Class: JOCLoudness

Inherits:
Object
  • Object
show all
Defined in:
lib/JOCLoudness.rb

Overview

JOCLoudness class, used to compute the loudness of a wav file (Based on ITU-R BS.1770)

Instance Method Summary collapse

Constructor Details

#initialize(filename, logfile = nil, loglevel = Logger::INFO) ⇒ JOCLoudness

Initialize JOCLoudness

Parameters:

  • filename (String)

    audio wav file to analize

  • logfile (String) (defaults to: nil)

    log file to save the logs (optional)

  • loglevel (defaults to: Logger::INFO)

    log level, could be Logger::FATAL, Logger::ERROR, Logger::WARN, Logger::INFO, Logger::DEBUG (optional)


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# File 'lib/JOCLoudness.rb', line 19

def initialize (filename, logfile = nil, loglevel = Logger::INFO)
  #Instanciate wav reader
  @wav = Wavfile.new(filename)

  #Start logger
  # Keep data for today and the past 3 days.
  @log = nil
  if (logfile != nil)
    @log = Logger.new(logfile)  
    @log.level = loglevel

    #Set logger (optional)
    @wav.Setlogger(@log)      
  end  

  #Read wav header
  @wav.ReadHeader()

  #Get file info (fs, number of channels)
  @fs, @nch = @wav.GetFileInfo()
end

Instance Method Details

#CalcLoudnessFloat

Calculates the loudness of the audio file

Returns:

  • (Float)

    the resulting loudness in LKFS


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# File 'lib/JOCLoudness.rb', line 43

def CalcLoudness ()
  #Instantiate & initialize loudness moudule
  loudness = JOCLoud.new
  
  #Set logger
  if (@log != nil)
    loudness.Setlogger(@log)
  end

  loudness.ini(@fs,@nch) 

  #Read wav file and send the samples to loudness module
  n = 0
  samples = 1

  while samples != nil
    samples = @wav.GetAudioSamples(n)
    if (samples != nil) 
      if (n % @fs == 0)
        puts "Processed #{n / @fs} secs"          
      end

      loudness.Addsample(samples)
  
      n = n + 1
    end
  end 

  loudnessLKFS = loudness.GetLoudnessLKFS()
  
  if (@log != nil)
    strloudnessdata = "Loudness = #{loudnessLKFS.round(1)} LKFS" 
    @log.debug(strloudnessdata)  
  end
  
  return loudnessLKFS 
end

#CloseObject

Closes the opened file


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# File 'lib/JOCLoudness.rb', line 82

def Close()
  if (@log!=nil)
    @log.debug("End logger")
  end
  
  if (@wav != nil)
    @wav.Close()
  end
end