How to install openCV with Gstreamer capabilities?

Hey guys! I am trying to add Gstreamer with my openCV on the Jetson Nano.

I used this website:
to get a rough idea of how to build it.

It actually worked at first but once i did

sudo apt install opencv-python

, it somehow overrided the opencv(with Gstreamer installed).

Now in the terminal when i enter


and then

import cv2 
print cv2.getBuildInformation()

I get this

General configuration for OpenCV 3.2.0 =====================================
  Version control:               unknown

  Extra modules:
    Location (extra):            /build/opencv-XDqSFW/opencv-3.2.0+dfsg/contrib/modules
    Version control (extra):     unknown

    Timestamp:                   2018-09-20T09:28:13Z
    Host:                        Linux 4.4.0-135-generic aarch64
    CMake:                       3.10.2
    CMake generator:             Unix Makefiles
    CMake build tool:            /usr/bin/make
    Configuration:               Release

    Built as dynamic libs?:      YES
    C++ Compiler:                /usr/bin/c++  (ver 7.3.0)
    C++ flags (Release):         -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security  -DNDEBUG
    C++ flags (Debug):           -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wundef -Winit-self -Wpointer-arith -Wshadow -Wsign-promo -Wno-narrowing -Wno-delete-non-virtual-dtor -Wno-comment -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fvisibility=hidden -fvisibility-inlines-hidden -g  -O0 -DDEBUG -D_DEBUG
    C Compiler:                  /usr/bin/cc
    C flags (Release):           -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fvisibility=hidden -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security  -DNDEBUG
    C flags (Debug):             -g -O2 -fdebug-prefix-map=/build/opencv-XDqSFW/opencv-3.2.0+dfsg=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2   -fsigned-char -W -Wall -Werror=return-type -Werror=non-virtual-dtor -Werror=address -Werror=sequence-point -Wformat -Werror=format-security -Wmissing-declarations -Wmissing-prototypes -Wstrict-prototypes -Wundef -Winit-self -Wpointer-arith -Wshadow -Wno-narrowing -Wno-comment -fdiagnostics-show-option -pthread -fomit-frame-pointer -ffunction-sections -fvisibility=hidden -g  -O0 -DDEBUG -D_DEBUG
    Linker flags (Release):      -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now
    Linker flags (Debug):        -Wl,-Bsymbolic-functions -Wl,-z,relro -Wl,-z,now
    ccache:                      NO
    Precompiled headers:         NO
    Extra dependencies:          /usr/lib/aarch64-linux-gnu/ gdcmMSFF /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/ gtk-3 gdk-3 pangocairo-1.0 pango-1.0 atk-1.0 cairo-gobject cairo gdk_pixbuf-2.0 gio-2.0 gobject-2.0 glib-2.0 gthread-2.0 dc1394 avcodec avformat avutil swscale avresample gphoto2 gphoto2_port /usr/lib/aarch64-linux-gnu/hdf5/serial/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ vtkRenderingOpenGL vtkImagingHybrid vtkIOImage vtkCommonDataModel vtkCommonMath vtkCommonCore vtksys vtkCommonMisc vtkCommonSystem vtkCommonTransforms vtkCommonExecutionModel vtkDICOMParser vtkIOCore /usr/lib/aarch64-linux-gnu/ vtkmetaio /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ vtkImagingCore vtkRenderingCore vtkCommonColor vtkFiltersExtraction vtkFiltersCore vtkFiltersGeneral vtkCommonComputationalGeometry vtkFiltersStatistics vtkImagingFourier vtkalglib vtkFiltersGeometry vtkFiltersSources vtkInteractionStyle vtkRenderingLOD vtkFiltersModeling vtkIOPLY vtkIOGeometry vtkFiltersTexture vtkRenderingFreeType /usr/lib/aarch64-linux-gnu/ vtkftgl vtkIOExport vtkRenderingAnnotation vtkImagingColor vtkRenderingContext2D vtkRenderingGL2PS vtkRenderingContextOpenGL /usr/lib/aarch64-linux-gnu/ vtkRenderingLabel tesseract lept dl m pthread rt tbb
    3rdparty dependencies:

  OpenCV modules:
    To be built:                 core flann hdf imgproc ml photo reg surface_matching video viz freetype fuzzy imgcodecs shape videoio highgui objdetect plot superres ts xobjdetect xphoto bgsegm bioinspired dpm face features2d line_descriptor saliency text calib3d ccalib datasets rgbd stereo stitching videostab ximgproc aruco optflow phase_unwrapping structured_light java python2 python3
    Disabled:                    world contrib_world
    Disabled by dependency:      tracking
    Unavailable:                 cudaarithm cudabgsegm cudacodec cudafeatures2d cudafilters cudaimgproc cudalegacy cudaobjdetect cudaoptflow cudastereo cudawarping cudev cnn_3dobj cvv dnn matlab sfm

