MLT Framework. Make sliding transition with blur

Question

Need to make transition between two video clips with sliding from top to bottom and add blur effect:

https://www.dropbox.com/s/epavjs1zbo12hc7/test%20down%20transition.mp4?dl=0

melt 1.mp4 2.mp4 -mix 30 -mixer affine transition.geometry="0=0/0:100%x100%;74=-100/-100:120%x120%;75=-60/-60:110%x110%;149=0/0:110%x110%;150=0/-60:110%x110%;224=-60/0:110%x110%"

Can't finer any examples with transitions on mlt website...

Answer 1

melt \
21.mp4 \
-filter boxblur start=1 end=300 in=65 out=70 \
-transition \
composite in=65 out=70 a_track=0 b_track=1 \
start=0/0:100%x100%:100 \
end=-100%/0:100%x100%:100 \
-track \
-blank 65 \
22.mp4 \
-transition \
composite in=65 out=70 a_track=0 b_track=1 \
start=100%/0:100%x100%:100 \
end=0/0:100%x100%:100 \
-filter boxblur start=300 end=1 in=65 out=70 \
-consumer avformat:out20.mp4