The VideoLAN Forums

Here's a link

Here's the full info:

Stream 1
Type: Audio
Codec: mp4a
Lang: English
Channels: Stereo
Sample Rate: 44100 Hz
AAC extension: SBR

I downloaded some MPEG-4 videos from the Prelinger archive (the highest rez ones), and am not getting audio. The video looks great, cheesey haircuts aside.

The audio codec is mp4a.
Operating system: Vista 64-bit, all current updates

Any suggestions?