script for twopass encoding of webms

webm_twopass.txt

#!/bin/bash -e

src="2QO90IaN_UM.mkv"
dst="a.webm"
opts="-vf scale=1280:720 -threads 10"
aopts="-c:a libopus -b:a 128k"
vopts="-c:v libvpx-vp9 -b:v 1024k -tile-columns 6 -frame-parallel 1 -row-mt 1"
vopts_final="-auto-alt-ref 1 -lag-in-frames 25"

ffmpeg -i "$src" $opts \
	-pass 1 -passlogfile "ffmpeg2pass-${src%.*}" \
	$vopts -speed 4 \
	-an \
	-f webm -y /dev/null

ffmpeg -i "$src" $opts \
	-pass 2 -passlogfile "ffmpeg2pass-${src%.*}" \
	$vopts $vopts_final \
	$aopts \
	"$dst"