ffms can convert vfr to cfr as well:
E.g.
Code:
DirectShowSource("2018-09-21.1900.wv.MS-v-FL.1sec-sample.mp4", fps=59.94, convertfps=true)
is similar to
Code:
a=ffaudiosource("2018-09-21.1900.wv.MS-v-FL.1sec-sample.mp4")
v=ffvideosource("2018-09-21.1900.wv.MS-v-FL.1sec-sample.mp4", fpsnum=60000, fpsden=1001)
AudioDub(v, a)