ghy
Alejandro Acuña
2025-03-12 26319e4c5bfbee722c15b8e7ccca9b6127bb1cb8
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// RTPAudioStream.cpp: implementation of the RTPAudioStream class.
//
//////////////////////////////////////////////////////////////////////
 
#include "RTPAudioStream.h"
#include "Parameters.h"
#include "AudioSample.h"
#include "AudioSampleManager.h"
#include "RTPPacket.h"
 
#define STATS_INTERVAL 100
int avgBufferSize(0);
int minBufferSize(0);
int numRepeats(0);
int numPackets(0);
 
using namespace std;
 
//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
 
RTPAudioStream::RTPAudioStream(unsigned long ssrc)
{
    char subFacilityName[100];
    sprintf(subFacilityName, "RTPAudioStream:%x", this);
    tracer.SetSubFacilityName(subFacilityName);
    SetTraceLevel();
    dynamicJitterBuffer = GetRegKeyBool(HKEY_CURRENT_USER, "Software\\Cisco Systems\\CCNMediaTerm\\1.0", "UseDynamicJitterBuffer", true);
    jitterBufferDepth = 0;
    lastOutputDuration = 0;
    lastOutputTimestamp = 0;
    lastPacketRepeatCount = 0;
    lastPacketTransmitted = NULL;
    numSIDPackets = 0;
    restartThreshold = DEFAULT_JITTERBUFFER_SIZE;
    silenceIntervalInProgress = true;
    this->ssrc = ssrc;
    this->tracer = tracer;
    InitializeCriticalSection(&packetQueueMutex);
    InitializeCriticalSection(&audioStreamMutex);
}
 
RTPAudioStream::~RTPAudioStream()
{
    EnterCriticalSection(&audioStreamMutex);
    SetLastTransmittedPacket(NULL);
    while (packetQueue.size() > 0)
    {
        AudioSample *audioSample = NULL;;
        PopNextPacket(&audioSample);
        audioSample->Release(this);
        audioSample = NULL;
    }
    LeaveCriticalSection(&audioStreamMutex);
    DeleteCriticalSection(&packetQueueMutex);
    DeleteCriticalSection(&audioStreamMutex);
}
 
int
RTPAudioStream::SetTraceLevel()
{
    long SystemMask = 0;
    if ((SystemMask = GetRegKeyLong(HKEY_CURRENT_USER, "Software\\Cisco Systems\\MTC\\Tracing", "AllComponents", 0x0)) == 0)
    {
        SystemMask = GetRegKeyLong(HKEY_CURRENT_USER, "Software\\Cisco Systems\\MTC\\Tracing", "RTPJitterBuffer", 0x100000);
    }
    tracer.SetSystemMask(SystemMask);
    return 0;
}
 
int
RTPAudioStream::SetRestartThreshold(int depthInMillisec)
{
    EnterCriticalSection(&audioStreamMutex);
    restartThreshold = depthInMillisec;
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}
 
int
RTPAudioStream::NumQueuedPackets()
{
    EnterCriticalSection(&audioStreamMutex);
    int numQdPackets = packetQueue.size();
    LeaveCriticalSection(&audioStreamMutex);
    return numQdPackets;
}
 
int
RTPAudioStream::JitterBufferDepth()
{
    EnterCriticalSection(&audioStreamMutex);
    int depth = jitterBufferDepth;
    LeaveCriticalSection(&audioStreamMutex);
    return depth;
}
 
unsigned long
RTPAudioStream::SSRC()
{
    EnterCriticalSection(&audioStreamMutex);
    unsigned long ssrcValue= this->ssrc;
    LeaveCriticalSection(&audioStreamMutex);
    return ssrcValue;
}
 
int
RTPAudioStream::SetLastTransmittedPacket(AudioSample *newPacket)
{
    EnterCriticalSection(&audioStreamMutex);
    if (newPacket != lastPacketTransmitted)
    {
        if (lastPacketTransmitted)
        {
            lastPacketTransmitted->Release(this);
            lastPacketTransmitted = NULL;
            lastPacketRepeatCount = 0;
        }
        lastPacketTransmitted = newPacket;
        if (newPacket)
        {
            newPacket->AddRef(this);
        }
    }
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}
 
int
RTPAudioStream::TimeDifference(unsigned long timestamp1, unsigned long timestamp2)
{
    int result(0);
    unsigned long timediff = timestamp1 > timestamp2 ? timestamp1 - timestamp2 : timestamp2 - timestamp1;
    if (timediff < 0x8fffffff)
    {
        result = timediff;
        return timestamp1 > timestamp2 ? -result : result;
    }
    else
    {
        unsigned long temp = (0xffffffff - timediff) + 1;
        result = temp;
        return timestamp1 > timestamp2 ? result : -result;
    }
}
 
