Player Buttons - How do I insert the button into the player?

Hello Mairlist users. I know this topic has been discussed before, but I still can’t find a proper solution for inserting or adding new buttons to the player. I’m asking for help.

  1. What size should the buttons in the player be? Does it have to be expressed in pixels?
  2. How should I properly label them? Should I use button_start.png or button_start.svg?
  3. Where should the buttons be placed?
  4. Where can I find pre-made buttons?
    Below is a screenshot of my settings.
    In the skin.ini settings, I have the button size set to 34.
    ButtonSize=34