NR-480384: Added QOE Aggregate

[swatijha23]

KPIs are calculated based on this doc - https://newrelic.atlassian.net/wiki/spaces/VERTSOL/pages/4702274467/KPIs+Transformation+QOE+Score

kpi.startupTime
kpi.startupTime = timeSinceRequested
Source: TimeSince mechanism tracking time from CONTENT_REQUEST to current moment

kpi.peakBitrate
Formula: Maximum value tracking
kpi.peakBitrate = MAX(bitrate_1, bitrate_2, ..., bitrate_n)

kpi.hadStartupFailure

Formula: Boolean logic based on playback state
kpi.hadStartupFailure = (timeSinceStarted == null)

Logic:

true = Error occurred before CONTENT_START (no timeSinceStarted attribute exists)
false = Playback started successfully
kpi.hadPlaybackFailure
Formula: Boolean flag set on error during playback
kpi.hadPlaybackFailure = qoeHadPlaybackFailure

Tracking Logic:
// On CONTENT_ERROR:

kpi.totalRebufferingTime
Formula: Cumulative sum of rebuffering durations
kpi.totalRebufferingTime = Σ(rebuffer_duration_i) where buffer_type ≠ "initial"

Tracking Logic:
// On each CONTENT_BUFFER_END:

kpi.rebufferingRatio
Formula: Percentage of time spent rebuffering
double rebufferingRatio = ((double) qoeTotalRebufferingTime / totalPlaytime) * 100;

7. kpi.totalPlaytime
   Formula: Direct attribute mapping
   kpi.totalPlaytime = totalPlaytime

Source: Accumulated through updatePlaytime() mechanism

kpi.averageBitrate (NEW: Time-Weighted)
Formula: Time-weighted average of bitrates
// Primary calculation (time-weighted):
if (qoeTotalActiveTime > 0) {
kpi.averageBitrate = qoeTotalBitrateWeightedTime / qoeTotalActiveTime
}

// Fallback calculation (simple average):
else if (qoeBitrateCount > 0) {
kpi.averageBitrate = qoeBitrateSum / qoeBitrateCount
}

Time-Weighted Tracking:
// On each rendition change:
segmentDuration = currentTime - qoeLastRenditionChangeTime
qoeTotalBitrateWeightedTime += (previousBitrate × segmentDuration)
qoeTotalActiveTime += segmentDuration

// During calculation, include current segment:
currentSegmentDuration = currentTime - qoeLastRenditionChangeTime
totalWeightedTime = qoeTotalBitrateWeightedTime + (currentBitrate × currentSegmentDuration)
totalTime = qoeTotalActiveTime + currentSegmentDuration

averageBitrate = totalWeightedTime / totalTime

Mathematical Representation:
Average = Σ(bitrate_i × duration_i) / Σ(duration_i)

Where:

bitrate_i = bitrate during segment i
duration_i = time duration of segment i
i = 1 to n rendition changes

#58