the camcorder returns a content uri... a simple Do it could have shown this to you... it seems to be, you are not familiar with Do it?
use Do it to debug your blocks, see also tip 4 here App Inventor: How to Learn | Pura Vida Apps
see also Live Development, Testing, and Debugging Tools
to convert a content uri into the path to a file you can use the file extension and its GetFileName method App Inventor Extensions: File | Pura Vida Apps
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by
Taifun.