A deposition in a foreign country is extremely, extremely complicated, and can take months to set up if either the deponent or the other party wants to throw up roadblocks.
A declaration of a witness in Canada, under penalty of perjury of the laws of the State of California, might be acceptable as evidence -- but the rules here are also tricky. Whether a videotaped declaration, again under penalty of perjury, might be acceptable is not something I have ever tried. At a minimum, you need to make absolutely sure that each statement made is admissible in evidence -- it isn't inadmissible hearsay, for instance. There are undoubtedly other things to be wary of.
You really need to plan this with an experienced litigator, to make sure the statement you want to obtain has a reasonable chance of being admitted into evidence. You do not want to go to the time and expense here, only to have the judge say that your videotape is inadmissible.