old_contents: # -*- coding: utf-8 -*-
  
  from __future__ import (division, absolute_import, unicode_literals,
                          print_function)
  
  import audioread
  
  from file_metadata.generic_file import GenericFile
  
  
  class AudioFile(GenericFile):
      mimetypes = ()
  
      def analyze_audioread(self):
          try:
              with audioread.audio_open(self.filename) as f:
                  return {
                      'AudioRead:Duration': f.duration,
                      'AudioRead:SampleRate': f.samplerate,
                      'AudioRead:NumChannels': f.channels}
          except audioread.NoBackendError, audioread.DecodeError:
              return {}
  
new_contents: # -*- coding: utf-8 -*-
  
  from __future__ import (division, absolute_import, unicode_literals,
                          print_function)
  
  import audioread
  
  from file_metadata.generic_file import GenericFile
  from file_metadata.mixins import FFProbeMixin
  
  
  class AudioFile(FFProbeMixin, GenericFile):
      mimetypes = ()
  
      def analyze_audioread(self):
          try:
              with audioread.audio_open(self.filename) as f:
                  return {
                      'AudioRead:Duration': f.duration,
                      'AudioRead:SampleRate': f.samplerate,
                      'AudioRead:NumChannels': f.channels}
          except audioread.NoBackendError, audioread.DecodeError:
              return {}
  
subject: Use FFProbeMixin