LAC 2019 Workshop
Links
The following are a collection of links I am using in this project. The Spatial Workstation is a great free VST I use for binaural decoding. Wigware is an amazing collection of plug-ins used in this project for multi-channel monitoring. Reaper is the DAW of choice for multi-channel audio and JUCE is the C++ framework used to design these plug-ins. I recommend getting all these tools if you are interested in learning about ambisonic software. Sennheiser also has some valuable free tools.
Facebook Spatial Workstation // Wigware // Reaper // JUCE // Sennheiser Ambeo Tools
Downloads
This is a collection of downloadables I am using to produce these simple ambisonic plug-ins. They include audio and images. JUCE also allows import of 3D models but I have not yet perfected the use of these.
Click to Download FOA Mic Encoder Image
Click to Download FOA Mic Encoder Reaper Session
Code Snippets
These code snippets are being used to expedite the creation of the plug-ins during the workshop. They are meant to help the reader succeed without any major issues. The code is heavily commented, please read the comments for clarification.
FoaMicEncAudioProcessorEditor
This code is used in the FOA Microphone Encoder’s editor.
void FoaMicEncAudioProcessorEditor::paint (Graphics& g)
{
// fill the whole window black
g.fillAll (Colours::black);
// set the current drawing colour to white
g.setColour (Colours::white);
// set the font size and draw text to the screen
g.setFont (22.0f);
//set some values for fitted text functions
int titleHeight = 50;
int subTitleOffset = 20;
//draw the title
g.drawFittedText ("FOA Mic Encoder", 0, 0, getWidth(), titleHeight, Justification::centred, 1);
//change the font size
g.setFont (18.0f);
//draw the subtitle
g.drawFittedText ("ACN + SN3D", 0, subTitleOffset, getWidth(), titleHeight, Justification::centred, 1);
//draw the image from cache
Image background = ImageCache::getFromMemory (BinaryData::mark2_JPG, BinaryData::mark2_JPGSize);
//set values for image offset
int imageOffsetX = 56;
int imageOffsetY = 60;
//draw the image on the canvas
g.drawImageAt (background, imageOffsetX, imageOffsetY);
}
FoaMicEncAudioProcessor
This code is used for the PluginProcessor part of the FOA mic encoder.
void FoaMicEncAudioProcessor::processBlock (AudioBuffer<float>& buffer, MidiBuffer& midiMessages)
{
//default JUCE code, leave as is...
ScopedNoDenormals noDenormals;
auto totalNumInputChannels = getTotalNumInputChannels();
auto totalNumOutputChannels = getTotalNumOutputChannels();
//clear buffer
for (auto i = totalNumInputChannels; i < totalNumOutputChannels; ++i)
buffer.clear (i, 0, buffer.getNumSamples());
/* DESCRIPTION
This takes 4 channels and spits back out 4 new channels after encoding.
W = FLU + FRD + BLD + BRU
Y = FLU - FRD + BLD - BRU
Z = FLU - FRD - BLD + BRU
X = FLU + FRD - BLD - BRU
ordering ACN, normalization SN3D.
*/
//make 4 write pointers (output)
auto* outDataW = buffer.getWritePointer (0);
auto* outDataY = buffer.getWritePointer (1);
auto* outDataZ = buffer.getWritePointer (2);
auto* outDataX = buffer.getWritePointer (3);
//make 4 read pointers (input)
auto* inDataFLU = buffer.getReadPointer (0);
auto* inDataFRD = buffer.getReadPointer (1);
auto* inDataBLD = buffer.getReadPointer (2);
auto* inDataBRU = buffer.getReadPointer (3);
//calculate SN3D normalization coefficient
//pi declared in header (public), defined in this file (PrepareToPlay())
float wNormFactor = sqrt(0.25f*pi);
//traverse samples
for(int index = 0; index < buffer.getNumSamples(); index++) {
//ACN = W Y Z X
outDataW[index] = wNormFactor * (inDataFLU[index] + inDataFRD[index] +
inDataBLD[index] + inDataBRU[index]);
outDataY[index] = inDataFLU[index] - inDataFRD[index] + inDataBLD[index] - inDataBRU[index];
outDataZ[index] = inDataFLU[index] - inDataFRD[index] - inDataBLD[index] + inDataBRU[index];
outDataX[index] = inDataFLU[index] + inDataFRD[index] - inDataBLD[index] - inDataBRU[index];
}
}
FoaPanAudioProcessorEditor (constructor declaration - header)
Notice the addition of the listener in the initialization list.
class FoaPanAudioProcessorEditor : public AudioProcessorEditor,
private Slider::Listener //add listener to initialization list!
{
public:
FoaPanAudioProcessorEditor (FoaPanAudioProcessor&);
~FoaPanAudioProcessorEditor();
//==============================================================================
void paint (Graphics&) override;
void resized() override;
//declare our slider function
void sliderValueChanged (Slider* slider) override;
Slider azimuthSlider; // declare slider for azi
Slider elevationSlider; // declare slider for elev
//declare scoped pointers to add sliders to VTS
ScopedPointer<AudioProcessorValueTreeState::SliderAttachment> azimuthSliderAttachment;
ScopedPointer<AudioProcessorValueTreeState::SliderAttachment> elevationSliderAttachment;
//declare some float variables
float aziPosX, aziPosY; //use to draw smaller circle
float aziVal, elevVal; //used to store slider value
private:
// This reference is provided as a quick way for your editor to
// access the processor object that created it.
