The band[0] and band[1] correspond respectively to the lower band and higher band.
int32_t s_zero
previous output signal from zero predictor
int prev_samples_pos
the number of values in prev_samples
int16_t log_factor
delayed 2-logarithmic quantizer factor
int16_t scale_factor
delayed quantizer scale factor
int16_t prev_qtzd_reconst
previous quantized reconstructed signal (internal value, using low_inv_quant4)