private handleSupportedVideoReceiveCodecIntersection()

in src/task/ReceiveVideoStreamIndexTask.ts [213:283]
55 lines of code
12 McCabe index (conditional complexity)

  private handleSupportedVideoReceiveCodecIntersection(index: SdkIndexFrame): void {
    if (this.context.videoSendCodecPreferences === undefined) {
      return;
    }

    // The following list contains the configured send codec preferences filtered to
    // only what is supported by the meeting
    const newMeetingSupportedVideoSendCodecPreferences: VideoCodecCapability[] = [];
    // Will be set to true if we need to force a negotiation to change the codec
    let willNeedUpdate = false;

    // Intersect `this.context.videoSendCodecPreferences` with `index.supportedReceiveCodecIntersection`
    // and filter out any send video codecs we have determined to be degraded
    for (const capability of this.context.videoSendCodecPreferences) {
      if (
        this.context.degradedVideoSendCodecs.some(degradedCapability =>
          capability.equals(degradedCapability)
        )
      ) {
        this.logger.info(
          `Skipping ${capability.codecName} since the codec has been identfied as degraded`
        );
        continue;
      }
      for (const signaledCapability of index.supportedReceiveCodecIntersection) {
        if (capability.equals(VideoCodecCapability.fromSignaled(signaledCapability))) {
          newMeetingSupportedVideoSendCodecPreferences.push(capability);
          break;
        }
      }
    }

    if (newMeetingSupportedVideoSendCodecPreferences.length > 0) {
      // We need to renegotiate if we are currently sending a codec that is no longer supported in the call, or if we can
      // start sending a higher preference codec again (due to a constrained remote attendee leaving)

      // First we find the first codec from our send preferences that has already been intersected with the
      // codecs supported by the meeting, that we know we can support. This is what we want to send.
      const firstMatchingCodecPreference = newMeetingSupportedVideoSendCodecPreferences.find(
        capability =>
          this.context.prioritizedSendVideoCodecCapabilities.some(prioritizedCapability =>
            capability.equals(prioritizedCapability)
          )
      );
      // If that codec is not what we are sending, trigger an update
      if (
        this.context.currentVideoSendCodec !== undefined &&
        (firstMatchingCodecPreference === undefined ||
          !this.context.currentVideoSendCodec.equals(firstMatchingCodecPreference))
      ) {
        willNeedUpdate = true;
      }
      this.context.meetingSupportedVideoSendCodecPreferences = newMeetingSupportedVideoSendCodecPreferences;
    } else {
      this.logger.warn(
        'Interesection of meeting receive codec support and send codec preferences has no overlap, falling back to just values provided in `setVideoCodecSendPreferences`'
      );
      this.context.meetingSupportedVideoSendCodecPreferences = undefined;
    }

    if (this.context.videoUplinkBandwidthPolicy.setMeetingSupportedVideoSendCodecs) {
      this.context.videoUplinkBandwidthPolicy.setMeetingSupportedVideoSendCodecs(
        this.context.meetingSupportedVideoSendCodecPreferences,
        this.context.videoSendCodecPreferences
      );
    }

    if (willNeedUpdate) {
      this.context.audioVideoController.update({ needsRenegotiation: true });
    }
  }