Method and device for decoding an audio soundfield representation for audio playback

摘要

Soundfield signals such as e.g. Ambisonics carry a representation of a desired sound field. The Ambisonics format is based on spherical harmonic decomposition of the soundfield, and Higher Order Ambisonics (HOA) uses spherical harmonics of at least 2nd order. However, commonly used loudspeaker setups are irregular and lead to problems in decoder design. A method for improved decoding an audio soundfield representation for audio playback comprises calculating (110) a panning function (W) using a geometrical method based on the positions of a plurality of loudspeakers and a plurality of source directions, calculating (120) a mode matrix (&Xgr;) from the loudspeaker positions, calculating (130) a pseudo-inverse mode matrix (&Xgr;+) and decoding (140) the audio soundfield representation. The decoding is based on a decode matrix (D) that is obtained from the panning function (W) and the pseudo-inverse mode matrix (&Xgr;+).