Data Rate
DVD-Video discs have a raw bitrate of 11.08 Mbit/s, with a 1.0 Mbit/s overhead, leaving a payload bitrate of 10.08 Mbit/s. Of this, up to 3.36 Mbit/s can be used for subtitles and a maximum of 9.80 Mbit/s can be split amongst audio and video. In the case of multiple angles the data is stored interleaved, and so there's a bitrate penalty leading to a max bitrate of 8 Mbit/s per angle to compensate for additional seek time. This limit is not cumulative, so each additional angle can still have up to 8 Mbit/s of bitrate available.
Professionally encoded videos average a bitrate of 4-5 Mbit/s with a maximum of 7–8 Mbit/s in high-action scenes. This is typically done to allow greater compatibility amongst players, and to help prevent buffer underruns in the case of dirty or scratched discs.
Aiming to improve picture quality over standard editions, Columbia TriStar Home Entertainment offered "Superbit" – a premium line of DVD-Video titles having average bitrates closer to 6 Mbit/s. Audio quality was also improved by the mandatory inclusion of both Dolby Digital and DTS 5.1 surround audio tracks. Multiple languages, angles, and extra audio tracks were eliminated to free up more space for the main title and thereby to ensure the highest data rate possible. In January 2007 the Superbit line was discontinued.
Read more about this topic: DVD-Video
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