diff --git a/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java b/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
index fb3fe00..570f729 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
@@ -41,7 +41,6 @@ import android.widget.TextView;
 
 import com.github.axet.androidlibrary.activities.AppCompatThemeActivity;
 import com.github.axet.androidlibrary.animations.MarginBottomAnimation;
-import com.github.axet.androidlibrary.app.AlarmManager;
 import com.github.axet.androidlibrary.services.FileProvider;
 import com.github.axet.androidlibrary.services.StorageProvider;
 import com.github.axet.androidlibrary.sound.AudioTrack;
@@ -65,6 +64,7 @@ import com.github.axet.audiorecorder.app.AudioApplication;
 import com.github.axet.audiorecorder.app.Storage;
 import com.github.axet.audiorecorder.services.BluetoothReceiver;
 import com.github.axet.audiorecorder.services.RecordingService;
+import com.github.axet.wget.SpeedInfo;
 
 import java.io.File;
 import java.nio.ShortBuffer;
@@ -335,8 +335,14 @@ public class RecordingActivity extends AppCompatThemeActivity {
         public long resume;
         public long msecPause; // encoding progress on pause
         public long msecResume; // encoding progress on resume
+        SpeedInfo current;
+        SpeedInfo foreground;
+        SpeedInfo background;
         LinearLayout view;
+        View speed;
+        TextView text;
         View warning;
+        View slow;
 
         public ProgressEncoding(Context context) {
             super(context);
@@ -344,14 +350,17 @@ public class RecordingActivity extends AppCompatThemeActivity {
             setCancelable(false);
             setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
             setIndeterminate(false);
-            view = new LinearLayout(context);
-            view.setOrientation(LinearLayout.VERTICAL);
         }
 
         @Override
-        public void setView(View view) {
-            super.setView(this.view);
-            this.view.addView(view);
+        public void setView(View v) {
+            view = new LinearLayout(getContext());
+            view.setOrientation(LinearLayout.VERTICAL);
+            super.setView(view);
+            view.addView(v);
+            LayoutInflater inflater = LayoutInflater.from(getContext());
+            speed = inflater.inflate(R.layout.encoding_speed, view);
+            text = (TextView) speed.findViewById(R.id.speed);
         }
 
         public void onPause(long cur) {
@@ -365,13 +374,44 @@ public class RecordingActivity extends AppCompatThemeActivity {
         }
 
