Distributed Audio Playback (for System Applications Only)

Distributed audio playback enables an application to continue audio playback on another device in the same network.

You can use distributed audio playback to transfer all audio streams or the specified audio stream being played on the current device to a remote device.

How to Develop

Before continuing audio playback on another device in the same network, you must obtain the device list on the network and listen for device connection state changes. For details, see Querying and Listening for Audio Output Devices.

When obtaining the device list on the network, you can specify DeviceFlag to filter out the required devices.

Name	Description
NONE_DEVICES_FLAG⁹⁺	No device is available. This is a system API.
OUTPUT_DEVICES_FLAG	Local output device.
INPUT_DEVICES_FLAG	Local input device.
ALL_DEVICES_FLAG	Local input and output device.
DISTRIBUTED_OUTPUT_DEVICES_FLAG⁹⁺	Remote output device. This is a system API.
DISTRIBUTED_INPUT_DEVICES_FLAG⁹⁺	Remote input device. This is a system API.
ALL_DISTRIBUTED_DEVICES_FLAG⁹⁺	Remote input and output device. This is a system API.

For details about the API reference, see AudioRoutingManager.

Continuing the Playing of All Audio Streams

Obtain the output device information.
Create an AudioDeviceDescriptor instance to describe an audio output device.
Call selectOutputDevice to select a remote device, on which all the audio streams will continue playing.

import { audio } from '@kit.AudioKit';
import { BusinessError } from '@kit.BasicServicesKit';

let audioManager = audio.getAudioManager();
let audioRoutingManager = audioManager.getRoutingManager();
let outputAudioDeviceDescriptor: audio.AudioDeviceDescriptors = [{
  deviceRole: audio.DeviceRole.OUTPUT_DEVICE,
  deviceType: audio.DeviceType.SPEAKER,
  id: 1,
  name: "",
  address: "",
  sampleRates: [44100],
  channelCounts: [2],
  channelMasks: [0],
  networkId: audio.LOCAL_NETWORK_ID,
  interruptGroupId: 1,
  volumeGroupId: 1,
  displayName: ""
}];

async function selectOutputDevice(): Promise<void> {
  audioRoutingManager.selectOutputDevice(outputAudioDeviceDescriptor, (err: BusinessError) => {
    if (err) {
      console.error(`Invoke selectOutputDevice failed, code is ${err.code}, message is ${err.message}`);
    } else {
      console.info('Invoke selectOutputDevice succeeded.');
    }
  });
}

Continuing the Playing of the Specified Audio Stream

Obtain the output device information.
Create an AudioRendererFilter instance, with uid to specify an application and rendererId to specify an audio stream.
Create an AudioDeviceDescriptor instance to describe an audio output device.
Call selectOutputDeviceByFilter to select a remote device, on which the specified audio stream will continue playing.

import { audio } from '@kit.AudioKit';
import { BusinessError } from '@kit.BasicServicesKit';

let audioManager = audio.getAudioManager();
let audioRoutingManager = audioManager.getRoutingManager();
let outputAudioRendererFilter: audio.AudioRendererFilter  = {
  uid: 20010041,
  rendererInfo: {
    usage: audio.StreamUsage.STREAM_USAGE_MUSIC, // Audio stream usage type: music. Set this parameter based on the service scenario.
    rendererFlags: 0 // AudioRenderer flag.
  } as audio.AudioRendererInfo,
  rendererId: 0
};

let outputAudioDeviceDescriptor: audio.AudioDeviceDescriptors = [{
  deviceRole: audio.DeviceRole.OUTPUT_DEVICE,
  deviceType: audio.DeviceType.SPEAKER,
  id: 1,
  name: "",
  address: "",
  sampleRates: [44100],
  channelCounts: [2],
  channelMasks: [0],
  networkId: audio.LOCAL_NETWORK_ID,
  interruptGroupId: 1,
  volumeGroupId: 1,
  displayName: ""
}];

async function selectOutputDeviceByFilter(): Promise<void> {
  audioRoutingManager.selectOutputDeviceByFilter(outputAudioRendererFilter, outputAudioDeviceDescriptor, (err: BusinessError) => {
    if (err) {
      console.error(`Invoke selectOutputDeviceByFilter failed, code is ${err.code}, message is ${err.message}`);
    } else {
      console.info('Invoke selectOutputDeviceByFilter succeeded.');
    }
  });
}