hi Matt,
Please refer to the source code:
ubuntu@tegra-ubuntu:~$ ls VisionWorks-1.6-Samples/samples/nvgstcamera_capture/
main_nvgstcamera_capture.cpp Makefile nvgstcamera_capture_user_guide.md obj
ubuntu@tegra-ubuntu:~$ ls VisionWorks-1.6-Samples/nvxio/src/NVX/FrameSource/GStreamer/
GStreamerBaseFrameSourceImpl.cpp GStreamerImagesFrameSourceImpl.hpp
GStreamerBaseFrameSourceImpl.hpp GStreamerNvCameraFrameSourceImpl.cpp
GStreamerCameraFrameSourceImpl.cpp GStreamerNvCameraFrameSourceImpl.hpp
GStreamerCameraFrameSourceImpl.hpp GStreamerNvMediaFrameSourceImpl.cpp
GStreamerCommon.cpp GStreamerNvMediaFrameSourceImpl.hpp
GStreamerCommon.hpp GStreamerOpenMAXFrameSourceImpl.cpp
GStreamerEGLStreamSinkFrameSourceImpl.cpp GStreamerOpenMAXFrameSourceImpl.hpp
GStreamerEGLStreamSinkFrameSourceImpl.hpp GStreamerVideoFrameSourceImpl.cpp
GStreamerImagesFrameSourceImpl.cpp GStreamerVideoFrameSourceImpl.hpp
And apply your case.