[gdal-dev] Large Raw Files

Frank Warmerdam warmerdam at p...
Wed Dec 12 17:46:19 EST 2001

ldjohn at u... wrote:

> I just tested with LDF format and it seems to work fine. Created a
> 3-band image with:
> band 1: 40,000 lines x 60,000 samples, GDT_Byte
> band 2: 250 x 250 , GDT_Int16
> band 3: 500 x 500 , GDT_Int32
> Image file (.img) size: 2,401,125,000


Excellent! It would be good to test over 4GB too. What platform was
this testing on?

> One thing I've noticed is that the RawRasterBand->nImgOffset member is of
> type unsigned int. That will take us up to 4GB, but what after
> that? Should this be a long long?

The type of nImgOffset in the constructor calls, and within the class for
RawRasterBand (as found in rawdataset.h:1.7) is vsi_l_offset which should
be a 64bit type on platforms where a 64bit type is available. Note that
the default configuration on Linux does not (as far as I know) support large
file IO. It has been successfully tested on Solaris, NT and IRIX. Some
linux versions can also support large file IO, but I doubt the configure
logic finds it.

Best regards,
I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at p...
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | Geospatial Programmer for Rent

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