[Gdal-dev] Windows CE - GDALDatasetRasterIO error

[jetelus at centrum.cz]

>> 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
>

Thank you, I understand but why it works with 4 bpp version of same raster
which is even bigger?