davenewham

ffmpeg -i input_file.mp4 -framerate 30 -c:v libvpx-vp9 -an -vf scale=512:512 -pix_fmt yuva420p output_sticker.webm

xacnio

Command

ffmpeg -y -i animated_sticker.mov -r 30 -t 2.99 -an -c:v libvpx-vp9 -pix_fmt yuva420p -s 512x512 -b:v 400K output.webm

• If .webm file size greater than 256 KB, you should reduce "-b:v 400K"
• .mov video file may has alpha channel but not required.
• My video sticker pack for example: https://t.me/addstickers/msn_animations

Telegram Sticker Command