Module: JpegReader

Defined in:
lib/jpeg_reader.rb

Class Method Summary collapse

Class Method Details

.fetch_data_from(filename) ⇒ Object 



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# File 'lib/jpeg_reader.rb', line 2

def self.fetch_data_from(filename)
  data = ""

  File.open(filename, "r") do |f|
    if f.read(2) == "\xff\xd8".to_b
      while !f.eof?
        break if f.read(1) != "\xff".to_b

        if f.read(1) == "\xe0".to_b # APP0
          quickroute_segment = false
          length = BinData::Uint16be.read(f)

          if length >= 12
            if f.read(10) == "QuickRoute".to_b
              data << f.read(length - 12)
              quickroute_segment = true
            else
              f.seek(length - 12, ::IO::SEEK_CUR)
            end
          else
            f.seek(length - 2, ::IO::SEEK_CUR)
          end

          break if !quickroute_segment && !data.empty?
        else
          break
        end
      end
    end
  end

  data
end