/// <summary>
/// Creates a new resampler with the supplied quality parameters.
///
/// Can be used to create a variable-rate resampler by supplying SOXR_HQ as recipe
/// and SOXR_VR as flag. For a variable resampler, inputRate/outputRate must equate
/// to the maximum IO ratio that will be set by calling SetRatio. To set the initial
/// ratio, call SetRatio with a transitionLength of 0 on the created instance.
/// </summary>
/// <param name="inputRate"></param>
/// <param name="outputRate"></param>
/// <param name="channels"></param>
/// <param name="qualityRecipe"></param>
/// <param name="qualityFlags"></param>
/// <exception cref="SoxrException">when parameters are incorrect; see error message for details</exception>
public SoxResampler(double inputRate, double outputRate, int channels,
QualityRecipe qualityRecipe, QualityFlags qualityFlags)
{
if (inputRate <= 0 || outputRate <= 0 || channels <= 0)
{
throw new SoxrException("one or more parameters are invalid (zero or negative)");
}
SoxrError error = SoxrError.Zero;
// Apply the default configuration as per soxr.c
InteropWrapper.SoxrIoSpec ioSpec = InteropWrapper.soxr_io_spec(Datatype.SOXR_FLOAT32_I, Datatype.SOXR_FLOAT32_I);
InteropWrapper.SoxrQualitySpec qSpec = InteropWrapper.soxr_quality_spec(qualityRecipe, qualityFlags);
InteropWrapper.SoxrRuntimeSpec rtSpec = InteropWrapper.soxr_runtime_spec(1);
if (qualityFlags == QualityFlags.SOXR_VR)
{
if (qualityRecipe != QualityRecipe.SOXR_HQ)
{
throw new SoxrException("Invalid parameters: variable rate resampling only works with the HQ recipe");
}
variableRate = true;
maxRatio = inputRate / outputRate;
}
soxr = InteropWrapper.soxr_create(inputRate, outputRate, (uint)channels,
out error, ref ioSpec, ref qSpec, ref rtSpec);
if (error != SoxrError.Zero)
{
throw new SoxrException(GetError(error));
}
this.channels = channels;
}
public Resampler(ResamplingQuality quality, int channels, double sampleRateRatio)
{
Quality = quality;
Channels = channels;
Ratio = sampleRateRatio;
QualityRecipe qr = QualityRecipe.SOXR_HQ;
QualityFlags qf = QualityFlags.SOXR_ROLLOFF_SMALL;
switch (quality)
{
case ResamplingQuality.VeryLow:
qr = QualityRecipe.SOXR_QQ; break;
case ResamplingQuality.Low:
qr = QualityRecipe.SOXR_LQ; break;
case ResamplingQuality.Medium:
qr = QualityRecipe.SOXR_MQ; break;
case ResamplingQuality.High:
qr = QualityRecipe.SOXR_HQ; break;
case ResamplingQuality.VeryHigh:
qr = QualityRecipe.SOXR_VHQ; break;
case ResamplingQuality.VariableRate:
qr = QualityRecipe.SOXR_HQ; qf = QualityFlags.SOXR_VR; break;
}
double inputRate = 1;
double outputRate = sampleRateRatio;
if (qf == QualityFlags.SOXR_VR)
{
// set max variable rate
inputRate = 10.0;
outputRate = 1.0;
}
_soxr = new SoxResampler(inputRate, outputRate, channels, qr, qf);
}
public static extern InteropWrapper.SoxrQualitySpec soxr_quality_spec(QualityRecipe recipe, QualityFlags flags);
