Blu-ray Audio General Information

[concept7man]

By:concept7man

Is Blu-ray technology offering more options for sound professionals when it comes to the depth of the sound design in their projects and the quality of special features available? Blu-ray was developed by The Blu-ray Disc Association (BDA) which is “a group of the world's leading consumer electronics, personal computer and media manufacturers (including Apple, Dell, Hitachi, HP, JVC, LG, Mitsubishi, Panasonic, Pioneer, Philips, Samsung, Sharp, Sony, TDK and Thomson),” according to www.blu-ray.com/info/, the official “source for anything related to Blu-ray disc (BD).” In cd players and DVD players, the information is read from the discs with a red laser. In Blu-ray players the information is obviously read with a blue laser. At first it doesn’t seem to be all that much of a change, but it really is. The wavelength of a red laser is longer (650 nm) in nanometers than the wavelength of a blue laser (405nm). This means that the information on a DVD has to be laid out on the disc on a wider surface to allow for the longer wavelength of the red laser. In Blu-ray discs, the information can be written much smaller allowing for more room on the disc and much more information to be recorded. The difference between the amounts of data available on DVD vs. Blu-ray is about 8G for DVD and 50G for Blu-ray. Recent advances in the technology by Pioneer allow a single Blu-ray disc to store about 500GB of information on 20 layers.
In the movie business when they have the film totally finished and the soundtrack is mastered and everything is done, it is made into a studio master. This is the edition of the movie, both video and audio, that the Director and sound engineers created, exactly as they meant for it to be. It is as clear and perfect as it can get. Now, in DVD there isn’t enough room on the disc to save almost any of this information. These surround-sound files are compressed by what is called lossy compression, meaning that some of the original audio information is lost in the compression process. Blu-ray discs, as I’ve already stated, have much more room for information to be stored, making it possible to compress the audio so it can be stored without losing any audio information along the way. The result is a fuller, richer surround-sound audio image. There are five main soundtrack formats which are readily available for Blu-ray, Dolby Digital Plus, Dolby TrueHD, DTS-HD High Resolution, DTS-HD Master Audio, and Linear PCM. Only in very high-end systems can anyone tell the difference between most of these formats. Dolby TrueHD is the format that is the closest to being identical to the version of the film that the people who made it hear and see when they watch the original studio master.
A movie that on DVD might offer just the deleted scenes and maybe a director’s commentary audio track to listen to while watching the movie now has a menu with a plethora of options from screen in screen documentaries the viewer can watch while the movie is playing to nearly full length documentaries on the making of the film and smaller mini documentaries on the specific aspects of production, such as cinematography and sound design. Blu-ray opens up a whole new world when it comes to added special features. I sometimes think it’s almost to the point where someone could watch a lot of special features now and actually learn from the pros what people used to have to go to school for years to learn.

Sources includes: https://www.blu-ray.com/info/, https://forum.blu-ray.com/showthread.php?t=66681, http://query.nytimes.com/gst/fullpag...t%20War&st=cse, http://reviews.cnet.com/4520-6463_7-6462511-2.html