Add HDR mode APIs

src/ControlStream.c

@@ -49,6 +49,7 @@ static int lastSeenFrame;
 static bool stopping;
 static bool disconnectPending;
 static bool encryptedControlStream;
+static bool hdrEnabled;
 
 static int intervalGoodFrameCount;
 static int intervalTotalFrameCount;
@@ -76,6 +77,7 @@ static PPLT_CRYPTO_CONTEXT decryptionCtx;
 #define IDX_INPUT_DATA 5
 #define IDX_RUMBLE_DATA 6
 #define IDX_TERMINATION 7
+#define IDX_HDR_INFO 8
 
 #define CONTROL_STREAM_TIMEOUT_SEC 10
 #define CONTROL_STREAM_LINGER_TIMEOUT_SEC 2
@@ -89,6 +91,7 @@ static const short packetTypesGen3[] = {
     -1,     // Input data (unused)
     -1,     // Rumble data (unused)
     -1,     // Termination (unused)
+    -1,     // HDR mode (unused)
 };
 static const short packetTypesGen4[] = {
     0x0606, // Request IDR frame
@@ -99,6 +102,7 @@ static const short packetTypesGen4[] = {
     -1,     // Input data (unused)
     -1,     // Rumble data (unused)
     -1,     // Termination (unused)
+    -1,     // HDR mode (unused)
 };
 static const short packetTypesGen5[] = {
     0x0305, // Start A
@@ -109,6 +113,7 @@ static const short packetTypesGen5[] = {
     0x0207, // Input data
     -1,     // Rumble data (unused)
     -1,     // Termination (unused)
+    -1,     // HDR mode (unknown)
 };
 static const short packetTypesGen7[] = {
     0x0305, // Start A
@@ -119,6 +124,7 @@ static const short packetTypesGen7[] = {
     0x0206, // Input data
     0x010b, // Rumble data
     0x0100, // Termination
+    0x010e, // HDR mode
 };
 static const short packetTypesGen7Enc[] = {
     0x0302, // Request IDR frame
@@ -129,6 +135,7 @@ static const short packetTypesGen7Enc[] = {
     0x0206, // Input data
     0x010b, // Rumble data
     0x0109, // Termination (extended)
+    0x010e, // HDR mode
 };
 
 static const char requestIdrFrameGen3[] = { 0, 0 };
@@ -267,6 +274,7 @@ int initializeControlStream(void) {
     usePeriodicPing = APP_VERSION_AT_LEAST(7, 1, 415);
     encryptionCtx = PltCreateCryptoContext();
     decryptionCtx = PltCreateCryptoContext();
+    hdrEnabled = false;
 
     return 0;
 }
@@ -799,6 +807,19 @@ static void controlReceiveThreadFunc(void* context) {
 
                 ListenerCallbacks.rumble(controllerNumber, lowFreqRumble, highFreqRumble);
             }
+            else if (ctlHdr->type == packetTypes[IDX_HDR_INFO]) {
+                BYTE_BUFFER bb;
+                uint8_t enableByte;
+
+                BbInitializeWrappedBuffer(&bb, (char*)ctlHdr, sizeof(*ctlHdr), packetLength - sizeof(*ctlHdr), BYTE_ORDER_LITTLE);
+
+                // FIXME: There are 7 additional bytes that appear to always be all zeros. What do they mean?
+                // Is there some way that GFE tells us the HDR mastering metadata (NV_HDR_COLOR_DATA) set by the game?
+                BbGet8(&bb, &enableByte);
+
+                hdrEnabled = (enableByte != 0);
+                ListenerCallbacks.setHdrMode(hdrEnabled);
+            }
             else if (ctlHdr->type == packetTypes[IDX_TERMINATION]) {
                 BYTE_BUFFER bb;
 
@@ -1396,3 +1417,7 @@ int startControlStream(void) {
 
     return 0;
 }
+
+bool LiGetCurrentHostDisplayHdrMode(void) {
+    return hdrEnabled;
+}

src/FakeCallbacks.c

@@ -36,6 +36,7 @@ static void fakeClConnectionTerminated(int errorCode) {}
 static void fakeClLogMessage(const char* format, ...) {}
 static void fakeClRumble(unsigned short controllerNumber, unsigned short lowFreqMotor, unsigned short highFreqMotor) {}
 static void fakeClConnectionStatusUpdate(int connectionStatus) {}
+static void fakeClSetHdrMode(bool enabled) {}
 
 static CONNECTION_LISTENER_CALLBACKS fakeClCallbacks = {
     .stageStarting = fakeClStageStarting,
@@ -45,7 +46,8 @@ static CONNECTION_LISTENER_CALLBACKS fakeClCallbacks = {
     .connectionTerminated = fakeClConnectionTerminated,
     .logMessage = fakeClLogMessage,
     .rumble = fakeClRumble,
-    .connectionStatusUpdate = fakeClConnectionStatusUpdate
+    .connectionStatusUpdate = fakeClConnectionStatusUpdate,
+    .setHdrMode = fakeClSetHdrMode,
 };
 
 void fixupMissingCallbacks(PDECODER_RENDERER_CALLBACKS* drCallbacks, PAUDIO_RENDERER_CALLBACKS* arCallbacks,
@@ -121,5 +123,8 @@ void fixupMissingCallbacks(PDECODER_RENDERER_CALLBACKS* drCallbacks, PAUDIO_REND
         if ((*clCallbacks)->connectionStatusUpdate == NULL) {
             (*clCallbacks)->connectionStatusUpdate = fakeClConnectionStatusUpdate;
         }
+        if ((*clCallbacks)->setHdrMode == NULL) {
+            (*clCallbacks)->setHdrMode = fakeClSetHdrMode;
+        }
     }
 }

src/Limelight.h

@@ -421,6 +421,12 @@ typedef void(*ConnListenerRumble)(unsigned short controllerNumber, unsigned shor
 #define CONN_STATUS_POOR    1
 typedef void(*ConnListenerConnectionStatusUpdate)(int connectionStatus);
 
+// This callback is invoked to notify the client of a change in HDR mode on
+// the host. The client will probably want to update the local display mode
+// to match the state of HDR on the host. This callback may be invoked even
+// if enableHdr is false in the stream configuration.
+typedef void(*ConnListenerSetHdrMode)(bool hdrEnabled);
+
 typedef struct _CONNECTION_LISTENER_CALLBACKS {
     ConnListenerStageStarting stageStarting;
     ConnListenerStageComplete stageComplete;
@@ -430,6 +436,7 @@ typedef struct _CONNECTION_LISTENER_CALLBACKS {
     ConnListenerLogMessage logMessage;
     ConnListenerRumble rumble;
     ConnListenerConnectionStatusUpdate connectionStatusUpdate;
+    ConnListenerSetHdrMode setHdrMode;
 } CONNECTION_LISTENER_CALLBACKS, *PCONNECTION_LISTENER_CALLBACKS;
 
 // Use this function to zero the connection callbacks when allocated on the stack or heap
@@ -654,6 +661,10 @@ bool LiPeekNextVideoFrame(PDECODE_UNIT* decodeUnit);
 void LiWakeWaitForVideoFrame(void);
 void LiCompleteVideoFrame(VIDEO_FRAME_HANDLE handle, int drStatus);
 
+// This function returns the last reported HDR mode from the host PC.
+// See ConnListenerSetHdrMode() for more details.
+bool LiGetCurrentHostDisplayHdrMode(void);
+
 #ifdef __cplusplus
 }
 #endif