Enhancing perceptual performance of SBR and related HFR coding methods by adaptive noise-floor addition and noise substitution limiting

USRE43189E1 · kind E1 · reissue

Assignee

• Dolby International AB · IE

Inventors

• Lars G. Liljeryd · Solna, SE
• Kristofer Kjoerling · Solna, SE
• Per Ekstrand · Saltsjöbaden, SE
• Frederik Henn · Bromma, SE

Key dates

• Filing date: Jan 26, 2000
• Grant date: Feb 14, 2012
• Expiry date: Jan 26, 2020

Classification

• Technology area (CPC —): General

Abstract

Methods and an apparatus for enhancement of source coding systems utilizing high frequency reconstruction (HFR) are introduced. The problem of insufficient noise contents is addressed in a reconstructed highband, by using Adaptive Noise-floor Addition. New methods are also introduced for enhanced performance by means of limiting unwanted noise, interpolation and smoothing of envelope adjustment amplification factors. The methods and apparatus used are applicable to both speech coding and natural audio coding systems.