 Understanding System Parameters - SPRMs
A DVD player continually tracks its ongoing operation in a group of
memory registers called System Parameter Register Memories
(SPRMs or “spirms”). The status of the player’s operation (i.e., which
track is playing, what audio stream is currently selected, the last
menu button selected, last chapter marker passed, and so on) can
be read by script commands that access the SPRMs. Unlike the
generic GPRMs, SPRMs have very specific predefined functions...
Here is a list of the System Parameters and their uses:
• SPRM 0: Menu language description code; DVD player setup by user
• SPRM 1: Current audio stream number; set by user or program
• SPRM 2: Current subtitle stream number; set by user or program
• SPRM 3: Current angle number; set by user or program
• SPRM 4: Current playing title number (Title); set by DVD player
• SPRM 5: Current Video Title Set (VTS) number; set by DVD player
• SPRM 6: Current title PGC number; set by DVD player
• SPRM 7: Current part of title number (chapter); set by DVD player
• SPRM 8: Current highlighted button; set by viewer in DVD player
• SPRM 9: Navigation timer; set by program, then times out
• SPRM 10: Timer target; DVD track to play when SPRM 9 times out
• SPRM 11: Audio mix mode for Karaoke; set by program or DVD player
• SPRM 12: Country code for parental management
• SPRM 13: Parental management level currently in effect
• SPRM 14: Player video configuration (Aspect Ratio, Letterbox Mode)
• SPRM 15: Player audio configuration (DTS, AC-3, MPEG, PCM, SDDS)
• SPRM 16: Initial language code for audio, player setup by user
• SPRM 17: Initial language code extension for audio
• SPRM 18: Initial language code for subtitle, player setup by user
• SPRM 19: Initial language code extension for subtitle
• SPRM 20: Player region code
• SPRM 21: Reserved – not currently defined or in use
• SPRM 22: Reserved – not currently defined or in use
• SPRM 23: Reserved – not currently defined or in use
The DVD Studio Pro Scripting language allows you to write values to three of these parameters (SPRM 1, 2, and 3) by using the Set System Stream command.
The usefulness of a fourth, SPRM 8, can be exploited using the Jump Menu command with a specific Button as Target.
SPRM 8 always contains the value of the last Menu button selected by the user multiplied x 1024 (because it’s a binary bit value).
Divide the value of SPRM 8 by 1024 to determine the number of that button. You can use that knowledge to target a jump to the appropriate button on that menu or any other one.
Other SPRMs
The remaining SPRMs cannot be written to by the scripting language. Many of these other SPRMs contain values set by the player owner during setup, or by the manufacturer.
The player’s Region Code (SPRM 20) cannot be changed by the owner, or by scripting, but it can be read by Script commands, so you can determine for what region the player was
originally manufactured. Check the DVD Studio Pro Manual for a complete listing of SPRMs and their values, some of which may look peculiar because of the binary bitmapping used.
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