MediaPlayer, SeekBar, and Chronometer sync issue

I'm trying to implement a MediaPlayer to play an audio file in a DialogFragment. I've successfully managed to get the SeekBar and Chronometer to progress in sync with the MediaPlayer, but cannot get the MediaPlayer and Chronometer to change properly when I am seeking through the audio file using the SeekBar. (Also, is there a way to get the seekbar to progress smoothly? currently it jumps to the new position every second).

public class PlaybackFragment extends DialogFragment {

    private static final String LOG_TAG = "PlaybackFragment";

    private static final String ARG_ITEM = "recording_item";
    private RecordingItem item;

    private Handler mHandler = new Handler();

    private static final SimpleDateFormat mLengthFormatter = new SimpleDateFormat("mm:ss", Locale.getDefault());
    private MediaPlayer mMediaPlayer = null;

    private SeekBar mSeekBar = null;
    private FloatingActionButton mPlayButton = null;
    private Chronometer mCurrentProgress = null;

    private boolean startPlaying = true;
    long timeWhenPaused = 0;

    @NonNull
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {

        Dialog dialog = super.onCreateDialog(savedInstanceState);

        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
        View view = getActivity().getLayoutInflater().inflate(R.layout.fragment_media_playback, null);

        mFileNameTextView = (TextView) view.findViewById(R.id.file_name_text_view);
        mFileLengthTextView = (TextView) view.findViewById(R.id.file_length_text_view);
        mCurrentProgress = (Chronometer) view.findViewById(R.id.current_progress);

        mSeekBar = (SeekBar) view.findViewById(R.id.seekbar);
        mSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if(mMediaPlayer != null && fromUser){
                    mMediaPlayer.seekTo(progress);
                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                if(mMediaPlayer != null) {
                    //CHANGE CHRONOMETER TIME BASED ON SEEKBAR POSITION??
                    pausePlaying();
                }
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                //CHANGE MEDIAPLAYER TO PLAY AT CURRENT SEEKBAR POSITION?
                startPlaying();
            }
        });

        mPlayButton = (FloatingActionButton) view.findViewById(R.id.fab_play);
        mPlayButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onPlay(startPlaying);
                startPlaying = !startPlaying;
            }
        });

        builder.setView(view);

        return builder.create();
}

    @Override
    public void onPause() {
        super.onPause();

        if (mMediaPlayer != null) {
            mMediaPlayer.release();
            mMediaPlayer = null;
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (mMediaPlayer != null) {
            stopPlaying();
        }
    }

    // Play start/stop
    private void onPlay(boolean start){
        if (start) {
            startPlaying();

        } else {
            pausePlaying();
        }
    }

    private void startPlaying() {
        mPlayButton.setImageResource(R.drawable.ic_media_pause);
        mCurrentProgress.setBase(SystemClock.elapsedRealtime() + timeWhenPaused);

        mCurrentProgress.start();

        mMediaPlayer = new MediaPlayer();

        try {
            mMediaPlayer.setDataSource(item.getFilePath());
            mMediaPlayer.prepare();
            mSeekBar.setMax(mMediaPlayer.getDuration());
            mMediaPlayer.start();

            mMediaPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mp) {
                    stopPlaying();
                }
            });

        } catch (IOException e) {
            Log.e(LOG_TAG, "prepare() failed");
        }

        mHandler.postDelayed(mRunnable, 0);
    }

    private void pausePlaying() {
        mPlayButton.setImageResource(R.drawable.ic_media_play);
        mMediaPlayer.stop();
        mCurrentProgress.stop();
        timeWhenPaused = mCurrentProgress.getBase() - SystemClock.elapsedRealtime();
    }

    private void stopPlaying() {
        mPlayButton.setImageResource(R.drawable.ic_media_play);
        mMediaPlayer.release();
        mMediaPlayer = null;
        timeWhenPaused = 0;

        mCurrentProgress.stop();
    }

    //updating mSeekBar every second
    private Runnable mRunnable = new Runnable() {
        @Override
        public void run() {
            if(mMediaPlayer != null){
                int mCurrentPosition = mMediaPlayer.getCurrentPosition();
                mSeekBar.setProgress(mCurrentPosition);

                mHandler.postDelayed(this, 1000);
            }
        }
    };
}