The volume control did not find any elements and/or devices to control. This means either that you don't have the right GStreamer plugins installed, or that you don't have a sound card configured.
Wnaeth rheolwr lefel y sain ddim canfod unrhyw elfennau a/neu ddyfeisiau i'w rheoli. Golyga hyn naill ai nad yw'r ategion GStreamer cywir wedi eu gosod, neu nad oes gerdyn sain wedi ei chyflunio.