public static void ProcessBiquadFilter(ReadOnlySpan <BiquadFilterParameter> parameters, Span <BiquadFilterState> states, Span <float> outputBuffer, ReadOnlySpan <float> inputBuffer, uint sampleCount)
{
for (int stageIndex = 0; stageIndex < parameters.Length; stageIndex++)
{
BiquadFilterParameter parameter = parameters[stageIndex];
ref BiquadFilterState state = ref states[stageIndex];
float a0 = FixedPointHelper.ToFloat(parameter.Numerator[0], FixedPointPrecisionForParameter);
float a1 = FixedPointHelper.ToFloat(parameter.Numerator[1], FixedPointPrecisionForParameter);
float a2 = FixedPointHelper.ToFloat(parameter.Numerator[2], FixedPointPrecisionForParameter);
float b1 = FixedPointHelper.ToFloat(parameter.Denominator[0], FixedPointPrecisionForParameter);
float b2 = FixedPointHelper.ToFloat(parameter.Denominator[1], FixedPointPrecisionForParameter);
for (int i = 0; i < sampleCount; i++)
{
float input = inputBuffer[i];
float output = input * a0 + state.State0 * a1 + state.State1 * a2 + state.State2 * b1 + state.State3 * b2;
state.State1 = state.State0;
state.State0 = input;
state.State3 = state.State2;
state.State2 = output;
outputBuffer[i] = output;
}
}
/// <summary>
/// Create a new <see cref="BiquadFilterCommand"/>.
/// </summary>
/// <param name="baseIndex">The base index of the input and output buffer.</param>
/// <param name="filter">The biquad filter parameter.</param>
/// <param name="biquadFilterStateMemory">The biquad state.</param>
/// <param name="inputBufferOffset">The input buffer offset.</param>
/// <param name="outputBufferOffset">The output buffer offset.</param>
/// <param name="needInitialization">Set to true if the biquad filter state needs to be initialized.</param>
/// <param name="nodeId">The node id associated to this command.</param>
public void GenerateBiquadFilter(int baseIndex, ref BiquadFilterParameter filter, Memory <BiquadFilterState> biquadFilterStateMemory, int inputBufferOffset, int outputBufferOffset, bool needInitialization, int nodeId)
{
BiquadFilterCommand command = new BiquadFilterCommand(baseIndex, ref filter, biquadFilterStateMemory, inputBufferOffset, outputBufferOffset, needInitialization, nodeId);
command.EstimatedProcessingTime = _commandProcessingTimeEstimator.Estimate(command);
AddCommand(command);
}
public BiquadFilterCommand(int baseIndex, ref BiquadFilterParameter filter, Memory <BiquadFilterState> biquadFilterStateMemory, int inputBufferOffset, int outputBufferOffset, bool needInitialization, int nodeId)
{
_parameter = filter;
BiquadFilterState = biquadFilterStateMemory;
InputBufferIndex = baseIndex + inputBufferOffset;
OutputBufferIndex = baseIndex + outputBufferOffset;
NeedInitialization = needInitialization;
Enabled = true;
NodeId = nodeId;
}
public static void ProcessBiquadFilter(ref BiquadFilterParameter parameter, ref BiquadFilterState state, Span <float> outputBuffer, ReadOnlySpan <float> inputBuffer, uint sampleCount)
{
float a0 = FixedPointHelper.ToFloat(parameter.Numerator[0], FixedPointPrecisionForParameter);
float a1 = FixedPointHelper.ToFloat(parameter.Numerator[1], FixedPointPrecisionForParameter);
float a2 = FixedPointHelper.ToFloat(parameter.Numerator[2], FixedPointPrecisionForParameter);
float b1 = FixedPointHelper.ToFloat(parameter.Denominator[0], FixedPointPrecisionForParameter);
float b2 = FixedPointHelper.ToFloat(parameter.Denominator[1], FixedPointPrecisionForParameter);
for (int i = 0; i < sampleCount; i++)
{
float input = inputBuffer[i];
float output = input * a0 + state.State0;
state.State0 = input * a1 + output * b1 + state.State1;
state.State1 = input * a2 + output * b2;
outputBuffer[i] = output;
}
}
