private void CheckForSamples()
{
try
{
Thread.Sleep(CHECK_FORSAMPLE_PERIOD); // Wait until the first sample is likely to be ready.
while (m_checkForSamples)
{
RTCPReport report = CheckForAvailableSample(m_windowLastSeqNum);
if (report != null && RTCPReportReady != null)
{
try
{
RTCPReportReady(report);
}
catch
{
}
}
m_checkForSampleEvent.Reset();
m_checkForSampleEvent.WaitOne(CHECK_FORSAMPLE_PERIOD, false);
}
}
catch (Exception excp)
{
Logger.Logger.Debug("Exception CheckForSamples. " + excp.Message);
}
}
private void m_rtcpSampler_RTCPReportReady(RTCPReport rtcpReport)
{
if (rtcpReport != null && RTCPReportReady != null)
{
try
{
RTCPReportReady(rtcpReport);
rtcpReport.LastReceivedReportNumber = LastReceivedReportNumber;
//if (rtcpReport.ReportNumber % 3 != 0)
//{
SendRTCPReport(RTCPReportTypesEnum.RTCP, rtcpReport.GetBytes());
//}
}
catch (Exception excp)
{
Logger.Logger.Error("Exception m_rtcpSampler_RTCPReportReady. ->" + excp.Message);
}
}
}
/// <summary>
/// All times passed into this method should already be UTC.
/// </summary>
private RTCPReport Sample(UInt16 sampleStartSequenceNumber, UInt16 sampleEndSequenceNumber,
TimeSpan sampleDuration)
{
try
{
RTCPReport sample = new RTCPReport(m_rtpStreamId, m_syncSource, m_remoteEndPoint);
sample.ReportNumber = m_reportNumber;
sample.SampleStartTime = DateTime.MinValue;
//sample.SampleEndTime = DateTime.MinValue;
sample.StartSequenceNumber = sampleStartSequenceNumber;
sample.Duration = Convert.ToUInt64(sampleDuration.TotalMilliseconds);
double jitterTotal = 0;
//double transitTotal = 0;
int endSequence = (sampleEndSequenceNumber < sampleStartSequenceNumber)
? sampleEndSequenceNumber + UInt16.MaxValue + 1
: sampleEndSequenceNumber;
// logger.Debug("Sampling range " + sampleStartSequenceNumber + " to " + endSequence);
for (int index = sampleStartSequenceNumber; index <= endSequence; index++)
{
UInt16 testSeqNum = (index > UInt16.MaxValue)
? Convert.ToUInt16((index % UInt16.MaxValue) - 1)
: Convert.ToUInt16(index);
//logger.Debug("Sampling " + testSeqNum + ".");
if (m_rcvdSeqNums.ContainsKey(testSeqNum))
{
RTPReceiveRecord measurement = m_rcvdSeqNums[testSeqNum];
//sample.SampleEndTime = measurement.SendTime;
if (sample.SampleStartTime == DateTime.MinValue)
{
sample.SampleStartTime = measurement.ReceiveTime;
}
sample.SampleEndTime = measurement.ReceiveTime;
sample.EndSequenceNumber = measurement.SequenceNumber;
sample.TotalPackets++;
sample.BytesReceived += (uint)measurement.RTPBytes;
if (measurement.Duplicates > 0)
{
Logger.Logger.Debug("Duplicates for " + testSeqNum + " number " + measurement.Duplicates);
sample.Duplicates += (uint)measurement.Duplicates;
}
if (!measurement.InSequence)
{
Logger.Logger.Debug("OutOfOrder for " + testSeqNum);
sample.OutOfOrder++;
}
else
{
// It is possible for the jitter to be negative as an average measurement is being used for the transit time and
// some transits could be slightly less than the average.
