Fix signature of notifyFrameLost() and add additional assert

src/Limelight-internal.h

@@ -98,7 +98,7 @@ void destroyVideoDepacketizer(void);
 void queueRtpPacket(PRTPV_QUEUE_ENTRY queueEntry);
 void stopVideoDepacketizer(void);
 void requestDecoderRefresh(void);
-void notifyFrameLost(int frameNumber);
+void notifyFrameLost(unsigned int frameNumber);
 
 void initializeVideoStream(void);
 void destroyVideoStream(void);

src/VideoDepacketizer.c

@@ -893,10 +893,13 @@ static void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length,
 // if it determines the frame to be unrecoverable. This lets us
 // avoid having to wait until the next received frame to determine
 // that we lost a frame and submit an RFI request.
-void notifyFrameLost(int frameNumber) {
+void notifyFrameLost(unsigned int frameNumber) {
     // This may only be called at frame boundaries
     LC_ASSERT(!decodingFrame);
 
+    // We may not invalidate frames that we've already received
+    LC_ASSERT(frameNumber >= startFrameNumber);
+
     // If RFI is enabled, we will notify the host PC now
     if (isReferenceFrameInvalidationEnabled()) {
         Limelog("Sending predictive RFI request for probable loss of frame %d\n", frameNumber);