Alex Rivera | Logout

Bit fields in C#

Asked 2008-08-18T11:19:28.367
88

I have a structure which I need to populate and write to disk (several actually).

An example is:

byte-6    
bit0 - original_or_copy  
bit1 - copyright  
bit2 - data_alignment_indicator  
bit3 - PES_priority  
bit4-bit5 - PES_scrambling control.  
bit6-bit7 - reserved  

In C I might do something like the following:

struct PESHeader  {
    unsigned reserved:2;
    unsigned scrambling_control:2;
    unsigned priority:1;
    unsigned data_alignment_indicator:1;
    unsigned copyright:1;
    unsigned original_or_copy:1;
};

Is there any way to do this in C# that would enable me to access the bits using the struct dereferencing dot operator?

For a couple of structures, I can just do bit shifting wrapped in an accessor function.

I have loads of structures to handle in this way, so I'm looking for something that's easier to read and quicker to write.

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26

By using an enum you can do this, but will look awkward.

[Flags]
public enum PESHeaderFlags
{
    IsCopy = 1, // implied that if not present, then it is an original
    IsCopyrighted = 2,
    IsDataAligned = 4,
    Priority = 8,
    ScramblingControlType1 = 0,
    ScramblingControlType2 = 16,
    ScramblingControlType3 = 32,
    ScramblingControlType4 = 16+32,
    ScramblingControlFlags = ScramblingControlType1 | ScramblingControlType2 | ... ype4
    etc.
}
answered 2008-08-18T12:25:51.697

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