Bit Stream
Posted: Sat Feb 26, 2005 6:26 pm
DTV is designed for a 19MB bit stream using MPEG2 encoding. If your local station transmits one DTV channel then you are getting 19MB from your station. That does not mean the national feed is 19MB. Due to the variation in the way DTV receivers work a minimum of 2MB is required to add a sub channel. That means 2MB will be taken from the 19MB total dropping the main channel to 17MB. Adding further sub channels requires reducing the bit rate of the main channel.
Per research by Steve Martin1080I HDTV applications require a minimum of 16MB to prevent artifacts. 720P HDTV applications require a minimum of 14.2MB
In depth HDTV bit stream and compression analysis by Steve Martin
D-VHS records the actual 19MB bit stream from a DTV receiver. D-VHS D-Theater uses a 26MB bit stream and has been favorably compared to Sony D5 masters for video production with the main difference being a slightly softer image. This bit stream is only available as prerecorded D-Theater movies.
DVD has a potential bit stream rate of 10MB. That means a maximum of 1 hour per layer for a maximum of 2 hours with dual layered discs based on average video content. When you rent or buy a movie that is 1:45 and the extra features are 1:00 then you have 2:45 hours and there is no choice but to reduce the bit stream rate which can only diminish picture or sound quality. This is the advantage of SuperBit DVD and any other titles where the special features and movie are on two discs rather than one.
Per research by Steve Martin1080I HDTV applications require a minimum of 16MB to prevent artifacts. 720P HDTV applications require a minimum of 14.2MB
In depth HDTV bit stream and compression analysis by Steve Martin
D-VHS records the actual 19MB bit stream from a DTV receiver. D-VHS D-Theater uses a 26MB bit stream and has been favorably compared to Sony D5 masters for video production with the main difference being a slightly softer image. This bit stream is only available as prerecorded D-Theater movies.
DVD has a potential bit stream rate of 10MB. That means a maximum of 1 hour per layer for a maximum of 2 hours with dual layered discs based on average video content. When you rent or buy a movie that is 1:45 and the extra features are 1:00 then you have 2:45 hours and there is no choice but to reduce the bit stream rate which can only diminish picture or sound quality. This is the advantage of SuperBit DVD and any other titles where the special features and movie are on two discs rather than one.