Continuously Variable Slope Delta modulation is a voice coding method. It is a delta modulation with variable step size (adaptive delta modulation), first proposed by Greefkes and Riemens in 1970
Ogg is a free open video format file which is designed to provide efficient streaming and manipulation of high quality digital multimedia. The Ogg file is similar to an MP3 file, but has better sound quality than an MP3 file of same size. It can include song metadata, such as artist information and track data, and is supported by many media players and some portable music players.