JitterBuffer.h

//
// libtgvoip is free and unencumbered public domain software.
// For more information, see http://unlicense.org or the UNLICENSE file
// you should have received with this source code distribution.
//

#ifndef LIBTGVOIP_JITTERBUFFER_H
#define LIBTGVOIP_JITTERBUFFER_H

#include <stdlib.h>
#include <vector>
#include <stdio.h>
#include "MediaStreamItf.h"
#include "BlockingQueue.h"
#include "Buffers.h"
#include "threading.h"

#define JITTER_SLOT_COUNT 64
#define JITTER_SLOT_SIZE 1024
#define JR_OK 1
#define JR_MISSING 2
#define JR_BUFFERING 3


namespace tgvoip{
class JitterBuffer{
public:
	JitterBuffer(MediaStreamItf* out, uint32_t step);
	~JitterBuffer();
	void SetMinPacketCount(uint32_t count);
	int GetMinPacketCount();
	unsigned int GetCurrentDelay();
	double GetAverageDelay();
	void Reset();
	void HandleInput(unsigned char* data, size_t len, uint32_t timestamp, bool isEC);
	size_t HandleOutput(unsigned char* buffer, size_t len, int offsetInSteps, bool advance, int& playbackScaledDuration, bool& isEC);
	void Tick();
	void GetAverageLateCount(double* out);
	int GetAndResetLostPacketCount();
	double GetLastMeasuredJitter();
	double GetLastMeasuredDelay();

private:
	struct jitter_packet_t{
		unsigned char* buffer = nullptr;
		size_t size = 0;
		uint32_t timestamp = 0;
		bool isEC = false;
		double recvTimeDiff = 0.;
	};
	static size_t CallbackIn(unsigned char* data, size_t len, void* param);
	static size_t CallbackOut(unsigned char* data, size_t len, void* param);
	void PutInternal(jitter_packet_t* pkt, bool overwriteExisting);
	int GetInternal(jitter_packet_t* pkt, int offset, bool advance);
	void Advance();

	BufferPool bufferPool;
	Mutex mutex;
	jitter_packet_t slots[JITTER_SLOT_COUNT];
	int64_t nextTimestamp=0;
	uint32_t step;
	double minDelay=6;
	uint32_t minMinDelay;
	uint32_t maxMinDelay;
	uint32_t maxUsedSlots;
	uint32_t lastPutTimestamp;
	uint32_t lossesToReset;
	double resyncThreshold;
	unsigned int lostCount=0;
	unsigned int lostSinceReset=0;
	unsigned int gotSinceReset=0;
	bool wasReset=true;
	bool needBuffering=true;
	HistoricBuffer<int, 64, double> delayHistory;
	HistoricBuffer<int, 64, double> lateHistory;
	bool adjustingDelay=false;
	unsigned int tickCount=0;
	unsigned int latePacketCount=0;
	unsigned int dontIncMinDelay=0;
	unsigned int dontDecMinDelay=0;
	int lostPackets=0;
	double prevRecvTime=0;
	double expectNextAtTime=0;
	HistoricBuffer<double, 64> deviationHistory;
	double lastMeasuredJitter=0;
	double lastMeasuredDelay=0;
	int outstandingDelayChange=0;
	unsigned int dontChangeDelay=0;
	double avgDelay=0;
	bool first=true;
#ifdef TGVOIP_DUMP_JITTER_STATS
	FILE* dump;
#endif
};
}

#endif //LIBTGVOIP_JITTERBUFFER_H