Fixed. These will play on Oracular.
ffmpeg -c:v libvpx-vp9 -i INFILE -vf alphaextract,colorize=hue=0:saturation=0:lightness=1:mix=0.8 -metadata:s:v:0 alpha_mode=0 -pix_fmt yuv420p OUTFILE
Fixed. These will play on Oracular.
ffmpeg -c:v libvpx-vp9 -i INFILE -vf alphaextract, colorize= hue=0:saturatio n=0:lightness= 1:mix=0. 8 -metadata:s:v:0 alpha_mode=0 -pix_fmt yuv420p OUTFILE