.
Although this won't guarantee the disc_id to be 100% unique I haven't
seen any discs where it fails, and it works if you have copies of the
dvd files on hd as well, unlike approaches where info from the udf/iso
filesystem on the dvd is used. Of course you could use a combination of both.

/Bj|rn