top
Parameters
value
See the description in left\_offset. For top\_offset, specify the position of the top edge of the rectangle, as a percentage of the underlying frame height, and relative to the top edge of the frame. For example, "10" means the measurement is 10% of the underlying frame height. The rectangle top edge starts at that position from the top edge of the frame. This field corresponds to tts:origin - Y in the TTML standard.