What Is H.264 Video Codec and How It’s Shaping the Online Video World

Video codecs are essential to pre-recorded and on-demand video delivery over the web. They are the reason billions of people can enjoy buffer-free content on video-sharing websites like YouTube and streaming services like Netflix nowadays. Thanks to codecs, encoders can compress and prepare video files before delivering them to our devices.

It shouldn’t be surprising to hear that video encoding is complex, with more nuances than any layperson can see. Still, choosing the right video codec plays a critical role in it. 

Unfortunately, that is not an easy task. There are dozens of video codecs to pick from, and each offers different image quality and bitrate. However, one of them stands out as the most widely-used video codec in the industry — H.264. This codec is why users worldwide can enjoy high-quality video at low bitrates in a single standardized format.

Let’s take a more detailed look at how the H.264 video codec works, how widely it’s been adopted, and why it’s still considered to be one of the best video codecs for live streaming and on-demand video.

What Is H.264 Video Codec?

H.264 video codec or Advanced Video Coding (AVC) is the world’s most-used video compression standard for HD video. This codec is a block-oriented, compensation-based standard that encompasses several max video bitrates and resolutions (it even supports 4K and 8K video).

H.264 is a codec co-developed by the International Telecommunications Union as H.264 and International Organization for Standardization/International Electrotechnical Commission as Advanced Video Coding (AVC), meaning these two terms are interchangeable.

H.264 video codec supports a wide variety of container formats, making it one of the most versatile codecs in the industry. It most commonly uses MPEG-4, but it frequently appears in some other ones too. Here are some of the most common H.264 container formats:

• MP4
• MOV
• F4V
• 3GP
• TS

Although H.264 is not the best compression codec, it is easy and cheap to implement. It also more than halves a video’s file size while keeping its quality at a high standard. That makes it a more efficient choice than most of its predecessors.

Many famous vendors even use H.264 in their own codec versions. Some of these include:

• Apple Codec (used by Apple and QuickTime Pro)
• MainConcept Codec (used by Microsoft, Adobe, Telestream, etc.)
• x264 Codec (most shareware encoders and custom encoding systems use this one)

Thanks to the H.264 codec, video producers and viewers worldwide have easier access to better-quality on-demand and live video on a wide range of streaming platforms.

How Does H.264 Video Codec Work?

H.264 video codec uses a block-oriented standard with motion competition to analyze and process video frames. The H.264 encoder carries out predictions, transformation, and encoding to generate a bitstream. The encoder creates several macroblocks (16×16) throughout the process and divides them into smaller prediction blocks for transportation. Once these blocks reach the decoder, it puts them back together and prepares for playback.

H.264 codecs can use different profiles, i.e., encoding techniques when encoding videos. Depending on the compression technique you choose, the codec will specify different maximum bitrates and video resolutions. That’s why you’ll need to adjust your encoder’s settings based on the video quality rendition you’re looking to get.

Best Video Encoder Settings When Using H.264

When encoding videos with H.264, it’s crucial to set up your encoder’s video bandwidth and resolution adequately to get your desired video quality. Most videos that use H.264 will have the following quality renditions:

• Ultra-Low Definition (240p)
• Low Definition (360p)
• Standard Definition (480p)
• High Definition (720p)
• Full High Definition (1080p)

The table below will illustrate how you should configure your hardware encoder for streaming in each of these quality renditions:

Settings	Ultra-Low Definition	Low Definition	Standard Definition	High Definition	Full High Definition
Video Bitrate (kbps)	350	350–800	800–1200	1200–1900	1900–4500
Width (px)	426	640	854	1280	1920
Height (px)	240	360	480	720	1080
Profile	Main	Main	High	High	High

Depending on your resolution of choice, you’ll need different amounts of bandwidth to deliver your content buffer-free. The higher your resolution is, the more bandwidth it will consume. That means users with slower internet speeds may experience more disruption in video playback.

An excellent way to circumvent this issue is to find an HTML5 video player with support for adaptive bitrate streaming. This technology enables you to adapt your videos’ quality to match your users’ internet speeds to minimize latency and eliminate buffering.

H.264 Adoption Rates

H.264 first appeared in 2003, but it took many more years before it became the global video encoding standard that it is today. One of H.264’s first adopters was Apple, as it started using this codec in 2007. Adobe’s Flash adopted this codec in 2008, while many browsers and devices soon followed suit.

However, H.264’s true boom came after YouTube and Vimeo started using it in 2010 when it became unofficially recognized as the industry-standard codec for online video. Although it took some time for internet browsers to implement support for H.264 codec, most popular browsers and devices have it nowadays.

Besides browsers and online use, H.264 is also the standard video codec for Blu-Ray disks, most video-conferencing software, TV broadcasting companies, OTT apps, and other video delivery systems worldwide.

Which Browsers Support H.264 Codec?

Although H.264 is widely accepted worldwide, it has mixed support online. The number of browsers that adopted H.264 has grown over the years, but a few still only partially support it. Here’s a complete list of browsers (and their versions) that support H.264:

Chrome	Firefox	Internet Explorer	Safari	iPhone	Android
4.0+	2.1+ (Partial Support)	9+	3.2+	3.2+	2.1+ (Partial Support)

Why H.264 Is the Right Choice for You

Here’s a quick recap of why choosing H.264 codec for your encoding needs is a good and reliable choice:

• It is affordable and easy to implement (H.264 license price goes between $0.08 and $0.28 per unit)
• H.264 is highly flexible and can be used on various apps and video delivery and broadcasting systems. 
• Most contemporary devices (e.g., professional encoders/decoders, Blu-Ray disks) and browsers support H.264, making it the go-to choice for online and offline video delivery.
• It offers excellent compression without compromising on video quality.

Although video encoding technology has advanced significantly since this codec’s early days, it will be a while before any other codec dethrones H.264 as the industry standard. So if you’re looking for a well-rounded and safe video codec for your encoding needs, H.264 is the way to go!

However, if you care more about content quality and compression rates, there are better options out there. One of the better choices would be AVC’s successor — H.265/HEVC. If you’re interested to see how these two compare, check out our H.264 vs. H.265 article below.

FAQ