diff --git a/app/src/main/java/com/frank/ffmpeg/activity/FilterActivity.kt b/app/src/main/java/com/frank/ffmpeg/activity/FilterActivity.kt
index 415e1d8..d42c24a 100644
--- a/app/src/main/java/com/frank/ffmpeg/activity/FilterActivity.kt
+++ b/app/src/main/java/com/frank/ffmpeg/activity/FilterActivity.kt
@@ -106,14 +106,16 @@ class FilterActivity : BaseActivity(), SurfaceHolder.Callback {
     }
 
     private fun registerLister() {
-        horizontalAdapter!!.setOnItemClickListener(OnItemClickListener { position ->
-            if (!surfaceCreated)
-                return@OnItemClickListener
-            if (!FileUtil.checkFileExist(videoPath)) {
-                showSelectFile()
-                return@OnItemClickListener
+        horizontalAdapter!!.setOnItemClickListener(object : OnItemClickListener {
+            override fun onItemClick(position: Int) {
+                if (!surfaceCreated)
+                    return
+                if (!FileUtil.checkFileExist(videoPath)) {
+                    showSelectFile()
+                    return
+                }
+                doFilterPlay(position)
             }
-            doFilterPlay(position)
         })
 
         surfaceView!!.setOnClickListener {
@@ -167,7 +169,7 @@ class FilterActivity : BaseActivity(), SurfaceHolder.Callback {
         super.onDestroy()
         isPlaying = false
         //FIXME
-        //        videoPlayer.release();
+//        videoPlayer?.release()
         videoPlayer = null
         horizontalAdapter = null
     }
@@ -187,8 +189,8 @@ class FilterActivity : BaseActivity(), SurfaceHolder.Callback {
 
     companion object {
 
-        private val MSG_HIDE = 222
-        private val DELAY_TIME = 5000
+        private const val MSG_HIDE = 222
+        private const val DELAY_TIME = 5000
     }
 
 }
diff --git a/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.java b/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.java
deleted file mode 100644
index a5c688b..0000000
--- a/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package com.frank.ffmpeg.format;
-
-/**
- * layout of video
- * Created by frank on 2018/6/18.
- */
-
-public class VideoLayout {
-
-    //horizontal join
-    public final static int LAYOUT_HORIZONTAL = 1;
-    //vertical join
-    public final static int LAYOUT_VERTICAL = 2;
-
-}
diff --git a/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.kt b/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.kt
new file mode 100644
index 0000000..916c26b
--- /dev/null
+++ b/app/src/main/java/com/frank/ffmpeg/format/VideoLayout.kt
@@ -0,0 +1,15 @@
+package com.frank.ffmpeg.format
+
+/**
+ * layout of video
+ * Created by frank on 2018/6/18.
+ */
+
+object VideoLayout {
+
+    //horizontal join
+    const val LAYOUT_HORIZONTAL = 1
+    //vertical join
+    const val LAYOUT_VERTICAL = 2
+
+}
diff --git a/app/src/main/java/com/frank/ffmpeg/handler/FFmpegHandler.java b/app/src/main/java/com/frank/ffmpeg/handler/FFmpegHandler.java
index 7e4871a..f6f597a 100644
--- a/app/src/main/java/com/frank/ffmpeg/handler/FFmpegHandler.java
+++ b/app/src/main/java/com/frank/ffmpeg/handler/FFmpegHandler.java
@@ -130,6 +130,11 @@ public class FFmpegHandler {
                 mHandler.obtainMessage(MSG_BEGIN).sendToTarget();
             }
 
+            @Override
+            public void onProgress(int progress, int duration) {
+
+            }
+
             @Override
             public void onEnd(int resultCode, String resultMsg) {
                 Log.i(TAG, "handle ffprobe onEnd result=" + resultMsg);
diff --git a/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.java b/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.java
deleted file mode 100644
index cc54ab5..0000000
--- a/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.frank.ffmpeg.listener;
-
-/**
- * listener of FFmpeg processing
- * Created by frank on 2019/11/11.
- */
-public interface OnHandleListener {
-    void onBegin();
-    default void onProgress(int progress, int duration){}
-    void onEnd(int resultCode, String resultMsg);
-}
diff --git a/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.kt b/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.kt
new file mode 100644
index 0000000..026be1b
--- /dev/null
+++ b/app/src/main/java/com/frank/ffmpeg/listener/OnHandleListener.kt
@@ -0,0 +1,11 @@
+package com.frank.ffmpeg.listener
+
+/**
+ * listener of FFmpeg processing
+ * Created by frank on 2019/11/11.
+ */
+interface OnHandleListener {
+    fun onBegin()
+    fun onProgress(progress: Int, duration: Int)
+    fun onEnd(resultCode: Int, resultMsg: String)
+}
diff --git a/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.java b/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.java
deleted file mode 100644
index d46444e..0000000
--- a/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.java
+++ /dev/null
@@ -1,11 +0,0 @@
-package com.frank.ffmpeg.listener;
-
-/**
- * listener of RecyclerView item clicking
- * Created by frank on 2018/6/6.
- */
-
-public interface OnItemClickListener {
-
-    void onItemClick(int position);
-}
diff --git a/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.kt b/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.kt
new file mode 100644
index 0000000..c6b8553
--- /dev/null
+++ b/app/src/main/java/com/frank/ffmpeg/listener/OnItemClickListener.kt
@@ -0,0 +1,11 @@
+package com.frank.ffmpeg.listener
+
+/**
+ * listener of RecyclerView item clicking
+ * Created by frank on 2018/6/6.
+ */
+
+interface OnItemClickListener {
+
+    fun onItemClick(position: Int)
+}