GitLab

videoscale: fix passthrough ENCODED format

Videoscale can passthrough non-sysmem ENCODED buffer just fine. However,
its pad template prevents it from doing that. This commit opens up its
pad template to allow ENCODED format with feature ANY.

However, as ANY feature is a superset of sysmem feature, special care is
given in _transform_caps function to make sure that if the caps uses
sysmem, it won't have ENCODED in it.

Test cases has been updated to check if videotestsrc can use the format
before testing. As videotestsrc doesn't support ENCODED, failure to do
so will make the test fails.