It was not possible to set a profile before, the builtin profile
parameter does not seem to work propperly.
To be compatible with libx264, this overlays it with a local parameter
that expects a string, instead of an int, that takes the well known values
"high", "main" or "baseline".
Reviewed-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>