diff --git a/trunk/conf/srs.conf b/trunk/conf/srs.conf
index 6d2c91400..8d3276674 100755
--- a/trunk/conf/srs.conf
+++ b/trunk/conf/srs.conf
@@ -72,18 +72,19 @@ vhost __defaultVhost__ {
 vhost dev {
     enabled         on;
     gop_cache       on;
-    hls             on;
+    hls             off;
     hls_path        ./objs/nginx/html;
     hls_fragment    5;
     hls_window      30;
     #forward         127.0.0.1:19350;
-    forward         127.0.0.1:1936;
+    #forward         127.0.0.1:1936;
     transcode {
-        enabled     off;
+        enabled     on;
         ffmpeg      ./objs/ffmpeg/bin/ffmpeg;
         engine dev {
             enabled         on;
             vfilter {
+                t   10;
             }
             vcodec          libx264;
             vbitrate        300;
diff --git a/trunk/src/core/srs_core_encoder.cpp b/trunk/src/core/srs_core_encoder.cpp
index c42763e5e..97aac00d1 100644
--- a/trunk/src/core/srs_core_encoder.cpp
+++ b/trunk/src/core/srs_core_encoder.cpp
@@ -25,6 +25,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #include <stdlib.h>
 #include <unistd.h>
+#include <sys/wait.h>
 
 #include <algorithm>
 
@@ -356,6 +357,34 @@ int SrsFFMPEG::start()
 	return ret;
 }
 
+int SrsFFMPEG::cycle()
+{
+	int ret = ERROR_SUCCESS;
+	
+	if (!started) {
+		return ret;
+	}
+	
+	int status = 0;
+	pid_t p = waitpid(pid, &status, WNOHANG);
+	
+	if (p < 0) {
+		ret = ERROR_SYSTEM_WAITPID;
+		srs_error("transcode waitpid failed, pid=%d, ret=%d", pid, ret);
+		return ret;
+	}
+	
+	if (p == 0) {
+		srs_info("transcode process pid=%d is running.", pid);
+		return ret;
+	}
+	
+	srs_trace("transcode process pid=%d terminate, restart it.", pid);
+	started = false;
+	
+	return ret;
+}
+
 void SrsFFMPEG::stop()
 {
 	if (!started) {
@@ -538,18 +567,23 @@ int SrsEncoder::cycle()
 {
 	int ret = ERROR_SUCCESS;
 	
-	// start all ffmpegs.
 	std::vector<SrsFFMPEG*>::iterator it;
 	for (it = ffmpegs.begin(); it != ffmpegs.end(); ++it) {
 		SrsFFMPEG* ffmpeg = *it;
+		
+		// start all ffmpegs.
 		if ((ret = ffmpeg->start()) != ERROR_SUCCESS) {
 			srs_error("ffmpeg start failed. ret=%d", ret);
 			return ret;
 		}
+
+		// check ffmpeg status.
+		if ((ret = ffmpeg->cycle()) != ERROR_SUCCESS) {
+			srs_error("ffmpeg cycle failed. ret=%d", ret);
+			return ret;
+		}
 	}
 	
-	// TODO: cycle all processes.
-	
 	return ret;
 }
 
diff --git a/trunk/src/core/srs_core_encoder.hpp b/trunk/src/core/srs_core_encoder.hpp
index 5a8ad9eb2..73c345ae1 100644
--- a/trunk/src/core/srs_core_encoder.hpp
+++ b/trunk/src/core/srs_core_encoder.hpp
@@ -73,6 +73,7 @@ public:
 public:
 	virtual int initialize(SrsRequest* req, SrsConfDirective* engine);
 	virtual int start();
+	virtual int cycle();
 	virtual void stop();
 };
 
diff --git a/trunk/src/core/srs_core_error.hpp b/trunk/src/core/srs_core_error.hpp
index eea5f56ad..ddfeb053a 100644
--- a/trunk/src/core/srs_core_error.hpp
+++ b/trunk/src/core/srs_core_error.hpp
@@ -86,6 +86,7 @@ CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define ERROR_SYSTEM_IP_INVALID			411
 #define ERROR_SYSTEM_CONFIG_TOO_LARGE	412
 #define ERROR_SYSTEM_FORWARD_LOOP		413
+#define ERROR_SYSTEM_WAITPID			414
 
 // see librtmp.
 // failed when open ssl create the dh
diff --git a/trunk/src/core/srs_core_hls.cpp b/trunk/src/core/srs_core_hls.cpp
index 1cca34985..6f0f3ec12 100644
--- a/trunk/src/core/srs_core_hls.cpp
+++ b/trunk/src/core/srs_core_hls.cpp
@@ -502,6 +502,7 @@ SrsM3u8Muxer::SrsM3u8Muxer()
 	video_stream_dts = 0;
 	file_index = 0;
 	current = NULL;
+	_is_open = false;
 }
 
 SrsM3u8Muxer::~SrsM3u8Muxer()
@@ -516,6 +517,11 @@ SrsM3u8Muxer::~SrsM3u8Muxer()
 	srs_freep(current);
 }
 
+bool SrsM3u8Muxer::is_open()
+{
+	return _is_open;
+}
+
 int SrsM3u8Muxer::update_config(
 	std::string _app, std::string _stream, 
 	std::string path, int fragment, int window
@@ -571,6 +577,8 @@ int SrsM3u8Muxer::segment_open()
 	srs_info("open HLS muxer success. vhost=%s, path=%s", 
 		vhost.c_str(), current->full_path.c_str());
 	
+	_is_open = true;
+	
 	return ret;
 }
 
@@ -709,6 +717,8 @@ int SrsM3u8Muxer::segment_close()
 		return ret;
 	}
 	
+	_is_open = false;
+	
 	return ret;
 }
 
@@ -1171,12 +1181,14 @@ void SrsHls::on_unpublish()
 {
 	int ret = ERROR_SUCCESS;
 	
-	// close muxer when unpublish.
-	ret = ts_cache->flush_audio(muxer);
-	ret += muxer->segment_close();
-	if (ret != ERROR_SUCCESS) {
-		srs_error("ignore m3u8 muxer flush/close audio failed. ret=%d", ret);
-		return;
+	if (muxer->is_open()) {
+		// close muxer when unpublish.
+		ret = ts_cache->flush_audio(muxer);
+		ret += muxer->segment_close();
+
+		if (ret != ERROR_SUCCESS) {
+			srs_error("ignore m3u8 muxer flush/close audio failed. ret=%d", ret);
+		}
 	}
 	
 	hls_enabled = false;
diff --git a/trunk/src/core/srs_core_hls.hpp b/trunk/src/core/srs_core_hls.hpp
index 0a8aa79d6..8b326ac7d 100644
--- a/trunk/src/core/srs_core_hls.hpp
+++ b/trunk/src/core/srs_core_hls.hpp
@@ -131,6 +131,7 @@ private:
 	int hls_fragment;
 	int hls_window;
 private:
+	bool _is_open;
 	int file_index;
 	std::string m3u8;
 private:
@@ -148,6 +149,7 @@ public:
 	SrsM3u8Muxer();
 	virtual ~SrsM3u8Muxer();
 public:
+	virtual bool is_open();
 	virtual int update_config(std::string _app, std::string _stream, std::string path, int fragment, int window);
 	virtual int segment_open();
 	virtual int flush_audio(SrsMpegtsFrame* af, SrsCodecBuffer* ab);