+/**
+ * Restores past LSP quantizer output using LSF from previous frame
+ * @param lsfq [in/out] (2.13) quantized LSF coefficients
+ * @param past_quantizer_outputs [in/out] (2.13) quantizer outputs from previous frames
+ * @param ma_predictor_prev MA predictor from previous frame
+ * @param lsfq_prev (2.13) quantized LSF coefficients from previous frame
+ */
+static void lsf_restore_from_previous(int16_t* lsfq,
+ int16_t* past_quantizer_outputs[MA_NP + 1],
+ int ma_predictor_prev)
+{
+ int16_t* quantizer_output = past_quantizer_outputs[MA_NP];
+ int i,k;
+
+ for (i = 0; i < 10; i++) {
+ int tmp = lsfq[i] << 15;
+
+ for (k = 0; k < MA_NP; k++)
+ tmp -= past_quantizer_outputs[k][i] * cb_ma_predictor[ma_predictor_prev][k][i];
+
+ quantizer_output[i] = ((tmp >> 15) * cb_ma_predictor_sum_inv[ma_predictor_prev][i]) >> 12;
+ }
+}
+