Limit the number of queued frames in Pacer to prevent excessive memory consumption if the renderer gets blocked for a while

app/streaming/video/ffmpeg-renderers/pacer/pacer.h

@@ -31,6 +31,8 @@ private:
 
     void renderFrame(AVFrame* frame);
 
+    void dropFrameForEnqueue(QQueue<AVFrame*>& queue);
+
     QQueue<AVFrame*> m_RenderQueue;
     QQueue<AVFrame*> m_PacingQueue;
     QQueue<int> m_PacingQueueHistory;