Post-Quantization Gain Correction in Audio Coding
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsErik Norvell, Volodya Grancharov
Life of this patent
Estimating the term…
Abstract
A gain adjustment apparatus for use in decoding of audio that has been encoded with separate gain and shape representations includes an accuracy meter configured to estimate an accuracy measure of the shape representation, and to determine a gain correction based on the estimated accuracy measure. An envelope adjuster further included in the apparatus is configured to adjust the gain representation based on the determined gain correction.
Claims15
An audio decoder for decoding an audio signal that has been encoded with separate gain and shape representations, said audio decoder comprising:
- means or decoding an encoded gain representation;
- means or deriving a bit allocation for a shape representation;
- means or decoding an encoded shape representation, wherein the shape has been encoded using a pulse vector coding scheme where pulses may be added on top of each other to form pulses of different height;
- means for estimating an accuracy measure of the shape representation for a frequency band, the frequency band comprising plurality of coefficients, wherein the accuracy measure is based on a number of pulses and a height of a maximum pulse, and for determining a gain correction, wherein the gain correction is determined based on the estimated accuracy measure;
- means for adjusting the gain representation based on the determined gain correction.
A method for decoding an audio signal that has been encoded with separate gain and shape representations, said method comprising:
- receiving and decoding an encoded gain representation;
- deriving a bit allocation for a shape representation;
- receiving and decoding an encoded shape representation, wherein the shape has been encoded using a pulse vector coding scheme where pulses may be added on top of each other to form pulses of different height;
- estimating an accuracy measure of the shape representation for a frequency band, the frequency band comprising plurality of coefficients, wherein the accuracy measure is based on a number of pulses and a height of a maximum pulse;
- determining a gain correction based on the estimated accuracy measure;
- and
- adjusting the gain representation based on the determined gain correction.
Dependencies are inferred from the claim text.