The New Codec That Will Replace H.264

Codecs make most people’s eyes glaze over. But, in this case, you need to pay attention.

H.264 – the codec that is ubiquitous on the web – is about to be replaced. Why? Because data networks, and especially cell networks, are getting too crowded. With video files taking up the majority of network bandwidth, we need to reduce the size of video files or suffer increasing traffic jams on the web.

In April, 2013, a new codec was approved as a standard by the ITU-T. Called HEVC (High-Efficiency Video Coding) or H.265, this new codec has the goal of reducing the bit rate of compressed video by 50% with no apparent loss in quality, or provide higher image quality at the same bit rate as H.264.

In Oct. 2014, Microsoft announced that Windows 10 would support HEVC natively. June 5, 2017, Apple announced at WWDC that it would support HEVC in the upcoming releases of High Sierra (macOS 10.13), iOS 11, and tvOS; along with HTTP Live Streaming and Safari. Intel, QualComm, Nvidia and AMD have also announced support and created products to support it.

WHAT DOES THIS MEAN?

Short-term, not a lot. Long-term, this will change how we deliver files to the web and, potentially, broadcast.

According to Wikipedia, HEVC contains intellectual property covered by patents from 23 companies. The royalties charged to hardware and software developers which allow them to create HEVC products are more than double that of H.264. These fees, along with the process of creating H.265-enabled products, have delayed the roll-out of this technology.

But, all of that is about to change.

All current Mac computers support HEVC directly in hardware for both encode (recording) and decode (playback). This means that – once the new OS is released – we can work with H.265 files as easily as H.264, while using less storage space and still maintaining high image quality.

NOTE: HEVC hardware support requires a sixth-generation Intel processor or newer; these are also called “Skylake.” In general, that means a Mac released in late 2015 or newer. Any iOS device running iOS 11, or later, will be able to encode or decode HEVC.

According to Wikipedia, there are several big advantages to HEVC:

• Support for frame sizes larger than HD, in fact, up to 8K; H.264 maxes out at 4K
• Support for 10-bit-depth files, allowing HDR to be encoded
• Smaller file sizes, up to 50% smaller than H.264
• Decoding takes fewer computer resources than H.264, which means older systems should still be able to play movies compressed in this format

NOTE: Apple, in its WWDC announcement, said that HEVC enables video streaming and playback of 4K video files that are up to 40% smaller than those created by H.264.

However, encoding HEVC is more complex and requires beefier computers than H.264.

NOTE: HDR won’t be supported in the initial release, but Apple expects to add that in an up-coming update. Encoding and decoding HEVC will be supported in both macOS and iOS.

WHAT WE NEED TO KNOW NOW

In addition to operating system support, which means that any app that plays video can play H.265 media, Apple, at WWDC, spoke in general terms about forthcoming support for HEVC in Final Cut Pro, Motion, and Compressor. Apple hasn’t provided additional details since the updates are not yet available (or in public beta).

But there is a lot we can learn about the codec, which allows us to start making plans for the future.

First, while HEVC is built into all current Apple hardware, encoding using hardware is limited to 8-bit video. (Decoding supports 10-bit.) This means that if you are creating HDR material, you’ll need to use software encoding to take full advantage of the 10-bit architecture of HEVC. Software encoding will be slower than hardware; however the actual speed difference won’t be known until after Apple ships the new operating system and Final Cut software

At its core, HEVC is a codec:

• It is designed to make files much smaller without damaging image quality.
• It provides more settings for fine-tuning compression, however, as usual, Apple will balance ease of use with the ability to tweak the settings in applications that encode video; specifically Compressor.

INTERESTING GEEK STUFF

HEVC is specifically designed to improve streaming by reducing bandwidth requirements.

If you currently use HTTP Live Streaming to optimize your files for streaming, the new codec won’t change this. HTTP Live Streaming is deliberately designed to be codec-independent. Everything you do now using H.264 remains the same with H.265.

Unlike H.264, H.265 has more flexibility in choosing GOP size, eliminates propagation of error problems, and handles transitions – such as abrupt lighting changes or sudden movement – much more elegantly.

Essentially, when it comes to compression, H.265 is just like H.264 – except it is more flexible, creates smaller files and is designed for the future of media.

WHAT YOU NEED TO DO RIGHT NOW

Media today is:

• Rapidly moving to higher resolutions. H.264 won’t support that.
• Moving to support more color saturation and wider gamut. H.264 won’t support that.
• Moving to streaming more video over the web. H.264 creates files that are too big and are already choking our network infrastructure.

We need to change and H.265 is part of the change.

To make the most of HEVC, getting a newer computer will help. What I’ve done in my office is dedicate one computer specifically to video compression. To make the most of HEVC, this computer needs to be fairly recent, with a fast CPU.

Remember, if you plan to encode HDR material, you’ll need to use software compression, which is slower than hardware. Since H.264 is currently compressed using hardware, this means that HEVC compression will take longer than H.264.

Also keep in mind that compression times slow down as frame size increases simply because there are so many more pixels that need to be processed.

For the next year, we’ll need to deliver both H.264 and H.265 projects. After that, the world will quickly shift to H.265.

I’m excited about the potential for H.265 and look forward to testing it when Apple releases products to support it. For now, I’m saving my pennies for a new compression computer.