Below the content list are the controls to set content properties. To adjust the properties for a piece of content, click its name in the content list. The content property controls will then become active for that piece of content.
If you want to change the properties for multiple pieces of content at the same time, select the content in the list by clicking the first piece then clicking the other pieces with shift key held down. Note that not all settings can be changed in this way.
The content properties are split up into four sections: Video, Audio, Subtitles and Timing. Not all of these sections will be active for all content types. The controls in each section are described below.