Check displayAlign, overflow and computed line height for safe area #4
Description
Recently observed example EBU-TT-D file had computed line height of 8% and regions with tts:displayAlign="before" tts:overflow="visible" and bottom edge was set to 95%, but the top edge was too low for a line to fit without going outside the region, and overflowing into the safe area.
Can check this easily for regions whose height is set for 1 line, but more complex for regions whose size is intended for 2 or 3 lines - could count the actual number of lines (by <br> elements) in the region and work it out that way.