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2016
Conference Paper
Titel
Low complexity tonality control in the Intelligent Gap Filling tool
Abstract
When coding audio signals at low bitrates with a transform coder the most prominent artifacts are spectral holes resulting from spectral lines being quantized to zero. State of the art codecs circumvent this by Noise Filling [1] and Bandwidth Extension (BWE) [2]. Both methods have in common that they do not code parts of the waveform itself but code a coarse description of the signal. At decoder side a synthetic signal is generated and adjusted according to the coded parameters. The presented system called Intelligent Gap Filling (IGF) is a combination of both methods. Spectral holes are filled with random noise or with copied decoded signal components from lower frequency regions. In the latter case a control mechanism is required to adjust the tonality of the copied signal components to reach good audio quality. This paper describes the way of controlling the tonality of IGF.