diff --git a/Live/src/main/cpp/AudioStream.cpp b/Live/src/main/cpp/AudioStream.cpp
index f986b4f..edfd904 100644
--- a/Live/src/main/cpp/AudioStream.cpp
+++ b/Live/src/main/cpp/AudioStream.cpp
@@ -8,7 +8,8 @@ AudioStream::AudioStream() {
 }
 
 AudioStream::~AudioStream() {
-    DELETE(buffer);
+    delete buffer;
+    buffer = nullptr;
     if (audioCodec) {
         faacEncClose(audioCodec);
         audioCodec = nullptr;
@@ -39,7 +40,7 @@ void AudioStream::setAudioEncInfo(int samplesInHZ, int channels) {
     buffer = new u_char[maxOutputBytes];
 }
 
-int AudioStream::getInputSamples() {
+int AudioStream::getInputSamples() const {
     return static_cast<int>(inputSamples);
 }
 
diff --git a/Live/src/main/cpp/AudioStream.h b/Live/src/main/cpp/AudioStream.h
index f37d9d2..c246ddb 100644
--- a/Live/src/main/cpp/AudioStream.h
+++ b/Live/src/main/cpp/AudioStream.h
@@ -18,7 +18,7 @@ public:
 
     void setAudioCallback(AudioCallback audioCallback);
 
-    int getInputSamples();
+    int getInputSamples() const;
 
     void encodeData(int8_t *data);
 
diff --git a/Live/src/main/cpp/PacketQueue.h b/Live/src/main/cpp/PacketQueue.h
index 1010924..b2c3ac5 100644
--- a/Live/src/main/cpp/PacketQueue.h
+++ b/Live/src/main/cpp/PacketQueue.h
@@ -12,7 +12,7 @@ class PacketQueue {
 public:
 
     void push(T new_value) {
-        std::lock_guard<std::mutex> lk(m_mutex);
+        std::lock_guard<std::mutex> lock(m_mutex);
         if (m_running) {
             m_queue.push(new_value);
             m_cond.notify_one();
@@ -21,7 +21,7 @@ public:
 
     int pop(T &value) {
         int ret = 0;
-        std::unique_lock<std::mutex> lk(m_mutex);
+        std::unique_lock<std::mutex> lock(m_mutex);
         if (!m_running) {
             return ret;
         }
@@ -34,22 +34,22 @@ public:
     }
 
     void setRunning(bool run) {
-        std::lock_guard<std::mutex> lk(m_mutex);
+        std::lock_guard<std::mutex> lock(m_mutex);
         m_running = run;
     }
 
     int empty() {
-        std::lock_guard<std::mutex> lk(m_mutex);
+        std::lock_guard<std::mutex> lock(m_mutex);
         return m_queue.empty();
     }
 
     int size() {
-        std::lock_guard<std::mutex> lk(m_mutex);
+        std::lock_guard<std::mutex> lock(m_mutex);
         return static_cast<int>(m_queue.size());
     }
 
     void clear() {
-        std::lock_guard<std::mutex> lk(m_mutex);
+        std::lock_guard<std::mutex> lock(m_mutex);
         int size = m_queue.size();
         for (int i = 0; i < size; ++i) {
             T value = m_queue.front();
diff --git a/Live/src/main/cpp/PushInterface.h b/Live/src/main/cpp/PushInterface.h
index 9058608..f930545 100644
--- a/Live/src/main/cpp/PushInterface.h
+++ b/Live/src/main/cpp/PushInterface.h
@@ -7,6 +7,4 @@
 #define LOGI(...) __android_log_print(ANDROID_LOG_INFO,"FrankLive",__VA_ARGS__)
 #define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,"FrankLive",__VA_ARGS__)
 
-#define DELETE(obj) if(obj){ delete obj; obj = 0; }
-
 #endif
diff --git a/Live/src/main/cpp/RtmpPusher.cpp b/Live/src/main/cpp/RtmpPusher.cpp
index 1ac9cee..13416e8 100644
--- a/Live/src/main/cpp/RtmpPusher.cpp
+++ b/Live/src/main/cpp/RtmpPusher.cpp
@@ -12,7 +12,6 @@
 
