Two-pass ffmpeg transcode to WebM(VP8/Vorbis)

ffmpeg -i /mnt/scratch/test_source/Sintel.2010.720p.mkv \
-map 0:0 -map 0:1 -sn \
-c:0 libvpx -crf 8 -b:v 60M \
-threads 3 -quality good -speed 0 \
-pass 1 \
-c:1 libvorbis -aq 4 -b:a 384k \
/mnt/scratch/test_out/Sintel.2010.720p.webm

ffmpeg -i /mnt/scratch/test_source/Sintel.2010.720p.mkv \
-map 0:0 -map 0:1 -sn \
-c:0 libvpx -crf 8 -b:v 60M \
-threads 3 -quality good -speed 0 \
-pass 2 \
-c:1 libvorbis -aq 4 -b:a 384k \
/mnt/scratch/test_out/Sintel.2010.720p.webm