    QT:                          NO
    GTK+ 3.x:                    YES (ver 3.22.30)
    GThread :                    YES (ver 2.56.2)
    GtkGlExt:                    NO
    OpenGL support:              NO
    VTK support:                 YES (ver 6.3.0)

  Media I/O: 
    ZLib:                        /usr/lib/aarch64-linux-gnu/ (ver 1.2.11)
    JPEG:                        /usr/lib/aarch64-linux-gnu/ (ver )
    WEBP:                        /usr/lib/aarch64-linux-gnu/ (ver encoder: 0x020e)
    PNG:                         /usr/lib/aarch64-linux-gnu/ (ver 1.6.34)
    TIFF:                        /usr/lib/aarch64-linux-gnu/ (ver 42 - 4.0.9)
    JPEG 2000:                   NO
    OpenEXR:                     /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ /usr/lib/aarch64-linux-gnu/ (ver 2.2.0)
    GDAL:                        /usr/lib/
    GDCM:                        YES (ver 2.8.4)

  Video I/O:
    DC1394 1.x:                  NO
    DC1394 2.x:                  YES (ver 2.2.5)
    FFMPEG:                      YES
      avcodec:                   YES (ver 57.107.100)
      avformat:                  YES (ver 57.83.100)
      avutil:                    YES (ver 55.78.100)
      swscale:                   YES (ver 4.8.100)
      avresample:                YES (ver 3.7.0)
    GStreamer:                   NO
    OpenNI:                      NO
    OpenNI PrimeSensor Modules:  NO
    OpenNI2:                     NO
    PvAPI:                       NO
    GigEVisionSDK:               NO
    Aravis SDK:                  NO
    UniCap:                      NO
    UniCap ucil:                 NO
    V4L/V4L2:                    NO/YES
    XIMEA:                       NO
    Xine:                        NO
    gPhoto2:                     YES

  Parallel framework:            TBB (ver 2017.0 interface 9107)

  Other third-party libraries:
    Use IPP:                     NO
    Use VA:                      NO
    Use Intel VA-API/OpenCL:     NO
    Use Lapack:                  NO
    Use Eigen:                   YES (ver 3.3.4)
    Use Cuda:                    NO
    Use OpenCL:                  YES
    Use OpenVX:                  NO
    Use custom HAL:              NO

  OpenCL:                        <Dynamic loading of OpenCL library>
    Include path:                /usr/include/CL
    Use AMDFFT:                  NO
    Use AMDBLAS:                 NO

  Python 2:
    Interpreter:                 /usr/bin/python2.7 (ver 2.7.15)
    Libraries:                   /usr/lib/aarch64-linux-gnu/ (ver 2.7.15rc1)
    numpy:                       /usr/lib/python2.7/dist-packages/numpy/core/include (ver 1.13.3)
    packages path:               lib/python2.7/dist-packages

  Python 3:
    Interpreter:                 /usr/bin/python3 (ver 3.6.5)
    Libraries:                   /usr/lib/aarch64-linux-gnu/ (ver 3.6.5)
    numpy:                       /usr/lib/python3/dist-packages/numpy/core/include (ver 1.13.3)
    packages path:               lib/python3.6/dist-packages

  Python (for build):            /usr/bin/python2.7

    ant:                         /usr/bin/ant (ver 1.10.3)
    JNI:                         /usr/lib/jvm/default-java/include /usr/lib/jvm/default-java/include/linux /usr/lib/jvm/default-java/include
    Java wrappers:               YES
    Java tests:                  NO

  Matlab:                        Matlab not found or implicitly disabled

    Doxygen:                     /usr/bin/doxygen (ver 1.8.13)

  Tests and samples:
    Tests:                       NO
    Performance tests:           YES
    C/C++ Examples:              YES

  Install path:                  /usr

  cvconfig.h is in:              /build/opencv-XDqSFW/opencv-3.2.0+dfsg/obj-aarch64-linux-gnu

Under the video I/O, it shows Gstreamer OFF

How do I add Gstreamer to my already installed OpenCV? Thank you!

There is a reference script:

For hooking with python, you probably need to execute

echo 'export PYTHONPATH=$PYTHONPATH:'$PWD'/python_loader/' >> ~/.bashrc
source ~/.bashrc