I would like to know, what exactly happens during the process of reading a disc.
What does the drive do? What does each sound mean? What exactly does the lens and the drive
do in the timespan of these few seconds?
May not be in this exact sequence.
Check disc type.
Read the table that has the track layout of the disc.
Read the book type.
Check region info if any.
Check DRM if any.
Read the menu if any.
It can also vary.
DVD-ROM drive report every disc as finalized and write-protected.
Alternatively, they could report them as they actually are,but deny writing access.