has different uses for consumer products. Many video games store in-game audio as Vorbis, including Amnesia: The Dark Descent, Grand Theft Auto: San Andreas, Halo: Combat Evolved, Minecraft, and World of Warcraft, among others. Popular software players support Vorbis playback either natively or through an external plugin. A number of websites, including Wikipedia, use it. Others include Jamendo and Mindawn, as well as several national radio stations like JazzRadio, Absolute Radio, NPR, Radio New Zealand and Deutschlandradio. The Spotify audio streaming service has used Vorbis in a basket of codecs for its audio streams, but now has also been using AAC profiles. Also, the French music site Qobuz offers its customers the possibility to download their purchased songs in Vorbis format, as does the American music site Bandcamp. Technical details Outline of coder algorithm Vorbis I is a forward-adaptive monolithic transform codec based on the modified discrete cosine transform (MDCT). Vorbis uses the modified discrete cosine transform for converting sound data from the time domain to the frequency domain. The resulting frequency-domain data is broken into noise floor and residue components, and then quantized and entropy coded using a codebook-based vector quantization algorithm. The decompression algorithm reverses these stages. The noise-floor approach gives Vorbis its characteristic analog noise-like failure mode when the bitrate is too low to encode the audio without perceptible loss. The sound of compression artifacts at low bitrates can be perhaps described as reverberations in an amphitheater or a room. Container formats Vorbis streams can be encapsulated in other media container formats besides Ogg. A commonly used alternative is Matroska. It is also used in WebM, a container format based on a subset of Matroska. Vorbis streams can also be encapsulated in an RTP payload format. Metadata Vorbis metadata, called Vorbis comments, supports metadata tags similar to those implemented in the ID3 standard for MP3. The metadata is stored in a vector of byte strings of arbitrary length and size. The size of the vector and the size of each string in bytes is limited to 232 − 1 (about 4.3 billion, or any positive integer that can be expressed in 32 bits). This vector is stored in the second header packet that begins a Vorbis bitstream. The strings are assumed to be encoded as UTF-8. Music tags are typically implemented as strings of the form "[TAG]=[VALUE]", for instance, "ARTIST=The John Smith Band". The tag names are