LA1.1: Identify the formats used when encoding video

 What are video encoding formats?

Video encoding formats are also called file formats and they are methods of optimising digital video files for different platforms, devices and programs. Video encoding format considerations: Upload bandwidth constraints or storage stability (hard drive/storage saved in a cloud) The quality of the actual video, Compression quality File size and Compatibility.

How does video encoding work?

It is the process of turning uncompressed video into a form that can be stored/played by a variety of compatible devices. Video encoding involves two main processes, they are compression and transcoding.

Compression is the discard of superfluous (unnecessary) data, It significantly decreases the file size to allow it to be more manageable. Without a proper compression, most files are far too large to easily upload, load quick and perform smoothly on users devices.

Transcoding is referring to the audio and video conversion process from a specific format to another. it makes sure the video file is compatible with the video player and the platform it is uploaded on, Without transcoding there would be no way to watch the video file.

What is a codec?

A codec(coder/decoder) is a method used to compress and decompress data for it to be easily transported and received by different applications. Separate codecs are used to compress video and audio, but they work in a very similar manner. Codecs encode files by either using lossy or lossless compression.                                                                                                                                         Lossy compression simplifies the data and only keeps essential parts, this is usually why a lossy compressed video may seem pixelated. For example, if you saw a video compressed using lossy, it will depict all of the imagery, but some colours may blend together, not accurately depicting each subtle colour in the shot. Lossy files are smaller yet are held black by the quality.

Lossless compression preserves the high quality of an original video file, so if you compressed the video stated in the previous paragraph in lossless instead of lossy, the subtle colours will be significantly more noticeable. Lossless files are higher in video quality but are held back by the larger file size.

What is a container?

A container combines an encoded audio stream, video stream and metadata in a singular file, Metadata tells the video player how to coordinate different audio and video codecs and can also provide some additional elements, such as subtitles and alternative audio streams. Each container supports a different range of video codecs, some only work with a single, specific type of codec and video player, which drastically limits playback options, Other containers are compatible with different types of video codecs and players. Usually video files are named for the containers they use, rather than the video and audio codecs they contain (for an example, an MP4 video file is actually an MP4 container) and the video file can only play properly if both the codec and container are compatible with the video player.

What are the common types of video encoding formats?

There are more than 10 types of video encoding formats, but they are not all compatible with the same platforms, browsers and devices. The most commonly used video files are;

MP4: (MPEG-4 Part 14) is a video file format created by the motion picture expert group, it compresses video and audio separately, which allows the file to retain high quality after compression, most browsers, iOS and android devices Have MP4 file compatibility.

MOV: (QuickTime Movie) is a video file format created by Apple, Although it can run on Mac OS and Windows OS, it is only compatible with QuickTime video players. It preserves the video quality, but doesn't offer as much file compression as other video formats.

AVI: (Audio Video Interleave) is a video file format created by Microsoft, It is one of the oldest video file container specifications. AVI works with a number of codecs which can affect how well it is supported by different operating systems and browsers. It priorities video quality over compression, meaning that the video files are larger and better quality overall.

FLV: (Flash Video Format) is a video file format created by Adobe Flash. One advantage of FLV is its ability to compress video files without a severe loss of video quality. unfortunately it is less compatible across devices and OSes than other file formats, Though it is supported by most browsers and Android devices, It cannot be used to play video files on iOS devices. Some browsers have stopped allowing FLV because it is considered to be insecure.

MKV: (Matroska Multimedia Container) is a free, open-standard container format. A file format that can hold and unlimited number of video, audio, picture or subtitle tracks in one file. It is a universal format for storing common multimedia content. Such as movies or TV shows. Matroska is similar in concept to other containers such as MP4, AVI or ASF, But it is entirely open in specifications.