Tremor by the
Xiph.Org Foundation
Xiph.Org Foundation is a nonprofit organization that produces free multimedia formats and software tools. It focuses on the Ogg family of formats, the most successful of which has been Vorbis, an open and freely licensed audio format and codec d ...
is a
fixed-point version of the
Vorbis
Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder (codec) for lossy audio compression. Vorbis is most commonly used in conjun ...
decoder for those platforms without
floating point
In computing, floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base. For example, 12.345 can be ...
operations.
It is a software library that decodes the Vorbis audio format. It is
free software
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...
released under the
New BSD license
BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...
. Tremor uses fixed-point and movable-point arithmetic numeric representations in its implementation so that it can be used by small embedded devices, which typically do not have
floating-point processors. Thus, Tremor enables small
embedded device
An embedded system is a computer system—a combination of a computer processor, computer memory, and input/output peripheral devices—that has a dedicated function within a larger mechanical or electronic system. It is ''embedded'' as ...
s to play audio files stored in the Vorbis format. Tremor was originally developed by Xiph.Org as a part of a contract for the
Iomega
Iomega (later LenovoEMC) produced external, portable, and networked data storage products. Established in the 1980s in Roy, Utah, United States, Iomega sold more than 410 million digital storage drives and disks, including the Zip drive floppy d ...
HipZip
The PocketZip is a medium-capacity floppy disk storage system that was made by Iomega in 1999 that uses proprietary, small, very thin, 40 MB disks. Its relation to the original Zip drive and disk is the floppy medium and relatively much hig ...
, but was since opened up to encourage wider use of the Vorbis format. Almost all hardware devices that can play Vorbis, and many software implementations on embedded devices (such as mobile phones) use Tremor or some descendant.
Xiph.Org has expressed interest in modifying Tremor into a floating-point version, which would replace the current floating-point reference decoder, after the release of libogg2.
References
External links
Tremorat the Xiph.Org Foundation wiki
{{Xiph.org
Audio codecs
Xiph.Org projects