vDSP_biquad

Declaration

extern void vDSP_biquad(const struct vDSP_biquad_SetupStruct *__Setup, float *__Delay, const float *__X, vDSP_Stride __IX, float *__Y, vDSP_Stride __IY, vDSP_Length __N);

Parameters

• __Setup:

  The Vdsp_biquad_setup object defining the filter to apply.

• __Delay:

  An array of single-precision values initialized with direct-form 1 “past” state data for each section of the biquad. The length of the array should be (2 * M) + 2, where M is the number of sections. For each section m, Delay[2*m:2*m+1] represent the two delayed input values for section m and Delay[2*M:2*M+1] represent the two delayed output values of the filter. After this function executes, this array contains the final state data of the filters.

• __X:

  An array of single-precision input data for the channel.

• __IX:

  Stride for X.

• __Y:

  An array to be filled with single-precision output data for the channel.

• __IY:

  Stride forY.

• __N:

  The number of elements to filter.

Discussion

This function applies a cascaded biquad filter to the input values in X, and places the results in Y.

The state contained in the setup object is updated upon return.

See Also

Applying a single-channel biquadratic filter

• vDSP_biquadD