Endec

An endec is a device which both encodes and decodes video or audio, or other signals, either with the same or separate circuitry or algorithm. The combining of these names is a portmanteau.

The general difference between an endec (encoder/decoder) and a codec (compressor/decompressor) is that hardware is usually considered to be an endec, while software is considered to be the codec. Similarly, the word "encoding" is usually used for hardware, while "coding" is usually used in regard to software.

A program (or hardware) which uses a compression algorithm to create MPEG audio and/or video is often called an encoder, and one which plays back such files is a decoder. However, this is technically a codec, especially if performed in software.

Examples of encoders, decoders, and endecs:
*a modem is an endec, likewise a modulator is an encoder and a demodulator is a decoder
*an Emergency Alert System unit is usually an endec, but sometimes just a decoder
*a stereo generator used in broadcasting is an encoder
*A combination ADC and DAC would technically be an endec, though they are usually called CODECs
* Hardware that encodes data bits to a run length limited line code, and decodes the line code back to data bits, is an endec. [United States Patent 5844507]
* When implementing the Infrared Data Association (IrDA) protocol, often a endec is used between the UART and the optoelectronics [ [http://search.maxim-ic.com/search?q=%22ENDEC%22&restrict=english_appnotes&site=Maxim&output=xml_no_dtd&client=Maxim&num=20&proxystylesheet=http%3A%2F%2Fwww.maxim-ic.com%2Fsearch%2Fsearch3.xcgi&go= Maxim-IC search for "endec" app notes] ] [ [http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0183g/I31065.html "IrDA SIR ENDEC functional description"] ] .

Other things which are encoded or decoded:
*MIME, to send binary files over text email
*PGP, using a cryptographic algorithm

ee also

* encoder
* decoder

References