Large Raw Files

Frank Warmerdam warmerdam at p...
Wed Dec 12 13:50:05 EST 2001

Lowell and Others,

I have altered the RawRasterBand class so it includes an optional
extra bIsVSIL parameter. If FALSE (the default), then the normal
VSI API will be used for file IO, and files may only be up to 2GB. If
TRUE then the large file API (ie. VSIFSeekL(), VSIFReadL() and VSIFWriteL())
will be used instead of the regular one.

I have altered the PAux, and HKV (aka MFF2) formats to utilize this.

To utilize this for LDF please ensure that you use the large file API
to open and access your file, and pass bIsVSIL=TRUE when in the constructor
call to RawRasterDataset. Let me know if you have questions about how to
use the large file API.

I don't have any convenient way to test this, so if you could do some testing
with 5GB LDF and PAux files I would appreciate it.

The large file API changes can be extented to other formats like ESRI labelled
BIL, Envisat, and SAR_CEOS if needed. Anyone who wants this, and is willing
to test it let me know and I will make the changes.

Best regards,

I set the clouds in motion - turn up | Frank Warmerdam, warmerdam at p...
light and sound - activate the windows |
and watch the world go round - Rush | Geospatial Programmer for Rent

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