Intelligent Sound

Audio file formats are formats for storing audio data on a computer system. Generally they are container formats or audio data formats with a defined storage layer, but can be a raw bit stream too. The storage of digital audio involves sampling the audio voltage, which would correspond to a certain level of signal in a channel with a particular resolution in regular intervals, on playback. The data can then be stored uncompressed or compressed. Compression reduces the file size.

Super Audio CD is a read-only optical audio disc format with high-resolution. It was developed by Sony and Philips Electronics and designed to provide high-resolution audio in both stereo and surround sound modes. In addition to the optional CD-compatible layer using PCM, SACDs also use as audio format called DSD. It is mainly used in the audiophile community.

Proprietary formats are file formats with an opaque presentation of data and unlike open formats; their specifications are not publicly available. They are generally controlled by a private person or organization and can be protected with patents or copyrights. The copyrights provide the exclusive control over the technology to the license holder. These formats are developed by software companies to encode data produced by their applications since they prevent Reverse engineering.

HD DVD is a redundant high-density optical disc format that was designed for storing data and high-definition video. It was proposed to be the successor to the standard DVD format. However, after the abandonment by Toshiba, the HD DVD Promotion Group was dissolved in 2008.

Also known as High-Definition/Density DVD, it employs a blue laser with a shorter wavelength. This enables it to store about three and a half times as much data per layer as the standard DVD format.