But this bootleg is still interesting, even if it’s unnecessary to this project, since it had 640kbps Dolby Digital audio on a standard DVD.
Something many people though was impossible, most people thought than 448 was the maximum, guess they were wrong.
The DVD specification limits AC-3 tracks to 448kbps. You can go beyond that bitrate with DTS, PCM, or MPEG-2 audio. If your disc has a 640kbps AC-3 track all it means is that it isn’t within DVD specifications, it’s certainly possible (and quite easy) to create such a disc.