VAR_TEXT_H       1432 libavfilter/vf_drawtext.c     s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;
VAR_TEXT_H       1541 libavfilter/vf_drawtext.c            (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],