//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// RadioEffectUnit::RadioEffectKernel::Process
//
// pass-through unit
//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
void RadioEffectUnit::RadioEffectKernel::Process( const AudioUnitSampleType * InSourceP,
AudioUnitSampleType * InDestP,
UInt32 InFramesToProcess,
UInt32 InNumChannels,
bool & IOSilence )
{
// we should be doing something with the silence flag if it is true
// like not doing any work because:
// (1) we would only be processing silence and
// (2) we don't have any latency or tail times to worry about here
//
// So, we don't reset this flag, because it is true on input and we're not doing anything
// to it so we want it to be true on output.
// BUT: your code probably will need to take into account tail processing (or latency) that
// it has once its input becomes silent... then at some point in the future, your output
// will also be silent.
UInt32 NumSampleFrames = InFramesToProcess;
const AudioUnitSampleType *SourceP = InSourceP;
AudioUnitSampleType *DestP = InDestP;
const FLOAT ChebyshevPowerMultiplier = GetParameter(RadioParam_ChebyshevPowerMultiplier);
const FLOAT ChebyshevPower = GetParameter(RadioParam_ChebyshevPower);
const FLOAT ChebyshevCubedMultiplier = GetParameter(RadioParam_ChebyshevCubedMultiplier);
const FLOAT ChebyshevMultiplier = GetParameter(RadioParam_ChebyshevMultiplier);
while (NumSampleFrames-- > 0) {
AudioUnitSampleType InputSample = *SourceP;
SourceP += InNumChannels; // advance to next frame (e.g. if stereo, we're advancing 2 samples);
// we're only processing one of an arbitrary number of interleaved channels
// here's where you do your DSP work
// Early-out of processing if the sample is zero because a zero sample
// will still create some static even if no audio is playing.
if( InputSample != 0.0f ) {
// Waveshape it
const FLOAT SampleCubed = InputSample * InputSample * InputSample;
InputSample = ( ChebyshevPowerMultiplier * appPow( InputSample, ChebyshevPower ) ) - ( ChebyshevCubedMultiplier * SampleCubed ) + ( ChebyshevMultiplier * InputSample );
// Again with the bandpass
InputSample = GFinalBandPassFilter.Process( InputSample );
}
*DestP = InputSample;
DestP += InNumChannels;
}
}
/**
* Adds a radio distortion to the input buffer if the radio effect is enabled.
*
* @param InputProcessParameterCount Number of elements in pInputProcessParameters.
* @param pInputProcessParameters Input buffer containing audio samples.
* @param OutputProcessParameterCount Number of elements in pOutputProcessParameters.
* @param pOutputProcessParameters Output buffer, which is not touched by this xAPO.
* @param IsEnabled true if this effect is enabled; false, otherwise.
*/
STDMETHOD_( void, Process )( UINT32 InputProcessParameterCount,
const XAPO_PROCESS_BUFFER_PARAMETERS *pInputProcessParameters,
UINT32 OutputProcessParameterCount,
XAPO_PROCESS_BUFFER_PARAMETERS *pOutputProcessParameters,
BOOL IsEnabled )
{
// Verify several condition based on the registration
// properties we used to create the class.
check( IsLocked() );
check( InputProcessParameterCount == 1 );
check( OutputProcessParameterCount == 1 );
check( pInputProcessParameters[0].pBuffer == pOutputProcessParameters[0].pBuffer );
// Check the global volume multiplier because this effect
// will continue to play if the editor loses focus.
if (IsEnabled && FApp::GetVolumeMultiplier() != 0.0f)
{
FAudioRadioEffect* RadioParameters = ( FAudioRadioEffect* )BeginProcess();
check( RadioParameters );
// The total sample size must account for multiple channels.
const uint32 SampleSize = pInputProcessParameters[0].ValidFrameCount * WaveFormat.nChannels;
const float ChebyshevPowerMultiplier = Radio_ChebyshevPowerMultiplier->GetValueOnAnyThread();
const float ChebyshevPower = Radio_ChebyshevPower->GetValueOnAnyThread();
const float ChebyshevCubedMultiplier = Radio_ChebyshevCubedMultiplier->GetValueOnAnyThread();
const float ChebyshevMultiplier = Radio_ChebyshevMultiplier->GetValueOnAnyThread();
// If we have a silent buffer, then allocate the samples. Then, set the sample values
// to zero to avoid getting NANs. Otherwise, the user may hear an annoying popping noise.
if( pInputProcessParameters[0].BufferFlags == XAPO_BUFFER_VALID )
{
float* SampleData = ( float* )pInputProcessParameters[0].pBuffer;
// Process each sample one at a time
for( uint32 SampleIndex = 0; SampleIndex < SampleSize; ++SampleIndex )
{
float Sample = SampleData[SampleIndex];
// Early-out of processing if the sample is zero because a zero sample
// will still create some static even if no audio is playing.
if( Sample == 0.0f )
{
continue;
}
// Waveshape it
const float SampleCubed = Sample * Sample * Sample;
Sample = ( ChebyshevPowerMultiplier * FMath::Pow( Sample, ChebyshevPower ) ) - ( ChebyshevCubedMultiplier * SampleCubed ) + ( ChebyshevMultiplier * Sample );
// Again with the bandpass
Sample = GFinalBandPassFilter.Process( Sample );
// Store the value after done processing
SampleData[SampleIndex] = Sample;
}
EndProcess();
}
}
}
