Hi There, I am not quite sure that I understood your problem, but I am pretty sure that you can write whatever bock size you want. On the "GDAL implementation tutorial" [1] you should that especial attention to fill up those attributes:
GDALDataset::nRasterXSize GDALDataset::nRasterYSize GDALRasterBand::nBlockYSize GDALRasterBand::nBlockXSize GDALRasterBand::eDataType That will tell how GDAL will handle its internal block buffers. You can take a look at one of the drivers that I wrote as example: http://trac.osgeo.org/gdal/browser/trunk/gdal/frmts/idrisi/IdrisiDataset.cpp#L500 http://trac.osgeo.org/gdal/browser/trunk/gdal/frmts/idrisi/IdrisiDataset.cpp#L1261 Regards, Ivan > -------Original Message------- > From: Cherif Oueslati <[EMAIL PROTECTED]> > Subject: [gdal-dev] [GDAL dev][GDALRasterBand::IReadBlock] About how to read > all the raster bands. > Sent: Oct 10 '08 07:22 > > Hello, > > > I am implementing a format specific driver to add new format. So i have to > read raster bands from a file in addition of the metadata given in the > header. > > The gdalinfo.exe is working effeciently, by using an OGRSpatialReference > object. However i found a problem with the gdal_translate.exe application. > > > In fact, and when debugging, an error appears indicating that it's > impossible to write in certain memory address, knowing that the input file > to read contain 501 pixels (corresponding to nBlockXSize) and 501 lines > (corresponding to nBlockYSize). > > To avoid this problem, i changed the number of iterations in the for loop, > which is allowing reading all the raster bands and filling into the pImage, > from (nBlockXSize*nBlockYSize) to (nBlockXSize*125). > > As a consequence i obtain an image that is a part of the whole image to > read which is logic, since i'm not putting all the raster bands. > > > So to summarise the problem: (nBlockXSize*125) is the maximum rows that i > can put into the destination file image or i have to use all the > (nBlockXSize*nBlockYSize) raster bands. > > I think that it's related to the default size of the destination file > image. > > I used CPLMalloc, CPLRealloc, memset and memcpy functions but it was > fruitless. Could you tell me how to modify this default size? > > Otherwise have you any other suggestions. > > > With all my regards. > > Cherif OUESLATI > -------------------- > _______________________________________________ > gdal-dev mailing list > [LINK: [EMAIL PROTECTED] [email protected] > [LINK: http://lists.osgeo.org/mailman/listinfo/gdal-dev] > http://lists.osgeo.org/mailman/listinfo/gdal-dev _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
