Class: WSK::RIFFReader

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

Overview

Class reading RIFF files

Instance Method Summary collapse

Constructor Details

#initialize(iFile) ⇒ RIFFReader

Constructor

Parameters
  • iFile (IO): File to read


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# File 'lib/WSK/RIFFReader.rb', line 15

def initialize(iFile)
  @File = iFile
end

Instance Method Details

#setFilePos(iRIFFName) ⇒ Object

Position the file on the data associated to a given RIFF name

Parameters
  • iRIFFName (String): The RIFF name
Return
  • Exception: An error, or nil in case of success
  • Integer: The RIFF chunk size


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# File 'lib/WSK/RIFFReader.rb', line 26

def setFilePos(iRIFFName)
  rError = nil
  rSize = nil

  # Loop through the names until we find ours
  @File.seek(12)
  lRIFFName, rSize = @File.read(8).unpack('a4V')
  lCurrentPos = 20
  while (lRIFFName != nil)
    if (lRIFFName == iRIFFName)
      # We are positioned correctly
      lRIFFName = nil
      log_debug "Found RIFF chunk #{iRIFFName} of size #{rSize}"
    else
      log_debug "Skip RIFF chunk #{lRIFFName} of size #{rSize}"
      # Go to the next chunk
      @File.seek(lCurrentPos + rSize)
      lData = @File.read(8)
      lCurrentPos += rSize + 8
      if (lData == nil)
        # End of the file
        rError = RuntimeError.new("End of file met: no RIFF #{iRIFFName} chunk found.")
        lRIFFName = nil
      else
        lRIFFName, rSize = lData.unpack('a4V')
      end
    end
  end

  return rError, rSize
end