Videos take up a lot of space. Uncompressed 1080 HD video footage takes up about 10.5 GB of space per minute of video but can vary with the frame rate.
If you use a smartphone to shoot your video, 1080p footage at the standard 30 frames per second takes up 130 MB per minute of footage, while 4K video takes up 375 MB of space for each minute of film.
Because videos take up so much space, and because bandwidth is limited, video compression is used to reduce the size of the file. Compression involves packing the file’s information into a smaller space. This works through two different kinds of compression: lossy and lossless.
It is a type of compression technique that reduces the size of video file formats by eliminating redundant and non-functional data from the original video file.
Video compression is performed through a video codec that works on one or more compression algorithms. Usually video compression is done by removing repetitive images, sounds and/or scenes from a video. For example, a video may have the same background, image or sound played several times or the data displayed/attached with video file is not that important. Video compression will remove all such data to reduce the video file size.
Once a video is compressed, its original format is changed into a different format (depending on the codec used). The video player must support that video format or be integrated with the compressing codec to play the video file.
However, you can lose a relatively large amount of data before you start to notice a difference (think MP3 audio files, which use lossy compression). Lossy compression makes up for the loss in quality by producing comparatively small files. For example, DVDs are compressed using the MPEG-2 format, which can make files 15 to 30 times smaller than the originals, but viewers still perceive DVDs as having high-quality pictures.
Lossless Compression Formats:
Lossless compression is exactly what it sounds like: the original and the compressed versions are nearly identical. None of the data is lost in the compression process. Lossless compression formats are not nearly as useful as lossy compression in many cases because files often end up being the same size as they were before compression.
Using lossless video compression might seem pointless, given that reducing the file size is the primary goal of compression. However, if the file size is not an issue, using lossless compression results in a perfect-quality picture.
However, someone who wants to upload a two-hour-long, 4K video to a video streaming site probably wouldn’t use lossless compression. The file would be so large that it’d take a long time to upload.
Lossless compression formats include Free Lossless Audio Codec (FLAC), Apple Lossless Audio Codec (ALAC), and Windows Media Audio Lossless (WMAL), among others.