Quoting proverbs311031:
Quote:
disclosure: I've been in IT for over 25 years
long story short: when replacing the existing driver with older driver provided by iPatsa, my DVD-RW drive does not show as installed, even with all matching account permissions including TrustedInstaller when compared to existing build 18363 cdrom.sys driver, so there must be another "software hook or call being made".
Any suggestions on what I might be missing?
Hmm, I tackled the problem differently, I started to work the problem from DVD profiler to the drive, not the other way round.
Initially, I ran Process Monitor tool and an API monitoring tool to check what happens when dvdpro.exe adds a DVD Disc ID in the database. I could see files in the VIDEO_TS directory were being read and some attributes such as filename, file size and date and times were also read. But all the read data was correct and matched the values found on the DVD.
I ran the same test on many DVDs over many versions of Windows (XPsp2, Win7sp1, Win10v1709, Win10v1809, v1903, v1909) and found no evidence of corrupted data read from the DVDs.
Eventually, I did more research on the 64-bit CRC and found Microsoft's US patent which descibed the concept of the unique 64-bit CRC and how it could support bookmarking. I learnt that there were four steps in the calculation process:
Step 1:The filenames in the VIDEO_TS directory are collected and sorted alphabetically into a list
Step 2:For each filename in the list, the following structure is filled out and added to the CRC (all data fields are in LSB first):
==> unsigned 64 bit Integer: dateTime (the time elapsed in 100 nanosecond intervals from Jan. 1, 1601)
==> unsigned 32 bit Integer: FileSize
==> BYTE: Filename [filename Length]
==> BYTE: FilenameTermNull=0
Step 3:If present, the first 65,536 bytes of "VIDEO_TS.IFO are read and added to the CRC (if smaller then the entire file is added)
Step 4:If present, the first 65,536 bytes of "VTS_01_0.IFO are read and added to the CRC (if smaller then the entire file is added)
In a nutshell, each file's attributes in the VIDEO_TS directory and the first 65,536 bytes of data from VIDEO_TS.IFO and VTS_01_0.IFO are the inputs added to the concatenated binary polynomial equation that generates the 64-bit CRC.
With the above steps in mind, I revisited the previous capture files I had and it finally dawned on me something did change with Win10 ver1809.
On every Windows platform, steps 2,3 and 4 were being carried out properly.
On the other hand, step 1 had changed:
==> Prior to Win10 ver1809, step 1 was being carried out properly.
==> From Win10 ver 1809 and onwards, only a subset of files in the VIDEO_TS directory were being read (VIDEO_TS.IFO, BUP and VOB, and VTS_01_0.IFO, BUP and VOB).
I can't give you a reason as to why the algorithm for calculating the DVD's unique 64-bit CRC changed, but I do note that both Microsoft's Windows Media Center application and Windows DVD Player application were both forcibly removed by the Win10 ver1809 upgrade, and both used the bookmarking feature via the DVD's unique 64-bit CRC!
Was the change just collateral damage? I'll leave that to someone else to take up the gauntlet. All I know is I finally convinced myself that CDROM.SYS was not the problem.