Parental Management
| Microsoft DirectShow 9.0 |
Parental Management
This topic applies to Windows XP Service Pack 1 or later.
Any title or portion of a title on a disc allows eight parental management levels (PMLs), one through eight, with eight being the most restrictive. The idea is to provide a way of preventing children from viewing certain content without adult consent. However, there is no requirement that these levels be accurately set, nor is there any direct correlation between these values and the Motion Picture Association of America (MPAA) film ratings, and you cannot rely on DVDs to have parental levels set predictably or accurately.
Disc parental permissions may also be set dynamically, in which case the application must have enabled notification of parental level change using NotifyParentalLevelChange. Enable notification immediately upon running the movie, as parental levels are sometimes changed during the FBI warning section of the disc.
DVD authors have two ways to set the parental levels on a disc. One is through the video title set information. This automatically stops playback without allowing the user to override the settings if a more restrictive parental level is encountered.
The second method sends parental level change notifications to the application, which must then decide what to do. The DVD Navigator filter sends an EC_DVD_PARENTAL_LEVEL_CHANGE message when it encounters PMLs on the disc. By default, it does nothing else. However, if NotifyParentalLevelChange has been set to True, playback will be halted until AcceptParentalLevelChange is called to accept or reject the new level. For more information on handling disc events, see MSVidWebDVD Events.
Parental level is returned by the player as a two-byte value consisting of a series of bit flags indicating whether or not a DVD is playable by a particular parental level. The low byte of the return value is ignored, so the value 1111111100000000 would become 11111111. As an example, a return value of 11100000 (after the low byte has been removed) indicates a disc is playable by a parental level 6 and above. It is possible for all bits to be set to zero, in which case parental levels must be disabled using SelectParentalLevel to watch the movie.
The following code illustrates a message box popup that handles a temporary parental management level message. It is part of the Select Case block that handles DVDNotify event messages, and assumes NotifyParentalLevelChange has been set to True.
Private Sub ovidwebdvd_DVDNotify(ByVal lEventCode As Long, _
ByVal lParam1 As Variant, ByVal lParam2 As Variant)
Select Case lEventCode
If Not (2 ^ (oVidWebDVD.PlayerParentalLevel + 7) And lParam1) Then
Dim strPassword As String
strPassword = InputBox("The disc has encountered restricted_
material. Please enter your password", "Restricted title")
oVidWebDVD.AcceptParentalLevelChange True, "", strPassword
End If
End Select
End Sub
See Also