Types

This page doesn’t replicate every internal implementation field from the source code; it covers the public types most commonly used and most important to understand when integrating.

JoinOptions

Optional parameters for joining a channel.

Field	Type	Description
`autoSubscribeAudio`	`Bool`	Whether to auto-subscribe to existing remote audio; default `false`
`autoSubscribeVideo`	`Bool`	Whether to auto-subscribe to existing remote video; default `false`
`preferVideoCodec`	`Codec?`	Preferred video codec
`preferAudioCodec`	`Codec?`	Preferred audio codec
`userName`	`String?`	User name
`props`	`[String: String]?`	Custom business properties

Example:

let options = JoinOptions(
    autoSubscribeAudio: true,
    autoSubscribeVideo: false,
    userName: "alice"
)

ChannelInfo

Channel info.

Field	Type	Description
`appId`	`String`	App ID
`channel`	`String`	Channel name
`streamVendor`	`String?`	The current media streaming engine
`props`	`[String: AnyCodable]?`	Custom channel properties
`whiteBoard`	`String?`	Whiteboard page URL with the authorization code already appended; just load it in a `WKWebView`—see Whiteboard
`createdAt`	`TimeInterval?`	Creation time
`updatedAt`	`TimeInterval?`	Update time

UserInfo

User info.

Field	Type	Description
`uid`	`String`	User ID
`sid`	`String?`	Session ID
`name`	`String?`	User name
`deviceType`	`DeviceType?`	Device type
`deviceId`	`String?`	Device ID
`version`	`String?`	SDK version
`network`	`String?`	Network type
`streamTracks`	`[TrackInfo]?`	Tracks the user has published
`props`	`[String: AnyCodable]?`	Custom user properties

TrackInfo

Track description.

Field	Type	Description
`id`	`String`	Track ID
`desc`	`String`	Track description, such as `mic`, `screen`, or `camera_big`
`kind`	`TrackKind`	`audio` or `video`
`codec`	`Codec?`	Codec
`width` / `height`	`Int?`	Video width and height
`fps`	`Int?`	Frame rate
`angle`	`Int?`	Video angle
`maxBitrate`	`Int?`	Maximum bitrate
`sampleRate`	`Int?`	Audio sample rate
`channels`	`Int?`	Number of audio channels
`props`	`[String: String]?`	Custom properties
`simulcasts`	`[SimulcastInfo]?`	Simulcast encoding layer info

Codec

Codec enum.

Enum value	Description
`h264`	H.264 video codec
`h265`	H.265 video codec
`vp8`	VP8 video codec
`vp9`	VP9 video codec
`av1`	AV1 video codec
`aac`	AAC audio codec
`opus`	Opus audio codec

VideoRotation

Video frame rotation, used by pushFrame(_:rotation:timestampNs:) and VideoFrame.

Enum value	Raw value	Description
`_0`	`0`	No rotation (default)
`_90`	`90`	90 degrees clockwise
`_180`	`180`	180 degrees
`_270`	`270`	270 degrees clockwise

The raw value is the angle, using the same convention as the rotation parameter of inputData on Android.

StreamVendor

Media streaming engine vendor.

Enum value	Raw value	Description
`seastart`	`"seastart"`	SeaStart in-house SFU engine
`wangsuCDN`	`"wangsucdn"`	Wangsu CDN engine

The SDK automatically selects the engine based on stream_vendor in the token / join response.

ConnectionState

Enum value	Description
`disconnected`	Initial state or not connected
`connected`	Connected
`reconnecting`	Reconnecting
`left`	Left

DisconnectReason

Enum value	Raw value	Description
`error`	`-1`	Disconnected due to an error
`self`	`1`	Left voluntarily
`kicked`	`2`	Removed from the channel
`replaced`	`3`	Replaced by another session with the same uid
`timeout`	`4`	Disconnected due to timeout
`destroyed`	`5`	The channel was destroyed

Preset types

MicPreset

Common presets:

.speech
.music
.musicStereo
.musicHighQuality
.musicHighQualityStereo

CameraPreset

Common presets:

.h180p
.h360p
.h720p
.h1080p

ScreenPreset

Common presets:

.h720p
.h1080p

ScreenAudioPreset

Common presets:

.default

These presets are essentially combinations of “capture parameters + publishing parameters”. In other words, a preset isn’t syntactic sugar; it packages a set of sensible defaults into one object, reducing repeated configuration in your app.

