inigo \
-blank 49 \
clip2.dv in=100 \
-track \
clip1.dv in=0 out=100 \
-transition \
luma in=50 out=55 a_track=0 b_track=1 reverse=1 \
-transition \
mix:1 in=50 out=98 a_track=0 b_track=1 \
-transition \
mix start=1 end=0 in=99 out=100 a_track=0 b_track=1 \
$*