Determining a DVD drive's region code in OS X in C WITHOUT requiring that a DVD be in the drive

Question

Basically I run a network of computers and need to know what region code the drives of the various computers are set to. I don't need to change the region, but I have no idea how to determine the region without going to each computer individually and sticking in a disc. I tried using Apple's cocoa DVD playback framework, but that requires that a disk be inserted into the drive, which sort of defeats the purpose.

So are there any APIs that I can use to determine the region code on a Mac Pro's DVD drive without requiring that a disc be inserted? I am willing to code in pretty much any language.

Thanks

Answer 1

I found some utilities that are capable of dealing with DVD region settings on OS X: DVD Info X, and Region X. DVD Info X will display the region code of your drive without requiring to have a DVD inserted.

Region X is more interesting because although it doesn't directly serve your purpose, its source is available. Looking at it I found that the ScanAll method in Region X.m is what you need. More specifically, the interesting case is the one where the disk name isn't found (because there's no disk mounted) and a SCSI command is used to find out the DVD drive's properties (the printf calls are my addition):

task = (*scsitaskinterface)->CreateSCSITask(scsitaskinterface);
if (task)
{
    cdb[0] = 0xa4;
    cdb[1] = 0x00;
    cdb[2] = 0x00;
    cdb[3] = 0x00;
    cdb[4] = 0x00;
    cdb[5] = 0x00;
    cdb[6] = 0x00;
    cdb[7] = 0x00;
    cdb[8] = (sizeof(DVDInfo) >> 8) & 0xff;
    cdb[9] = sizeof(DVDInfo) & 0xff;
    cdb[10] = 0x08;
    cdb[11] = 0x00;
    memset(&DVDInfo, 0, sizeof(DVDInfo));
    ProcessCDB(task, cdb, 12, DirIn, &DVDInfo, sizeof(DVDInfo), 30000);

    printf("drive region %#hhx\n", DVDInfo.driveRegion);
    printf("number of region changes left: %hhu\n", DVDInfo.numberUserResets);

    if (DVDInfo.rpcScheme == 0) RPC1++;
    if (DVDInfo.rpcScheme != 0) RPC2++;

    (*task)->Release(task);
}

I ran this on my Macbook Pro and the result was as expected.

Obviously you'll need to massage it in order to isolate that part into something you can use, but I think that this code will be a useful starting point.