//double jitter = Math.Abs(measurement.ReceiveTime.Subtract(measurement.SendTime).TotalMilliseconds - averageTransitTime);
jitterTotal += measurement.Jitter;
//transitTotal += measurement.AverageTransit;
if (measurement.Jitter > sample.JitterMaximum)
{
//logger.Debug("Jitter max set to " + measurement.Jitter + " for sequence number " + measurement.SequenceNumber);
sample.JitterMaximum = (uint)measurement.Jitter;
}
}
if (measurement.JitterBufferDiscard)
{
Logger.Logger.Debug("Jitter discard for " + testSeqNum);
sample.JitterDiscards++;
}
// Remove the measurement from the buffer.
// Remove the RTP measurements now that they have been sampled.
lock (m_rcvdSeqNums)
{
//logger.Debug("Removing " + index);
m_rcvdSeqNums.Remove(testSeqNum);
}
}
else
{
Logger.Logger.Debug("Packet drop for " + index);
sample.PacketsLost++;
}
}
// Calculate the average jitter.
if (sample.TotalPackets > 0)
{
sample.JitterAverage = Convert.ToUInt32(jitterTotal / sample.TotalPackets);
}
// Calculate the average transit.
//if (sample.TotalPackets > 0)
//{
// sample.AverageTransitTime = Convert.ToUInt32(transitTotal / sample.TotalPackets);
//}
// Calculate the transmission rate.
double packetRate = 0;
if (sampleDuration.TotalMilliseconds > 0)
{
sample.TransmissionRate = Convert.ToUInt32(sample.BytesReceived * 8 / sampleDuration.TotalSeconds);
packetRate = sample.TotalPackets / sampleDuration.TotalSeconds;
}
string rtcpReport = String.Format(RTCP_FORMAT_STRING, new object[]
{
sample.SyncSource,
sample.SampleStartTime.ToString("HH:mm:ss:fff"),
sample.SampleEndTime.ToString("HH:mm:ss:fff"),
sampleDuration.TotalMilliseconds.ToString("0"),
sample.StartSequenceNumber.ToString(),
sample.EndSequenceNumber.ToString(),
sample.TotalPackets.ToString(),
sample.JitterMaximum.ToString("0"),
sample.JitterAverage.ToString("0.##"),
sample.AverageTransitTime.ToString("0.##"),
packetRate.ToString("0.##"),
sample.BytesReceived.ToString(),
sample.TransmissionRate.ToString("0.##"),
sample.PacketsLost.ToString(),
sample.JitterDiscards.ToString(),
sample.Duplicates.ToString(),
sample.OutOfOrder.ToString()
});
Logger.Logger.Info(rtcpReport);
//logger.Info("start=" + sample.SampleStartTime.ToString("HH:mm:ss:fff") + ",end=" + sample.SampleEndTime.ToString("HH:mm:ss:fff") + ",dur=" + sampleDuration.TotalMilliseconds.ToString("0") + "ms" +
// ",seqnnumstart=" + sample.StartSequenceNumber + ",seqnumend=" + sample.EndSequenceNumber + ",pktstotal=" + sample.TotalPackets + "p,pktrate=" + packetRate.ToString("0.##") + "pps,bytestotal=" + sample.BytesReceived + "B,bw=" + sample.TransmissionRate.ToString("0.##") + "Kbps,jitteravg=" +
// sample.JitterAverage.ToString("0.##") + ",jittermax=" + sample.JitterMaximum.ToString("0.##") + ",pktslost=" + sample.PacketsLost + ",jitterdiscards=" + sample.JitterDiscards + ",duplicates=" + sample.Duplicates + ",outoforder=" + sample.OutOfOrder);
return(sample);
}
catch (Exception excp)
{
Logger.Logger.Error("Exception Sample. ->" + excp.Message);
return(null);
}
finally
{
m_reportNumber++;
}
}
/// <summary>
/// A sample is taken if the last RTP measurement recorded is 4x the sample time since the last last smaple was taken.
/// The 4x is needed in order to be able to take into account late arriving packets as out of order rather then as drops.
