Media player controls should receive focus (meaning that the person using an assisitive device should be able to navigate around the page) using the Tab key and arrow keys. Depending on the control, the media player should be operated using the Enter key, space bar, and arrow keys. Check for the following to determine keyboard accessibility:
The Enter key or space bar activates the Play/Pause control.
The arrow keys, usually up and down arrow keys, manipulate the Volume control.
The arrow keys, usually left and right keys, manipulate the Forward and Rewind controls.
Depending on their design, other controls
like Captions and Full Screen are activated by the keyboard.
The functionality above emerges from the html level of the page, and we will rely on the software vendors and our tech colleagues to help us in achieving this. See this section of WebAIM’s Accessibility website