BoxCast Team • September 20, 2018
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 post, we compare H.265 to its predecessor, H.264, and explore what H.265 means for your live broadcasts.
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 (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 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.
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.
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.
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.
BoxCast follows movement in the industry closely and constantly strives to be at the forefront of any changes. With the BoxCaster Pro, we allow broadcasters to incorporate HEVC compression in streams that are capable of up to 4K! In staying true to our belief that every event that is watched live should be streamed live, we make this affordable to our customers.