Re: Commercial DVD makes libdvdread go nuts

On Sun, 9 Apr 2006, Bj|rn Englund wrote:

>> All in all, it seems like some applications do not understand anything
>> about what libdvdread tells them about the DVD, while others (Xine) do.
>> Could this DVD trigger libdvdread to produce any unusual output? Maybe the
>> problem is that the libdvdread output is correct, but so unusual that it
>> triggers bugs in applications that try to interpret it?
>
> Yes I think the applications don't process the information correctly.

Ok, so I should file bugs with MPlayer, Transcode and lsdvd... I have 
one question regarding submitting these bug resports: Should it be 
possible for the developers of these projects to find the bug when they 
only have the IFO files? I know *nothing* about the libdvdread API, so 
maybe you can guess what will be needed to find the bugs.

> I don't know if you got my email explaining the ifo_dump result of your dvd,
> (I'll post it here in case you didn't).

Yes, I got that one.

> But from ifo_dump everything seems ok.
> Problem with dvds is that the "chapter structure" isn't hardwired in
> the format but can be 'defined' through the dvd vm/navigation commands,
> so programs that only want to get chapter data,
> and do not run the dvd commands,
> might not find the 'correct' chapter structure.

Ah, so an application needs to implement a DVD command interpreter in 
order to correctly determine the correct chapter positions?

Is there any way to see if a certain DVD uses dvd vm/navigation commands 
to define its structure?

So, If the problem is caused by MPlayer, Transcode and lsdvd not looking 
at the DVD commands, then I guess DVD titles that use dvd vm/navigation 
commands to define their structure are quite rare, because virtually any 
DVD 'works' prefectly with MPlayer, Transcode and lsdvd. Is that correct?

> Though they should still be able to list all the parts
> (which they obviously do not do correctly in this case).

I am a bit confused here. I know about 'titles' and 'chapters', but I 
never heard about 'parts' before. What is a 'part' exactly?

Thanks,

Dik