It's not clear to me if this parameter is a pointer to a single AnalogVideoStandard, or a enumeration.
It's neither1:
Pointer to a variable that receives a bitwise OR of zero or more flags from the AnalogVideoStandard enumeration.
It's a pointer to a value that represents zero or more AnalogVideoStandard
s.
This answer should explain the rest. You should be able to apply this answer to your .NET code.
1 Technically it could be an enumeration value in C# because enum
types can have a FlagsAttribute
applied to them but there's no equivalent in C++, you just |
values together with no special fanfare.