feat: add missing data in stream detector

Author: eugeny-dementev

src/WebRTCIssueDetector.ts

@@ -27,6 +27,7 @@ import {
 } from './detectors';
 import { CompositeRTCStatsParser, RTCStatsParser } from './parser';
 import createLogger from './utils/logger';
+import { MissingStreamDataDetector } from './detectors/MissingStreamDataDetector';
 
 class WebRTCIssueDetector {
   readonly eventEmitter: WebRTCIssueEmitter;
@@ -67,6 +68,7 @@ class WebRTCIssueDetector {
       new AvailableOutgoingBitrateIssueDetector(),
       new UnknownVideoDecoderImplementationDetector(),
       new FrozenVideoTrackDetector(),
+      new MissingStreamDataDetector(),
     ];
 
     this.networkScoresCalculator = params.networkScoresCalculator ?? new DefaultNetworkScoresCalculator();

src/detectors/MissingStreamDataDetector.ts

@@ -0,0 +1,152 @@
+import {
+  IssueDetectorResult,
+  IssueReason,
+  IssueType,
+  ParsedInboundAudioStreamStats,
+  ParsedInboundVideoStreamStats,
+  WebRTCStatsParsed,
+} from '../types';
+import BaseIssueDetector from './BaseIssueDetector';
+
+interface MissingStreamDetectorParams {
+  timeoutMs?: number;
+}
+
+export class MissingStreamDataDetector extends BaseIssueDetector {
+  readonly #lastMarkedAt = new Map<string, number>();
+  readonly #timeoutMs: number;
+
+  constructor(params: MissingStreamDetectorParams = {}) {
+    super();
+    this.#timeoutMs = params.timeoutMs ?? 10_000;
+  }
+
+  performDetection(data: WebRTCStatsParsed): IssueDetectorResult {
+    const { connection: { id: connectionId } } = data;
+    const issues = this.processData(data);
+    this.setLastProcessedStats(connectionId, data);
+    return issues;
+  }
+
+  private processData(data: WebRTCStatsParsed): IssueDetectorResult {
+    const { connection: { id: connectionId } } = data;
+    const previousStats = this.getLastProcessedStats(connectionId);
+    const issues: IssueDetectorResult = [];
+
+    if (!previousStats) {
+      return issues;
+    }
+
+    const { video: { inbound: newVideoInbound } } = data;
+    const { video: { inbound: prevVideoInbound } } = previousStats;
+    const { audio: { inbound: newAudioInbound } } = data;
+    const { audio: { inbound: prevAudioInbound } } = previousStats;
+
+    const mapVideoStatsByTrackId = (items: ParsedInboundVideoStreamStats[]) => new Map<string, ParsedInboundVideoStreamStats>(
+      items.map((item) => [item.track.trackIdentifier, item] as const),
+    );
+    const mapAudioStatsByTrackId = (items: ParsedInboundAudioStreamStats[]) => new Map<string, ParsedInboundAudioStreamStats>(
+      items.map((item) => [item.track.trackIdentifier, item] as const),
+    );
+
+    const newVideoInboundByTrackId = mapVideoStatsByTrackId(newVideoInbound);
+    const prevVideoInboundByTrackId = mapVideoStatsByTrackId(prevVideoInbound);
+    const newAudioInboundByTrackId = mapAudioStatsByTrackId(newAudioInbound);
+    const prevAudioInboundByTrackId = mapAudioStatsByTrackId(prevAudioInbound);
+    const unvisitedTrackIds = new Set(this.#lastMarkedAt.keys());
+
+    Array.from(newVideoInboundByTrackId.entries()).forEach(([trackId, newInboundItem]) => {
+      unvisitedTrackIds.delete(trackId);
+
+      const prevInboundItem = prevVideoInboundByTrackId.get(trackId);
+      if (!prevInboundItem) {
+        return;
+      }
+
+      const deltaFramesReceived = newInboundItem.framesReceived - prevInboundItem.framesReceived;
+
+      if (deltaFramesReceived === 0 && !newInboundItem.track.detached && !newInboundItem.track.ended) {
+        const hasIssue = this.markIssue(trackId);
+
+        if (!hasIssue) {
+          return;
+        }
+
+        const statsSample = {
+          framesReceived: newInboundItem.framesReceived,
+          framesDropped: newInboundItem.framesDropped,
+          trackDetached: newInboundItem.track.detached,
+          trackEnded: newInboundItem.track.ended,
+        };
+
+        issues.push({
+          type: IssueType.Stream,
+          reason: IssueReason.MissingVideoStreamData,
+          statsSample,
+        });
+      } else {
+        this.removeMarkIssue(trackId);
+      }
+    });
+
+    Array.from(newAudioInboundByTrackId.entries()).forEach(([trackId, newInboundItem]) => {
+      unvisitedTrackIds.delete(trackId);
+
+      const prevInboundItem = prevAudioInboundByTrackId.get(trackId);
+      if (!prevInboundItem) {
+        return;
+      }
+
+      const deltaFramesReceived = newInboundItem.bytesReceived - prevInboundItem.bytesReceived;
+
+      if (deltaFramesReceived === 0 && !newInboundItem.track.detached && !newInboundItem.track.ended) {
+        const hasIssue = this.markIssue(trackId);
+
+        if (!hasIssue) {
+          return;
+        }
+
+        const statsSample = {
+          bytesReceived: newInboundItem.bytesReceived,
+          packetsDiscarded: newInboundItem.packetsDiscarded,
+          trackDetached: newInboundItem.track.detached,
+          trackEnded: newInboundItem.track.ended,
+        };
+
+        issues.push({
+          type: IssueType.Stream,
+          reason: IssueReason.MissingAudioStreamData,
+          statsSample,
+        });
+      } else {
+        this.removeMarkIssue(trackId);
+      }
+    });
+
+    unvisitedTrackIds.forEach((trackId) => {
+      const lastMarkedAt = this.#lastMarkedAt.get(trackId);
+      if (lastMarkedAt && Date.now() - lastMarkedAt > this.#timeoutMs) {
+        this.removeMarkIssue(trackId);
+      }
+    });
+
+    return issues;
+  }
+
+  private markIssue(trackId: string): boolean {
+    const now = Date.now();
+    const lastMarkedAt = this.#lastMarkedAt.get(trackId);
+
+    if (!lastMarkedAt || now - lastMarkedAt > this.#timeoutMs) {
+      this.#lastMarkedAt.set(trackId, now);
+      return true;
+    }
+
+    return false;
+  }
+
+  private removeMarkIssue(trackId: string): void {
+    this.#lastMarkedAt.delete(trackId);
+  }
+}
+

src/types.ts

@@ -83,6 +83,8 @@ export enum IssueReason {
   LowInboundMOS = 'low-inbound-mean-opinion-score',
   LowOutboundMOS = 'low-outbound-mean-opinion-score',
   FrozenVideoTrack = 'frozen-video-track',
+  MissingVideoStreamData = 'missing-video-stream-data',
+  MissingAudioStreamData = 'missing-audio-stream-data',
 }
 
 export type IssuePayload = {