Hello,

I need to be able to read a binary file that contains fields written in
BOTH big endian and little endian byte orders. I am currently unable to
read the big endian fields (erroneous values because of the different
byte orders).

I am currently using FileStream and BinaryReader objects to open and
read the file. As I mentioned above calls to ReadInt32() return
erroneous values becuase of the byte order on the big endian fields.

Is there some sort of "magic" converter, like...

BigEndianToLittleEndian(r.ReadInt32());

that I can use to correctly get at the data?

What is the best method to use to crack this problem?

Thanks in advance.

Hello, (E-Mail Removed)!

jp> I need to be able to read a binary file that contains fields written in
jp> BOTH big endian and little endian byte orders. I am currently unable to
jp> read the big endian fields (erroneous values because of the different
jp> byte orders).

jp> I am currently using FileStream and BinaryReader objects to open and
jp> read the file. As I mentioned above calls to ReadInt32() return
jp> erroneous values becuase of the byte order on the big endian fields.

jp> Is there some sort of "magic" converter, like...

jp> BigEndianToLittleEndian(r.ReadInt32());

Yep, there is :8-)
Look at
IPAddress.HostToNetworkOrder and vice versa IPAddress.NetworkToHostOrder

--
Regards, Vadym Stetsyak
www: http://vadmyst.blogspot.com

(E-Mail Removed) wrote:

> Hello,
>
> I need to be able to read a binary file that contains fields written in
> BOTH big endian and little endian byte orders. I am currently unable to
> read the big endian fields (erroneous values because of the different
> byte orders).
>
> I am currently using FileStream and BinaryReader objects to open and
> read the file. As I mentioned above calls to ReadInt32() return
> erroneous values becuase of the byte order on the big endian fields.
>
> Is there some sort of "magic" converter, like...
>
> BigEndianToLittleEndian(r.ReadInt32());
>
> that I can use to correctly get at the data?
>
> What is the best method to use to crack this problem?
>
> Thanks in advance.

Hi Joey,

Try this out for size:

///
public int SwitchEndian ( int i )
{
return ( (i & 0xFF000000) >> 24 ) |
( (i & 0xFF0000) >> 8 ) |
( (i & 0xFF00) << 8 ) |
( (i & 0xFF) << 24 );
}
///

-- Tom Spink

Wow! Thanks man.

Vadym Stetsyak wrote:
> Hello, (E-Mail Removed)!
>
> jp> I need to be able to read a binary file that contains fields written in
> jp> BOTH big endian and little endian byte orders. I am currently unable to
> jp> read the big endian fields (erroneous values because of the different
> jp> byte orders).
>
> jp> I am currently using FileStream and BinaryReader objects to open and
> jp> read the file. As I mentioned above calls to ReadInt32() return
> jp> erroneous values becuase of the byte order on the big endian fields.
>
> jp> Is there some sort of "magic" converter, like...
>
> jp> BigEndianToLittleEndian(r.ReadInt32());
>
> Yep, there is :8-)
> Look at
> IPAddress.HostToNetworkOrder and vice versa IPAddress.NetworkToHostOrder
>
> --
> Regards, Vadym Stetsyak
> www: http://vadmyst.blogspot.com

"(E-Mail Removed)" wrote:

> Hello,
>
> I need to be able to read a binary file that contains fields written in
> BOTH big endian and little endian byte orders. I am currently unable to
> read the big endian fields (erroneous values because of the different
> byte orders).
>
> I am currently using FileStream and BinaryReader objects to open and
> read the file. As I mentioned above calls to ReadInt32() return
> erroneous values becuase of the byte order on the big endian fields.
>
> Is there some sort of "magic" converter, like...
>
> BigEndianToLittleEndian(r.ReadInt32());
>
> that I can use to correctly get at the data?
>
> What is the best method to use to crack this problem?

I've made some tests some time ago (try to search for "bigendian" and you'll
find the post/discussion).

The best method is: since you've reading a file, read the contents to a
byte[] array and then do this:

byte[] myArr; // where you read
int mSLittleEndian;

// i is the current index

mSLittleEndian = myArr[i] | (myArr[i+1] << 8) | (myArr[i+2] << 16) |
(myArr[i+3]
<< 24);

That is faster than reading it to a int and do the "& 0xFF00000 >> 24" twist.

best
doc