[Gdal-dev] how to use GDAL MEM driver

[Zhaoqiang Bi]

Hi,

I am trying to create an array in memory as a GDAL dataset. Below is the code snippet to do it, but it crashes at the functions which uses dataset as inputs. Any help is appreciated!

Bi
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     char gdal_driver[20] = "GTiff";

    GDALAllRegister();
    int lines = _lines;
    int pixels = _pixels;

    GDALDataType datatype = get_datatype();
    pixelbytes = GDALGetDataTypeSize(datatype)/8;
    mode = 2;
    seedmode=1;
    modified = 0;

    /*reset datatype to float if not specified*/
    if (datatype == GDT_Unknown)
       datatype = GDT_Float32;

    /* Allocate memory for block */
    dat=(type *)malloc(block_lines*block_pixels*pixelbytes);
    if(dat==NULL)
       throw "No memory";

    dat2=(type **)malloc(block_lines*sizeof(type *));
    if(dat2==NULL)
    {
        free(dat);
        throw "No memory";
    }
    tmp=(type *)dat;
    for(i=0;i<block_lines;i++) dat2[i]=&tmp[i*block_pixels];

    /* Create a GDAL object */
    long int datpt =(long int) &dat2;
    char* filename = (char*) malloc(1024);
        sprintf(filename,"MEM:::DATAPOINTER=%d,PIXELS=%d,LINES=%d,BANDS=1,DATATYPE=%d,PIXELOFFSET=0,LINEOFFSET=0,BANDOFFSET=0",datpt,pixels,lines,datatype);
    dataset = GDALOpen(filename,GA_Update);

    if (dataset == NULL)
      printf("Failed to create file %s. Might exist already.\n",filename);
      throw "fail";
        }
    band = GDALGetRasterBand(dataset,1);
    for (i = 0; i<lines; i++)
        GDALRasterIO(band, GF_Write,0,i,pixels,1, dat, pixels,1, datatype,0,0);

    GDALFlushCache(dataset); //crash here
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