rt_band_new_offline_from_path()

rt_band rt_band_new_offline_from_path	(	uint16_t	width,
		uint16_t	height,
		int	hasnodata,
		double	nodataval,
		uint8_t	bandNum,
		const char *	path,
		int	force
	)

Create an out-db rt_band from path.

Parameters

width	: number of pixel columns
height	: number of pixel rows
hasnodata	: indicates if the band has nodata value
nodataval	: the nodata value, will be appropriately
bandNum	: 1-based band number in the external file to associate this band with.
path	: NULL-terminated path string pointing to the file containing band data. The string will NOT be copied, ownership is left to caller which is responsible to keep it allocated for the whole lifetime of the returned rt_band.
force	: if True, ignore all validation checks

Returns

an rt_band, or 0 on failure

Definition at line 199 of file rt_band.c.

  {
        GDALDatasetH hdsSrc = NULL;
        int nband = 0;
        GDALRasterBandH hbandSrc = NULL;
 
        GDALDataType gdpixtype;
        rt_pixtype pt = PT_END;
 
        /* open outdb raster file */
        rt_util_gdal_register_all(0);
        hdsSrc = rt_util_gdal_open(path, GA_ReadOnly, 1);
        if (hdsSrc == NULL && !force) {
                rterror("rt_band_new_offline_from_path: Cannot open offline raster: %s", path);
                return NULL;
        }
 
        nband = GDALGetRasterCount(hdsSrc);
        if (!nband && !force) {
                rterror("rt_band_new_offline_from_path: No bands found in offline raster: %s", path);
                GDALClose(hdsSrc);
                return NULL;
        }
        /* bandNum is 1-based */
        else if (bandNum > nband && !force) {
                rterror(
                        "rt_band_new_offline_from_path: Specified band %d not found in offline raster: %s",
                        bandNum,
                        path
                );
                GDALClose(hdsSrc);
                return NULL;
        }
 
        hbandSrc = GDALGetRasterBand(hdsSrc, bandNum);
        if (hbandSrc == NULL && !force) {
                rterror(
                        "rt_band_new_offline_from_path: Cannot get band %d from GDAL dataset",
                        bandNum
                );
                GDALClose(hdsSrc);
                return NULL;
        }
 
        gdpixtype = GDALGetRasterDataType(hbandSrc);
        pt = rt_util_gdal_datatype_to_pixtype(gdpixtype);
        if (pt == PT_END && !force) {
                rterror(
                        "rt_band_new_offline_from_path: Unsupported pixel type %s of band %d from GDAL dataset",
                        GDALGetDataTypeName(gdpixtype),
                        bandNum
                );
                GDALClose(hdsSrc);
                return NULL;
        }
 
        /* use out-db band's nodata value if nodataval not already set */
        if (!hasnodata)
                nodataval = GDALGetRasterNoDataValue(hbandSrc, &hasnodata);
 
        GDALClose(hdsSrc);
 
        return rt_band_new_offline(
                width, height,
                pt,
                hasnodata, nodataval,
                bandNum - 1, path
        );
}

References PT_END, rt_band_new_offline(), rt_util_gdal_datatype_to_pixtype(), rt_util_gdal_open(), rt_util_gdal_register_all(), and rterror().

Referenced by RASTER_addBandOutDB(), RASTER_setBandPath(), and test_band_new_offline_from_path().

Here is the call graph for this function:

Here is the caller graph for this function: