To add a custom image to your video in your Vocal Video account, you'll go to the Editor, click on the Scenes Tab, and then select "Add Text Scene".
Then click on the new text scene to select it, and go to the Background option on the left side to upload your new background image.
Currently, we don't have an easy way to upload videos recorded outside of Vocal Video into your account. However, we've received quite a few requests for this capability and we've added it to our near term product roadmap - stay tuned.
In the meantime, if you share a Google Drive/Dropbox/Boxetc link with the files with us at firstname.lastname@example.org, we are happy to upload up to four videos to your account.