[2019] Under The Hood: An Inside Look At HDR Audio Coming To Rocket League

I apologize that our post didn’t do a good job of communicating our intent. Our main focus is on making the game cleaner. Right now the audio is fairly muddy and not useful. Rocket League is a 'fishbowl'esk physics game, so we have little control over how the player utilizes it. This new mix takes advantage of priorities to help carve away space.

While it seems that HDR is less realistic (and in some ways it is) the ending effect is an attempt to achieve more realism by increasing the perceivable dynamic range of the audio in the game. This system was spearheaded by DICE in wonderful sounding games such as Battlefield: Bad Company and Battlefield 3.

Here are a few quotes and some sources that will hopefully help explain the system better.

" In HDR audio, you can assign volume values to sounds of the game's virtual world that span over a much larger dynamic range than the standard 96 dB of 16-bit output devices, much like they would in the real world. It is the task of the HDR system to translate these values into dBFS " - source

" The technique consists of using an automatic mixing system that maps virtual world loudness to living room loudness. Clerwall’s phrase “every sound is important, but not at the same time” [2] summarizes the essence of its algorithm " -Source

Of course! Any large feature has that kind of potential. We have tested this thoroughly and have done everything in our power to receive feedback and iterate. That being said, once going to a live environment with millions of games happening, you can't account for everything and we will likely find bugs. But we will fix them quickly and hopefully keep you playing with sound! Be sure to give us feedback once it goes live, I promise we will read all of it and use your input to keep making Rocket League better.

The term is actually an industry one.

Numerous games before us have employed an HDR mixing structure with great success. Most noteably would be the work done by DICE. It is these games and many others that paved the way for Rocket League. Typically this type of iteration happens before a game ships, but the HDR system was popularized after Rocket League's launch. Once HDR came out, we saw an opportunity to improve Rocket League!

In a sense, yes. However, in some other ways, it’s not quite compression. If you’re really curious you can take a look at how HDR works in the audio middleware we currently use.
HDR Examples

Sound in games all too often falls prey to the “good enough” mindset. Especially in the multiplayer realm where most games don't sound as great as the single player experiences where the developer has more control and insight into how the game is being played.

Yes, Rocket Leauge sounded O.K. in the beginning, but we know it can be better. We want the best possible experience for the community and work extremely hard to achieve that.

Not at all! It scales wonderfully to a higher fidelity system. We just built ground up rather than top-down this time.

Also mentioned in the article is the next aspect we intend to add which is dynamic range selection. With this, if you have a big surround system, you can extend the actual dynamics of the game to match a 'theater' like experience.

Yes! I've posted a few in other locations in the thread. :)

I promise you we have done nothing to mess with the sensation of proximity in an unexpected way. In fact, one aspect in this new mix different from the current live version of the game is that we went back to the attenuation curves the game previously had. Specifically because of feedback that the community didn't like our last changes.

So from that aspect, the sound of the game will be more akin to the 2015-2018 version of the game.

With regards to the HDR system being used for atmospheric games, I do see where you concluded that. That being said, it probably could be viewed as more of a case by case basis. The system frequently works best in games where you're trying to control the chaos, such as the Battlefield, Crackdown, Sunset Overdrive, etc.

Here's an interesting article from the Last of Us crew about their decision not to use HDR, specifically because they have a heavily atmospheric game.

So let's talk about 'quiet things in a game'. There are no quiet things in Rocket League. Our game is a series of loud things in constant succession. This is why we chose to do HDR. When an event happens, it is always important. So in a world like that, how do you effectively balance all-important, all loud things using a non-dynamic mixer in an environment that we have no idea what is exactly transpiring. You really can't... the 2015 version of the game and the slight iterations up to 2018 did their best, but the game was still muddy.

In HDR we have not changed the prioritization of things far away, we tried that earlier this year based upon player feedback and it turns out it didn't work for the large majority of our community. So that was removed. What we have done in this new mix is that when an event happens, other things move away for the new event for a very slight moment, and then everything is normal. Let's take a look at a hypothetical example:

-You're driving, your engine is roaring, your feathering boost, there are two cars in front of you with engines and boosts as well.

-you're colliding with those cars and all sorts of impact and tire noises are happening

-the crowd is additionally roaring, and you are on salty shores map with a ton of ambient audio.

-Your teammate boosts immediately behind you. How can you pick that out of the 75+ other audio events occurring?

-The old system (2015-2018) nothing changes about your car, your audio events are the most important because they are yours, and we want them to be impactful.

-The new system (next patch :) ) Your engine audio turns down ever so slightly, the crowd audio sharply reduces for a second, the ambience is almost gone at this moment, if you were impacting something and causing all sorts of collision and tire noises, those also dip out slightly. It isn't faking the distance, it is right there... right behind you... easy to read and understand not only where it's from, but what it is.

-And just as suddenly all those things were dipped out, they are back. You can't hear this all happen, because in that space we opened in the mix is filled with the boost ignition immediately behind you.

That's the general idea. It actually works pretty well too. We've had quite a few people test it at this point and it's been a pretty resounding positive response with this mix. The big reason it is a win for Rocket League is that the game is built around the premise of noisy things that make audio hard to pinpoint. Crowds and Engines are basically noise, so we need a way to get them out of the way to help you read the game.

I will end with reiterating the fact that all of this happens extremely fast. It may read that your engine turns down for that boost but it's a transient system. Which means that as the attack of that boost hits, the engine reduces, then the audio returns to normal as that transient event is gone.

I sincerely hope that this helps you understand what our intent is here. We really do care what our community thinks, and every patch I go and read anything regarding the sound and/or music and we discuss it and a plan of attack for it.

We hear you. (pun intended)

We have had numerous discussions internally of how it's not an ideal name. Absolutely agree.

Thank you for your support on the new system! Once it's out, if you have feedback be sure to post it!

Basically what I'm getting at is that you have full control over the experience given it's a physics driven game and everything happens in one place (fishbowl).