DIOS-5950 Use weak_ptr to capture this pointer in SimulcastMediaFrame…

…Listener and do proper detach to avoid crash (#303)

include/SimulcastMediaFrameListener.h

@@ -15,7 +15,7 @@
 class SimulcastMediaFrameListener :
 	public MediaFrame::Listener,
 	public MediaFrame::Producer,
-	public std::enable_shared_from_this<MediaFrame::Listener>
+	public std::enable_shared_from_this<SimulcastMediaFrameListener>
 
 {
 public:

src/SimulcastMediaFrameListener.cpp

@@ -77,6 +77,7 @@ void SimulcastMediaFrameListener::Detach(const MediaFrame::Producer::shared& pro
 {
 	Debug("-SimulcastMediaFrameListener::Detach() [this:%p,producer:%p]\n", this, producer.get());
 	timeService.Sync([=](std::chrono::milliseconds) {
+		producer->RemoveMediaListener(shared_from_this());
 		producers.erase(producer);
 	});
 }
@@ -153,46 +154,50 @@ void SimulcastMediaFrameListener::ForwardFrame(VideoFrame& frame)
 
 void SimulcastMediaFrameListener::Push(std::shared_ptr<VideoFrame>&& frame)
 {
-	timeService.Async([this, frame = std::move(frame)](std::chrono::milliseconds) mutable {
+	timeService.Async([selfWeak = weak_from_this(), frame = std::move(frame)](std::chrono::milliseconds) mutable {
+
+		auto self = selfWeak.lock();
+		if (!self) return;
+
 		DWORD ssrc = frame->GetSSRC();
 
-		if (!referenceFrameTime)
+		if (!self->referenceFrameTime)
 		{
 			if (!frame->IsIntra()) return;
-			referenceFrameTime = frame->GetTime();
+			self->referenceFrameTime = frame->GetTime();
 		}
 
-		if (initialTimestamps.find(ssrc) == initialTimestamps.end())
+		if (self->initialTimestamps.find(ssrc) == self->initialTimestamps.end())
 		{
 			if (!frame->IsIntra()) return;
-			auto offset = (int64_t(frame->GetTime()) - int64_t(*referenceFrameTime)) * frame->GetClockRate() / 1000;
-			initialTimestamps[ssrc] = frame->GetTimeStamp() - offset;
+			auto offset = (int64_t(frame->GetTime()) - int64_t(*self->referenceFrameTime)) * frame->GetClockRate() / 1000;
+			self->initialTimestamps[ssrc] = frame->GetTimeStamp() - offset;
 		}
 
-		if (layerDimensions.find(ssrc) == layerDimensions.end())
+		if (self->layerDimensions.find(ssrc) == self->layerDimensions.end())
 		{
 			if (!frame->IsIntra()) return;
-			layerDimensions[ssrc] = frame->GetWidth() * frame->GetHeight();
+			self->layerDimensions[ssrc] = frame->GetWidth() * frame->GetHeight();
 		}
 
 		// Convert to relative timestamp
-		auto tm = frame->GetTimeStamp() > initialTimestamps[ssrc] ? frame->GetTimeStamp() - initialTimestamps[ssrc] : 0;
+		auto tm = frame->GetTimeStamp() > self->initialTimestamps[ssrc] ? frame->GetTimeStamp() - self->initialTimestamps[ssrc] : 0;
 		frame->SetTimestamp(tm);
 
 		// Update the layer latest timestamp
-		layerTimestamps[ssrc] = tm;
+		self->layerTimestamps[ssrc] = tm;
 
 		// Initially, select the first intra frame. Will later to update to higher
 		// quality one if exists
-		if (selectedSsrc == 0 && frame->IsIntra())
+		if (self->selectedSsrc == 0 && frame->IsIntra())
 		{
-			selectedSsrc = ssrc;
+			self->selectedSsrc = ssrc;
 		}
 
-		if (maxQueueSize == 0)
+		if (self->maxQueueSize == 0)
 		{
-			assert(numLayers == 1);
-			initialised = true;
+			assert(self->numLayers == 1);
+			self->initialised = true;
 		}
 
 		// Enqueue the selected layer frame.
@@ -202,38 +207,38 @@ void SimulcastMediaFrameListener::Push(std::shared_ptr<VideoFrame>&& frame)
 		// 2. The frame is at least later than the last forwarded frame.
 		// 3. The frame has higher dimension or it has been too long since the current
 		//    layer frame was queued.
-		if (ssrc == selectedSsrc)
+		if (ssrc == self->selectedSsrc)
 		{
-			Enqueue(std::move(frame));
+			self->Enqueue(std::move(frame));
 		}
-		else if (frame->IsIntra() && (!lastForwardedTimestamp || frame->GetTimeStamp() > *lastForwardedTimestamp))
+		else if (frame->IsIntra() && (!self->lastForwardedTimestamp || frame->GetTimeStamp() > *self->lastForwardedTimestamp))
 		{
-			if (layerDimensions[ssrc] > layerDimensions[selectedSsrc] ||
-				frame->GetTime() > (lastEnqueueTimeMs + MaxWaitingTimeBeforeSwitchingLayerMs))
+			if (self->layerDimensions[ssrc] > self->layerDimensions[self->selectedSsrc] ||
+				frame->GetTime() > (self->lastEnqueueTimeMs + MaxWaitingTimeBeforeSwitchingLayerMs))
 			{
 				//UltraDebug("layer switch: 0x%x -> 0x%x, time: %lld, timestamp: %lld\n", ssrc, selectedSsrc, frame->GetTime(), tm);
 
-				selectedSsrc = ssrc;
-				Enqueue(std::move(frame));
+				self->selectedSsrc = ssrc;
+				self->Enqueue(std::move(frame));
 			}
 		}
 
 		// Select the best available frame in the queue during initialising
-		if (!initialised && (queue.size() == maxQueueSize || layerDimensions.size() == numLayers))
+		if (!self->initialised && (self->queue.size() == self->maxQueueSize || self->layerDimensions.size() == self->numLayers))
 		{
-			assert(maxQueueSize > 0);
-			auto bestLayerFrame = std::max_element(queue.begin(), queue.end(),
-				[this](const auto& elementA, const auto& elementB) {
-					return layerDimensions[elementA->GetSSRC()] < layerDimensions[elementB->GetSSRC()];
+			assert(self->maxQueueSize > 0);
+			auto bestLayerFrame = std::max_element(self->queue.begin(), self->queue.end(),
+				[self](const auto& elementA, const auto& elementB) {
+					return self->layerDimensions[elementA->GetSSRC()] < self->layerDimensions[elementB->GetSSRC()];
 				});
 
-			selectedSsrc = (*bestLayerFrame)->GetSSRC();
-			while(!queue.empty() && queue.front()->GetSSRC() != selectedSsrc)
+			self->selectedSsrc = (*bestLayerFrame)->GetSSRC();
+			while(!self->queue.empty() && self->queue.front()->GetSSRC() != self->selectedSsrc)
 			{
-				queue.pop_front();
+				self->queue.pop_front();
 			}
 
-			initialised = true;
+			self->initialised = true;
 		}
 	});
 }