Add support for HDR streaming

src/Limelight.h

@@ -37,6 +37,14 @@ typedef struct _STREAM_CONFIGURATION {
     // if the server is able to provide one.
     int supportsHevc;
 
+    // Specifies that the client is requesting an HDR H.265 video stream.
+    //
+    // This should only be set if:
+    // 1) The client decoder supports HEVC Main10 profile (supportsHevc must be set too)
+    // 2) The server has support for HDR as indicated by ServerCodecModeSupport in /serverinfo
+    // 3) The app supports HDR as indicated by IsHdrSupported in /applist
+    int enableHdr;
+
     // Specifies the percentage that the specified bitrate will be adjusted
     // when an HEVC stream will be delivered. This allows clients to opt to
     // reduce bandwidth when HEVC is chosen as the video codec rather than

src/RtspConnection.c

@@ -538,8 +538,8 @@ int performRtspHandshake(void) {
         if (StreamConfig.supportsHevc && strstr(response.payload, "sprop-parameter-sets=AAAAAU")) {
             NegotiatedVideoFormat = VIDEO_FORMAT_H265;
 
-            // Apply bitrate adjustment for HEVC if the client requested one
+            // Apply bitrate adjustment for SDR HEVC if the client requested one
-            if (StreamConfig.hevcBitratePercentageMultiplier != 0) {
+            if (StreamConfig.hevcBitratePercentageMultiplier != 0 && !StreamConfig.enableHdr) {
                 StreamConfig.bitrate *= StreamConfig.hevcBitratePercentageMultiplier;
                 StreamConfig.bitrate /= 100;
             }

src/SdpGenerator.c

@@ -283,6 +283,16 @@ static PSDP_OPTION getAttributesList(char*urlSafeAddr) {
             
             // Disable slicing on HEVC
             err |= addAttributeString(&optionHead, "x-nv-video[0].videoEncoderSlicesPerFrame", "1");
+
+            if (AppVersionQuad[0] >= 5) {
+                // Enable HDR if requested
+                if (StreamConfig.enableHdr) {
+                    err |= addAttributeString(&optionHead, "x-nv-video[0].dynamicRangeMode", "1");
+                }
+                else {
+                    err |= addAttributeString(&optionHead, "x-nv-video[0].dynamicRangeMode", "0");
+                }
+            }
         }
         else {
             unsigned char slicesPerFrame;
@@ -290,6 +300,16 @@ static PSDP_OPTION getAttributesList(char*urlSafeAddr) {
             err |= addAttributeString(&optionHead, "x-nv-clientSupportHevc", "0");
             err |= addAttributeString(&optionHead, "x-nv-vqos[0].bitStreamFormat", "0");
 
+            if (AppVersionQuad[0] >= 5) {
+                // HDR is not supported on H.264
+                err |= addAttributeString(&optionHead, "x-nv-video[0].dynamicRangeMode", "0");
+            }
+
+            // We shouldn't be able to reach this path with enableHdr set. If we did, that means
+            // the server or client doesn't support HEVC and the client didn't do the correct checks
+            // before requesting HDR streaming.
+            LC_ASSERT(!StreamConfig.enableHdr);
+
             // Use slicing for increased performance on some decoders
             slicesPerFrame = (unsigned char)(VideoCallbacks.capabilities >> 24);
             if (slicesPerFrame == 0) {