BeatRoot

Field Detail

• audioFileName

  protected java.lang.String audioFileName

  Source of input data. Could be extended to include live input from the sound card.

• audioFormat

  protected javax.sound.sampled.AudioFormat audioFormat

  Format of the audio data in pcmInputStream

• audioOut

  protected javax.sound.sampled.SourceDataLine audioOut

  Line for audio output (not used, since output is done by AudioPlayer)

• batchMode

  public static boolean batchMode

  Flag for batch mode.

• cbIndex

  protected int cbIndex

  The index of the next position to write in the circular buffer.

• channels

  protected int channels

  Number of channels of audio in audioFormat

• circBuffer

  protected double[] circBuffer

  Audio data is scaled to the range [0,1] and averaged to one channel and stored in a circular buffer for reuse (if hopTime < fftTime).

• debug

  public static boolean debug

  Flag for enabling or disabling debugging output

• doOnsetPlot

  public static boolean doOnsetPlot

  Flag for plotting onset detection function.

• energy

  protected double[] energy

  The RMS energy of all frames.

• energyOversampleFactor

  public static int energyOversampleFactor

  Ratio between rate of sampling the signal energy (for the amplitude envelope) and the hop size

• fftSize

  protected int fftSize

  The size of an FFT frame in samples (see fftTime)

• fftTime

  protected double fftTime

  The approximate size of an FFT frame in seconds, as set by the command line option -f FFTTime. (Default = 0.04644s). The value is adjusted so that fftSize is always power of 2.

• frameCount

  protected int frameCount

  The number of overlapping frames of audio data which have been read.

• frameRMS

  protected double frameRMS

  RMS amplitude of the current frame.

• frames

  protected double[][] frames

  The magnitude spectra of all frames, used for plotting the spectrogram.

• freqMap

  protected int[] freqMap

  A mapping function for mapping FFT bins to final frequency bins. The mapping is linear (1-1) until the resolution reaches 2 points per semitone, then logarithmic with a semitone resolution. e.g. for 44.1kHz sampling rate and fftSize of 2048 (46ms), bin spacing is 21.5Hz, which is mapped linearly for bins 0-34 (0 to 732Hz), and logarithmically for the remaining bins (midi notes 79 to 127, bins 35 to 83), where all energy above note 127 is mapped into the final bin.

• freqMapSize

  protected int freqMapSize

  The number of entries in freqMap. Note that the length of the array is greater, because its size is not known at creation time.

• hopSize

  protected int hopSize

  Spacing of audio frames in samples (see hopTime)

• hopTime

  protected double hopTime

  Spacing of audio frames (determines the amount of overlap or skip between frames). This value is expressed in seconds and can be set by the command line option -h hopTime. (Default = 0.020s)

• imBuffer

  protected double[] imBuffer

  The imaginary part of the data for the in-place FFT computation. Since input data is real, this initially contains zeros.

• inputBuffer

  protected byte[] inputBuffer

  Audio data is initially read in PCM format into this buffer.

• liveInputBufferSize

  public static final int liveInputBufferSize

  Audio buffer for live input. (Not used yet)

  See Also:

  Constant Field Values

• ltAverage

  protected double ltAverage

  Long term average frame energy (in frequency domain representation).

• MAX_LENGTH

  public static final int MAX_LENGTH

  Maximum file length in seconds. Used for static allocation of arrays.

  See Also:

  Constant Field Values

• newFrame

  protected double[] newFrame

  The magnitude spectrum of the current frame.

• normaliseMode

  public static int normaliseMode

  Determines method of normalisation. Values can be:

  • 0: no normalisation
  • 1: normalisation by current frame energy
  • 2: normalisation by exponential average of frame energy

• onsetList

  protected EventList onsetList

  The estimated onset times and their saliences.

• onsets

  protected double[] onsets

  The estimated onset times from peak-picking the onset detection function(s).

• pcmInputStream

  protected javax.sound.sampled.AudioInputStream pcmInputStream

  Uncompressed version of rawInputStream. In the (normal) case where the input is already PCM data, rawInputStream == pcmInputStream

• phaseDeviation

  protected double[] phaseDeviation

  Phase deviation onset detection function, indexed by frame.

• prevFrame

  protected double[] prevFrame

  The magnitude spectrum of the most recent frame. Used for calculating the spectral flux.

• prevPhase

  protected double[] prevPhase

  Phase of the previous frame, for calculating an onset function based on spectral phase deviation.

• prevPrevPhase

  protected double[] prevPrevPhase

  Phase of the frame before the previous frame, for calculating an onset function based on spectral phase deviation.

