I know that data is written to the DVD starting near the hub and going out, and then in the case of dual layer (reverse spiral dual layer) discs, back from the outside to the center. I've also read that the 2nd layer can begin without ever reaching the absolute outer limit of the recording media.

What I would love to know is this: Is the data written in some sort of ascending title sequence, where the first title is completed before the second, and so on?

If there is a physical problem with the disc at the 99% point, but the disc has the bonus material in the upper title sets, I'm trying to figure out what would be the probability of being able to play the movie but just not the bonus materials.

Quoting lasitter:

Quote:
What I would love to know is this: Is the data written in some sort of ascending title sequence, where the first title is completed before the second, and so on?

Since the generally used "copy-protection" for DVDs is CSS (Content Scramble System) this idea would be a contradiction in itself wouldn't it?

Quoting lasitter:

Quote:
I know that data is written to the DVD starting near the hub and going out, and then in the case of dual layer (reverse spiral dual layer) discs, back from the outside to the center.

Not necessarily; the first Doctor Who: The Movie release sent the laser all the wasy back to the middle to start layer 2 which is why the layer cange pause was so horribly long... it all depends on who encodes the disc how they do so.