Do you know what audio and video compression is? It is the technology that allows you to play and store multimedia files on PCs, mobile phones and tablets.
Internet users are consuming more and more multimedia content. The audiovisual format is estimated to represent 80% of online content by 2020.
However, files are often heavy and may not run easily on all computers, so understanding what audio and video compression is is essential.
To work with audiovisuals, the professional needs to understand how compression of multimedia files works. In this post, you will know what audio and video compression is and why it is so important to do so.
After all, what is audio and video compression?
It is reducing a large volume of data in a file so that it takes up less space in the memory of a device or requires less transmission bandwidth. It can happen with or without loss, although most eliminate some almost imperceptible details.
However, the higher the audio and video compression, the lower the quality.
This is how each type of compression works:
Audio compression
By compressing sound files, the software reduces or simplifies the repetition of bits and eliminates the data considered imperceptible to the human ear.
To play an audio format on a certain device, you must select a codec, a program that encodes and decodes the media file.
In short, it compresses the file into a smaller format and unzips it, converting it back to sound when the user wants to listen to it. However, the same codec will not be used for all types of compressions and decodes.
The standard computer audio storage (WAV) file is too heavy to hold from essential data to unnecessary data to maintain its quality. This is because it transforms information into sounds that are not perceived by our ears. Codecs remove this less important data and offer a quality format, playable by the vast majority of gamers.
Modern techniques explore the perception of the human ear and provide compression that has apparently not suffered any loss. The most popular are:
FLAC (Free Lossless Audio Codec; Lossless Compression) – Unlike most, it doesn’t remove any information from the sound file, but it can shrink by up to 50%. Despite the decrease, it can be up to ten times heavier than MP3 format;
ALAC (Apple Lossless): compression of audio data produced by Apple;
MP3 (MPEG-1/2 Audio Layer 3; lossy) – The most popular audio compression format greatly reduced file size and still maintained its quality. It was officially discontinued in 2017, but is still very popular;
Ogg Vorbis (lossy) – Audio format that offers a lower bit rate and more quality than MP3. It is divided into two parts, Ogg, responsible for the file’s metadata, and Vorbis, an encoder that compresses the songs;
AAC (lossy) – Designed to be the successor to MP3, AAC is the standard format for playing audio on computers like iPhone, iPad, and PlayStation 3.
Video compression
Like audio, video compression involves reducing the file size, but in this case, removing the parts that have already been designed.
When not lost, no part of the data is discarded from the image.
In lossy compression, bits are selectively discarded. One way to do this is to reduce the number of frames, which is generally the same as on television (30 per second).
Once compressed, each type of video uses a specific set of codecs. Some of the most popular compression formats are:
MKV (Matroska Video): Widely used for high resolution videos, MKV offers effective compression and maintains quality. To make this happen, the codec encapsulates the audio, video, and subtitle tracks in a single container;
MPEG (Moving Picture Experts Group): defined by ISO as the standard video compression format, it can vary between MPEG-1 (for VCD), MPEG-2 (DVD) and MPEG-4;
AVI (Audio Video Interleave): Like MKV, AVI encapsulates audio and video in the same container. With this, both play synchronously. As it was produced by Microsoft, the format runs easily on Windows and is recognized by DVD and Blu-Ray players that are compatible with the DivX codec.
Why is audio and video compression technology important?
In addition to taking up less space, downloading and uploading a compressed file takes much less time. This makes it much easier when you want to post a video file on social media.