ScreenCaptureMode

iOS screen capture mode, passed to createLocalScreenTrack(mode:). Ignored on macOS (which always uses ScreenCaptureKit).

Value	Description
`.inApp`	Default. In-app capture with no extra integration, but it can capture only your own app’s content
`.broadcast(appGroup: String)`	Full-screen capture of the entire system screen; requires integrating a Broadcast Upload Extension and an App Group

let track = srtc.createLocalScreenTrack(
    preset: .h720p,
    mode: .broadcast(appGroup: "group.your.app.group")
)

For integration steps, see Screen sharing.

DeviceInfo

The unified device structure returned by the device manager.

Field	Type	Description
`deviceId`	`String`	Unique device identifier
`name`	`String`	Device name
`kind`	`DeviceInfo.DeviceKind`	Device type
`isDefault`	`Bool`	Whether it’s the default device

Possible values of DeviceKind:

audioInput
audioOutput
videoInput

On iOS, getDevices(kind: .audioOutput) returns an empty array—the system doesn’t expose output device enumeration. To control where output goes, use the audio route types below—see Audio routing.

AudioRoute

iOS only. The current audio output route, read-only, for reporting, with five states.

Value	Description
`speaker`	Built-in speaker (speakerphone)
`receiver`	Built-in receiver
`bluetooth`	Bluetooth headphones
`headset`	Wired headphones (3.5 mm / Lightning / USB)
`unknown`	Other outputs (AirPlay, CarPlay, HDMI, etc.)

Helper properties:

Member	Type	Description
`displayName`	`String`	Chinese display name (such as 扬声器), usable directly in the UI
`isBuiltIn`	`Bool`	Whether it’s a built-in route (speaker / receiver)
`isExternal`	`Bool`	Whether it’s an external route (Bluetooth / wired)

AudioRouteTarget

iOS only. Route targets you can switch to actively, with only two states.

Value	Description
`speaker`	Speaker (speakerphone)
`earpiece`	Receiver

It’s deliberately separate from AudioRoute: iOS doesn’t provide the ability to switch to a specific Bluetooth / wired device; external devices are taken over by the system, and the SDK can only control “built-in speaker or receiver”. asRoute maps back to AudioRoute (.earpiece → .receiver).

AudioRouteInfo

iOS only. A snapshot of a system audio port, for diagnostics / display, not a list to choose from.

Field	Type	Description
`id`	`String`	Port UID; the fixed value `"speaker"` for the speaker
`route`	`AudioRoute`	The semantic route this port corresponds to
`name`	`String`	Port name, such as “AirPods Pro”
`isActive`	`Bool`	Whether it’s the route currently in effect

AudioCallState

iOS only. The system call state, from CallKit. The SDK uses it to decide when it can recover after an audio interruption.

Value	Description
`dialing`	Outgoing call dialing
`incoming`	Incoming call ringing
`connected`	Call connected
`disconnected`	No call / call ended
`unknown`	Unknown

ConnectionQuality

Connection quality level, parsed from the reports sent by the server.

Value	Description
`unknown`	Initial placeholder; no report yet
`excellent`	Excellent
`good`	Good
`poor`	Poor
`lost`	Lost

When comparing which level is worse, the order is unknown < excellent < good < poor < lost.

QualitySample

A snapshot of quality values in one direction; a signal-strength icon / network panel can render directly from these fields.

Field	Type	Description
`level`	`ConnectionQuality`	Level given by the server
`score`	`Int`	0–100, higher is better
`mos`	`Double`	1.0–4.5, higher is better
`loss`	`Double`	Packet loss rate as a ratio (0–1, not a percentage)
`rtt`	`Double`	Round-trip time, in milliseconds
`jitter`	`Double`	Jitter, in milliseconds
`packets`	`Int`	Number of packets included in this round of statistics
`bitrate`	`Int`	Average bitrate, in kbps
`bytes`	`Int`	Bytes in this window

QualityReport

A complete quality report. The SDK emits one each time the server sends a report.

Field	Type	Description
`ts`	`Int64`	Unix timestamp in milliseconds when the server generated the report
`pub`	`QualitySample`	Uplink (client to SFU)
`sub`	`QualitySample`	Downlink (SFU to client)

QualityEvaluation

A simplified level evaluation snapshot, used by getConnectionQuality() and the level-change event.

