MorseListener
Direct Subclass:
A class to 'listen' for Morse code from the microphone or an audio file, filter the sound and pass timings to a decoder to convert to text.
Constructor Summary
| Public Constructor | ||
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constructor(fftSize: number, volumeFilterMin: number, volumeFilterMax: number, frequencyFilterMin: number, frequencyFilterMax: number, volumeThreshold: number, decoder: Object, spectrogramCallback: function(), frequencyFilterCallback: function(), volumeFilterCallback: function(), volumeThresholdCallback: function(), micSuccessCallback: function(), micErrorCallback: function(), fileLoadCallback: function(), fileErrorCallback: function(), EOFCallback: function()) |
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Member Summary
| Public Members | ||
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analyserNode: * |
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audioContext: * |
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decoder: * |
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defaults: {"fftSize": number, "volumeFilterMin": *, "volumeFilterMax": *, "frequencyFilterMin": number, "frequencyFilterMax": number, "volumeThreshold": number} |
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fftSize: * |
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freqBins: * |
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freqStep: * |
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Set the minimum and maximum frequency filter values to be closely surrounding a specific frequency. |
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Set the maximum threshold on the frequency filter. |
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Set the minimum threshold on the frequency filter. |
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input: * |
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jsNode: * |
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maxFreq: * |
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sampleRate: * |
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sourceNode: * |
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timeStep: * |
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Set the maximum threshold on the volume filter. |
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Set the minimum threshold on the volume filter. |
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Set the threshold used to determine if an anlaysed region has sufficient sound to be "on". |
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| Private Members | ||
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Method Summary
| Public Methods | ||
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fileErrorCallback(error: *) |
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fileLoadCallback(audioBuffer: *) |
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flush(on: *) Flush the current ticks to the decoder. |
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frequencyFilterCallback(jsonData: *) |
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@access: private |
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loadArrayBuffer(arrayBuffer: ArrayBuffer) Load audio data from an ArrayBuffer. |
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micErrorCallback(error: *) |
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Play a loaded audio file (through speakers) and decode it. |
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This ScriptProcessorNode is called when it is full, we then actually look at the data in the analyserNode node to measure the volume in the frequency band of interest. |
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recordOnOrOff(soundIsOn: *) Called each tick with whether the sound is judged to be on or off. |
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spectrogramCallback(jsonData: *) |
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Start the decoder listening to the microphone. |
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stop() Stop listening. |
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volumeFilterCallback(jsonData: *) |
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volumeThresholdCallback(volume: *) |
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Public Constructors
public constructor(fftSize: number, volumeFilterMin: number, volumeFilterMax: number, frequencyFilterMin: number, frequencyFilterMax: number, volumeThreshold: number, decoder: Object, spectrogramCallback: function(), frequencyFilterCallback: function(), volumeFilterCallback: function(), volumeThresholdCallback: function(), micSuccessCallback: function(), micErrorCallback: function(), fileLoadCallback: function(), fileErrorCallback: function(), EOFCallback: function()) source
Params:
| Name | Type | Attribute | Description |
| fftSize | number | Size of the discrete Fourier transform to use. Must be a power of 2 >= 256 (defaults to 256). A smaller fftSize gives better time resolution but worse frequency resolution. |
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| volumeFilterMin | number |
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Sound less than this volume (in dB) is ignored. |
| volumeFilterMax | number |
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Sound greater than this volume (in dB) is ignored. |
| frequencyFilterMin | number |
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Sound less than this frequency (in Hz) is ignored. |
| frequencyFilterMax | number |
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Sound greater than this frequency (in Hz) is ignored. |
| volumeThreshold | number |
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If the volume is greater than this then the signal is taken as "on" (part of a dit or dah) (range 0-255). |
| decoder | Object | An instance of a configured decoder class. |
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| spectrogramCallback | function() | Called every time fftSize samples are read. Called with a dictionary parameter: { frequencyData: output of the DFT (the real values including DC component) frequencyStep: frequency resolution in Hz timeStep: time resolution in Hz filterBinLow: index of the lowest frequency bin being analysed filterBinHigh: index of the highest frequency bin being analysed filterRegionVolume: volume in the analysed region isOn: whether the analysis detected a signal or not } |
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| frequencyFilterCallback | function() | Called when the frequency filter parameters change. Called with a dictionary parameter: { min: lowest frequency in Hz max: highest frequency in Hz } The frequencies may well be different to that which is set as they are quantised. |
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| volumeFilterCallback | function() | Called when the volume filter parameters change. Called with a dictionary parameter: { min: low volume (in dB) max: high volume (in dB) } If the set volumes are not numeric or out of range then the callback will return in range numbers. |
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| volumeThresholdCallback | function() | Called with a single number as the argument when the volume filter threshold changes. |
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| micSuccessCallback | function() | Called when the microphone has successfully been connected. |
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| micErrorCallback | function() | Called with the error as the argument if there is an error connecting to the microphone. |
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| fileLoadCallback | function() | Called with the AudioBuffer object as the argument when a file has successfully been loaded (and decoded). |
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| fileErrorCallback | function() | Called with the error as the argument if there is an error in decoding a file. |
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| EOFCallback | function() | Called when the playback of a file ends. |
Public Members
public analyserNode: * source
public audioContext: * source
public decoder: * source
public defaults: {"fftSize": number, "volumeFilterMin": *, "volumeFilterMax": *, "frequencyFilterMin": number, "frequencyFilterMax": number, "volumeThreshold": number} source
public fftSize: * source
public fileAudioBuffer: * source
public freqBins: * source
public freqStep: * source
public frequencyData: * source
public set frequencyFilter(f: number) source
Set the minimum and maximum frequency filter values to be closely surrounding a specific frequency.
