Improving the perceptual quality of sbr coding methods (spectral band replication) and hfr (high frequency reconstruction) by addition of Adaptive Noise-floor and the limitation of spare parts ucion noise.

摘要

Apparatus for enhancing a source decoder, decoder generating source one decoded audio signal by decoding an encoded signal obtained by source of an original signal coding, the original signal having a low band portion and high band portion, including the signal encoded the low band portion of the original signal and not including the high band portion of the original signal, wherein the decoded signal is used for high frequency reconstruction to obtain a reconstructed high frequency signal including a part of highband of the original signal, comprising: an adjuster (907, 909, 910, 911) for adjusting a power of the reconstructed high-frequency signal using limited for selected frequency bands of the reconstructed signal at higher frequencies amplification factors including adjuster: a calculating amplification factor to calculate the factor is deajuste amplification envelope for frequency bands of the reconstructed signal at high frequencies; a limiter (909) to limit the amplification factors of envelope adjustment for selected frequency bands, the limiter being operative to observe factors envelope adjustment to set the selected frequency bands as the frequency bands that have factors amplification exceeding a certain amplification factor limit and to limit the amplification factors of the selected frequency bands.