Capture feature is used to go live from some camera that you have.
To use Capture feature go inside the campaign and click Add Media and select Capture.
By checking enable sound capture you will enable microphone while capturing with the camera.
NOTE: By default this option is disabled.
Choose the time and channel in when and where section.
The last settings about this feature are on the player side. When running CM Player Configuration you need to select Camera and Microphone, also Image and Videos to play with VLC Media Player.