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MPEG-H: A threat to Dolby Atmos?

Streaming services, soundbars and also movies on Ultra HD Blu-ray discs. Almost all choose resolutely for Dolby Atmos. The great rival DTS: X seems to have no chance. But what about MPEG-H, a surround standard that is slowly gaining ground?

Never heard of MPEG-H? That is not so strange. This surround format is barely even on the radar of seasoned audio connoisseurs. And yet more and more devices support it. Sennheiser’s soundbars, for example, such as the recent Ambeo Plus. It also features on the specification list of quite a few Samsung soundbars. Support for MPEG-H audio can also be found in AV receivers from Denon and Marantz, the Chromecast adapters, and Amazon’s smart speakers. StreamUnlimited, a streaming module supplier built into many audio devices, is also licensed MPEG-H. Sony is perhaps the biggest fan because they use the 360 ​​Reality Audio format that the Japanese brand strongly promotes. MPEG-H is also the basis of the Tempest Engine, the 3D audio engine of the PlayStation 5.

The Atmos steamroller

Why isn’t MPEG-H well-known? This is mainly due to the incredible dominance of Dolby Atmos. Because although the trophy has not yet been distributed, Dolby is the winner in this round of the surrounding war. No one else comes close when it comes to 3D sound combining ear-level surround sound with so-called ceiling-height height speakers to achieve total envelopment. Dolby has therefore done its best to talk its technology into content creators. Starting with the major film studios in Hollywood and streaming services, but also with game developers. On the Xbox consoles, it is the dominant technology, too. The American company has understood that a surround format ‘wins’ if used in a lot of content. It also seems that Dolby recognized early on that streaming services would become more critical. After all, it developed different flavors of Atmos, including one that uses relatively little bandwidth. And that is an essential requirement from Netflix and Co.

Small Belgian rival Auro and eternal competitor DTS has not been able to offer much resistance. It’s gotten to the point where TV manufacturers looking for things to save on are increasingly not licensing DTS codecs. They no longer find it relevant, but as a result, older Blu-rays and DVDs also play without surround sound, and those formats are not passed through to soundbars. So why would MPEG-H succeed in conquering a place?

What is MPEG-H right?

Standards are always complex and bureaucratic. And that is even more the case for media-related standards devised by the ISO/IEC Moving Picture Experts Group. MPEG-H is, therefore, not just one thing. It includes fifteen very different and separate parts, of which HEVC, or High-Efficiency Video Codec, is the best known. Under another name, H.265, streaming services (and movie pirates) widely use this video compression algorithm to compact high-resolution video very efficiently. It is also used on Ultra HD Blu-rays. It’s incredible how well the algorithm works.

In this article, we are talking about MPEG-H 3D Audio, another part of MPEG-H. It comes from the Moving Picture Experts Group; the German research institute Fraunhofer devised the underlying technology. If all that sounds familiar, yes, the same people came up with AAC and MP3. However, MPEG-H 3D Audio has nothing to do with those previous codecs. And that is immediately a big difference with Dolby Atmos, an extra, new layer on top of the older Dolby TrueHD or Dolby Digital + codecs. This is also why you can safely play Atmos soundtracks on an older soundbar. You get surround sound but without the Atmos effects. However, MPEG-H 3D Audio is something new and separate from previous codecs.

You may not have noticed that the word ‘standard’ was often mentioned in what we just wrote. That’s no coincidence. MPEG-H 3D Audio is a true standard, co-developed by several organizations, with much discussion and a selection process to choose the underlying technologies. The result is not necessarily free to use, but soundbar manufacturers can trust that MPEG-H 3D Audio stands for something very concrete. And manufacturers also know what to do if they want to support MPEG-H. For example, this was also the case for a standard such as 5G or WiFi. However, Dolby Atmos is a commercial product where the control is with one company. That difference is significant for some applications and companies.

