HDR AUDIO ? (in video games)

Question

I was recently looking for some additional audio infos about Dice's Battlefield Bad Caompany. Which is a really really good game in audio terms.

And I found this : http://www.slideshare.net/aclerwall/how-high-dynamic-range-audio-makes-battlefield-bad-company-go-boom-1292018

I'm planning to create an audio workflow for a racing game. And I was questionning myself : How can I make this game's audio goes BOOM like BFBC. Is there's any book talking about real-time audio mix & mastering ? What basics may I know before stepping into this ?

By the way, I hope you'll like this slideshow if you didn't knew about it.

PS: Sorry for my poor english guys.. Hope everybody could understand :)

Answer 1

There's quite allot of info about DICE's HDR system knocking about on the net. If you google it you will find it.

Essentially its a system that prioritises and mixes audio based on the loudness perceived by the player at any one time. It works by taking a dB range (lets say 50dB) and culling any sound quieter than 50dB less than the loudest sound perceived by the player. This "window" in which sounds are heard shifts depending on the loudest sound perceived by the player.

See diagram

alt text http://dl.dropbox.com/u/4790383/HDR.jpg

What you need to know before attempting this? A good level of audio programming is essential. If you don't have a background in programming you will need to find someone, to my knowledge there isn't a freely available version of this tech it's all proprietary.

Short example of the system in action;

I should probably add that this is a vast over-simplification of one of the best sounding game engines at the moment.

Answer 2

DICE was at the AES convention last week talking specifically about their HDR mixing process in the Battlefield games. I believe recordings will go up for purchase on the AES website later this week, so that might be useful to you. It was an interesting talk, but don't expect too much on the technical side. The discussion was really more about rules for mixing than the specific technology. There are some basic rules to mixing that carry across any medium: what's important, spectral content, dynamics and pacing, etc. Approach your workflow design in those terms, and you'll find a lot of things fall into place on their own.

There's going to be those wonderful trouble spots that don't, but I personally like problem solving. ;)

Answer 3

Dice were also explaining their HDR system at GDC in 2009 I think. DICE use their own tech written from the ground up - and it's designed very much to suit their style of games. Racing games have a whole different set of requirements, mostly revolving around the perception of speed and power ;) - Creating something like DICE's HDR system might be overkill for the racing game genre. Also from what I understand it is quite resource hungry. Something a bit simpler but equally as effective like using Wwise's ingame sidechaining might be a good option. Sorry if I've burst your bubble ;)

Answer 4

Since you didn't really specify whether you plan on implementing or designing the audio pipeline then I would recommend looking into the many articles by e.g. Rob Bridgett who won't supply you code, but will supply techniques and general design concepts that might inspire you. Gamasutra and DesigningSound has a wealth of material on the subject.