Issue: Errors from juce_convolution.h file

Audio Plugins
1

Hi Guys, I’m working on a plugin and using the dsp::convolution class. I’m not sure what’s wrong with my implementation but I keep getting errors in Visual Studio from the juce_convolutionn.h file. The errors are as follows;

‘ProcessContext’: must be a class or namespace when followed by ‘::’
‘ProcessContext’: left of ‘::’ must be a class/struct/union - similar errors for ‘.getInputBlock’, ‘.getOutputBlock’, ‘.isBypassed’.
Convolution engine only supports single precision floating point data.

The code in my process block is as follows;

dsp::AudioBlock <float> block;

dsp::ProcessContextReplacing<float>::SampleType context;


convolution.loadImpulseResponse (impulseResponse01, 0, true, true, 0);
void process(dsp::ProcessContextReplacing<float>(block));

Any help on this will be greatly appreciated
Thanks

2

Which version of Visual Studio are you using?

3

VS enterprise 2017
version 15.6.1

4

Have you added the JUCE DSP module in Projucer into your project and enabled at least C++14 support?

5

Why do you have a void in the last line of your code?

6

because without it I get ‘Identifier “process” is undefined’

7

Yes i have the dsp module added, where do I find the option to enable c++ 14 support?

8

Can you show your actual code? The above code fragment doesn’t really make much sense.

9

I do have c++ 14 support enabled

10

PluginProcessor.cpp file is;

#include “PluginProcessor.h”
#include “PluginEditor.h”

//=================================================================
Vle02AudioProcessor::Vle02AudioProcessor()
#ifndef JucePlugin_PreferredChannelConfigurations
: AudioProcessor (BusesProperties()
#if ! JucePlugin_IsMidiEffect
#if ! JucePlugin_IsSynth
.withInput (“Input”, AudioChannelSet::stereo(), true)
#endif
.withOutput (“Output”, AudioChannelSet::stereo(), true)
#endif
)
#endif
{
}

Vle02AudioProcessor::~Vle02AudioProcessor()
{
}

//=================================================================
const String Vle02AudioProcessor::getName() const
{
return JucePlugin_Name;
}

bool Vle02AudioProcessor::acceptsMidi() const
{
#if JucePlugin_WantsMidiInput
return true;
#else
return false;
#endif
}

bool Vle02AudioProcessor::producesMidi() const
{
#if JucePlugin_ProducesMidiOutput
return true;
#else
return false;
#endif
}

bool Vle02AudioProcessor::isMidiEffect() const
{
#if JucePlugin_IsMidiEffect
return true;
#else
return false;
#endif
}

double Vle02AudioProcessor::getTailLengthSeconds() const
{
return 0.0;
}

int Vle02AudioProcessor::getNumPrograms()
{
return 1; // NB: some hosts don’t cope very well if you tell them there are 0 programs,
// so this should be at least 1, even if you’re not really implementing programs.
}

int Vle02AudioProcessor::getCurrentProgram()
{
return 0;
}

void Vle02AudioProcessor::setCurrentProgram (int index)
{
}

const String Vle02AudioProcessor::getProgramName (int index)
{
return {};
}

void Vle02AudioProcessor::changeProgramName (int index, const String& newName)
{
}

//=================================================================
void Vle02AudioProcessor::prepareToPlay (double sampleRate, int samplesPerBlock)
{
dsp::ProcessSpec spec;
spec.sampleRate = sampleRate;
spec.maximumBlockSize = samplesPerBlock;
spec.numChannels = getMainBusNumInputChannels();

convolution.reset();
convolution.prepare(spec);

}

void Vle02AudioProcessor::releaseResources()
{
// When playback stops, you can use this as an opportunity to free up any
// spare memory, etc.
}

#ifndef JucePlugin_PreferredChannelConfigurations
bool Vle02AudioProcessor::isBusesLayoutSupported (const BusesLayout& layouts) const
{
#if JucePlugin_IsMidiEffect
ignoreUnused (layouts);
return true;
#else
// This is the place where you check if the layout is supported.
// In this template code we only support mono or stereo.
if (layouts.getMainOutputChannelSet() != AudioChannelSet::mono()
&& layouts.getMainOutputChannelSet() != AudioChannelSet::stereo())
return false;

// This checks if the input layout matches the output layout

#if ! JucePlugin_IsSynth
if (layouts.getMainOutputChannelSet() != layouts.getMainInputChannelSet())
return false;
#endif

return true;

#endif
}
#endif

void Vle02AudioProcessor::processBlock (AudioBuffer& buffer, MidiBuffer& midiMessages)
{
ScopedNoDenormals noDenormals;
auto totalNumInputChannels = getTotalNumInputChannels();
auto totalNumOutputChannels = getTotalNumOutputChannels();

for (auto i = totalNumInputChannels; i < totalNumOutputChannels; ++i)
    buffer.clear (i, 0, buffer.getNumSamples());

// This is the place where you'd normally do the guts of your plugin's
// audio processing...
// Make sure to reset the state if your inner loop is processing
// the samples and the outer loop is handling the channels.
// Alternatively, you can process the samples with the channels
// interleaved by keeping the same state.
dsp::AudioBlock <float> block;

dsp::ProcessContextReplacing<float>::SampleType context;


convolution.loadImpulseResponse (impulseResponse01, 0, true, true, 0);
process(dsp::ProcessContextReplacing<float>(block));

}

//=================================================================
bool Vle02AudioProcessor::hasEditor() const
{
return true; // (change this to false if you choose to not supply an editor)
}

AudioProcessorEditor* Vle02AudioProcessor::createEditor()
{
return new Vle02AudioProcessorEditor (*this);
}

//=================================================================
void Vle02AudioProcessor::getStateInformation (MemoryBlock& destData)
{
// You should use this method to store your parameters in the memory block.
// You could do that either as raw data, or use the XML or ValueTree classes
// as intermediaries to make it easy to save and load complex data.
}

void Vle02AudioProcessor::setStateInformation (const void* data, int sizeInBytes)
{
// You should use this method to restore your parameters from this memory block,
// whose contents will have been created by the getStateInformation() call.
}

//=================================================================
// This creates new instances of the plugin…
AudioProcessor* JUCE_CALLTYPE createPluginFilter()
{
return new Vle02AudioProcessor();
}

11

I can’t find ProcessContext in that code, I can only find ProcessContextReplacing, so it’s going to be very hard to help you…
I also can’t find the declaration or definition of the process function. Is it in another file?

12

did you mean to call

convolution.process(dsp::ProcessContextReplacing<float>(block));

instead of

process(dsp::ProcessContextReplacing<float>(block));

maybe?

And you shouldn’t load the impulse in processBlock, do it in prepareToPlay.

N.B. please put three backticks ``` on a single line before and after a block of code, that way it is displayed correctly…

13

yes, I was, thank you, but having just changed, I’ve got an error saying ‘‘juce::dsp::Convolution::process’: cannot access private member declared in class ‘juce::dsp::Convolution’’.

And thank you for the loadimpulse and backticks comment.