[gdal-dev] Utilities as a library, C API

[Even Rouault]

On Thursday 20 October 2016 15:03:03 Ivan Lucena wrote:
> Hi Even,
> 
> 
> OK. It is what it is. I guess.
> 
> 
> I wrote a little test code:
> 
> 
> #include <gdal.h>
> #include <gdal_utils.h>
> 
> int main( int argc, char** argv )
> {
>    char* papszArgv[1024];
>    int i = 0;
> 
>    const char*     pszSrcFilename = "rgbsmall.tif";
>    const char*     pszDstFilename = "test90.tif";
> 
>    GDALDatasetH    hSrcDataset = NULL;
>    GDALDatasetH    hDstDataset = NULL;
> 
>    GDALTranslateOptions* psOptions = NULL;
> 
>    GDALAllRegister();
> 
>    papszArgv[i++] = "-of";
>    papszArgv[i++] = "GTIFF";
> 
>    papszArgv[i++] = "-b";
>    papszArgv[i++] = "3";
> 
>    papszArgv[i++] = "-b";
>    papszArgv[i++] = "2";
> 
>    papszArgv[i++] = "-b";
>    papszArgv[i++] = "1";
> 
>    papszArgv[i++] = "-srcwin";
>    papszArgv[i++] = "10";
>    papszArgv[i++] = "10";
>    papszArgv[i++] = "30";
>    papszArgv[i++] = "30";
> 
>    papszArgv[i++] = "-co";
>    papszArgv[i++] = "BLOCKXSIZE=4";
> 
>    papszArgv[i++] = "-co";
>    papszArgv[i++] = "BLOCKYSIZE=4";
> 
>    papszArgv[i++] = NULL;
> 
>    psOptions   = GDALTranslateOptionsNew( papszArgv, NULL );
> 
>    hSrcDataset = GDALOpen( pszSrcFilename, GA_ReadOnly );
> 
>    hDstDataset = GDALTranslate( pszDstFilename, hSrcDataset, psOptions, NULL
> );
> 
>    GDALTranslateOptionsFree( psOptions );
> 
>    GDALClose( hSrcDataset );
> 
>    GDALClose( hDstDataset );
> }
> 
> 
> And I can say that it does work as expected. Maybe we should put that
> example somewhere on the wiki.
> 
> 
> I found to interesting issues. That is just a C application using the GDAL C
> API but I could only compile with g++, not with gcc.

Could you be more specific about the error you got ? It should be usable from 
pure C, but I'm not 100% positive this has been tested

> The GTIFF create-option BLOCKXSIZE doesn't seems to work. I tries with
> larger images and it seems like we can only control the number of rows on a
> block (BLOCKYSIZE),  but not the number of columns (BLOCKXSIZE).

BLOCKXSIZE is only taken into account if you also define TILED=YES.

Even

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