[Liblas-devel] ReadPointAt bug

[Mateusz Loskot]

Howard Butler wrote:
> I'm not sure, and we would need a spec hound to verify, but I think that 
> the file in question is not following the spec.  It *says* it is 1.0, 
> but it has a 28 byte record length (this would imply a 1.1 version file, 
> right)?  So, who are we to believe?  The file version, like we were 
> doing, or the record length, which in this case produces the correct 
> results?
> 
> Mateusz, do you have anything to add on this?

There are two identifiers that control LAS file processing:

1. LAS File Version (1.0 or 1.1)
2. Point Format ID (0 or 1)

So, following combinations are valid:

- point record size is 20 bytes
1.0 & 0
1.1 & 0

- point record size is 28 bytes
1.0 & 1
1.1 & 1

The libLAS strongly depends on what's written to the header, so this 
information must be as stated above, otherwise we are dealing with 
invalid LAS file.

If the information in header is correct, then we likely are having a bug.

Which one is true?

Greetings
--
Mateusz Loskot
http://mateusz.loskot.net