int
RTPAudioStream::TimeDifference(AudioSample *sample1, AudioSample *sample2)
{
    return TimeDifference(sample1->RTPHeader()->Timestamp(), sample2->RTPHeader()->Timestamp());
}
 
int
RTPAudioStream::TimeDifferenceMillisec(AudioSample *sample1, AudioSample *sample2)
{
    int timestampDiff = TimeDifference(sample1, sample2);
    return (int)(((double)timestampDiff * sample1->MinFrameDuration())/1000.0 + 0.5);
}
 
int
RTPAudioStream::Clear()
{
    EnterCriticalSection(&audioStreamMutex);
    while(packetQueue.size() > 0)
    {
        AudioSample *audioSample = NULL;
        PopNextPacket(&audioSample);
        if (audioSample)
        {
            audioSample->Release(this);
            audioSample = NULL;
        }
    }
    silenceIntervalInProgress = true;
    SetLastTransmittedPacket(NULL);
    lastOutputTimestamp = 0;
    lastOutputDuration = 0;
    lastPacketRepeatCount = 0;
    numSIDPackets = 0;
    jitterBufferDepth = 0;
    numPackets = 0;
    numRepeats = 0;
    dynamicJitterBuffer = GetRegKeyBool(HKEY_CURRENT_USER, "Software\\Cisco Systems\\CCNMediaTerm\\1.0", "UseDynamicJitterBuffer", true);
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}
 
/**
 *  AddPacket makes sure that all samples added to the queue have an RTP header
 */
int
RTPAudioStream::AddPacket(AudioSample *newPacket)
{
    RTPPacket *rtpHeader = newPacket->RTPHeader();
    if (rtpHeader)
    {
        EnterCriticalSection(&audioStreamMutex);
        if (jitterBufferDepth < restartThreshold * JITTERBUFFER_MAXSIZE_MULTIPLE)
        {
            if (rtpHeader->PayloadType() == RTP_PAYLOADTYPE_SID)
            {
                numSIDPackets++;
            }
            newPacket->AddRef(this);
            packetQueue.push(newPacket);
            jitterBufferDepth += newPacket->GetDuration();
            tracer.tracef(ARB, "RTPAudioStream:%x : AddPacket : pushed audioSample 0x%x, ssrc %u, seqNo %u\n", this, newPacket, rtpHeader->Ssrc(), rtpHeader->SeqNo());
        }
        LeaveCriticalSection(&audioStreamMutex);
    }
    return 0;
}
 
int
RTPAudioStream::PopNextPacket(AudioSample **pAudioSample)
{
    *pAudioSample = NULL;
    EnterCriticalSection(&audioStreamMutex);
    if (packetQueue.size() > 0)
    {
        *pAudioSample = packetQueue.top();
        packetQueue.pop();
        RTPPacket *rtpHeader = (*pAudioSample)->RTPHeader();
        tracer.tracef(ARB, "RTPAudioStream:%x : PopNextPacket : popped audioSample 0x%x, ssrc %u, seqNo %u\n", this, *pAudioSample, rtpHeader->Ssrc(), rtpHeader->SeqNo());
        if (rtpHeader->PayloadType() == RTP_PAYLOADTYPE_SID)
        {
            numSIDPackets--;
        }
        else
        {
            jitterBufferDepth -= (*pAudioSample)->GetDuration();
        }
    }
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}
 
int
RTPAudioStream::PopNextPacketForTransmit(AudioSample **pOutSample)
{
    AudioSample *audioSample = NULL;
    EnterCriticalSection(&audioStreamMutex);
    PopNextPacket(&audioSample);
    if (audioSample)
    {
        RTPPacket *rtpHeader = audioSample->RTPHeader();
        SetLastTransmittedPacket(audioSample);
        *pOutSample = audioSample;
        lastOutputTimestamp = rtpHeader->Timestamp();
        lastOutputDuration = audioSample->GetDuration();
        lastPacketRepeatCount = 1;
    }
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}
 
/*
    makes sure that only audiosamples with valid rtpheader are added
*/
int
RTPAudioStream::InsertRTPPacket(AudioSample *audioSample)
{
    tracer.tracef(DET, "RTPAudioStream:%x : InsertRTPPacket 0x%x\n", this, audioSample);
    RTPPacket *newPacketRTPHeader = audioSample->RTPHeader();
    if (newPacketRTPHeader)
    {
        EnterCriticalSection(&audioStreamMutex);
        if (lastPacketTransmitted && (TimeDifference(lastPacketTransmitted, audioSample) < 0))
        {
            RTPPacket *lastPacketRTPHeader = lastPacketTransmitted->RTPHeader();
            // if we receive a packet that is 25 packets before the last transmitted packet, it means a new stream
            if ((int)(newPacketRTPHeader->SeqNo()) - ((int)lastPacketRTPHeader->SeqNo()) < -25)
            {
                Clear();
                AddPacket(audioSample);
            }
        }
        else
        {
            AddPacket(audioSample);
        }
        LeaveCriticalSection(&audioStreamMutex);
    }
    else
    {
        tracer.tracef(ERR, "RTPAudioStream:%x : InserRTPPacket : audioSample has no rtpHeader\n", this);
    }
    return 0;
}
 
