[Gdal-dev] Windows CE - GDALDatasetRasterIO error
Tom Kazimiers
2voodoo at gmx.de
Sat Nov 24 16:53:42 EST 2007
jetelus at centrum.cz schrieb:
> > _____________________________________________________________
> >
>
>> >> Od: jetelus at centrum.cz
>> >> Komu: <gdal-dev at lists.maptools.org>
>> >> Datum: 05.11.2007 14:22
>> >> Předmět: Re: [Gdal-dev] Windows CE - GDALDatasetRasterIO error
>> >>
>> >>
>>
>>> >>> jetelus at centrum.cz schrieb:
>>> >>>
>>>
>>>>> >>>>> 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
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>
>>>>>>> >>>>>>>
>>>>>>>
>>>>>> >>>>>> Thank you, I understand but why it works with 4 bpp version of same raster
>>>>>> >>>>>> which is even bigger?
>>>>>> >>>>>>
>>>>>> >>>>>>
>>>>>>
>>>>> >>>>> You wrote that you don't get any errors, but does it mean you can load it
>>>>> >>>>> and display?
>>>>> >>>>>
>>>>> >>>>> Perhaps there is a bug, we can not exclude this option :-)
>>>>> >>>>> If you want, you can send me your image file and piece of code presenting
>>>>> >>>>> what are you doing exactly, then I will be able to investigate the problem.
>>>>> >>>>>
>>>>> >>>>> Cheers
>>>>> >>>>> --
>>>>> >>>>> Mateusz Loskot
>>>>> >>>>> http://mateusz.loskot.net
>>>>> >>>>>
>>>>> >>>>>
>>>>> >>>>>
>>>>>
>>>> >>>> Yes, I can load and display image. I get this error only when zooming.
>>>> >>>> (and no errors at all for 4bpp version)
>>>> >>>>
>>>> >>>> I have this code:
>>>> >>>> (Windows Mobile 2003 Second Edition)
>>>> >>>>
>>>> >>>> --------------------------------------------------------------------------------
>>>> >>>> ...
>>>> >>>> int panBandMap[1];
>>>> >>>> panBandMap[0] = 1;
>>>> >>>>
>>>> >>>> unsigned char* pData = (unsigned char*) malloc(nBufXSize * nBufYSize);
>>>> >>>>
>>>> >>>> if (!pData)
>>>> >>>> {
>>>> >>>> CString msg("Not enough memory.");
>>>> >>>> TRACE(msg);
>>>> >>>> MessageBox(NULL,msg,NULL,0);
>>>> >>>> return false;
>>>> >>>> }
>>>> >>>>
>>>> >>>> CPLErr e=GDALDatasetRasterIO(HDataset, GF_Read, nXOff, nYOff, nXSize, nYSize,
>>>> >>>> pData, nBufXSize, nBufYSize, GDT_Byte, 1, panBandMap, 1, nBufXSize, 1);
>>>> >>>>
>>>> >>>> if (e != CE_None)
>>>> >>>> {
>>>> >>>> free(pData);
>>>> >>>> CString msg(CPLGetLastErrorMsg());
>>>> >>>> TRACE(msg);
>>>> >>>> MessageBox(NULL,msg,NULL,0);
>>>> >>>> return false;
>>>> >>>> }
>>>> >>>> ...
>>>> >>>> show loaded raster
>>>> >>>> ...
>>>> >>>> free(pData);
>>>> >>>> --------------------------------------------------------------------------------
>>>> >>>>
>>>> >>>> works for whole image:
>>>> >>>>
>>>> >>>> nXOff = 0
>>>> >>>> nYOff = 0
>>>> >>>> nXSize = 11953
>>>> >>>> nYSize = 10268
>>>> >>>> nBufXSize = 224
>>>> >>>> nBufYSize = 192
>>>> >>>>
>>>> >>>> gives "Out of memory allocating 59765 byte raster cache block." for
>>>> >>>> raster part (same for similar areas when zooming):
>>>> >>>>
>>>> >>>> nXOff = 3011
>>>> >>>> nYOff = 1571
>>>> >>>> nXSize = 7115
>>>> >>>> nYSize = 6561
>>>> >>>> nBufXSize = 248
>>>> >>>> nBufYSize = 228
>>>> >>>>
>>>> >>>> Image is here (450kB):
>>>> >>>>
>>>> >>>> http://rapidshare.com/files/67552472/tif_lzw.rar.html
>>>> >>>>
>>>> >>>> Thx for your time.
>>>> >>>>
>>>> >>>> _______________________________________________
>>>> >>>> Gdal-dev mailing list
>>>> >>>> Gdal-dev at lists.maptools.org
>>>> >>>> http://lists.maptools.org/mailman/listinfo/gdal-dev
>>>> >>>>
>>>> >>>>
>>>> >>>>
>>>>
>>> >>> Hi,
>>> >>>
>>> >>> I tryed your image out with my code and was surprised that my code can
>>> >>> handle that large images ;) - so just a question: Are there overviews in
>>> >>> the image?
>>> >>>
>>> >>> With my code I was able to pan and zoom around - but after about 8
>>> >>> actions (I do not know exactly what the problem is - well, I will look
>>> >>> after it) I get the same error with the same amount of memory:
>>> >>> Return: 3
>>> >>> Last Error: Out of memory allocating 59765 byte raster cache block./
>>> >>>
>>> >>> This error occured one time after I zoomed in (with about factor 2) and
>>> >>> another time when I zoomed out (about factor 0.4) -but not all the time.
>>> >>> I was also abtle to zoom deep in and out.
>>> >>> With only panning I get this error not that fast I think.
>>> >>>
>>> >>> I don't know if this helps- but I try to test some more tonight.
>>> >>>
>>> >>> Bye,
>>> >>> Tom
>>> >>>
>>> >>>
>>>
>> >> Hi,
>> >> thx for testing the image. I tryed to zoom to very small areas and it works.
>> >> So I added check for free memory before and after GDALDatasetRasterIO call
>> >> and discovered there is 11 MB difference. This is probably reason why all
>> >> following operations with larger areas are out of memory.
>> >>
>> >> _______________________________________________
>> >> Gdal-dev mailing list
>> >> Gdal-dev at lists.maptools.org
>> >> http://lists.maptools.org/mailman/listinfo/gdal-dev
>> >>
>> >>
>>
> >
> > Finally I solved it! I was hunting that lost memory and I
> > discovered there is cache system implemented in GDAL :-)
> > Problem is it's default size - 40 MB - too much for CE.
> > I set it to 4 MB using GDALSetCacheMax() and all errors are
> > gone - lol I suck I know :) but it would be nice to add some
> > note to GDALDatasetRasterIO documentation - something like
> > there is cache system which memory usage can be controlled.
> > I can display even 5 MB JPEGs now on CE! Have a nice day!
> >
> > to Tom: There are no overviews in that image. BTW how are you
> > doing with that CCITTFax? I am interested in it too :)
> >
> > _______________________________________________
> > Gdal-dev mailing list
> > Gdal-dev at lists.maptools.org
> > http://lists.maptools.org/mailman/listinfo/gdal-dev
> >
> >
>
I read this message somehow too late - sorry.
This tip works also for me quite well - thank you.
Up to now I was not able to solve the problem with CCITTFax - I just can
not read it with GDAL (see the other thread from November 2.)
Have you had any success with this?
Bye,
Tom
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