Title :
A harmonic bandwidth extension method for audio codecs
Author :
Nagel, Frederik ; Disch, Sascha
Author_Institution :
Fraunhofer Inst. for Integrated Circuits (IIS), Erlangen
Abstract :
Today´s efficient audio codecs for low bitrate application scenarios often rely on parametric coding of the upper frequency band portion of a signal while the lower frequency band portion of the same is conveyed by a waveform preserving coding method. At the decoder, the upper frequency signal is approximated from the lower frequency data using the upper frequency band parameters. However, commonly used methods of bandwidth extension almost inevitably suffer from a sensation of unpleasant roughness, which is especially present for tonal music items. In this paper we expose the origin of the roughness and propose a bandwidth extension method, which does not introduce roughness into the reconstructed audio signal. A listening test demonstrates the advantage of the proposed method compared to a standard bandwidth extension.
Keywords :
audio coding; bandwidth allocation; codecs; audio codecs; audio signal; frequency band portion; frequency signal; harmonic bandwidth extension; low bitrate application; parametric coding; waveform preserving coding method; Amplitude modulation; Bandwidth; Bit rate; Codecs; Frequency; Hafnium; Power harmonic filters; Signal synthesis; Timbre; Vocoders; Audio coding; Audio systems; Vocoders;
Conference_Titel :
Acoustics, Speech and Signal Processing, 2009. ICASSP 2009. IEEE International Conference on
Conference_Location :
Taipei
Print_ISBN :
978-1-4244-2353-8
Electronic_ISBN :
1520-6149
DOI :
10.1109/ICASSP.2009.4959541