Video Codec vs. Video Containers – Differences and Use Cases Simplified

Video codecs and video containers play a crucial role in multimedia and streaming. Understanding these terms’ differences can help you make informed decisions about manipulating and distributing video content.

This article will dive into the basics of video codecs and containers, explore their functions and types, and discuss their critical differences.

Additionally, we will delve into the interplay between codecs and containers and how they work together to deliver high-quality video streaming solutions.

Let’s go!

Video Codecs: The Heart of Video Compression

A video codec, an amalgamation of ‘Encoder’ and ‘Decoder,’ forms the heart of video compression and decompression.

The codec is responsible for encoding or reducing video file size by eliminating redundant or less critical data without degrading the video quality significantly. This process, known as lossy compression, enables smooth streaming experiences, reducing buffering times and ensuring the video can be delivered efficiently to users with different internet speeds.

If you are new to video compression, check out these articles to quickly get up to speed:

• What is Transcoding?
• What is a Video Codec?
• What is Per-Title Encoding?
• Discrete Cosine Transform – how does it work?
• BD-Rate & BD-PSNR: Calculation and Interpretation
• PSNR, VMAF, SSIM calculation in FFmpeg
• I, P, B Frames in Video Codecs
• IDR vs. CRA in HEVC
• Closed GOP and Open GOP
• CBR vs. VBR Rate Control
• Hardware vs. Software Transcoders

Various video codecs are available, each offering varying compression efficiency and quality levels. Examples of popular video codecs include H.264/AVC, H.265 (HEVC), VP9, and the open-source AV1 codec, which offers similar quality to H.265 but without the royalty fees.

The Role of Video Codecs in Video Streaming

In video streaming, codecs compress video content into a format easily transmitted over the internet.

They reduce the overall file size by removing unnecessary data and optimizing the remaining information to preserve video quality. This compression enables smooth streaming experiences, reducing buffering times and ensuring the video can be delivered efficiently to users with different internet speeds.

Moreover, video codecs are crucial not only for streaming platforms but also for video conferencing applications. In an era where remote communication has become the norm, codecs play a vital role in ensuring that video conferences are seamless and high-quality.

Popular Video Codecs

There are numerous video codecs available, each with its advantages and disadvantages. Let’s take a closer look at some widely used codecs:

H.264 (also known as AVC): H.264 remains popular due to its compatibility with various devices and the efficient balance between video quality and file size. It has become the industry standard for video compression and is widely supported by devices, browsers, and streaming platforms. Learn more about AVC and HEVC in this comparison article.

HEVC (or H.265): High-Efficiency Video Coding (HEVC) offers superior compression capabilities compared to H.264. It can reduce the file size further while maintaining the same level of video quality. However, one drawback of HEVC is that it requires more processing power for playback, which can be challenging for devices with limited resources. And it’s been encumbered by patents and licensing issues forever!

Note: if you want to learn more about HEVC, visit our “HEVC Recipes” post on OTTVerse.

VP9: Developed by Google, VP9 is an open-source video codec that provides excellent compression efficiency. It offers significant improvements in video quality at lower bitrates, making it a popular choice for streaming platforms like YouTube.

AV1: Another open-source codec, AV1, is gaining traction in the industry due to its efficient compression capabilities. It offers superior video quality while keeping file sizes relatively small. AV1 is designed to be royalty-free, making it an attractive option for streaming services and content creators.

LCEVC: The LCEVC Codec (MPEG-5 Part 2) or “Low Complexity Enhancement Video Coding” is one of the three new codecs being introduced by MPEG (others being Versatile Video Coding (VVC) and Essential Video Coding (EVC)) with the aim of increased compression efficiency for existing codecs at little to no increase in coding complexity by the use of a base bitstream and an enhancement bitstream. Read more about LCEVC here.

And several video codecs are under development, such as VVC, EVC (and here), and AV2, and extensive international committees have developed these to make files smaller and of better quality!

Video Containers: The Envelopes of Digital Media

While codecs focus on the compression and decompression of video files, video containers – often called formats or wrappers – encapsulate multiple data types into a single file.

A video container can hold various data types like compressed video and audio streams, subtitles, metadata, and even codec information.

