Christiaan Janssen wrote:
I was recently trying to open a NITF (jpeg blocked) file whose size was roughly 5GB using the stable 1.6 release and having quite a bit of trouble. Namely, I'm getting Access Violation Exception in the calls to CloseHandle. I dug around in the source a bit and noticed the code for the NITFdataset was referncing various file indexes that were stored in 32bit int's, this would obviously cause an issue for files of this size, maybe not specifically the issue I'm seeing but definitely with respect to raster data access. Does anyone know if this is a known issue and if so is there any way to work with this, or is this something thats needing to be addressed? Thanks.
Christian, You are correct that the GDAL NITF driver was written based on the assumption that NITF files are no larger than 4GB (the largest value representable in a 32bit unsigned integer). Reviewing the specification very briefly, I see that size values are specified in a variety of ways, and for image data segment size it is a 10 digit value which would in theory represent values up to nearly 10GB. The GDAL NITF driver could be upgraded to support large files but it seems there are still significant issues inherent in the format with large files. I don't have any large files to test with, but if you are able to provide your data file, and you are sufficiently motivated I could likely queue up the task of adding "big file" support to the driver, at least for reading. Best regards, -- ---------------------------------------+-------------------------------------- I set the clouds in motion - turn up | Frank Warmerdam, warmer...@pobox.com light and sound - activate the windows | http://pobox.com/~warmerdam and watch the world go round - Rush | Geospatial Programmer for Rent _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev