libdatachannel/include/rtc/rtcpreceivingsession.hpp

/**
 * Copyright (c) 2020 Staz Modrzynski
 * Copyright (c) 2020 Paul-Louis Ageneau
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */

#ifndef RTC_RTCP_RECEIVING_SESSION_H
#define RTC_RTCP_RECEIVING_SESSION_H

#if RTC_ENABLE_MEDIA

#include "common.hpp"
#include "mediahandler.hpp"
#include "message.hpp"
#include "rtp.hpp"

#include <atomic>

#define RTP_SEQ_MOD (1<<16)

namespace rtc {

// An RtcpSession can be plugged into a Track to handle the whole RTCP session
class RTC_CPP_EXPORT RtcpReceivingSession : public MediaHandler {
public:
	RtcpReceivingSession() = default;
	virtual ~RtcpReceivingSession() = default;

	void incoming(message_vector &messages, const message_callback &send) override;
	bool requestKeyframe(const message_callback &send) override;
	bool requestBitrate(unsigned int bitrate, const message_callback &send) override;

	// For backward compatibility
	[[deprecated("Use Track::requestKeyframe()")]] inline bool requestKeyframe() { return false; };
	[[deprecated("Use Track::requestBitrate()")]] inline void requestBitrate(unsigned int) {};

protected:
	void pushREMB(const message_callback &send, unsigned int bitrate);
	void pushRR(const message_callback &send,unsigned int lastSrDelay);
	void pushPLI(const message_callback &send);

	void initSeq(uint16_t seq);
	bool updateSeq(uint16_t seq);
	
	SSRC mSsrc = 0;
	uint32_t mGreatestSeqNo = 0;
    uint16_t mMaxSeq = 0;			// highest seq. number seen
    uint32_t mCycles = 0;			// shifted count of seq. number cycles
	uint32_t mBaseSeq = 0;			// base seq number
    uint32_t mBadSeq = 0;			// last 'bad' seq number + 1
	uint32_t mProbation = 0;		// sequ. packets till source is valid
    uint32_t mReceived = 0;			// packets received
    uint32_t mExpectedPrior = 0;	// packet expected at last interval
    uint32_t mReceivedPrior = 0;	// packet received at last interval
	uint32_t mTransit = 0;			// relative trans time for prev pkt
	uint32_t mJitter = 0;	
	
	uint64_t mSyncRTPTS, mSyncNTPTS;

	std::atomic<unsigned int> mRequestedBitrate = 0;
};

} // namespace rtc

#endif // RTC_ENABLE_MEDIA

#endif // RTC_RTCP_RECEIVING_SESSION_H