title: Android ffmpeg unable to merge audio(.wav file) with video(.mp4 file)
body: <p>i am working on FFMPEG library,in which i am merging audio (.wav file) with video (.mp4 file) , for that iam using following command here:</p>
  
  <pre><code>*String commandStr=    "ffmpeg,-y,-i,mnt/sdcard/Scatta/Scattatemp.mp4,-i,/storage/emulated/0/MicDroid/recordings/video.wav ,-strict,experimental,-map,0:0,-map,1:0,-vcodec,mpeg4,-vb,15496k,-ab,128k,-ac,2,-ar,22050,-shortest,mnt/sdcard/Scatta/mergedFile.mp4";
  </code></pre>
  
  <p>for that i am using following code,but my command is not working, i am getting Commandvalidation failed exception</p>
  
  <pre><code>GeneralUtils.deleteFileUtil(workFolder + "/vk.log");
  
          PowerManager powerManager = (PowerManager)_act.getSystemService(Activity.POWER_SERVICE);
          WakeLock wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "VK_LOCK"); 
          Log.d("Prefs.TAG", "Acquire wake lock");
          wakeLock.acquire();
  String commandStr=  "ffmpeg,-y,-i,mnt/sdcard/Scatta/Scattatemp.mp4,-i,/storage/emulated/0/MicDroid/recordings/video.wav ,-strict,experimental,-map,0:0,-map,1:0,-vcodec,mpeg4,-vb,15496k,-ab,128k,-ac,2,-ar,22050,-shortest,mnt/sdcard/Scatta/mergedFile.mp4"   ;
  
  LoadJNI vk = new LoadJNI();
          try {
  
              vk.run(GeneralUtils.utilConvertToComplex(commandStr), workFolder, getApplicationContext());
              GeneralUtils.copyFileToFolder(vkLogPath, demoVideoFolder);
  
          } catch (CommandValidationException e) {
              Log.e("Prefs.TAG", "vk run exeption.", e);
              commandValidationFailedFlag = true;
          } catch (Throwable e) {
              Log.e("Prefs.TAG", "vk run exeption.", e);
          }
          finally {
              if (wakeLock.isHeld())
                  wakeLock.release();
              else{
                  Log.i("Prefs.TAG", "Wake lock is already released, doing nothing");
              }
          }
          Log.i("Prefs.TAG", "doInBackground finished");
      }
      catch(Exception e){
          e.printStackTrace();
          System.out.println(".exception"+e.toString());
      }
  </code></pre>
  
  <p>i am getting following exception</p>
  
  <pre><code> 04-08 10:00:38.891: D/ffmpeg4android(7781): deleteing: /data/data/org.scatta.androidclient/files//vk.log isdeleted: false
   04-08 10:00:38.891: D/Prefs.TAG(7781): Acquire wake lock
   04-08 10:00:38.896: I/System.out(7781): &lt;--- command strffmpeg -i  mnt/sdcard/Scatta/Scattatemp.mp4 -i    /storage/emulated/0/MicDroid/recordings/video.wav -acodec copy mnt/sdcard/Scatta/mergedFile.mp4
   04-08 10:00:38.896: E/ffmpeg4android(7781): Command validation failed.
   04-08 10:00:38.896: E/ffmpeg4android(7781): Check if input file exists: /storage/emulated/0/MicDroid/recordings/video.wav
      04-08 10:00:38.896: E/Prefs.TAG(7781): vk run exeption.
    04-08 10:00:38.896: E/Prefs.TAG(7781): com.netcompss.ffmpeg4android.CommandValidationException
      04-08 10:00:38.896: E/Prefs.TAG(7781):  at com.netcompss.loader.LoadJNI.run(LoadJNI.java:26)
    04-08 10:00:38.896: E/Prefs.TAG(7781):    at com.scatta.androidclient.ui.PlaybackScreen$TranscdingBackground.doInBackground(PlaybackScreen.java:159)
     04-08 10:00:38.896: E/Prefs.TAG(7781):   at com.scatta.androidclient.ui.PlaybackScreen$TranscdingBackground.doInBackground(PlaybackScreen.java:1)
     04-08 10:00:38.896: E/Prefs.TAG(7781):   at android.os.AsyncTask$2.call(AsyncTask.java:287)
      04-08 10:00:38.896: E/Prefs.TAG(7781):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
      04-08 10:00:38.896: E/Prefs.TAG(7781):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
    04-08 10:00:38.896: E/Prefs.TAG(7781):    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
     04-08 10:00:38.896: E/Prefs.TAG(7781):   at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
    04-08 10:00:38.896: E/Prefs.TAG(7781):    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
   04-08 10:00:38.896: E/Prefs.TAG(7781):     at java.lang.Thread.run(Thread.java:856)
  </code></pre>