Field	Type	Description
`uplink`	`ConnectionQuality`	Uplink level
`downlink`	`ConnectionQuality`	Downlink level
`overall`	`ConnectionQuality`	The worse of the uplink and downlink levels
`mos`	`Double`	The smaller of the uplink and downlink values, reflecting the side the user perceives as weakest
`timestamp`	`Int64`	The `ts` of the corresponding report

ConnectionQualityChange

Field	Type	Description
`evaluation`	`QualityEvaluation`	The evaluation after the change
`previous`	`ConnectionQuality`	The level before the change; `unknown` on the first change

ActiveSpeakerInfo / ActiveSpeakersSnapshot

Type	Fields
`ActiveSpeakerInfo`	`uid`, `trackId`, `level` (normalized linear volume, 0–1)
`ActiveSpeakersSnapshot`	`ts`, `speakers: [ActiveSpeakerInfo]`

speakers is the full list: the SDK has already merged the server’s incremental protocol and sorted it by level in descending order; when nobody is speaking, it’s an empty array.

LayerSwitchedInfo

Field	Type	Description
`subKey`	`String`	Subscription key, in the form `publisherUid:trackId`
`fromTrackId`	`String?`	The layer before the switch
`toTrackId`	`String`	The layer after the switch
`reason`	`String`	Reason given by the server, such as `bwe_down`, `bwe_up`, or `track_ended`; `client` for a manual layer switch by the client
`latencyMs`	`Int`	Time from initiating the switch to actually reaching the target layer, in milliseconds

For how to use the quality-related types above, see Call quality and active speakers.

ReceiveStreamStatus

The payload of a receive status change for one remote video, delivered by the channel(_:didChangeReceiveStreamStatus:) callback.

Field	Type	Description
`uid`	`String`	Identifier of the user publishing the stream
`trackId`	`String`	Track identifier
`trackDesc`	`String`	Track description (`camera` / `screen`, etc., corresponding to `TrackInfo.desc`)
`timedOut`	`Bool`	`true` means receiving has timed out; `false` means receiving has recovered

It’s judged per track, looking only at whether this video is producing frames, and is unrelated to the quality level of the whole link—don’t use ConnectionQualityChange in its place; see Events for details.

It corresponds to engineChannel:onReceiveStreamStatusChange:trackId:status: in the older RTCEngineKit; timedOut has the same truth value as the old status (true means timed out), so you don’t need to invert it when migrating.

Overview

Web SDK

Android SDK

Swift SDK (iOS/macOS)

C SDK (server/embedded)

Python SDK (server-side AI)

Server API

JoinOptions

ChannelInfo

UserInfo

TrackInfo

Codec

VideoRotation

StreamVendor

ConnectionState

DisconnectReason

Preset types

MicPreset

CameraPreset

ScreenPreset

ScreenAudioPreset

ScreenCaptureMode

DeviceInfo

AudioRoute

AudioRouteTarget

AudioRouteInfo

AudioCallState

ConnectionQuality

QualitySample

QualityReport

QualityEvaluation

ConnectionQualityChange

ActiveSpeakerInfo / ActiveSpeakersSnapshot

LayerSwitchedInfo

ReceiveStreamStatus

​JoinOptions

​ChannelInfo

​UserInfo

​TrackInfo

​Codec

​VideoRotation

​StreamVendor

​ConnectionState

​DisconnectReason

​Preset types

​MicPreset

​CameraPreset

​ScreenPreset

​ScreenAudioPreset

​ScreenCaptureMode

​DeviceInfo

​AudioRoute

​AudioRouteTarget

​AudioRouteInfo

​AudioCallState

​ConnectionQuality

​QualitySample

​QualityReport

​QualityEvaluation

​ConnectionQualityChange

​ActiveSpeakerInfo / ActiveSpeakersSnapshot

​LayerSwitchedInfo

​ReceiveStreamStatus

JoinOptions

ChannelInfo

UserInfo

TrackInfo

Codec

VideoRotation

StreamVendor

ConnectionState

DisconnectReason

Preset types

MicPreset

CameraPreset

ScreenPreset

ScreenAudioPreset

ScreenCaptureMode

DeviceInfo

AudioRoute

AudioRouteTarget

AudioRouteInfo

AudioCallState

ConnectionQuality

QualitySample

QualityReport

QualityEvaluation

ConnectionQualityChange

ActiveSpeakerInfo / ActiveSpeakersSnapshot

LayerSwitchedInfo

ReceiveStreamStatus