Video Encoders

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

This post talks about the differences in H.265 and H.264 video compression. It's part of our series on video encoders.

We’ve all been there. We’ve been watching an online video, movie, or a sporting event when the screen suddenly freezes up, or the quality is not 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 - High Efficiency Video Coding) has emerged to combat this issue. In this post, we compare H.265 to its predecessor, H.264, and explore what H.265 means for your live broadcasts.

HEVC-AVC side-by-side comparison

H.264 - An Introduction

H.264 (also called AVC - 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 (see image below) typically consist of 16x16 pixel samples, that can be subdivided into transform blocks, and may be further subdivided into what are known as prediction blocks.

While that may sound confusing, here’s what you need to know: the H.264 algorithm can substantially lower bit rates better than previous standards and is widely used by streaming internet sources, such as videos from Vimeo, YouTube, iTunes, and more.

How is H.265 Different?

H.265 is more advanced than H.264 in several ways. The main difference is that HEVC 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 4x4 to 16x16 block sizes, CTUs can process as many as 64x64 blocks, giving it the ability to compress information more efficiently.

If you want to learn more about HEVC's impact, check out this post:

HEVC's Impact on Live Streaming

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. This also enables the streaming of 4K video over common network speeds.

4K Resolution.png


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. 


H.264 vs H.265 Streaming Guidelines



Final Thoughts + Further Reading

Where Does BoxCast Come In?

BoxCast has been following the movement in the industry closely and constantly strives to be at the forefront of any changes. With our release of the BoxCaster Pro, we allow broadcasters to incorporate HEVC compression on their streams that are capable of up to 4K! And in staying true to our belief that every event that is watched live should be streamed live, we’re making this affordable to our customers.

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