1.What is Dolby Digital ?+
What is Dolby Digital ?
Dolby Digital, initially similar with Dolby AC-3, is the name for family of audio compression technologies developed by Dolby Laboratories. Initially called Dolby Stereo till 1995, apart from Dolby TrueHD, the audio compression is lossy according to MDCT (modified discrete cosine transform) algorithm. Dolby Digital's earliest use was to deliver digital sound in cinemas from 35 mm film prints; today, applications include TV Broadcast, radio broadcast via satellite, digital video streaming, DVDs, Blu-ray discs and game consoles.
2.Dolby Surround 2.1 / 5.1 / 7.1+
3.What is AC-3 ?+
What is AC-3 ?
The MDCT (modified discrete consine transfrom) is the main basis of the Dolby AC-3 multi-channel audio coding standard, a lossy audio compression algorithm.
Dolby Laboratories used the MDCT algorithm together with perceptual coding principles to develop the AC-3 audio format for cinema needs.
4.What is DTS ?+
What is DTS ?
DTS, Inc. (initially Digital Theater Systems) is an American company that produces multichannel audio technologies for film and video. In 1993, The company presented it's DTS technology as a rival to Dolby Laboratories, incorporating DTS in the film Jurassic Park (in 1993). The DTS product is used for surround sound formats in both consumer-grade and commercial/theatrical applications. Until 1995, it was known as The Digital Experience. DTS authorizes its technologies to consumer electronics suppliers.
5.What is PCM ?+
What is PCM ?
PCM (Pulse-code modulation) is an approach used to digitally define sampled analog signals. It is the common form of digital audio in compact discs, digital telephony, computers and other digital audio applications. The amplitude of the analog signal is tested consistently at uniform intervals in a PCM stream. Each sample is quantized to the closest value in a range of digital steps.
6.What is LPCM ?+
What is LPCM ?
LPCM (Linear pulse-code modulation) is a certain type of PCM where the quantization levels are linearly uniform. This is in comparison to PCM encodings where quantization levels differ as a function of amplitude (with the A-law algorithm or the μ-law algorithm). Although PCM is a more general term, it often describes data encoded as LPCM.