Concept in Definition ABC

Sometimes when we try to play videos or songs on a computer or mobile device, the software The corresponding codec informs us that we have a codec problem, usually consisting of the lack of the correct codec installed to reproduce the content.

But what is this about codecs, that bothers us so much and causes us inconvenience? By definition, a codec is

A piece of software which can encode a certain signal and / or decode it

To put it in some way, it is an "interpreter" that allows us to understand a series of digital data encoded in a certain way.

And why are they so necessary? Because

digital audio and video information takes up a lot of space when it is treated in a “raw” way, what compression mechanisms are needed that allow to reduce the size of the files to handle

In this way, codecs allow us to listen to entire discs of music occupying only a few megabytes, in comparison with the gigabytes that they could occupy if we did not make use of the coding, and the same for movies.

Whenever we compress audiovisual data into Format digital, we lose information and, with it, quality. The smaller size we want, the more compression, and the more loss.

Codecs are simple mathematical algorithms whose function is to save a part of the information, playing, for example, with areas of similar colors in the frames of a film, or cutting certain frequencies imperceptible to the human ear in a Audio.

There are lossless codecs, although the size of file that they leave is quite large. We also find quite balanced codecs, which reduce the size of the files enough to be manageable, and whose quality loss is practically imperceptible.

In a movie, we can use one codec for video, and a different one for audio

And we will both have to save them, along with some type of signal or functionality that allows us to synchronize them, in the same file, with a file format called "containers".

A codec is not a specific program, but the idea to handle them is that they look more like a driver that we install on the system and, from that moment on, all programs may be able to work with the files encoded by that codec.

However, this is not always the case, and codec support is often found embedded in the same programs that allow reproduction of audiovisual content, without being shared through the rest of the programs that perform the same task and that are installed on the computer.

Photos: Fotolia - Avanne Troar / profit_