• progressCallback

  protected ProgressIndicator progressCallback

  GUI component which shows progress of audio processing.

• rangeThreshold

  public static double rangeThreshold

  For dynamic range compression, this value is added to the log magnitude in each frequency bin and any remaining negative values are then set to zero.

• rawInputStream

  protected javax.sound.sampled.AudioInputStream rawInputStream

  Input data stream for this performance (possibly in compressed format)

• reBuffer

  protected double[] reBuffer

  The real part of the data for the in-place FFT computation. Since input data is real, this initially contains the input data.

• sampleRate

  protected float sampleRate

  Sample rate of audio in audioFormat

• silenceThreshold

  public static double silenceThreshold

  RMS frame energy below this value results in the frame being set to zero, so that normalisation does not have undesired side-effects.

• silent

  protected static boolean silent

  Flag for suppressing all standard output messages except results.

• spectralFlux

  protected double[] spectralFlux

  Spectral flux onset detection function, indexed by frame.

• totalFrames

  protected int totalFrames

  Total number of audio frames if known, or -1 for live or compressed input.

• window

  protected double[] window

  The window function for the STFT, currently a Hamming window.

• y2Onsets

  protected double[] y2Onsets

  The y-coordinates of the onsets for plotting. Only used if doOnsetPlot is true

Constructor Detail

• AudioProcessor

  public AudioProcessor()

  Constructor: note that streams are not opened until the input file is set (see setInputFile()).

Method Detail

• print

  public void print()

  For debugging, outputs information about the AudioProcessor to standard error.

• readLine

  public java.lang.String readLine()

  For interactive pause - wait for user to hit Enter

• toString

  public java.lang.String toString()

  Gives some basic information about the audio being processed.

  Overrides:

  toString in class java.lang.Object

• setProgressCallback

  public void setProgressCallback(ProgressIndicator c)

  Adds a link to the GUI component which shows the progress of matching.

  Parameters:

  c - the AudioProcessor representing the other performance

• setLiveInput

  public void setLiveInput()

  Sets up the streams and buffers for live audio input (CD quality). If any Exception is thrown within this method, it is caught, and any opened streams are closed, and pcmInputStream is set to null, indicating that the method did not complete successfully.

• setInputFile

  public void setInputFile(java.lang.String fileName)

  Sets up the streams and buffers for audio file input. If any Exception is thrown within this method, it is caught, and any opened streams are closed, and pcmInputStream is set to null, indicating that the method did not complete successfully.

  Parameters:

  fileName - The path name of the input audio file.

• init

  protected void init()

  Allocates memory for arrays, based on parameter settings

• closeStreams

  public void closeStreams()

  Closes the input stream(s) associated with this object.

• makeFreqMap

  protected void makeFreqMap(int fftSize,
                             float sampleRate)

  Creates a map of FFT frequency bins to comparison bins. Where the spacing of FFT bins is less than 0.5 semitones, the mapping is one to one. Where the spacing is greater than 0.5 semitones, the FFT energy is mapped into semitone-wide bins. No scaling is performed; that is the energy is summed into the comparison bins. See also processFrame()

• weightedPhaseDeviation

  protected void weightedPhaseDeviation()

  Calculates the weighted phase deviation onset detection function. Not used. TODO: Test the change to WPD fn

• getFrame

  public boolean getFrame()

  Reads a frame of input data, averages the channels to mono, scales to a maximum possible absolute value of 1, and stores the audio data in a circular input buffer.

  Returns:

  true if a frame (or part of a frame, if it is the final frame) is read. If a complete frame cannot be read, the InputStream is set to null.

• processFrame

  protected void processFrame()

  Processes a frame of audio data by first computing the STFT with a Hamming window, then mapping the frequency bins into a part-linear part-logarithmic array, then computing the spectral flux then (optionally) normalising and calculating onsets.

• processFile

  public void processFile()

  Processes a complete file of audio data.

• findOnsets

  public void findOnsets(double p1,
                         double p2)

• getFeatures

  public static double[] getFeatures(java.lang.String fileName)

  Reads a text file containing a list of whitespace-separated feature values. Created for paper submitted to ICASSP'07.

  Parameters:

  fileName - File containing the data

  Returns:

  An array containing the feature values

• processFeatures

  public void processFeatures(java.lang.String fileName,
                              double hopTime)

  Reads a file of feature values, treated as an onset detection function, and finds peaks, which are stored in onsetList and onsets.

  Parameters:

  fileName - The file of feature values

  hopTime - The spacing of feature values in time

• setDisplay

  public void setDisplay(BeatTrackDisplay btd)

  Copies output of audio processing to the display panel.