ECW Files Larger than 2GB

[warmerdam]

It seems that ECW files larger than 2GB are not supported in the 1.2.0
release.  (reported by Timothy Mackey testing on Solaris I think).  

It seems that the file pointer is NULL and nHeaderBytes is zero.  

The code needs to be adjusted to not depend on the file pointer, since that is
NULL for large files.  But testing for a non-zero header bytes should be OK.
Need to track down why it might not be in some circumstances. 

Timothy can be contacted at Timothy.Mackey@ga gov au.

[warmerdam]

> Hi Frank,
> 
> I've just changed the function as you suggested and it works fine:
> 
>     if( !EQUAL(CPLGetExtension(poOpenInfo->pszFilename),"ecw") )
>          return( NULL );
> 
> Over to you to find a more robust fix for the next version. I'm happy to test
> any changes for you if you that helps...

Tim,

Thanks for the feedback.  I have created a bug report to track this problem.
 
  http://bugzilla.remotesensing.org/show_bug.cgi?id=556

My current suspicion is that the "large file support API" was not configured
into GDAL properly.  I try to get back to you in a week or two on this issue.

Best regards,

[warmerdam]

I have reviewed the updated ECWDataset::Open() method and it seems like
it no longer depents on the file pointer and so should be safe for large
files.  I have no way of testing it though.