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The Differences Between Video Codecs and Containers: A Technical Overview

As video technology has evolved over the years, so too has the way we encode, store, and deliver video content. Two key components of this process are video codecs and containers. In this post, we’ll provide a technical overview of these two elements and explain how they work together to create the video content we know and love.


First, let’s start with video codecs. At a basic level, a codec is a piece of software that compresses and decompresses digital video files. 

It determines how the video is compressed by analyzing the raw video data and applying mathematical algorithms to reduce its file size. The goal of a video codec is to achieve the smallest possible file size while maintaining a certain level of visual quality.

Codecs are necessary because video files are typically too large to be efficiently stored or transmitted over the internet without compression.

There are two types of codecs: lossy and lossless. 

Lossy codecs are designed to reduce the file size of a video by discarding some of the visual information that the human eye is less likely to notice. The most common lossy codecs are H.264 (also known as MPEG-4 AVC) and H.265 (also known as HEVC). 

Lossy codecs are typically used for streaming video content over the internet because they are able to compress the file size without sacrificing too much visual quality.

Lossless codecs, on the other hand, compress the video file without discarding any visual information. Examples of lossless codecs include Apple ProRes and Avid DNxHD. 

Lossless codecs are used in situations where the highest possible quality is necessary, such as in film production or video post-production.


Now let’s talk about video containers. A container is a type of file format that stores the video data, as well as any associated metadata, audio, and subtitle tracks. 

The most common video container formats are MP4, AVI, and MOV.

One important thing to note is that a container format is not the same thing as a codec. While a codec determines how the video is compressed, a container determines how that compressed video data is stored and transmitted. This means that you can have the same video content stored in different container formats, each with their own advantages and disadvantages.

For example, MP4 is a popular container format that is widely supported by web browsers, mobile devices, and video editing software. It also has the ability to store metadata such as video descriptions and subtitles. However, the MP4 container is not as flexible as some other container formats and can be problematic when editing video.

How do codecs and containers go together

The relationship between codecs and containers can be complex because a single video file can use multiple codecs and container formats. 

For example, you might have a video file that uses the H.264 codec to compress the video data and the MP4 container format to store the data. Or you might have a video file that uses the Apple ProRes codec to compress the video data and the QuickTime container format to store the data.

In general, the choice of codec and container depends on a number of factors, including the intended use of the video, the available storage and bandwidth, and the target audience. For example, if you are creating a video for distribution on the web, you might choose a codec that provides good compression while maintaining a high level of visual quality, such as H.264. You might also choose a container format that is widely supported by web browsers and mobile devices, such as MP4.

In summary, video codecs and containers are two key components of video technology that work together to compress, store, and deliver digital video content. While codecs determine how the video is compressed, containers determine how that compressed video data is stored and transmitted. By understanding the differences between these two elements, you can make more informed decisions when it comes to creating, editing, and delivering video content.