feat: [DIOS-5853] Media server - Handle scte35 messages as unregister…

…ed SEI user data

include/MediaFrameListenerBridge.h

@@ -68,15 +68,14 @@ class MediaFrameListenerBridge :
 	virtual int SendPLI(DWORD ssrc) override { return 1; };
 	virtual int Reset(DWORD ssrc) override { return 1; };
 
-
 private:
 	void Dispatch(const std::vector<RTPPacket::shared>& packet);
 
 public:
 	TimeService& timeService;
 	Timer::shared dispatchTimer;
 
-	std::queue<PacketScheduleInfo> packets;
+	std::queue<PacketScheduleInfo> packets;	
 
 	DWORD ssrc = 0;
 	DWORD extSeqNum = 0;

include/tools.h

@@ -513,4 +513,5 @@ inline size_t CountBits(uint64_t val)
 	}
 	return count;
 }
+
 #endif

src/h264/H264Packetizer.cpp

@@ -3,10 +3,19 @@
 #include "video.h"
 #include "h264/h264.h"
 
-
 H264Packetizer::H264Packetizer() : H26xPacketizer(VideoCodec::H264)
 {
-
+	sei.clear();            // Flush any previous data
+	sei.push_back(0x06);	// SEI NAL
+	sei.push_back(0x05);	// User unregistered data
+	sei.push_back(0x00);    // Payload size
+
+	uint8_t uuid[16] = {
+		0x2b, 0x69, 0xba, 0x1b, 0x77, 0x7e, 0x46, 0x53,
+		0x99, 0x7a, 0xc6, 0x75, 0xb9, 0xd3, 0xac, 0xaf
+	};
+	sei.insert(sei.end(), uuid, uuid + sizeof(uuid));
+	scteMessageId = 0;
 }
 
 void H264Packetizer::EmitNal(VideoFrame& frame, BufferReader nal)
@@ -175,6 +184,22 @@ void H264Packetizer::OnNal(VideoFrame& frame, BufferReader& reader, std::optiona
 		frame.AllocateCodecConfig(config.GetSize());
 		config.Serialize(frame.GetCodecConfigData(), frame.GetCodecConfigSize());
 	}
+
+	if (scteMessage.GetSize() != 0)
+	{	
+		//Escape nal
+		uint8_t seiEscaped[sei.size()*2];
+		auto seiSize = NalEscapeRbsp(seiEscaped, sizeof(seiEscaped), sei.data(), sei.size()).value();
+		Debug("H264Packetizer::OnNal() | Emit SCTE data as SEI Unregistered User Data, Size %lu \n", seiSize);
+
+		EmitNal(frame, BufferReader(seiEscaped, seiSize));
+		if (repeatFrameCounter-- <= 0)
+		{
+			scteMessage.Reset();
+			repeatFrameCounter = scteFrameRepeatCount;
+		}
+
+	}
 
 	EmitNal(frame, BufferReader(nalUnit, nalSize));
 }
@@ -186,3 +211,35 @@ std::unique_ptr<MediaFrame> H264Packetizer::ProcessAU(BufferReader& reader)
 
 	return H26xPacketizer::ProcessAU(reader);
 }
+
+void H264Packetizer::AppendScteData(uint64_t ts, const Buffer& data, uint8_t repeatCount)
+{
+	scteMessage.AppendData(data.GetData(), data.GetSize());
+	scteFrameRepeatCount = repeatFrameCounter = repeatCount;
+	scteTimestamp = ts;
+
+	// Clear just the scte payload and retain the 2 byte code, size and 16 bytes UUID
+	sei.erase(sei.begin() + 2 + 1 + 16, sei.end());
+
+	// Binary format - SEI NAL (0x06) + Unregistered User data code (0x05) + UUID (16 bytes) + SCTE ID (2 bytes) + TS (8 bytes) + Base64 encoded scte payload (x bytes)
+
+
+	// Modify the payload size at pos 2 (zero indexed) 
+	// [0] 0x06 SEI NAL 
+	// [1] 0x05 Unregistered user data
+	// [2] Payload size
+	sei.at(2) = 16 + 2 + 8 + scteMessage.GetSize(); // UUID 16 bytes + SCTE ID (2 bytes) + TS (8 bytes) + Scte payload (x bytes)
+
+	// Insert 2 byte scte message ID
+	scteMessageId++;
+	sei.insert(sei.end(), (uint8_t*)&scteMessageId, (uint8_t*)&scteMessageId + sizeof(uint16_t));
+
+	// Insert 8 byte timestamp
+	sei.insert(sei.end(), (uint8_t*)&scteTimestamp, (uint8_t*)&scteTimestamp + sizeof(uint64_t));
+
+	// scte payload
+	sei.insert(sei.end(), scteMessage.GetData(), scteMessage.GetData() + scteMessage.GetSize());
+
+	// rbsp_trailing_bits
+	sei.push_back(0x80);
+}

src/h264/H264Packetizer.h

@@ -16,6 +16,8 @@ class H264Packetizer : public H26xPacketizer
 	H264Packetizer();
 	std::unique_ptr<MediaFrame> ProcessAU(BufferReader &reader) override;
 
+	void AppendScteData(uint64_t ts, const Buffer& data, uint8_t repeatCount);
+
 protected:
 	void OnNal(VideoFrame& frame, BufferReader& nal, std::optional<bool>& frameEnd) override;
 	void EmitNal(VideoFrame& frame, BufferReader nal);
@@ -24,6 +26,17 @@ class H264Packetizer : public H26xPacketizer
 	bool noSPSInFrame = true;
 
 	std::unique_ptr<H264SeqParameterSet> sps;
+
+	Buffer scteMessage;
+	uint64_t scteTimestamp;
+	// To account for potential packet loss, we repeat the SEI containing 
+	// scte tags for 20 frames to provide added resiliency.
+	// Also, we assume that another scte message cannot arrive within is interval
+	uint8_t scteFrameRepeatCount;
+	uint8_t repeatFrameCounter;
+	//Unregistered SEI message NAL
+	std::vector<uint8_t> sei;
+	uint16_t scteMessageId;
 };
 
 #endif // H264PACKETIZER_H