Binaural Rendering in MPEG Surround

Abstract

This paper describes novel methods for evoking a multichannel audio experience over stereo headphones. In contrast to the conventional convolution-based approach where, for example, five input channels are filtered using ten head-related transfer functions, the current approach is based on a parametric representation of the multichannel signal, along with either a parametric representation of the head-related transfer functions or a reduced set of head-related transfer functions. An audio scene with multiple virtual sound sources is represented by a mono or a stereo downmix signal of all sound source signals, accompanied by certain statistical (spatial) properties. These statistical properties of the sound sources are either combined with statistical properties of head-related transfer functions to estimate "binaural parameters" that represent the perceptually relevant aspects of the auditory scene or used to create a limited set of combined head-related transfer functions that can be applied directly on the downmix signal. Subsequently, a binaural rendering stage reinstates the statistical properties of the sound sources by applying the estimated binaural parameters or the reduced set of combined head-related transfer functions directly on the downmix. If combined with parametric multichannel audio coders such as MPEG Surround, the proposed methods are advantageous over conventional methods in terms of perceived quality and computational complexity.

Phantom materialization for headphone reproduction

“…The HRTFs were sampled at a 6-degree azimuth and elevation resolution and were equalized for their diffuse-field response. The HRTFs were converted to a lossy but perceptually transparent parametric form [21,22,19] to allow seamless integration of spatial analysis and synthesis in the same domain without the need for additional transforms or zero padding operations.…”

Ultrasonic Sensor-Based Personalized Multichannel Audio Rendering for Multiview Broadcasting Services

“…Figure 4 presents the block diagram for the proposed parameter-based audio rendering method which is based on the constant power panning law using MPEG Surround parameters [16, 17]. In this figure, panning gains in the proposed method are first calculated according to the user's viewpoint, and N different channel level difference (CLD) parameters are extracted from the audio bitstream after applying a CLD parser.…”

“…In addition, pGout,X denotes the panning gain calculated for each channel, where X is replaced with R (right channel), L (left channel), C (center channel), Rs (right surround), and Ls (left surround). Subsequently, the panned CLDs are used for MPEG Surround decoding, resulting in the panned multichannel audio shown in Figure 7 [16, 17].…”

A Sparsity-Based Approach to 3D Binaural Sound Synthesis Using Time-Frequency Array Processing

“…Experiments with parametric HRTFs have confirmed that subjects cannot discriminate the parametric HRTF versions from the original ones if a suitable set of parameters are selected within each critical band [7]. Breebaart et al [8] proposed some methods to provide a multichannel audio experience over stereo headphones from a mixdown of sound source signals and a parametric representation (spatial parameters) of the multichannel original signal in a time-frequency domain. The binaural synthesis stage combines the spatial parameters of the multichannel signal with the HRTF parameters that describe the virtual loudspeaker setup, resulting in a set of combined binaural parameters that are later used to modify the downmix signal.…”