\r
size_t width; // output frame width\r
size_t height; // output frame height\r
+ size_t square_width;\r
+ size_t square_height;\r
field_mode::type field_mode; // progressive, interlaced upper field first, interlaced lower field first\r
double fps; // actual framerate, e.g. i50 = 25 fps, p50 = 50 fps\r
size_t time_scale;\r