distorted audio after extracion

file='take.avi'; %input file
file1='vipmen1.wav'; %o/p file name
   hmfr=video.MultimediaFileReader(file,'AudioOutputPort',true,'VideoOutputPort',false);
hmfw = video.MultimediaFileWriter(file1,'AudioInputPort',true,'FileFormat','WAV');
       while ~isDone(hmfr)
      audioFrame = step(hmfr);
         step(hmfw,audioFrame);
        end
close(hmfw);
close(hmfr);

I am using above code to extract audio from a video. The program works correctly without errors. However the audio is slow and completely distorted sound.It is of the same length and wav format. Any ideas ?

[Walter Roberson]

Where are you setting the frequency in the output file ?