HEVC (H.265) vs. AVC (H.264): What’s the Difference?

Broadcasting,

Live Streaming Hardware,

Live Streaming Software

We’ve all been there: Watching an online video, movie, or sporting event when suddenly, the screen freezes up, or the quality isn’t what it previously was. No matter what you’re watching, this abrupt loss of quality is incredibly frustrating.

Recent technology known as H.265 (also called HEVC, or High Efficiency Video Coding) has emerged to combat this issue. In this guide, we compare H.265 to its predecessor, H.264, and explore what H.265 means for your live broadcasts.

First, check out our cheeky visual comparison of the two standards in this video:

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The Major Difference Between H.264 and H.265

H.264 (AVC) and H.265 (HEVC) are both standards for video compression used in recording and distributing digital video. Why would you choose one over the other? The main difference between H.264 and H.265 is how each processes information and the resulting video file size and bandwidth consumption used with each standard.

H.264 processes frames of video using macroblocks, while H.265 processes information using coding tree units (CTUs). CTUs process information more efficiently, which results in a smaller file size and less bandwidth used for your streamed video. There’s more to learn about macroblocks, CTUs, and these standards, so keep reading this detailed guide.

AVC (H.264) – An Introduction

H.264 (also called AVC, or Advanced Video Coding) is an industry standard for video compression that allows for the recording, compression, and distribution of digital video content.

It works by processing frames of video using a block-oriented, motion-compensation-based video compression standard. Those units are called macroblocks. Macroblocks typically consist of 16×16 pixel samples that can be subdivided into transform blocks, and may be further subdivided into what are known as prediction blocks. See the example below.

While that might sound confusing, here’s what you need to know: The H.264 algorithm can substantially lower bitrates better than previous standards, and is widely used by streaming internet sources like Vimeo, YouTube, iTunes, and more.

What is HEVC (H.265)?

H.265 is newer and more advanced than H.264 in several ways. H.265 (also called HEVC, or High Efficiency Video Coding) allows for further reduced file size, and therefore reduced required bandwidth, of your live video streams.

Unlike H.264 macroblocks, H.265 processes information in what’s called coding tree units (CTUs). Whereas macroblocks can span 4×4 to 16×16 block sizes, CTUs can process as many as 64×64 blocks, giving it the ability to compress information more efficiently.

Learn more about how HEVC impacts live streaming in our article on high bitrates and high image quality.

In addition to the larger CTU sizes, HEVC also has better motion compensation and spatial prediction than AVC does. This means that HEVC requires more advanced hardware, such as the BoxCaster Pro, to be able to compress the data. Fortunately, however, it also means that viewers with H.265 compatible devices will require less bandwidth and processing power to decompress that data and watch a high-quality stream.

Macroblocks and CTUs grid example on image of musicians playing

Why You Need H.265

Recreational broadcasters can still use older, lower-quality streaming methods and technology, but professionals know that video quality should be a paramount concern.

As technology continues to rapidly develop, consumers have become used to the best possible quality of image on their screen. Anything less can be seen as the mark of an inferior product or service.

Now more than ever, consumers rely on video content to deliver concise, accurate information before they make a purchase. A well-produced video can be more informative and engaging than a document or brochure, and take less time to consume.

According to a study by Wyzowl:

96% of people have watched an explainer video to learn more about a product or service.
84% of people say they’ve been convinced to buy a product or service by watching a brand’s video.
79% of people say they’ve been convinced to buy or download a piece of software or app by watching a video.

H.265’s high efficiency codec allows users to broadcast in the lauded 4K resolution, the current gold standard for the industry. A sharper image will help your video content stand out from the competition and convey a polished, tech-savvy image of your business to your audience.

As video has become a crucial tool in both marketing and the buyer experience, the same care that goes into the actual content of your video should be given to the image quality.

Required bandwidth for broadcasting in 4K:

Required Bandwidth for 4K Broadcast

AVC

32 mbps

HEVC

15 mbps

*The average internet speed in the United States is 18 mbps (according to the Akamai State of the Internet Report).
mbps: Megabits per second

Because H.265 compresses your data so much more efficiently, using it as your video compression tool will drop your bandwidth and storage requirements by roughly 50%. The table below compares the recommended bandwidth for H.264 vs. H.265 encoding.

FAQ

Should I stream in H.264 or H.265?

Live streaming in H.265 will provide you with a higher-quality image while using less bandwidth. So, if possible, stream in H.265.

Does H.265 reduce quality?

No. It will give you higher quality when the network speed is lower.

Does H.265 use more CPU?

Yes. You’ll use more CPU when you try to stream in H.265 from a computer.

Which is better for YouTube, H.264 or H.265?

If your encoder can stream in H.265, we recommend streaming with that. A third-party service like YouTube may transcode or process your video data differently from time to time depending on a variety factors, so streaming at the highest quality you can achieve on your own is always a safe bet.

Is H.264 high quality?

Yes. You can create high-quality streams with H.264 — just make sure you have the correct network speeds to do so (5-10mbps upload).

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