TIME DOMAIN LEVEL ADJUSTMENT FOR AUDIO SIGNAL DECODING OR ENCODING

摘要

An audio signal decoder for providing a decoded audio signal representation on the basis of an encoded audio signal representation has a decoder preprocessing stage for obtaining a plurality of frequency band signals from the encoded audio signal representation, a clipping estimator, a level shifter, a frequency-to-time-domain converter, and a level shift compensator. The clipping estimator analyzes the encoded audio signal representation and/or side information relative to a gain of the frequency band signals in order to determine a current level shift factor. The level shifter shifts levels of the frequency band signals according to the level shift factor. The frequency-to-time-domain converter converts the level shifted frequency band signals into a time-domain representation. The level shift compensator acts on the time-domain representation for at least partly compensating a corresponding level shift and for obtaining a substantially compensated time-domain representation.

主权项

1. An audio signal decoder configured to provide a decoded audio signal representation on the basis of an encoded audio signal representation, the audio signal decoder comprising:
a decoder preprocessing stage configured to acquire a plurality of frequency band signals from the encoded audio signal representation; a clipping estimator configured to analyze side information relative to a gain of the frequency band signals of the encoded audio signal representation as to whether the side information suggests a potential clipping in order to determine a current level shift factor for the encoded audio signal representation, wherein when the side information suggest the potential clipping, the current level shift factor causes information of the plurality of frequency band signals to be shifted towards a least significant bit so that headroom at at least one most significant bit is gained; a level shifter configured to shift levels of the frequency band signals according to the current level shift factor for acquiring level shifted frequency band signals; a frequency-to-time-domain converter configured to convert the level shifted frequency band signals into a time-domain representation; and a level shift compensator configured to act on the time-domain representation for at least partly compensating a level shift applied to the level shifted frequency band signals by the level shifter and for acquiring a substantially compensated time-domain representation.