 PacketQueue<RTMPPacket *> packets;
 VideoStream *videoStream = nullptr;
-int isStart = 0;
 pthread_t pid;
 
 std::atomic<bool> isPushing;
@@ -76,7 +75,7 @@ void releasePackets(RTMPPacket *&packet) {
 
 void *start(void *args) {
     char *url = static_cast<char *>(args);
-    RTMP *rtmp = nullptr;
+    RTMP *rtmp;
     do {
         rtmp = RTMP_Alloc();
         if (!rtmp) {
@@ -131,7 +130,6 @@ void *start(void *args) {
         }
         releasePackets(packet);
     } while (0);
-    isStart = 0;
     isPushing = false;
     packets.setRunning(false);
     packets.clear();
@@ -162,10 +160,9 @@ RTMP_PUSHER_FUNC(void, native_1setVideoCodecInfo,
 
 RTMP_PUSHER_FUNC(void, native_1start, jstring path_) {
     LOGI("native start...");
-    if (isStart) {
+    if (isPushing) {
         return;
     }
-    isStart = 1;
     const char *path = env->GetStringUTFChars(path_, nullptr);
     char *url = new char[strlen(path) + 1];
     strcpy(url, path);
@@ -214,6 +211,8 @@ RTMP_PUSHER_FUNC(void, native_1stop) {
 RTMP_PUSHER_FUNC(void, native_1release) {
     LOGI("native release...");
     env->DeleteGlobalRef(jobject_error);
-    DELETE(videoStream);
-    DELETE(audioStream);
+    delete videoStream;
+    videoStream = nullptr;
+    delete audioStream;
+    audioStream = nullptr;
 }
\ No newline at end of file
diff --git a/Live/src/main/cpp/VideoStream.cpp b/Live/src/main/cpp/VideoStream.cpp
index a681520..dade40a 100644
--- a/Live/src/main/cpp/VideoStream.cpp
+++ b/Live/src/main/cpp/VideoStream.cpp
@@ -18,7 +18,8 @@ VideoStream::~VideoStream() {
     }
     if (pic_in) {
         x264_picture_clean(pic_in);
-        DELETE(pic_in);
+        delete pic_in;
+        pic_in = nullptr;
     }
 }
 
@@ -31,7 +32,8 @@ void VideoStream::setVideoEncInfo(int width, int height, int fps, int bitrate) {
     }
     if (pic_in) {
         x264_picture_clean(pic_in);
-        DELETE(pic_in);
+        delete pic_in;
+        pic_in = nullptr;
     }
 
     //setting x264 params
@@ -79,9 +81,12 @@ void VideoStream::setVideoCallback(VideoCallback callback) {
     this->videoCallback = callback;
 }
 
-void VideoStream::encodeVideo(int8_t *data, int8_t camera_type) {
+void VideoStream::encodeVideo(int8_t *data, int camera_type) {
     pthread_mutex_lock(&mutex);
 
+    if (!pic_in)
+        return;
+
     if (camera_type == 1) {
         memcpy(pic_in->img.plane[0], data, m_frameLen); // y
         for (int i = 0; i < m_frameLen/4; ++i) {
diff --git a/Live/src/main/cpp/VideoStream.h b/Live/src/main/cpp/VideoStream.h
index 00f8df3..80aad3d 100644
--- a/Live/src/main/cpp/VideoStream.h
+++ b/Live/src/main/cpp/VideoStream.h
@@ -17,7 +17,7 @@ public:
 
     void setVideoEncInfo(int width, int height, int fps, int bitrate);
 
-    void encodeVideo(int8_t *data, int8_t camera_type);
+    void encodeVideo(int8_t *data, int camera_type);
 
     void setVideoCallback(VideoCallback videoCallback);