ROCK64 - composite AV output not working?

    Hi,
    I installed libreelec on my rock64 and works perfectly via hdmi output, but there is no way I can get the image through the 3.5mm jack/av output to my crt tv.
    Tried to add in extlinux.config:
    video=Composite-1:720x480@60ie
    or
    video=composite:720x480@60ie cvbsmode=480cvbs cvbscable=1

    however nothing works..

    There are a lot of instructions for raspberry pi, but nothing for rock64.
    Please, could anyone help me with this? :-/

    The video=Composite approach is correct if the kernel drivers support composite output. If it doesn't work, I'd assume composite support hasn't been implemented. These days HDMI is generally the priority so composite isn't always guaranteed.