Hi Dilshan,
Typically, the goal of users working with Full Motion Video is to multiplex their drone video with their metadata. This will create a MISB compliant video that can be used for further analysis. The cameras that natively record MISB format video are usually quite expensive and so these tools provide an option to get a similar output with consumer grade hardware.
It sounds like you may be having some trouble with the mensuration tools. I went ahead and included some relevant links below; the mensuration tools behave the same between ArcMap and ArcGIS Pro.
ArcMap- http://desktop.arcgis.com/en/arcmap/latest/manage-data/raster-and-images/making-measurements-from-im...
ArcGIS Pro- https://pro.arcgis.com/en/pro-app/help/data/imagery/making-measurements-using-imagery.htm
If you are using drone imagery in full motion video, you are not going to have any metadata attached to the videos until you multiplex them. You will want to do this if you are looking to use all the tools available in the FMV extension. This process requires that you have the relevant metadata fields listed in this documentation.
Video Multiplexer tool - https://pro.arcgis.com/en/pro-app/tool-reference/image-analyst/video-multiplexer.htm
We also have a great tutorial on the Full Motion Video extension that covers the basic usage as well as doing mensuration on your videos. I would highly recommend it if you have a current maintenance subscription to access the Esri training site.
Working with Full Motion Video in ArcGIS - https://www.esri.com/training/catalog/5806637ec82bd5746b9143dd/working-with-full-motion-video-in-arc...
Regards,
Mark
