Need permit to work for Canadian company outside Canada?

[filmfly]

I'm interested in seeking work (as a film crew member) on projects in various places around the world, and I am trying to figure out if I would need a Canadian work permit to be paid by a Canadian company. I am a US citizen without a Canadian residence card or work permit yet. The work would be temporary (up to a couple weeks) in foreign countries (such as Brazil, Jerusalem, or other as of yet unknown places).

So do I need a work permit for the country I'm physically in, the country of the company that is paying me, or both?

Thank you for your help!