Bark amplitude component coder for a sampled analog signal and decoder for the coded signal

Apparatus for coding an analog audio signal having a repetitive nature, the apparatus comprising:

• means for performing a short-term prediction analysis on a quantized sampled analog audio signal and for providing coefficients determined in the short-term prediction analysis at a first output;
• a short-term prediction filter for receiving the sampled analog audio signal and for generating a segmented residual signal;
• means for diving the segmented residual signal into subsegments;
• means for transforming the subsegments from a time domain to a frequency domain and for providing several frequency components per subsegment, each frequency component having a frequency-components amplitude;
• means for calculating a number of new amplitudes of signal by combining the several frequency-component amplitudes, the number of new amplitudes being smaller in number than the several frequency-component amplitudes, at least one new amplitude being a function of at least two frequency-component amplitudes and at least one other new amplitude being a function of at least three frequency-component amplitudes, and for providing the new amplitudes at a second output;
• means for performing a long-term prediction analysis on the subsegments of the segmented residual signal and for providing coefficients determined in the long-term prediction analysis at a third output;
• means for calculating a gain factor G as a scaling value and for dividing each new amplitude by the gain factor and for providing the gain factor at a fourth output;
• means for multiplying each subsegment by a window function;
• and
• means for quantizing the new amplitudes;
• wherein thirteen frequency-component amplitudes A.sub.1 to A.sub.13 are combined to calculate four new amplitudes B.sub.1 to B.sub.4 in accordance with ##EQU6## and wherein the gain factor G is calculated in accordance with ##EQU7##