diff --git a/app/src/main/java/com/frank/ffmpeg/AudioPlayer.java b/app/src/main/java/com/frank/ffmpeg/AudioPlayer.java
index d6553f5..b411682 100644
--- a/app/src/main/java/com/frank/ffmpeg/AudioPlayer.java
+++ b/app/src/main/java/com/frank/ffmpeg/AudioPlayer.java
@@ -5,7 +5,7 @@ import android.media.AudioManager;
 import android.media.AudioTrack;
 
 /**
- * 音频播放器
+ * AudioPlayer: use AudioTrack and OpenSL ES to play audio
  * Created by frank on 2018/2/1.
  */
 
@@ -13,20 +13,22 @@ public class AudioPlayer {
     static {
         System.loadLibrary("media-handle");
     }
-    //调用AudioTrack播放
+
+    //using AudioTrack to play
     public native void play(String audioPath);
-    //调用OpenSL ES播放
+
+    //using OpenSL ES to play
     public native void playAudio(String audioPath);
-    //调用OpenSL ES播放
+
     public native void stop();
 
     public native static void lameInitDefault();
 
     public native static void lameInit(int inSamplerate, int outChannel,
-                                   int outSamplerate, int outBitrate, float scaleInput, int mode, int vbrMode,
-                                   int quality, int vbrQuality, int abrMeanBitrate, int lowpassFreq, int highpassFreq, String id3tagTitle,
-                                   String id3tagArtist, String id3tagAlbum, String id3tagYear,
-                                   String id3tagComment);
+                                       int outSamplerate, int outBitrate, float scaleInput, int mode, int vbrMode,
+                                       int quality, int vbrQuality, int abrMeanBitrate, int lowpassFreq, int highpassFreq, String id3tagTitle,
+                                       String id3tagArtist, String id3tagAlbum, String id3tagYear,
+                                       String id3tagComment);
 
     public native static int lameEncode(short[] buffer_l, short[] buffer_r,
                                         int samples, byte[] mp3buf);
@@ -39,19 +41,20 @@ public class AudioPlayer {
     public native static void lameClose();
 
     /**
-     * 创建一个AudioTrack对象
-     * @param sampleRate 采样率
-     * @param channels 声道布局
+     * Create an AudioTrack instance for JNI call
+     *
+     * @param sampleRate sampleRate
+     * @param channels   channel layout
      * @return AudioTrack
      */
-    public AudioTrack createAudioTrack(int sampleRate, int channels){
+    public AudioTrack createAudioTrack(int sampleRate, int channels) {
         int audioFormat = AudioFormat.ENCODING_PCM_16BIT;
         int channelConfig;
-        if(channels == 1){
+        if (channels == 1) {
             channelConfig = AudioFormat.CHANNEL_OUT_MONO;
-        }else if(channels == 2){
+        } else if (channels == 2) {
             channelConfig = AudioFormat.CHANNEL_OUT_STEREO;
-        }else{
+        } else {
             channelConfig = AudioFormat.CHANNEL_OUT_STEREO;
         }