Introduction
In streaming media industry codecs plays very important role. Codecs are used in streaming media from start to end. Development of codec algorithms are very important in our life because new algorithms or codec enable us to watch high resolution or pixels of videos as well as images too.
So in this articles we will cover what are codecs types of codecs and codec working.
What Are Codecs
Codec is a hardware device or a software used to encode a video or audio also used to decode video or audio at receiving end devices such as Setup boxes , Tablets and Smartphones.
In other words Codecs are used to encode a data stream in encrypted form, which need to decode at receiving end by decoder to get it back after transmission. This transmission medium can be OFC or Coaxial cable etc.
Basically there are two types of codecs available named as lossy and lossless codec. As its name indicates that lossy codec gives loss in output which results low bandwidth consumption in network. While lossless codec gives less loss in output which results high bandwidth consumption in network.
Examples of Codes are AVI , AVC, HEVC, MPEG 4, MP3, PKZIP and JPEG etc.
For better understanding implementation of these codecs we have divided them as following,
(1) Audio Codecs
These codecs are used to encode audios only. A audio codec convert analog audio signals into digital audio signals also at receiving end it converts digital audio signal back into analog audio signals. Just like we use sound cards in computer.
Most widely used audio format is PCM known as Pulse Coded Modulation. PCM is uncompressed format means it gives good quality audio. PCM is stored in AVI or WAV file format.
While on the other hand lossy audio codec which gives losses in audio are MPEG and AC-3.
(2) Video Codecs
In 1993 the first ISO video standard published was MPEG-1. Later on its next standards were MPEG-2, MPEG-3, MPEG-4, H.264. and H.265. The video codec is used to convert analog video signals into digital video signals. So it is used to encode the video in various file format like MP4 and AVI etc.
Lossy video codecs are used to encode the video because it is very efficient for us to deliver services at customer end. It reduces the network bandwidth consumption. So a high quality video can easily be transmitted to cable tv subscribers from Digital Headend.
(3) Image Codecs
In these codecs images are considered for the compression to save the disk space. If there will be low quality image then website downloading speed will be high. These codec are JPEG, PNG and GIF.
(4) Data Codecs
These codec are PNG and PKZIP etc. These are lossless codecs. We need lossless codec here because we do not want any loss in our data after decompression. So lossless video codec have high bandwidth consumption.
Working Of Codecs
To understand working of codecs we need to take example of CD-ROM codec where two frames were considered named as Key Frame and Delta Frame.
As shown above in the photo there is professional lady standing normally considered as Key Frame While in the next frame she is smiling. So in the Key Frame one whole frame is selected to compress. While Delta Frame take the only information which changes in Key Frame. That is smiling face of lady.
So during encoding a key frame is selected for the compression known as intra frame compression. After this intra-frame compression the moving information is gathered for delta frame while rest all information in frame remains same. So when decoding process take place then background and whole body of lady except face is repeated which results low bandwidth output.
Conclusion
Codecs are tools used to encode the video,and audio to save the bandwidth consumption and to maintain the good quality output. There are thousands of codec available in the market. Which costs from $0 to hundreds of dollar. These codec can be MP4, MP3 and MPEG etc.
Know More About MPEG1 MPEG2 MPEG3 MPEG4 Difference
