>> Thursday, July 22, 2010
The Kathy Smith's personal trainer CD was made possible by one of the techniques Philips invented: "MPEG seamless branching", which allows for a continuous video/audio MPEG stream to be displayed, even though it is made of a multiple of very short clips (about 7 second). There are only a few CD-i titles that use this technique; The best example is The Lost Ride, where Digital Video is presenting a virtual roller coaster. Interesting is that the development of this 'Seamless Branching' continued at Philips Research into development of a networked 3D car chasing game for CD-i. From the developer: "Two teams would compete against each other: the good cops and the bad villains. Each player would be part of one of the teams and through his car could see the whole city in 3D-generated MPEG video. MPEG seamless branching was going to be used to seamlessly arrange on the fly thousands of pre-produced road driving sequences (also played back at variable MPEG frame rates), in order to create the illusion of an interactive 3D of very high visual quality. Other cars were going to be shown as graphical sprites. The project did not get past the prototype stage because of its cost, but if it had been completed it would have been the most complex and ambitious CD-i game ever produced. Technically it was a combination of techniques applied in Kathy Smith Personal Trainer (seamless branching), Dead End (variable mpeg frame rates) and networked gaming (this was before the days of the Internet boom!). Too bad it did not happen. It was a lot of fun designing it though!"