Building GDAL

coworker tried to build/install/use gdal with ECW file type support. it was difficult. you need the ECW drivers from Hexagon Spatial: https://download.hexagongeospatial.com/en/downloads/ecw/erdas-ecw-jp2-sdk-v5-5-update-2-windows 2.5 methods that worked:

1. build vanilla GDAL with cmake 1.5 install gdal package with Nuget (likely works on other platforms and package managers)
   • there should be a file path of x64/Debug/gdal with the main binaries in the install location
   • under this GDAL folder create a plugins directory e.g. gdal/plugins
   • from Hexagon get their drivers (latest 5.5 at time of writing), you have to fill in their form
   • copy these DLLs into the plugins directory
   • GDAL should now be able to read ECW
   • if you want to write ECW files, you need to pay Hexagon for a license
   • quickly check on the command line with gdalinfo --formats and look for ECW in the output
2. build GDAL with ECW support
   • as above, get drivers from Hexagon in first cmake step: cmake -DECW_INCLUDE_DIR="/path/to/dll" -DECW_LIBRARY="/path/to/other/DLL" other cmake steps as normal
   • check on the command line with gdalinfo --formats and look for ECW in the output