         public void setProgress(long cur, long total) {
-            long diff = resume - pause; // real time
-            long diffrec = msecResume - msecPause; // encoding time
-            if (pause != 0 && diff > 0 && diffrec < diff && warning == null) {
-                LayoutInflater inflater = LayoutInflater.from(getContext());
-                warning = inflater.inflate(R.layout.optimization, view, false);
-                view.addView(warning);
+            if (current == null) {
+                current = new SpeedInfo();
+                current.start(cur);
+            } else {
+                current.step(cur);
             }
+            if (pause == 0 && resume == 0) { // foreground
+                if (foreground == null) {
+                    foreground = new SpeedInfo();
+                    foreground.start(cur);
+                } else {
+                    foreground.step(cur);
+                }
+            }
+            if (pause != 0 && resume == 0) { // background
+                if (background == null) {
+                    background = new SpeedInfo();
+                    background.start(cur);
+                } else {
+                    background.step(cur);
+                }
+            }
+            if (pause != 0 && resume != 0) { // resumed from background
+                long diffreal = resume - pause; // real time
+                long diffenc = msecResume - msecPause; // encoding time
+                if (diffreal > 0 && diffenc < diffreal && warning == null) { // paused
+                    LayoutInflater inflater = LayoutInflater.from(getContext());
+                    warning = inflater.inflate(R.layout.optimization, view);
+                }
+                if (diffreal > 0 && diffenc >= diffreal && slow == null && foreground != null && background != null && foreground.getAverageSpeed() / background.getAverageSpeed() > 1 && slow == null) {
+                    LayoutInflater inflater = LayoutInflater.from(getContext());
+                    slow = inflater.inflate(R.layout.slow, view);
+                }
+                pause = 0;
+                resume = 0;
+                background = null;
+            }
+            text.setText(AudioApplication.formatSize(getContext(), current.getAverageSpeed()) + getString(R.string.per_second));
             super.setProgress((int) (cur * 100 / total));
         }
     }
diff --git a/app/src/main/res/layout/encoding_speed.xml b/app/src/main/res/layout/encoding_speed.xml
new file mode 100644
index 0000000..ee0da0c
--- /dev/null
+++ b/app/src/main/res/layout/encoding_speed.xml
@@ -0,0 +1,25 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:padding="16dp">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:padding="5dp"
+            android:src="@drawable/ic_info_black_24dp"
+            android:tint="?android:attr/colorForeground" />
+
+        <TextView
+            android:id="@+id/speed"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center"
+            android:text="100 kbs" />
+    </LinearLayout>
+</FrameLayout>
diff --git a/app/src/main/res/layout/slow.xml b/app/src/main/res/layout/slow.xml
new file mode 100644
index 0000000..ae73320
--- /dev/null
+++ b/app/src/main/res/layout/slow.xml
@@ -0,0 +1,23 @@
+<?xml version="1.0" encoding="utf-8"?>
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:padding="16dp">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <ImageView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:padding="5dp"
+            android:src="@drawable/ic_warning_black_24dp"
+            android:tint="?android:attr/colorForeground" />
+
+        <TextView
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Background encoding significantly slowed down due to android Battery Optimization settings, please allow this application work in background" />
+    </LinearLayout>
+</FrameLayout>
diff --git a/app/src/main/res/values-da/strings.xml b/app/src/main/res/values-da/strings.xml
index 1f733c3..e6aff55 100644
--- a/app/src/main/res/values-da/strings.xml
+++ b/app/src/main/res/values-da/strings.xml
@@ -47,4 +47,5 @@
     <string name="tile_stop_recording">Stop optagelse</string>
     <string name="pref_application">App</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
\ No newline at end of file
diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
index 60731f4..3ed75a8 100644
--- a/app/src/main/res/values-de/strings.xml
+++ b/app/src/main/res/values-de/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-el/strings.xml b/app/src/main/res/values-el/strings.xml
index 5f4c2e6..e0c0786 100644
--- a/app/src/main/res/values-el/strings.xml
+++ b/app/src/main/res/values-el/strings.xml
@@ -68,4 +68,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-es/strings.xml b/app/src/main/res/values-es/strings.xml
index 7de7979..f608f07 100644
--- a/app/src/main/res/values-es/strings.xml
+++ b/app/src/main/res/values-es/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-fr/strings.xml b/app/src/main/res/values-fr/strings.xml
index 9d8302b..362a604 100644
--- a/app/src/main/res/values-fr/strings.xml
+++ b/app/src/main/res/values-fr/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-in/strings.xml b/app/src/main/res/values-in/strings.xml
index 7757926..8fa4e50 100644
--- a/app/src/main/res/values-in/strings.xml
+++ b/app/src/main/res/values-in/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Mulai Merekam</string>
     <string name="tile_stop_recording">Berhenti Merekam</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-it/strings.xml b/app/src/main/res/values-it/strings.xml
index ac77f2c..75cc319 100644
--- a/app/src/main/res/values-it/strings.xml
+++ b/app/src/main/res/values-it/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-ja/strings.xml b/app/src/main/res/values-ja/strings.xml
index ab506c5..1a19220 100644
--- a/app/src/main/res/values-ja/strings.xml
+++ b/app/src/main/res/values-ja/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-pl/strings.xml b/app/src/main/res/values-pl/strings.xml
index 35f93bd..c6899c4 100644
--- a/app/src/main/res/values-pl/strings.xml
+++ b/app/src/main/res/values-pl/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-pt-rBR/strings.xml b/app/src/main/res/values-pt-rBR/strings.xml
index 3c47d61..46ecec7 100644
--- a/app/src/main/res/values-pt-rBR/strings.xml
+++ b/app/src/main/res/values-pt-rBR/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-ru/strings.xml b/app/src/main/res/values-ru/strings.xml
index 990e397..437e954 100644
--- a/app/src/main/res/values-ru/strings.xml
+++ b/app/src/main/res/values-ru/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-sk/strings.xml b/app/src/main/res/values-sk/strings.xml
index 9a14437..1de6978 100644
--- a/app/src/main/res/values-sk/strings.xml
+++ b/app/src/main/res/values-sk/strings.xml
@@ -76,4 +76,5 @@
     <string name="tile_start_recording">Spustiť nahrávanie</string>
     <string name="tile_stop_recording">Zastaviť nahrávanie</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-tr/strings.xml b/app/src/main/res/values-tr/strings.xml
index da2deab..11a0e36 100644
--- a/app/src/main/res/values-tr/strings.xml
+++ b/app/src/main/res/values-tr/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-zh-rCN/strings.xml b/app/src/main/res/values-zh-rCN/strings.xml
index f961654..0c946de 100644
--- a/app/src/main/res/values-zh-rCN/strings.xml
+++ b/app/src/main/res/values-zh-rCN/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values-zh-rTW/strings.xml b/app/src/main/res/values-zh-rTW/strings.xml
index 908f6f5..16deea3 100644
--- a/app/src/main/res/values-zh-rTW/strings.xml
+++ b/app/src/main/res/values-zh-rTW/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">開始錄音</string>
     <string name="tile_stop_recording">停止錄音</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 46ca6d3..73d78fd 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -74,4 +74,5 @@
     <string name="tile_start_recording">Start Recording</string>
     <string name="tile_stop_recording">Stop Recording</string>
     <string name="encoding_optimization">Background encoding paused due to android Battery Optimization settings, please allow this application work in background</string>
+    <string name="per_second">/s</string>
 </resources>