Good news for Blu-Ray fans: it seems that Blu-Ray Regions are checked ONLY by the player software, NOT by the drive or by Windows. This means if you can reset the counter of the player,
you can change Blu-Ray Regions AS OFTEN AS YOU WANT TO.
On the Internet, I have found a trick for PowerDVD Ultra and a theory about how Blu-Ray-Region coding works. I give you this information, hoping it will inspire you for programming.
I. PowerDVD Ultra Blu-Ray-Region Reset
PowerDVD manages Blu-Ray Region information differently in XP and Vista.
In XP, it is stored in registry here:
Windows Registry Editor Version 5.00
[HKEY_CLASSES_ROOT\CLSID\{631400EE-60DF-4014-8A01-67106E57BDA8}]
@=dword:00000002
[HKEY_CLASSES_ROOT\CLSID\{9CB23675-4229-4630-AFF6-3668BA6AF33E}]
@=dword:00000004
Under the first location it stores the region (1 - Region A, 2 - Region B, 4 - Region C).
The number of remaining changes is stored under the second location. Every time you change region in PowerDVD, this number is decremented by 1. You can just put there something like FFFF (65535 changes) or better 1869F (99999 changes) and forget about it.
By default, there are no values in both locations. PowerDVD interprets this as Region A and 5 remaining changes. When you change region for the first time, it puts values there.
In Vista, region information is stored in Alternate Data Stream (ADS) attached to the file "CLDShowX.ini" located in "C:\ProgramData\CyberLink\PowerDVD\". You can view the content of that stream using, for example, "ADSLocator.exe" utility. If you run out of the number of remaining changes, just delete that file. Next time you start PowerDVD, it will be recreated with default settings.
II. Theory about Blu-Ray-Region Coding
So it is now 100% certain, that Blu-ray regions only exist on application level. "Blu-ray drive region" is completely out of the equation, because it does not exist.
Based on my experiments, I come up with a theory on how Blu-ray regions work. Here it is:
Blu-ray region settings on a disc are not flags indicating players configured for which regions are allowed to play the disc. They are rather rules telling the player what it should play if it relates to a given region. Rules are checked at the beginning of the playback. These rules are specified for players of each region, and the player does not know in advance what it will get if it follows rules for its region. If it is lucky, it will get a main movie. If not - a short clip saying that the player has a wrong region to play the movie.
What AnyDVD probably does when you opt to remove Blu-ray region coding and select a preferred region - it changes those rules for two other regions making them the same as the rules for the region you selected. Thus even players with 'wrong' region will get the same content as those with the 'right' one. All this is accomplished by altering a few bytes in MovieObject.bdmv file (so I assume these rules are not even encrypted or something).
An analogy is this: You are a good driver who always follow the rules. You intend to reach some City, and you are approaching (actually, starting at) a crossroad with a road sign saying "Red cars must turn left, Blue and Green cars must turn right." You are driving a green car, so you turn right hoping to reach the City. But instead you get to a dead end with a sign saying "Sorry, only red cars can reach the City." You might turn back, and go to the service and get your car painted in red (then you will be able to turn left at that crossroad), but you can (in theory) only do this trick 5 times. So instead you call your friend (Peer) in RTA and ask him to change the sign (it is an illuminated indicator board, so it can be changed remotely) so that it now says "All cars must turn left.". This way you reach the City.
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With this information, you could write a Blu-Ray-Region reset tool that changes the registry values (XP) or deletes the data-storing file (Vista), so the users no longer need to do it manually. If someone finds out how WinDVD Platinum handles its Blu-Ray-Region data, the tool could also support this player and become the Blu-Ray equivalent of "DVD Genie."
I hope you will find this information useful and the users can look forward to a reset tool. BTW, you could also add BD/HD support to "ZoomPlayer."
Many greetings,
A Friend