diff --git a/src/virtual-source/virtual-audio.cpp b/src/virtual-source/virtual-audio.cpp
index afd92e7..056487c 100644
--- a/src/virtual-source/virtual-audio.cpp
+++ b/src/virtual-source/virtual-audio.cpp
@@ -94,10 +94,10 @@ HRESULT CVAudioStream::FillBuffer(IMediaSample *pms)
 
 	hr = pms->GetPointer((BYTE**)&dst);
 
-	current_time = get_current_time();
-
-	if (prev_end_ts <= 0)
-		prev_end_ts = current_time;
+	if (system_start_time <= 0)
+		system_start_time = get_current_time();
+	else
+		current_time = get_current_time() - system_start_time;
 
 	if (!queue.hwnd)
 		shared_queue_open(&queue, ModeAudio);
@@ -105,6 +105,9 @@ HRESULT CVAudioStream::FillBuffer(IMediaSample *pms)
 	if (sync_timeout <= 0) {
 		SetTimeout();
 	}
+	else if (prev_end_ts >current_time) {
+		sleepto(prev_end_ts);
+	}
 	else if (current_time - prev_end_ts > sync_timeout) {
 		if (queue.header)
 			share_queue_init_index(&queue);
@@ -112,8 +115,6 @@ HRESULT CVAudioStream::FillBuffer(IMediaSample *pms)
 			prev_end_ts = current_time;
 	}
 
-	sleepto(prev_end_ts);
-
 	while (queue.header && !get_sample){
 
 		if (get_times > 20 || queue.header->state != OutputReady)
@@ -127,7 +128,6 @@ HRESULT CVAudioStream::FillBuffer(IMediaSample *pms)
 		}
 	}
 
-
 	if (get_sample && !obs_start_ts){
 		obs_start_ts = timestamp;
 		dshow_start_ts = prev_end_ts;
@@ -253,6 +253,7 @@ HRESULT CVAudioStream::OnThreadCreate()
 	obs_start_ts = 0;
 	dshow_start_ts = 0;
 	prev_end_ts = 0;
+	system_start_time = 0;
 	return NOERROR;
 } 
 
diff --git a/src/virtual-source/virtual-audio.h b/src/virtual-source/virtual-audio.h
index c27d960..8518cd2 100644
--- a/src/virtual-source/virtual-audio.h
+++ b/src/virtual-source/virtual-audio.h
@@ -107,6 +107,7 @@ class CVAudioStream : public CSourceStream, public IAMStreamConfig,
 	uint64_t obs_start_ts = 0;
 	uint64_t dshow_start_ts = 0;
 	uint64_t sync_timeout = 0;
+	uint64_t system_start_time = 0;
 	REFERENCE_TIME  prev_end_ts = 0;
 	ALLOCATOR_PROPERTIES alloc_prop;
 
diff --git a/src/virtual-source/virtual-cam.cpp b/src/virtual-source/virtual-cam.cpp
index c0f7a44..2fcc351 100644
--- a/src/virtual-source/virtual-cam.cpp
+++ b/src/virtual-source/virtual-cam.cpp
@@ -150,10 +150,11 @@ HRESULT CVCamStream::FillBuffer(IMediaSample *pms)
 
 	hr = pms->GetPointer((BYTE**)&dst);
 
-	current_time = get_current_time();
-
-	if (prev_end_ts <= 0)
-		prev_end_ts = current_time;
+	if (system_start_time <= 0) 
+		system_start_time = get_current_time();
+	else 
+		current_time = get_current_time() - system_start_time;
+	
 
 	if (!queue.hwnd) {
 		if (shared_queue_open(&queue, queue_mode)) {
@@ -167,6 +168,9 @@ HRESULT CVCamStream::FillBuffer(IMediaSample *pms)
 	if (sync_timeout <= 0) {
 		SetTimeout();
 	}
+	else if (prev_end_ts >current_time) {
+		sleepto(prev_end_ts);
+	}
 	else if (current_time - prev_end_ts > sync_timeout) {
 		if(queue.header) 
 			share_queue_init_index(&queue);
@@ -198,7 +202,6 @@ HRESULT CVCamStream::FillBuffer(IMediaSample *pms)
 		duration = time_perframe;
 	} else {
 		int size = pms->GetActualDataLength();
-		sleepto(prev_end_ts);
 		memset(dst, 127, size);
 		start_time = prev_end_ts;
 		duration = ((VIDEOINFOHEADER*)m_mt.pbFormat)->AvgTimePerFrame;
@@ -349,6 +352,7 @@ HRESULT CVCamStream::OnThreadCreate()
 	prev_end_ts = 0;
 	obs_start_ts = 0;
 	dshow_start_ts = 0;
+	system_start_time = 0;
 	return NOERROR;
 }
 
diff --git a/src/virtual-source/virtual-cam.h b/src/virtual-source/virtual-cam.h
index a30e5ba..e683c42 100644
--- a/src/virtual-source/virtual-cam.h
+++ b/src/virtual-source/virtual-cam.h
@@ -125,6 +125,7 @@ class CVCamStream : public CSourceStream, public IAMStreamConfig, public IKsProp
 	uint64_t obs_start_ts = 0;
 	uint64_t dshow_start_ts = 0;
 	uint64_t time_perframe = 0;
+	uint64_t system_start_time = 0;
 	uint64_t sync_timeout = 0;
 	REFERENCE_TIME  prev_end_ts = 0;