@100mslive/hms-video-store/src/media/streams/HMSRemoteStream.ts

@100mslive Core SDK which abstracts the complexities of webRTC while providing a reactive store for data management with a unidirectional data flow

import { HMSMediaStream } from './HMSMediaStream';
import HMSSubscribeConnection from '../../connection/subscribe/subscribeConnection';
import { HMSSimulcastLayer } from '../../interfaces';
import HMSLogger from '../../utils/logger';

/** @internal */
export class HMSRemoteStream extends HMSMediaStream {
  private readonly connection: HMSSubscribeConnection;
  private audio = true;
  private video = HMSSimulcastLayer.NONE;

  constructor(nativeStream: MediaStream, connection: HMSSubscribeConnection) {
    super(nativeStream);
    this.connection = connection;
  }

  async setAudio(enabled: boolean, trackId: string, identifier?: string) {
    if (this.audio === enabled) {
      return;
    }

    this.audio = enabled;
    HMSLogger.d(
      `[Remote stream] ${identifier || ''} 
    streamId=${this.id}
    trackId=${trackId}
    subscribing audio - ${this.audio}`,
    );
    await this.connection.sendOverApiDataChannelWithResponse({
      params: {
        subscribed: this.audio,
        track_id: trackId,
      },
      method: 'prefer-audio-track-state',
    });
  }

  /**
   * Sets the video layer after receiving new state from SFU. This is used when server side subscribe
   * degradation is ON.
   * @param layer is simulcast layer to be set
   * @param identifier is stream identifier to be printed in logs
   */
  setVideoLayerLocally(layer: HMSSimulcastLayer, identifier: string, source: string) {
    this.video = layer;
    HMSLogger.d(`[Remote stream] ${identifier}
    streamId=${this.id}
    source: ${source}
    Setting layer field to=${layer}`);
  }

  /**
   * Sets the video layer and updates the track state to SFU via api datachannel. This is used when client
   * side subscribe degradation is ON or client unsubscribes the current track.
   * @param layer is simulcast layer to be set
   * @param identifier is stream identifier to be printed in logs
   */
  setVideoLayer(layer: HMSSimulcastLayer, trackId: string, identifier: string, source: string) {
    HMSLogger.d(
      `[Remote stream] ${identifier} 
      streamId=${this.id}
      trackId=${trackId} 
      source: ${source} request ${layer} layer`,
    );
    this.setVideoLayerLocally(layer, identifier, source);
    return this.connection.sendOverApiDataChannelWithResponse({
      params: {
        max_spatial_layer: this.video,
        track_id: trackId,
      },
      method: 'prefer-video-track-state',
    });
  }

  /**
   * @deprecated
   * @returns {HMSSimulcastLayer}
   */
  getSimulcastLayer() {
    return this.video;
  }

  getVideoLayer() {
    return this.video;
  }

  isAudioSubscribed() {
    return this.audio;
  }
}