Disable RFI when streaming from a server that doesn't support it

src/Connection.c

@@ -24,6 +24,7 @@ OPUS_MULTISTREAM_CONFIGURATION HighQualityOpusConfig;
 int OriginalVideoBitrate;
 int AudioPacketDuration;
 bool AudioEncryptionEnabled;
+bool ReferenceFrameInvalidationSupported;
 uint16_t RtspPortNumber;
 uint16_t ControlPortNumber;
 uint16_t AudioPortNumber;

src/Limelight-internal.h

@@ -31,6 +31,7 @@ extern OPUS_MULTISTREAM_CONFIGURATION HighQualityOpusConfig;
 extern int OriginalVideoBitrate;
 extern int AudioPacketDuration;
 extern bool AudioEncryptionEnabled;
+extern bool ReferenceFrameInvalidationSupported;
 
 extern uint16_t RtspPortNumber;
 extern uint16_t ControlPortNumber;

src/Misc.c

@@ -121,6 +121,12 @@ void* extendBuffer(void* ptr, size_t newSize) {
 
 bool isReferenceFrameInvalidationEnabled(void) {
     LC_ASSERT(NegotiatedVideoFormat != 0);
+
+    // Even if the client wants it, we can't enable it without server support.
+    if (!ReferenceFrameInvalidationSupported) {
+        return false;
+    }
+
     return ((NegotiatedVideoFormat & VIDEO_FORMAT_MASK_H264) && (VideoCallbacks.capabilities & CAPABILITY_REFERENCE_FRAME_INVALIDATION_AVC)) ||
            ((NegotiatedVideoFormat & VIDEO_FORMAT_MASK_H265) && (VideoCallbacks.capabilities & CAPABILITY_REFERENCE_FRAME_INVALIDATION_HEVC));
 }

src/RtspConnection.c

@@ -806,6 +806,12 @@ int performRtspHandshake(void) {
             }
         }
 
+        // Look for the SDP attribute that indicates we're dealing with a server that supports RFI
+        ReferenceFrameInvalidationSupported = strstr(response.payload, "x-nv-video[0].refPicInvalidation") != NULL;
+        if (!ReferenceFrameInvalidationSupported) {
+            Limelog("Reference frame invalidation is not supported by this host\n");
+        }
+
         // Parse the Opus surround parameters out of the RTSP DESCRIBE response.
         ret = parseOpusConfigurations(&response);
         if (ret != 0) {