Changes between Version 1 and Version 2 of rfc45_virtualmem


Ignore:
Timestamp:
Dec 17, 2013, 12:21:02 PM (10 years ago)
Author:
Even Rouault
Comment:

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  • rfc45_virtualmem

    v1 v2  
    6868* GDALDatasetGetVirtualMem() : takes almost the same arguments as GDALDatasetRasterIO(), with the notable exception of a pData buffer. It returns a CPLVirtualMem* object, from which the base address of the virtual memory mapping can be obtained with CPLVirtualMemGetAddr().
    6969
     70[[Image(rfc_2d_array.png)]]
     71
    7072* GDALRasterBandGetVirtualMem(): equivalent of GDALDatasetGetVirtualMem() that operates on a raster band object rather than a dataset object.
    7173
    7274* GDALDatasetGetTiledVirtualMem(): this is a rather original API. Instead of presenting a 2D view of the image data (i.e. organized rows by rows), the mapping exposes it as an array of tiles, which is more suitable, performance wise, when the dataset is itself tiled.
    7375
    74                             [ INSERT SCHEMA HERE ]
    75 
    76   When they are several bands, 3 different organizations of band components are possible. To the best of our knowledge, there is no standard way of calling those organizations, which consequently will be best illustrated by the folowing schemas :
    77 
    78                             [ INSERT SCHEMAS HERE ]
     76[[Image(rfc_tiled.png)]]
     77
     78  When they are several bands, 3 different organizations of band components are possible. To the best of our knowledge, there is no standard way of calling those organizations, which consequently will be best illustrated by the following schemas :
     79
     80     - TIP / Tile Interleaved by Pixel : [[Image(rfc_TIP.png)]]
     81     - BIT / Band Interleaved by Tile : [[Image(rfc_BIT.png)]]
     82     - BSQ / Band SeQuential organization : [[Image(rfc_BSQ.png)]]
    7983
    8084* GDALRasterBandGetTiledVirtualMem(): equivalent of GDALDatasetGetTiledVirtualMem() that operates on a raster band object rather than a dataset object.
    … …  
    875879On a Linux AMD64 machine with 4 GB RAM, the Python binding of
    876880GDALDatasetGetTiledVirtualMem() has been successfully used to access random points
    877 on the new [http://www.eea.europa.eu/data-and-maps/data/eu-dem/ Europe 3'' DEM dataset],
     881on the new [http://www.eea.europa.eu/data-and-maps/data/eu-dem/#tab-original-data Europe 3'' DEM dataset],
    878882which is a 20 GB compressed GeoTIFF ( and 288000 * 180000 * 4 = 193 GB uncompressed )
    879883