Hi again,
Following this blog[1], I can import upstream sources with the below gbp.conf. But I don't know if I still needs the "ds" or "dfsg" prefix in the changelog
[import-orig]
filter = [ 'csmApi', 'csm_plugins','gsoc', 'libwms', 'oms', 'ossimGui', 'ossimPlanet', 'ossimPlanetQt', 'ossimPredator',
'ossim_package_support/cmake/build_scripts',
'ossim_package_support/cmake/CMakeModules/FindCPPUNIT.cmake',
'ossim_package_support/cmake/CMakeModules/FindcsmApi.cmake',
'ossim_package_support/cmake/CMakeModules/FindFFmpeg.cmake',
'ossim_package_support/cmake/CMakeModules/FindFFTW3.cmake',
'ossim_package_support/cmake/CMakeModules/FindGeotrans.cmake',
'ossim_package_support/cmake/CMakeModules/FindGPSTK.cmake',
'ossim_package_support/cmake/CMakeModules/FindHDF5A.cmake',
'ossim_package_support/cmake/CMakeModules/FindLASzip.cmake',
'ossim_package_support/cmake/CMakeModules/FindLCMS2.cmake',
'ossim_package_support/cmake/CMakeModules/FindLIBLAS.cmake',
'ossim_package_support/cmake/CMakeModules/FindMrSid.cmake',
'ossim_package_support/cmake/CMakeModules/FindOMS.cmake',
'ossim_package_support/cmake/CMakeModules/FindOpenCV.cmake',
'ossim_package_support/cmake/CMakeModules/FindOpenJPEG.cmake',
'ossim_package_support/cmake/CMakeModules/FindOSG.cmake',
'ossim_package_support/cmake/CMakeModules/FindossimPlanet.cmake',
'ossim_package_support/cmake/CMakeModules/FindossimPredator.cmake',
'ossim_package_support/cmake/CMakeModules/FindPDAL.cmake',
'ossim_package_support/cmake/CMakeModules/FindPodofo.cmake',
'ossim_package_support/cmake/CMakeModules/FindQt5.cmake',
'ossim_package_support/cmake/CMakeModules/FindRapier.cmake',
'ossim_package_support/cmake/CMakeModules/FindSQLITE.cmake',
'ossim_package_support/cmake/CMakeModules/FindWMS.cmake',
'ossim_package_support/cmake/CMakeModules/OssimCPack.cmake',
'ossim_package_support/cmake/CMakeModules/
OssimCPackConfig.cmake.in',
'ossim_package_support/cmake/CMakeModules/OssimQt4Macros.cmake',
'ossim_package_support/cmake/CMakeModules/OssimQt5Macros.cmake',
'ossim_package_support/cmake/packaging',
'ossim_package_support/geoids',
'ossim_package_support/License.rtfd',
'ossim_package_support/PlanetSnap.jpg',
'ossim_package_support/Welcome.rtfd',
'ossim_package_support/fonts',
'ossim_package_support/icons',
'ossim_package_support/Readme.rtfd',
'ossim_package_support/windows_package',
'ossim_package_support/images',
'ossim_package_support/*.pdf',
'ossim_package_support/cmake/*.txt',
'ossim_package_support/ossim*',
'ossim_package_support/rpms',
'ossim_package_support/Worldwind',
'ossim_plugins', 'ossim_qt4', 'ossimjni', 'planet_message', 'pqe']
The above list is also included in Files-Excluded in debian/copyright file.