Class: WSK::Actions::FFT

Inherits:
Object
  • Object
show all
Includes:
Common, FFT
Defined in:
lib/WSK/Actions/FFT.rb

Constant Summary

Constants included from FFT

FFT::FFTDISTANCE_AVERAGE_HISTORY_TOLERANCE_PC, FFT::FFTDISTANCE_MAX_HISTORY_TOLERANCE_PC, FFT::FFTDIST_MAX, FFT::FFTNBRSAMPLES_HISTORY, FFT::FFTSAMPLE_FREQ, FFT::FFT_SAMPLES_PREFETCH, FFT::FREQINDEX_FIRST, FFT::FREQINDEX_LAST

Instance Method Summary collapse

Methods included from FFT

#getNextFFTSample, #getNextNonSilentSample, #getNextSilentSample, #getSampleBeyondThresholds

Methods included from Common

#accessInputWaveFile, #accessOutputWaveFile, #getWaveFileAccesses, #parsePlugins, #readDuration, #readFFTProfile, #readThresholds, #val2db

Instance Method Details

#execute(iInputData, oOutputData) ⇒ Object

Execute

Parameters

  • iInputData (WSK::Model::InputData): The input data

  • oOutputData (Object): The output data to fill

Return

  • Exception: An error, or nil if success



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# File 'lib/WSK/Actions/FFT.rb', line 34

def execute(iInputData, oOutputData)

  # 1. Create the whole FFT profile
  log_info 'Creating FFT profile ...'
  # Object that will create the FFT
  lFFTComputing = FFTComputing.new(false, iInputData.Header)
  # Parse the data
  lIdxSample = 0
  iInputData.each_raw_buffer do |iInputRawBuffer, iNbrSamples, iNbrChannels|
    lFFTComputing.completeFFT(iInputRawBuffer, iNbrSamples)
    lIdxSample += iNbrSamples
    $stdout.write("#{(lIdxSample*100)/iInputData.NbrSamples} %\015")
    $stdout.flush
  end
  # Compute the result
  require 'WSK/FFTUtils/FFTUtils'
  lFFTUtils = FFTUtils::FFTUtils.new
  lFFTProfile = lFFTComputing.getFFTProfile
  lFFTReferenceProfile = lFFTUtils.createCFFTProfile(lFFTProfile)

  # 2. Compute the distance obtained by comparing this profile with a normal file pass
  log_info 'Computing average distance ...'
  lFFTComputing2 = FFTComputing.new(true, iInputData.Header)
  lIdxSample = 0
  lNbrTimes = 0
  lSumDist = 0
  while (lIdxSample < iInputData.NbrSamples)
    # Compute the number of samples needed to have a valid FFT.
    # Modify this number if it exceeds the range we have
    lNbrSamplesFFTMax = iInputData.Header.SampleRate/FFTSAMPLE_FREQ
    lIdxBeginFFTSample = lIdxSample
    lIdxEndFFTSample = lIdxSample+lNbrSamplesFFTMax-1
    if (lIdxEndFFTSample >= iInputData.NbrSamples)
      lIdxEndFFTSample = iInputData.NbrSamples-1
    end
    lNbrSamplesFFT = lIdxEndFFTSample-lIdxBeginFFTSample+1
    # Load an FFT buffer of this
    lFFTBuffer = ''
    iInputData.each_raw_buffer(lIdxBeginFFTSample, lIdxEndFFTSample, :nbr_samples_prefetch => iInputData.NbrSamples-lIdxBeginFFTSample) do |iInputRawBuffer, iNbrSamples, iNbrChannels|
      lFFTBuffer.concat(iInputRawBuffer)
    end
    # Compute its FFT profile
    lFFTComputing2.resetData
    lFFTComputing2.completeFFT(lFFTBuffer, lNbrSamplesFFT)
    lSumDist += lFFTUtils.distFFTProfiles(lFFTReferenceProfile, lFFTUtils.createCFFTProfile(lFFTComputing2.getFFTProfile), FFTDIST_MAX).abs
    lNbrTimes += 1
    lIdxSample = lIdxEndFFTSample+1
    $stdout.write("#{(lIdxSample*100)/iInputData.NbrSamples} %\015")
    $stdout.flush
  end
  lAverageDist = lSumDist/lNbrTimes
  log_debug "Average distance with silence: #{lAverageDist}"

  # Display results
  (FREQINDEX_FIRST..FREQINDEX_LAST).each_with_index do |iIdx, iIdxFreq|
    log_debug "[#{(440*(2**(iIdx/12.0))).round} Hz]: #{lFFTProfile[2][iIdxFreq].join(', ')}"
  end

  # Write the result in a file
  File.open('fft.result', 'wb') do |oFile|
    oFile.write(Marshal.dump([lAverageDist, lFFTProfile]))
  end

  return nil
end

#get_nbr_samples(iInputData) ⇒ Object

Get the number of samples that will be written. This is called before execute, as it is needed to write the output file. It is possible to give a majoration: it will be padded with silence.

Parameters

  • iInputData (WSK::Model::InputData): The input data

Return

  • Integer: The number of samples to be written



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# File 'lib/WSK/Actions/FFT.rb', line 23

def get_nbr_samples(iInputData)
  return 0
end