public get frequencyFilterMax: * source
public set frequencyFilterMax(v: number) source
Set the maximum threshold on the frequency filter. i.e. the maximum frequency to be considered. Input validation is done to set a sensible default on non-numeric input and the value is clamped to be between zero and the current maximum frequency. The actual minimum will be the maximum frequency of the frequency bin the chosen frequency lies in. Calls the frequencyFilterCallback with the new min and max.
public set frequencyFilterMin(v: number) source
Set the minimum threshold on the frequency filter. i.e. the minimum frequency to be considered. Input validation is done to set a sensible default on non-numeric input and the value is clamped to be between zero and the current maximum frequency. The actual minimum will be the minimum frequency of the frequency bin the chosen frequency lies in. Calls the frequencyFilterCallback with the new min and max.
public get frequencyFilterMin: * source
public input: * source
public jsNode: * source
public maxFreq: * source
public sampleRate: * source
public sourceNode: * source
public timeStep: * source
public set volumeFilterMax(v: number) source
Set the maximum threshold on the volume filter. i.e. the maximum volume considered to be a signal. Input validation is done to set a sensible default on non-numeric input and clamp the maximum to be zero. The volumFilterMin property is also set by this to be no more than the maximum. Calls the volumeFilterCallback with the new min and max.
public get volumeFilterMax: * source
public get volumeFilterMin: * source
public set volumeFilterMin(v: number) source
Set the minimum threshold on the volume filter. i.e. the minimum volume considered to be a signal. Input validation is done to set a sensible default on non-numeric input and clamp the maximum to be zero. The volumFilterMax property is also set by this to be no less than the minimum. Calls the volumeFilterCallback with the new min and max.
public get volumeThreshold: * source
public set volumeThreshold(v: number) source
Set the threshold used to determine if an anlaysed region has sufficient sound to be "on". Input validation is done to set a sensible default on non-numeric input and the value is clamped to be between zero and 255.
Private Members
private _filterBinHigh: * source
private _filterBinLow: * source
private _volumeThreshold: * source
Public Methods
public EOFCallback() source
public fileErrorCallback(error: *) source
Params:
| Name | Type | Attribute | Description |
| error | * |
public fileLoadCallback(audioBuffer: *) source
Params:
| Name | Type | Attribute | Description |
| audioBuffer | * |
public flush(on: *) source
Flush the current ticks to the decoder. Parameter is whether the ticks represent sound (on) or not.
Params:
| Name | Type | Attribute | Description |
| on | * |
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public frequencyFilterCallback(jsonData: *) source
Params:
| Name | Type | Attribute | Description |
| jsonData | * |
public loadArrayBuffer(arrayBuffer: ArrayBuffer) source
Load audio data from an ArrayBuffer. Use a FileReader to load from a file. Calls fileLoadCallback or fileErrorCallback on success or error.
Params:
| Name | Type | Attribute | Description |
| arrayBuffer | ArrayBuffer |
public micErrorCallback(error: *) source
Params:
| Name | Type | Attribute | Description |
| error | * |
public micSuccessCallback() source
public playArrayBuffer() source
Play a loaded audio file (through speakers) and decode it. Calls EOFCallback when buffer ends.
public processSound() source
This ScriptProcessorNode is called when it is full, we then actually look at the data in the analyserNode node to measure the volume in the frequency band of interest. We don't actually use the input or output of the ScriptProcesorNode. @access: private
public recordOnOrOff(soundIsOn: *) source
Called each tick with whether the sound is judged to be on or off. If a change from on to off or off to on is detected then the number of ticks of the segment is passed to the decoder. @access: private
Params:
| Name | Type | Attribute | Description |
| soundIsOn | * |
public spectrogramCallback(jsonData: *) source
Params:
| Name | Type | Attribute | Description |
| jsonData | * |
public startListening() source
Start the decoder listening to the microphone. Calls micSuccessCallback or micErrorCallback on success or error.
public volumeFilterCallback(jsonData: *) source
Params:
| Name | Type | Attribute | Description |
| jsonData | * |
public volumeThresholdCallback(volume: *) source
Params:
| Name | Type | Attribute | Description |
| volume | * |