[Gdal-dev] Windows CE - GDALDatasetRasterIO error

[Mateusz Loskot]

jetelus at centrum.cz wrote:
> Hi, I open and display raster without problems but when I
> try zooming I get CE_Failure from GDALDatasetRasterIO with
> this error message using GDAL 1.4.2:
> 
> "Assertion `nLockCount == 0' failed in file `..\..\..\gcore
> \gdalrasterblock.cpp', line 219"
> (and app crashs)
> 
> and this error message using GDAL 1.4.3:
> 
> "Out of memory allocating 59765 byte raster cache block."
> (its little better becasuse app doesnt crash)
> 
> RASTER INFO:
> bpp: 1
> compression: LZW
> resolution: 11953 x 10268.
> file size: 658kB
> 
> When I convert this raster to 4 bits per pixel everything
> is ok and I get no errors but raster file size grows to
> 1.7MB. Any ideas? Thx.

I don't know what device you have but you're trying to open ~120 MB
raster in one shot, on mobile device.
The error message is clear to me, you're dealing without of memory issue.

IMHO, it's not a good idea to feed mobile device with images of that
big. Better tile them into smaller pieces, use zoom levels, etc.
GDAL for Windows CE gives you with tools to solve this problem.

Keep in mind that "GDAL for Windows CE" does not mean you can use all
GDAL features on a mobile device the same way as on normal workstation.
There are obvious hardware limitations you can not overcome.

Cheers
-- 
Mateusz Loskot
http://mateusz.loskot.net