No sound, choppy video

[Glenn Haste]

The 'shorthand' title indicates the problem. The situation, briefly is
Mac G4, 467 MHz, 128+256 =384 MB, OS 10.2.8
External DVD player Iomega Super DVD, 8X All Format, shows up as
HL-DT-ST DVDRAM GSA-4082B A201 'IOMEGA USB 2.0 DEVICE'
VLC is selected to open DVD, Quicktime 6.5.2 is present

In Audio Midi Setup the window shows Default Device Unknown Device
Selected Audio Device Built-in Audio controller.
Elsewhere on the page it says "Device does not support input"

In VLC : Audio enabled, volume=1024
Audio Output Module -- Defalut
Video Output Module -- Default
The video is erratic - Sometimes a single page remains indefinitely and then moves forward, sometimes I start it moving by asking for next. Then it moves, maybe 4 to 40 frames (or more) and then stops. At no time is there any sound.