Skip to main content

H.265: high-quality video at half the bandwidth

When you watch a video or view a digital picture, it’s been digitally coded using a codec. You may not be aware that the most common video codec to date has been the H.264/AVC, used in practically everything, everywhere.

However, there’s now a new codec in town that’s capable of delivering better video quality at half the bit rate. The H.265/HEVC (High Efficiency Video Coding) has been in development since 2010 and Nokia Research Center (NRC) has been involved from the beginning.

You’ll be forgiven if you don’t know the intricacies of video creation and playback. I had no idea before last week. But in order for you to watch a video online, on your DVD player, or on your phone, that video was compressed using a codec. A codec is also responsible for decompressing the video so you can watch it.

Since 2003, the H.264/AVC has been the go-to-codec for most people. You may not be aware that Nokia played a significant part in creating that codec, too, just as the new H.265/HEVC as part of a collaboration from many companies across different industries.

Nokia has always innovated when it comes to imaging. Take PureView and Cinemagraph, for example. These visual experiences use codecs behind the scenes to make sure that you’re seeing the best image possible. Nokia works from all angles to make sure that happens, including the codecs.

To explain more about the differences between H.264/AVC and H.265/HEVC, we caught up with Dr. Kemal Ugur, principal researcher at NRC:

Kemal Ugur

“H.264/AVC is the dominant video codec now, but it’s not very efficient when coding high-resolution video. To support the emerging applications requiring high-resolution pictures, we contributed on developing H.265/HEVC. Compared to earlier standards, H.265/HEVC delivers similar, if not better quality video, at half the bit rate.

“Essentially, that means transmitting half the amount of data you’d normally receive from a video coded using the H.264 video codec.”

If you take that on board, that’s a huge amount of data, particular when we’re talking about video. For example, if you’ve got a 1GB video coded with H.264/AVC, coding it with H.265/HEVC will leave you with a 500MB file, or thereabouts. This means you’re saving half your data-allowance, or half your money, depending on your price plan.

Kemal also points out another interesting fact. Not only does this save you money – and time – on downloading or streaming videos, when the new codec becomes mainstream, it should also free up half of the networks’ bandwidth.

This gives the operators’ infrastructures a break from heavy load or, if they wish, they can push double the video content to their customers.


H.265/HEVC codec can also be used for imaging, not just videos as it includes a “Still Picture” profile to encode higher-quality digital photos, with smaller file size.

Does this mean that H.265/HEVC will immediately replace the existing codecs? Not necessarily, as Kemal explains:

“This new codec, H.265/HEVC, will gradually replace H.264/AVC. But that will take a while and in no way will it be immediate. However, it’s important for people to start using this codec to utilise its potential as soon as it’s available.”

Just like today, your DVD player probably uses MPEG-2, a codec created almost 20 years ago. In another 20 years time, H.265/HEVC will probably still be used in the future’s equivalent of a DVD player.

Having a vast library of codecs is important to ensure that all content is viewable around the world, with no limitations.

The H.265/HEVC was approved by the ITU-T and the ISO/IEC January this year and will be introduced into products over the coming months and years.

Image credit: john_a_ward.