int
RTPAudioStream::GiveNextRTPPacket(AudioSample **pOutSample)
{
    EnterCriticalSection(&audioStreamMutex);
    *pOutSample = NULL;
    if (silenceIntervalInProgress && (numSIDPackets > 0 || jitterBufferDepth >= restartThreshold))
    {
        silenceIntervalInProgress = false;
    }
    do
    {
        if (silenceIntervalInProgress)
        {
            break;
        }
        if (dynamicJitterBuffer && numPackets == 99)
        {
            tracer.tracef(EE, "RTPAudioStream:%x : GiveNextRTPPacket : numRepeats = %d\n", this, numRepeats);
            if (numRepeats <= 1)
            {
                int newThreshold(restartThreshold);
                if (jitterBufferDepth <= restartThreshold + 40)
                {
                    newThreshold = restartThreshold - 20;
                    if (newThreshold < 40) newThreshold = 40;
                }
                tracer.tracef(EE, "RTPAudioStream:%x : GiveNextRTPPacket : restartThreshold = %d, newThreshold = %d\n", this, restartThreshold, newThreshold);
                SetRestartThreshold(newThreshold);
                tracer.tracef(EE, "RTPAudioStream:%x : GiveNextRTPPacket : jitter buffer depth = %d\n", this, jitterBufferDepth);
                int durationDeleted(0);
                while(jitterBufferDepth > restartThreshold)
                {
                    AudioSample *discardSample = NULL;
                    PopNextPacketForTransmit(&discardSample);
                    if (discardSample)
                    {
                        durationDeleted += discardSample->GetDuration();
                        discardSample->Release(this);
                        discardSample = NULL;
                    }
                    if (durationDeleted >= 60)
                    {
                        break;
                    }
                }
                numRepeats = 0;
                numPackets = 100;
            }
            else
            {
                numRepeats = 0;
                restartThreshold = restartThreshold + 20;
                numPackets = 100;
                tracer.tracef(EE, "RTPAudioStream:%x : GiveNextRTPPacket : increased restartThreshold by 20 to %d\n", this, restartThreshold);
            }
        }
        if (packetQueue.size() <= 0)
        {
            if (lastPacketTransmitted && lastPacketRepeatCount < JITTERBUFFER_PLC_MAXREPEATS)
            {
                lastPacketTransmitted->AddRef(this);
                lastPacketRepeatCount++;
                if (lastPacketRepeatCount == 2)
                {
                    numRepeats++;
                }
                lastOutputTimestamp += (lastOutputDuration * 1000) / lastPacketTransmitted->MinFrameDuration();
                *pOutSample = lastPacketTransmitted;
                numPackets = (numPackets + 1) % 100;
                break;
            }
            else
            {
                silenceIntervalInProgress = true;
                SetLastTransmittedPacket(NULL);
                break;
            }
            break;
        }
 
        AudioSample *audioSample = packetQueue.top();
        tracer.tracef(DET, "RTPAudioStream:%x : GiveNextRTPPacket : packetQueue.top = audioSample 0x%x\n", this, audioSample);
        RTPPacket *rtpHeader = audioSample->RTPHeader();
        if (rtpHeader->PayloadType() == RTP_PAYLOADTYPE_SID)
        {
            PopNextPacket(&audioSample);
            audioSample->Release(this);
            audioSample = NULL;
            silenceIntervalInProgress = true;
            SetLastTransmittedPacket(NULL);
            break;
        }
        if (!lastPacketTransmitted)
        {
            // transmit whichever is the next packet
            PopNextPacketForTransmit(pOutSample);
            numPackets = (numPackets + 1) % 100;
            break;
        }
        int timeDifference = TimeDifferenceMillisec(lastPacketTransmitted, audioSample) - lastOutputDuration * lastPacketRepeatCount;
        if (timeDifference < (int)lastOutputDuration)
        {
            PopNextPacketForTransmit(pOutSample);
            numPackets = (numPackets + 1) % 100;
            break;
        }
        if (lastPacketRepeatCount < JITTERBUFFER_PLC_MAXREPEATS)
        {
            lastPacketTransmitted->AddRef(this);
            lastPacketRepeatCount++;
            lastOutputTimestamp += (lastOutputDuration * 1000) / lastPacketTransmitted->MinFrameDuration();
            *pOutSample = lastPacketTransmitted;
            numPackets = (numPackets + 1) % 100;
            break;
        }
        silenceIntervalInProgress = true;
        SetLastTransmittedPacket(NULL);
 
    } while(false);
    
    LeaveCriticalSection(&audioStreamMutex);
    return 0;
}