FoaPanAudioProcessor& processor;
JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (FoaPanAudioProcessorEditor)
};
FoaPanAudioProcessorEditor (constructor definition - cpp)
FoaPanAudioProcessorEditor::FoaPanAudioProcessorEditor (FoaPanAudioProcessor& p)
: AudioProcessorEditor (&p), processor (p)
{
// Make sure that before the constructor has finished, you've set the
// editor's size to whatever you need it to be.
setSize (400, 300);
int textEntryBoxWidth = 100;
int textEntryBoxHeight = 20;
float rangeMin = -180.0;
float rangeMax = +180.0;
bool readOnly = false;
// these define the parameters of our azimuth slider object
azimuthSlider.setRange(rangeMin, rangeMax);
azimuthSlider.setSliderStyle (Slider::LinearHorizontal);
azimuthSlider.setTextBoxStyle (Slider::TextBoxBelow, readOnly, textEntryBoxWidth, textEntryBoxHeight);
azimuthSlider.addListener(this);//this = Slider::Listener
addAndMakeVisible (&azimuthSlider);
// these define the parameters of our elevation slider object
elevationSlider.setRange(rangeMin, rangeMax);
elevationSlider.setSliderStyle (Slider::LinearVertical);
elevationSlider.setTextBoxStyle (Slider::TextBoxBelow, readOnly, textEntryBoxWidth, textEntryBoxHeight);
elevationSlider.addListener(this);//this = Slider::Listener
addAndMakeVisible (&elevationSlider);
//add the sliders to the VTS
azimuthSliderAttachment = new AudioProcessorValueTreeState::SliderAttachment (processor.parameters, "azimuth", azimuthSlider);
elevationSliderAttachment = new AudioProcessorValueTreeState::SliderAttachment (processor.parameters, "elevation", elevationSlider);
}
FoaPanAudioProcessorEditor::paint (editor .cpp)
void FoaPanAudioProcessorEditor::paint (Graphics& g)
{
float titleHeight = 15.0;//same as font size
float subTitleHeight = 10.0;//same as font size
// fill the whole window silver
g.fillAll (Colours::silver);
// set the current drawing colour to blueviolet
g.setColour (Colours::blueviolet);
// set the font size and draw text to the screen for title and subtitle
g.setFont (15.0f);
g.drawFittedText ("FOA Pan", 0, 0, getWidth(), titleHeight, Justification::centred, 1);//1=maxNumLines
g.setFont (10.0f);
g.drawFittedText ("ACN Ordering [WYZX]",
0, titleHeight, getWidth(), subTitleHeight, Justification::centred, 1);
//set font size for slider text and draw text to the screen for both sliders
g.setFont (12.0f);
g.drawFittedText ("Azimuth", 20, 215, 200, 20, Justification::centred, 1);//trial and error
g.drawFittedText ("Elevation", 200, 40, 200, 20, Justification::centred, 1);
//define large ellipsis params
int largeDiameter = 150;
float largeRadius = largeDiameter/2;
int lineThickness = 2;
//not "grabbable" [to do]
//draw the circle/"sphere" [to do]
//ellipses depict position of source on azimuth plane only
g.setColour (Colours::blueviolet);
g.drawEllipse(50, 50, largeDiameter, largeDiameter, lineThickness);//main big circle
//define small ellipsis params
int smallDiameter = 15;
float smallRadius = smallDiameter/2;
//go to corner of large circle, then its origin, then to the position, multiply it by radius.
//minus 90 degrees (pi/2) justifies the position so that 0 is above rather than on the right
aziPosX = 50 + largeRadius + cos(aziVal * (M_PI / 180) - M_PI/2) * largeRadius;
aziPosY = 50 + largeRadius + sin(aziVal * (M_PI / 180) - M_PI/2) * largeRadius;
g.setColour (Colours::skyblue);
//subtract the w and h of circle to have origin of mini circle at the circumference
//posX, posY, w, h, thickness.
g.drawEllipse(aziPosX - smallRadius, aziPosY - smallRadius, smallDiameter, smallDiameter, lineThickness);
repaint();//important, redraws every frame
}
FoaPanAudioProcessor - constructor definition
This bit is kind of tricky. Note the comma after the macro in lieu of the colon. Also note the added “: parameters (*this, nullptr)”
FoaPanAudioProcessor::FoaPanAudioProcessor() : parameters (*this, nullptr)
#ifndef JucePlugin_PreferredChannelConfigurations
, AudioProcessor (BusesProperties()
#if ! JucePlugin_IsMidiEffect
#if ! JucePlugin_IsSynth
.withInput ("Input", AudioChannelSet::mono(), true)
#endif
.withOutput ("Output", AudioChannelSet::ambisonic(1), true)
#endif
)
#endif
{
parameters.createAndAddParameter(std::make_unique<AudioParameterFloat>("azimuth",// parameter ID
"azimuth",// parameter name
NormalisableRange<float>
(-180.0f, 180.0f),// range
0.0f,// default value
"degrees"));
parameters.createAndAddParameter(std::make_unique<AudioParameterFloat>("elevation",// parameter ID
"elevation",// parameter name
NormalisableRange<float> (-180.0f, 180.0f),// range
0.0f,// default value
"degrees"));
parameters.state = ValueTree (Identifier ("FoaPanVT"));
}