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Re: Help needed on value translation of dissected bits


From: John Tapparo <jttdi () pobox com>
Date: Thu, 3 Dec 2009 15:52:45 -0500

Does defining it as
{ &hf_myproto_B,
  { "B Value", "myproto.b",
       FT_UINT16, BASE_DEC, NULL, 0xff80, NULL, HFILL
  }
}

And then using
proto_tree_add_item(tree, hf_myproto_B, tvb, o, 2, TRUE);
do what you want (basically telling it that the value is little_endian)?

On Wednesday 02 December 2009 11:55:55 Jarolin, Robert wrote:
Let me give an example:
Assume that you have 2 bytes to dissect that are formatted as follows:
- There are 2 values, A and B that are encoded into 2 Bytes
- Value A has a maximum size of 127 and is encoded using the lower 7
bits of Byte 1
- Value B has a maximum size of 511 and is encoded using all 8 bits in
Byte 2 along with bit 8 in Byte 1 representing the MSB for Value B

Normally, I would define the dissection in the hf structure as follows:
{ &hf_myproto_B,
  { "B Value", "myproto.b",
       FT_UINT16, BASE_DEC, NULL, 0x80ff, NULL, HFILL
  }
}
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