About a year ago, we brought news of Valve's Steam Audio SDK, a set of software tools designed to aid game and VR developers in adding positional audio effects to their titles. The game developer and publisher just released Steam Audio 2.0 beta 13, a release that adds support for AMD's TrueAudio Next technology (TAN). The new version supports TAN in the Unity and FMOD Studio development environments. TrueAudio Next uses standard GPU compute resources instead of the specialized audio processing hardware that the original TrueAudio required.
Latency—less is better
True Audio Next is a software library that implements audio convolution on supported GPUs. Convolution is a math operation that applies a specific type of filtering to an audio signal. Common convolutions implement delay (echo), frequency equalization, head-related transfer functions, and reverb. Those effects, especially reverb, are compute-intensive operations and usually run on the CPU. According to Valve, most game audio engines allow only two to four simultaneous convolution reverb filters in order to keep hardware load within acceptable limits.
The new Steam Audio release also supports Resource Reservation, a technology that allows developers to set aside up to 25% of a GPU's compute units for audio processing. Sound processing tends to be extremely sensitive to latency. Reserving computational resources for sound processing could potentially lead to decreased pops, clicks, and other audio glitches. According to Valve, CPU resources cannot be reserved for sound processing in the same way. The charts on Valve's announcement page say that a system with as few as four CUs set aside for audio processing could handle as many as 80 convolution sources while remaining within acceptable latency limits.
The big caveat for the majority of PC gamers is that the new features are limited to "compatible GPUs," which means Radeon R9 Fury, Fury X, Pro Duo, RX 470, RX 480, RX 570, and RX 580 cards. Those who want to read more can follow this link. Those looking to get their hands dirty right away can download Steam Audio here, and the Unreal Engine, Unity, and FMOD Studio plugins here. We were unable to find a list of games using Valve's Steam Audio, but given the relatively young age of the SDK and the importance of positional audio in VR, we suspect the list is heavy with Steam VR titles.