A 3D bubble

Technically, MPEG-H 3D Audio differs from Dolby Atmos, but there are also many similarities. It’s a format meant to bring sound around you in three dimensions. Not only sound from speakers that are set up at your ear height, such as with Dolby Digital Plus or DTS-HD MA. Those older technologies work with fixed channels: left, right, center, back left, etc. This meant, among other things, that the different speakers had to be in a particular place according to the rules. The new surround formats work with ‘objects’ (read: sounds, such as gunshots, the sound of rain, or an actor’s voice) placed during production in a virtual space where the viewer is central. Great for filmmakers because they can get much more creative with sound effects. Not only to highlight action but also to give your living room or cinema the feeling of the space in which the film is set. If that’s beyond your imagination, think how different a small bathroom with tiles sounds compared to a grand cathedral. For the film buff, formats such as Dolby Atmos and MPEG-H 3D Audio offer much more immersion. And also provides a better experience and flexibility because the surround sound is better suited to the room. We are, of course, greatly simplifying because, in reality, Atmos, among other things, combines fixed channels with virtual objects. There are also significant differences between Dolby Atmos at the cinema and at home. Then think how different a small bathroom with tiles sounds compared to a grand cathedral. Because, in reality, Atmos, among other things, combines fixed channels with virtual objects. 

MPEG-H 3D Audio also combines channels with objects. It also adds ambisonics, an older surround concept from the 1970s that is becoming much more feasible with the current computing power. There’s a lot to talk about, but one remarkable thing about ambisonics is that it supports a complete sphere around the listener. So not only sound in height but also depth. That is also why ambisonics has recently experienced a revival in VR applications. After all, you can look and hear in all directions with virtual reality glasses.

For live TV

Of course, standards often raise their heads only to disappear forever under the surface after a short time. That does not seem to be the case with MPEG-H 3D Audio. Partly because the group behind the technology does not attempt to compete directly with Dolby. For example, they don’t seem to be planning to offer their surround format to Hollywood. The format is mainly presented as a cheaper solution for broadcasters, for example, sports coverage. That seems wrong in an era where everyone around you opts for streaming services. But indeed (live) sports broadcasts still attract many millions of viewers. There are also many countries where TV channels are still viral, even via the antenna. MPEG-H 3D Audio has therefore been developed to fit into the broadcast chain. South Korea and Brazil are countries where TV channels are working with the technology. The first already explains why Samsung, among others, embraces the technology.

If you only associate surround with movies and games, it doesn’t seem that important. But the realistic 3D sound is also very impactful for a football match. Both to convey the atmosphere in the stadium and also because hearing what happens with the ball underlines the action. We have already experienced demos of sports broadcasts with surround; it adds something. An experiment has also been carried out to distribute the Eurosong Contest in surround via MPEG-H.

Immersion in music and gaming

The most significant breakthrough of MPEG-H 3D Audio to date can be found at Sony. It is important to remember that the Japanese company is an electronics giant and one of the most prominent music labels and film studios. That versatility often plays a role in Sony’s decisions about new products, including in this case. For example, in 2019, it released a new music surround format, 360 Reality Audio – essentially just another name for MPEG-H. Sony wanted to distinguish itself in the headphone and soundbar market by offering something extra that rival brands did not have. It also convinced several streaming services, such as Deezer and Tidal, to offer releases in the format. A few other brands now support 360 RA, such as Audio-Technica. Recently, Amazon also jumped on the bandwagon.

Not much is known about the role of MPEG-H 3D Audio in the Tempest Engine on the PlayStation 5. The Tempest Engine can do very spectacular things on paper. Thanks to a dedicated processor – a graphics chip that is being repurposed – the PS5 can theoretically generate surround sound dynamically. It can adjust a sound to your player’s position in a game and consider the environment. Fictional example: if you hear a moaning zombie approaching in the distance and take cover behind a thick curtain, that moaning will move appropriately and become duller. That is just one step further than the ‘passive’ surround sound in a home cinema. But there is more to tell about that Tempest Engine – fodder for a later article.