I am trying to convert a .mov file with alpha transparency into a .webm file and have been following this thread for help: Convert mov with Alpha to VP9 Webm with Alpha Using ffmpeg
The command line I have been using is
ffmpeg -r 24/1 -i Desktop/Skel_Walk_1.mov -c:v libvpx -pix_fmt yuva420p Desktop/Skel_Walk_1.webm
However when I go to run the command it comes up with 2 errors
Transparency encoding with auto_alt_ref does not work
and
Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0
- maybe incorrect parameters such as bit_rate, rate, width or height
I am not too sure what the problem is here, any suggestions, I am very confused!
I think I may have solved this, adding -auto-alt-ref 0
before the output fixed this issue!!
Working Command
ffmpeg -i Desktop/Skel_Walk_1.mov -c:v libvpx -pix_fmt yuva420p -auto-alt-ref 0 Desktop/Skel_Walk_1.webm