DvbSubtitleAlignment
Specify the alignment of your captions. If no explicit x_position is provided, setting alignment to centered will placethe captions at the bottom center of the output. Similarly, setting a left alignment willalign captions to the bottom left of the output. If x and y positions are given in conjunction with the alignment parameter, the font will be justified (either left or centered) relative to those coordinates. Within your job settings, all of your DVB-Sub settings must be identical.