title: Extract Audio from Mp4 and Save to Sd Card (MediaExtractor)
body: <p>I have a mp4 video file in my sd card. I would like to extract the audio from the video and then save the extracted audio as a separate file on the sd card using MediaExtractor Api. Here is the code I've tried:</p>
  
  <pre><code>  MediaExtractor extractor = new MediaExtractor();
    extractor.setDataSource(MEDIA_PATH_To_File_On_SDCARD);
    for (i = 0; i &lt; extractor.getTrackCount(); i++) {
              MediaFormat format = extractor.getTrackFormat(i);
              String mime = format.getString(MediaFormat.KEY_MIME);
              if (mime.startsWith("audio/")) {
                  extractor.selectTrack(i);
                  decoder = MediaCodec.createDecoderByType(mime);
  
                  if(decoder != null)
                  {
                     decoder.configure(format, null, null, 0);
                  }
  
                  break;
              }
          }
  </code></pre>
  
  <p>Am stuck here I have no idea of how to take the selected audio track and save it to the sd card.</p>