The check if drawing needs to be initialized and supported formats
should be drawable ones was flawed, as pad_stop/pad_start is only
populated from stop_duration/start_duration after these checks.

To fix that, check the _duration variants as well and for better
readability and maintainability break the check out into its own
helper.

Fixes a regression from 86b252ea
Fix #10621
Signed-off-by: Anton Khirnov <anton@khirnov.net>