ffmpeg -i "%%~x" -movflags faststart -pix_fmt yuv420p -c copy ^
	-c:v libvpx-vp9 -crf 36 -b:v 0 -threads 8 -speed 1 ^
	-tile-columns 6 -frame-parallel 1 -auto-alt-ref 1 -lag-in-frames 25 ^
	-vf scale="trunc(min(sqrt(1280*720/(iw*ih))*iw\,iw)/hsub)*hsub:trunc(ow/a/vsub)*vsub" ^
	-c:a libopus -b:a 96k ^
	-f webm "%%~dpnx_1.webm"