private void mixAudio(){
        if(mVoiceFile == null || mBeatFile == null || mRapFile == null)
            return;

        String [] command = new String []{
                "-ss",getConvertedValue(getSyncCalibration()),
                "-i", mVoiceFile.getAbsolutePath(),
                "-i", mBeatFile.getAbsolutePath(),
                "-filter_complex",
                "[0:a]volume="+ getConvertedValue(getVocalLevel()) +"[a1];[1:a]volume="+getConvertedValue(getBeatLevel())+"[a2];[a1][a2]amerge=inputs=2,pan=stereo|c0<c0+c2|c1<c1+c3[aout]",
                "-map",
                "[aout]",
                mRapFile.getAbsolutePath()};

        System.out.println("Audio Call: " + Arrays.toString(command));

        try {
            mFfmpeg.execute(command, new FFmpegExecuteResponseHandler() {
                @Override
                public void onSuccess(String message) {
                    Log.d("Studio Status", message);
                    mRecordButton.setIndeterminate(false);
                    mRecordButton.showProgress(false);
                    prepRapPreview();

                }

                @Override
                public void onProgress(String message) {
                    Log.e("Studio Process", message);
                    mRecordButton.setIndeterminate(true);
                }

                @Override
                public void onFailure(String message) {
                    Log.e(TAG, message);
                    JSONObject eventProperties = new JSONObject();
                    mProcessTimeEnd = System.currentTimeMillis();
                    long mProcessDifference = mProcessTimeEnd - mProcessTimeStart;
                    double mProcessTotalSeconds  = mProcessDifference / 1000.0;

                    try {
                        eventProperties.put("userId",mApp.getmUser().get_id() );
                        eventProperties.put("username", mApp.getmUser().getUsername());
                        eventProperties.put("Descripton", message);
                        eventProperties.put("Total Duration in Seconds", mProcessTotalSeconds);


                    } catch (JSONException exception) {
                    }
                    Amplitude.getInstance().logEvent("Mixing Rap Process - Failure", eventProperties);

                }

                @Override
                public void onStart() {
                    mRecordButton.showProgress(true);
                    mRecordButton.setIndeterminate(true);
                    mProcessTimeStart = System.currentTimeMillis();
                    showSnackBar("Mixing up your banger...  ", 1);
                    Log.d("Audio: ", "Mixing");
                    Log.d("Voice File Readable", mVoiceFile.canRead()+"");
                    Log.d("Beat File Readable", mBeatFile.canRead()+"");
                    Log.d("Final File Readable", mRapFile.canRead()+"");

                }

                @Override
                public void onFinish() {
                    mProcessTimeEnd = System.currentTimeMillis();
                    long mProcessDifference = mProcessTimeEnd - mProcessTimeStart;
                    double mProcessTotalSeconds  = mProcessDifference / 1000.0;
                    logRecordingProcessDuration(mProcessTotalSeconds);
                    Log.d("FINISHED Mixing: ", mProcessTotalSeconds + "seconds");
                }
            });
        } catch (FFmpegCommandAlreadyRunningException e) {

        }
    }