What is AC-3 VS?
Dolby Virtual Surround AC-3 uses the way your ears works to generate a surround feeling from a 2-channel signal. By using Virtual Surround you’re able to drop the AC3 bitrate from 384 Kbit/s down to 192kbit/s, while maintaining the surround feeling and superior quality. The best audio is uncompressed LPCM which is rare on DVD’s and consumes massive bitrate – especially in a surround configuration (I’ve never seen a surround LPCM DVD although it’s within the spec to make one). Second best is the DTS format. Unfortunately DTS is very expensive in bitrate and isn’t supported by all devices. Insignificantly worse than DTS is 5.1 AC3 which is typically 384 Kbit/s. Obviously 384 kbit/s is around 170 megabyte per hour of movie per audio track which may still be too much. For this situation AC3 VS is a great solution as it gives decent surround performance but at half the bitrate. Other Audio formats like MP3, Ogg-vorbis and so forth, have the significant disadvantage that they’re not supporte
