When a decoder requests an IDR frame, don't submit another frame until the IDR frame arrives

limelight-common/Limelight-internal.h

@@ -40,6 +40,7 @@ void destroyVideoDepacketizer(void);
 void processRtpPayload(PNV_VIDEO_PACKET videoPacket, int length);
 void queueRtpPacket(PRTP_PACKET rtpPacket, int length);
 void stopVideoDepacketizer(void);
+void requestDecoderRefresh(void);
 
 void initializeVideoStream(void);
 void destroyVideoStream(void);

limelight-common/VideoDepacketizer.c

@@ -225,8 +225,8 @@ static void reassembleAvcFrame(int frameNumber) {
                 freeQueuedDecodeUnit(qdu);
 
                 if (ret == DR_NEED_IDR) {
-                    Limelog("Request IDR frame on behalf of DR\n");
-                    requestIdrOnDemand();
+                    Limelog("Requesting IDR frame on behalf of DR\n");
+                    requestDecoderRefresh();
                 }
             }
 
@@ -330,6 +330,22 @@ static void processRtpPayloadSlow(PNV_VIDEO_PACKET videoPacket, PBUFFER_DESC cur
     }
 }
 
+// Dumps the decode unit queue and ensures the next frame submitted to the decoder will be
+// an IDR frame
+void requestDecoderRefresh(void) {
+    // Wait for the next IDR frame
+    waitingForIdrFrame = 1;
+    
+    // Flush the decode unit queue and pending state
+    dropAvcFrameState();
+    if ((VideoCallbacks.capabilities & CAPABILITY_DIRECT_SUBMIT) == 0) {
+        freeDecodeUnitList(LbqFlushQueueItems(&decodeUnitQueue));
+    }
+    
+    // Request the IDR frame
+    requestIdrOnDemand();
+}
+
 // Return 1 if packet is the first one in the frame
 static int isFirstPacket(char flags) {
     // Clear the picture data flag

limelight-common/VideoStream.c

@@ -136,7 +136,7 @@ static void DecoderThreadProc(void* context) {
 
         if (ret == DR_NEED_IDR) {
             Limelog("Requesting IDR frame on behalf of DR\n");
-            requestIdrOnDemand();
+            requestDecoderRefresh();
         }
     }
 }