Codec - definition

A program or a device capable of performingThere are basically three types of codecs namely
encoding and decoding on a digital data stream orAudio codecs, Video codecs, and Data codecs.
signal is known as Codec. The stream or signal forAudio codec - A computer program which
transmission, storage or encryption are encoded andcompresses/decompresses digital audio data is
decoded by the Codecs. In the video camera, theknown as audio codec. Most of these codecs are
ADC converts its analogue signals to digital signals,implemented as libraries that act as an interface to
which after passing through the video compressorone or more multimedia players such as Winamp,
for transmission or storage are decoded by the DACXMMS and Windows Media Player. At times, the audio
for analog display. An audio compressor convertscodec can refer to a hardware implementation or
analogue audio signals to digital signals forsound card. In such a context, the term audio codec
transmission or storage. The de-compressor at theactually refers to a combined audio AD/DA converter
receiving end converts the digital signals back toand a fine example of this would be the Intel
analog for playback. Essence is a term commonlyCorporation's AC'97.
associated with the raw encoded form of audio andVideo codec is the device or software module that
video data.enables the use of data compression for digital
Codec is an algorithm used to code and decode thevideos. Initially, videos were stored on magnetic
voice conversation in case of VoIP. The voice andtapes as an analogue signal. However with the
sound that we hear is in analogue form and needs toevolution of compact discs, it became feasible to
be converted into a digital form for transmission overstore and use video in a digital form. A combination
Internet. On the other side, it needs to be decodedof audio and video calls for customized methods of
once again to make it easy to hear for the recipient.compression. There lies the complexity between
The coding and decoding can be done in differentvideo quality bit rate, the complexity of coding and
ways by utilizing compression to reduce thedecoding, robustness of data loss and error, random
bandwidth of the conversation. It is pertinent toaccess and the art of compression.
mention that with VoIP, encoding with heavyThe Digital video codec are found in DVD, VCD in
compression takes more time and delays theemerging satellite and terrestrial broadcast systems
conversation. It is here that the codec becomesand on the Internet. Online video encoding has led to
eminent for it not only maintains good quality withthe availability of codec packs with installer as a
compression but also does the encoding and decodingsoftware package for PCs.
in a reasonable time.Data Codecs - Data that is not automatically handled
Different VoIP clients support different codecs andby quick time media operations and can be
each VoIP service provider supports the subset of acompressed and decompressed with the help of data
codec. In simpler terms when a VoIP call iscodecs. Quick time media would automatically
established, you need to use a codec that iscompress and decompress video and sound tracks
supported by both the parties and the provider. It iswith the help of image and sound codecs but it will
imperative to understand codecs so as to enable younot automatically compress or decompress sprites.
to have a better understanding as to why someData codes are useful for compressing and
VoIP service providers are better than others anddecompressing sprites, 3D models and arbitrary
also why audibility through IPS with some serviceblocks on data from other sources.
providers is better than others. In the followingKevin Whales is industry expert, author of articles for
paragraphs, the different types of codecs and theirnewbies.
utility are elaborated.