Video containers come in diverse types, including MP4, MKV, AVI, FLV, and MOV. They are responsible for synchronizing audio with video and, in more sophisticated instances, managing interactive elements, chapter points, or multiple audio and subtitle tracks.

The video codec would compress the item (video data) as if a video file were a mail parcel. At the same time, the container would be the envelope holding the item and possibly other components like a letter (audio) or a postcard (subtitles).

The Role of Video Containers in Multimedia

Video containers ensure seamless playback of multimedia content by organizing and synchronizing the audio and video streams, subtitles, and additional metadata. They provide a framework for combining compressed media types into cohesive entities.

For example, imagine watching a movie.

The video container holds the compressed video file, the audio track, and subtitles or captions. It also contains information about the video, such as the resolution, frame rate, and duration. When you play the movie, the video container allows the media player to decode and synchronize the video and audio streams, ensuring that you see and hear everything in perfect harmony.

Additionally, video containers support various features that enhance the overall user experience.

They can include chapter navigation, allowing you to jump to specific scenes or segments of a video. They can also support multiple audio tracks, allowing you to choose between different languages or audio commentaries. Some containers even provide interactive menus, similar to those found on DVDs, enabling you to navigate different options and extras.

Common Types of Video Containers

There are several popular video container formats, each with its characteristics and advantages. Let’s explore a few of them:

1. MP4: MP4 is a widely supported container format compatible with various devices and platforms, making it highly versatile. It is based on the MPEG-4 Part 14 standard and can store video, audio, subtitles, and metadata. MP4 files are known for their relatively small file sizes without compromising video quality.

2. AVI: AVI (Audio Video Interleave) is an older container format that remains popular for its compatibility with legacy systems. Microsoft introduced it in the early 1990s, supporting audio and video data. AVI files are larger than more modern formats, but they offer good video quality and are widely supported by media players.

3. MKV: MKV (Matroska Video) is a flexible, open-source container format supporting multiple audio and subtitle tracks. It is commonly used for storing high-definition videos and is known for retaining high-quality video and audio while keeping file sizes relatively small. MKV files also support advanced features like chapter navigation and metadata.

Note: Go here to learn how to convert MKV to MP4 using the VLC Media Player.

4. MOV: MOV is a video container format developed by Apple and is prevalent in the Mac ecosystem. However, MOV files can also be played on platforms with compatible media players. MOV files are commonly used for storing videos, especially those created using Apple’s QuickTime framework. They support various codecs and can contain multiple audio and video tracks, subtitles, and metadata.

Codecs and Containers: How they work Together

Understanding that codecs and containers perform different roles in video streaming is crucial.

In video streaming, codecs and containers work hand in hand to provide a seamless viewing experience.

Codecs are responsible for compressing the video, while containers encapsulate the compressed video and audio and other multimedia elements. Together, they enable efficient transmission and delivery of video content over the internet while ensuring compatibility across different devices and platforms.

Selecting the Right Codec and Container for Your Needs

Choosing the appropriate codec and container combination depends on intended use, target devices, and desired video quality. When selecting a codec, consider factors like compression efficiency, playback compatibility, and licensing requirements. For containers, consider the desired additional features, compatibility across devices and playback platforms, and the specific multimedia components you intend to include in your video file.

For example, the MP4 container paired with the H.264 codec has become a de facto standard for online video streaming. This combination provides excellent compression, quality, and compatibility with most devices and streaming services.

Similarly, the MKV container with the H.265/HEVC codec is gaining popularity for high-definition content due to its superior compression capabilities and versatility.

The Future of Video Streaming

Advancements in video technology continue to change the landscape of codecs and containers. For instance, the successor to H.265, VVC (Versatile Video Coding), promises a 50% improvement in compression efficiency over its predecessor, though a complex licensing model currently encumbers it.

Similarly, new container formats are emerging that offer greater flexibility and features. The CMAF (Common Media Application Format) is a contender that aims to unify the streaming world by enabling a single, universally compatible file format.

Knowledge of video codecs and containers empowers content creators, media professionals, and streaming platforms to optimize video files for distribution. By selecting the right codec and container combination, they can ensure high-quality video playback, efficient streaming experiences, and broad compatibility across different devices and platforms.