Two Pass Encoding ?

[Nyke Harewood]

Anyone have any examples of doing a two pass encode in this library?
I'm looking to convert my NodeJS transcoder to this library, here's and example of a job, also when trying to use the output options and submit a single string such as c:v libvpx-vp9 -pass 1 -b:v 1400K -crf 23 i get an error, is there a delimiter we should be using ?

`ffmpeg -i -c:v libvpx-vp9 -pass 1 -b:v 1400K -crf 23 -threads 8 -speed 4
-tile-columns 6 -frame-parallel 1
-an -f webm /dev/null

ffmpeg -i -c:v libvpx-vp9 -pass 2 -b:v 1400K -crf 23 -threads 8 -speed 2
-tile-columns 6 -frame-parallel 1 -auto-alt-ref 1 -lag-in-frames 25
-c:a libopus -b:a 64k -f webm out.webm`