/// </summary>
/// <param name="sequenceNumber"></param>
private RTCPReport CheckForAvailableSample(UInt16 sequenceNumber)
{
try
{
//logger.Debug("Check for available sample " + sequenceNumber + ".");
RTCPReport sample = null;
RTPReceiveRecord measurement = m_rcvdSeqNums[sequenceNumber];
//logger.Debug("window start seq num=" + m_windowStartSeqNum);
RTPReceiveRecord startSampleMeasuerment = m_rcvdSeqNums[m_windowStartSeqNum];
UInt16 endSampleSeqNum = 0;
UInt16 endSampleSeqNumMinusOne = 0;
int samplesAvailable = 0;
DateTime sampleCutOffTime;
bool sampleAvailable = false;
// Determine whether a sample of the RTP stream measurements should be taken.
if (DateTime.Now.Subtract(m_lastSampleTime).TotalMilliseconds > (4 * ReportSampleDuration))
{
// Make the sample a random size between N and 2N
int randomElement = Crypto.GetRandomInt(ReportSampleDuration, 2 * ReportSampleDuration);
int sampleDuration = ReportSampleDuration + randomElement;
sampleCutOffTime = m_lastSampleTime.AddMilliseconds(sampleDuration);
//logger.Debug("Sample duration=" + sampleDuration + "ms, cut off time=" + sampleCutOffTime.ToString("HH:mm:ss:fff") + ".");
// Get the list of RTP measurements from last time a sample was taken up to the last receive within the window.
int endSeqNum = (sequenceNumber < m_windowStartSeqNum)
? sequenceNumber + UInt16.MaxValue + 1
: sequenceNumber;
//logger.Debug("Checking for sample from " + m_windowStartSeqNum + " to " + endSeqNum + ".");
for (int seqNum = m_windowStartSeqNum; seqNum <= endSeqNum; seqNum++)
{
UInt16 testSeqNum = (seqNum > UInt16.MaxValue)
? Convert.ToUInt16((seqNum % UInt16.MaxValue) - 1)
: Convert.ToUInt16(seqNum);
if (m_rcvdSeqNums.ContainsKey(testSeqNum))
{
//logger.Debug(testSeqNum + " " + m_rcvdSeqNums[testSeqNum].ReceiveTime.ToString("ss:fff") + "<" + sampleCutOffTime.ToString("ss:fff") + ".");
if (m_rcvdSeqNums[testSeqNum].ReceiveTime < sampleCutOffTime)
{
samplesAvailable++;
endSampleSeqNum = testSeqNum;
}
else
{
endSampleSeqNumMinusOne = endSampleSeqNum;
endSampleSeqNum = testSeqNum;
sampleAvailable = true;
break;
}
}
}
}
/*if (m_rcvdSeqNums.Count > 200)
* {
* endSampleSeqNum = m_windowSecondLastSeqNum;
* sampleAvailable = true;
* }*/
if (sampleAvailable)
{
//logger.Debug(samplesAvailable + " ready for RTCP sampling, start seq num=" + m_windowStartSeqNum + " to " + endSampleSeqNumMinusOne + ".");
TimeSpan measurementsSampleDuration = m_rcvdSeqNums[endSampleSeqNumMinusOne].ReceiveTime
.Subtract(m_rcvdSeqNums[m_windowStartSeqNum].ReceiveTime);
//logger.Debug("Sample available start seq num=" + m_windowStartSeqNum + " end seq num=" + endSampleSeqNumMinusOne + ", " + measurementsSampleDuration.TotalMilliseconds.ToString("0") + ".");
sample = Sample(m_windowStartSeqNum, endSampleSeqNumMinusOne, measurementsSampleDuration);
m_windowStartSeqNum = endSampleSeqNum;
m_lastSampleTime = m_rcvdSeqNums[endSampleSeqNum].ReceiveTime;
}
return(sample);
}
catch (Exception excp)
{
Logger.Logger.Error("Exception CheckForAvailableSample. ->" + excp.Message);
return(null);
}
}