datamov.c

用dsp解压mp3程序的算法

/**************************************************************************
*  datamov - This function updates signal vector vector stored as
*            [x(n)  x(n-1) ... x(n-N+1)] for FIR filters
**************************************************************************/
void  datamov(x, N, new)

float *x;                     // signal vector
int N;                        // filter length
float new;                    // new sample
{
  int i;                      // index
  for (i=N-1; i>0; --i)
  {
    x[i] = x[i-1];            // shift old data x(n-i), i = 1, 2, ... N-1
  }
  x[0] = (float)new;          // insert new data to x(n)
}