Camera preset

This page describes the camera track preset PreOptionCamera, and PublishCustomOptions, which overrides the preset’s publish parameters at publish time. For microphone and screen sharing presets, see Microphone preset and Screen sharing preset.

General notes

All PreOption* presets share a “capture options + publish options” structure:

Capture options: control local capture behavior (resolution, frame rate, sample rate, device parameters, and so on).
Publish options: control publishing behavior (desc, codec, maxBitrate, simulcast parameters, and so on).

PreOptionCamera

Purpose: The camera track preset, combining camera capture parameters with video publish parameters.

Structure

PreOptionCamera(capture: CameraCaptureOptions, publish: VideoPublishOptions)

Property	Data type	Description
capture	`CameraCaptureOptions`	Camera capture options
publish	`VideoPublishOptions`	Camera video publish options

Capture options CameraCaptureOptions

Purpose: Configures camera capture parameters.

Property	Data type	Description
deviceId	`String`	The suggested camera device ID, taken from `CameraDeviceCapability.cameraId` returned by `RTCEngine.getCameraDevices`. An empty string means no device is specified and the SDK chooses one.
position	`CamraPosition`	Phone camera position: `FRONT` / `BACK` / `External`.
facingMode	`CameraFacingMode`	WebRTC facing mode: `USER` / `ENVIRONMENT` / `LEFT` / `RIGHT`.
width	`Int`	Capture width.
height	`Int`	Capture height.
maxFps	`Int`	Maximum capture frame rate.

Publish options VideoPublishOptions

Purpose: Configures video track publish parameters.

Property	Data type	Description
desc	`String`	Track description (the high stream usually uses `TRACK_MAIN`, the low stream usually uses `TRACK_SUB`).
codec	`CodecType`	Codec (usually `H264`).
maxBitrate	`Int`	Maximum bitrate in bps.
minBitrate	`Int?`	Minimum bitrate in bps. `null` uses the engine’s default lower bound; when non-null, it must satisfy `0 <= minBitrate <= maxBitrate`. Currently supported only by the SFU engine.
width	`Int`	Publish width.
height	`Int`	Publish height.
maxFps	`Int`	Maximum publish frame rate.
props	`Any?`	Custom properties.
simulcasts	`MutableList<VideoPublishOptions>?`	Simulcast / low stream configuration (in the camera scenario, you can currently configure 1 low stream).

Built-in presets

Purpose: The SDK provides presets by resolution tier: _1080P, _720P, _480P, and _180P (default _480P).

// _1080P
capture: deviceId="", position=FRONT, facingMode=USER, width=1920, height=1080, maxFps=15
publish(main): desc="camera_big"(TRACK_MAIN), codec=H264, maxBitrate=5000*1024, minBitrate=2500*1024, width=1920, height=1080, maxFps=15
publish(sub):  desc="camera_small"(TRACK_SUB), codec=H264, maxBitrate=160*1024, minBitrate=80*1024, width=320, height=180, maxFps=15

// _720P
capture: deviceId="", position=FRONT, facingMode=USER, width=1280, height=720, maxFps=15
publish(main): desc="camera_big"(TRACK_MAIN), codec=H264, maxBitrate=2400*1024, minBitrate=1500*1024, width=1280, height=720, maxFps=15
publish(sub):  desc="camera_small"(TRACK_SUB), codec=H264, maxBitrate=160*1024, minBitrate=80*1024, width=320, height=180, maxFps=15

// _480P
capture: deviceId="", position=FRONT, facingMode=USER, width=640, height=480, maxFps=15
publish(main): desc="camera_big"(TRACK_MAIN), codec=H264, maxBitrate=800*1024, minBitrate=400*1024, width=640, height=480, maxFps=15
publish(sub):  desc="camera_small"(TRACK_SUB), codec=H264, maxBitrate=160*1024, minBitrate=80*1024, width=320, height=180, maxFps=15

// _180P
capture: deviceId="", position=FRONT, facingMode=USER, width=320, height=180, maxFps=15
publish(main): desc="camera_big"(TRACK_MAIN), codec=H264, maxBitrate=160*1024, minBitrate=80*1024, width=320, height=180, maxFps=15
publish(sub):  desc="camera_small"(TRACK_SUB), codec=H264, maxBitrate=160*1024, minBitrate=80*1024, width=320, height=180, maxFps=15

Custom publish parameters: PublishCustomOptions

Purpose: Overrides the preset’s publish parameters at publish time in publishLocalVideo / publishLocalAudio, mainly to customize the track desc.

Fields

Property	Data type	Description
desc	`String?`	Custom track description; `null` leaves it unchanged.
props	`Any?`	Custom additional properties; `null` leaves them unchanged.
simulcasts	`MutableList<PublishCustomOptions>?`	Overrides simulcast / low stream parameters; `null` leaves them unchanged.

Recommendations

If you only need to change the track description, pass desc.
For the camera’s high / low streams, you can override the low stream parameters through simulcasts.
Microphone, screen sharing, and custom video tracks usually need only the main track parameters, not simulcasts.

Overview

Web SDK

Android SDK

Swift SDK (iOS/macOS)

C SDK (server/embedded)

Python SDK (server-side AI)

Server API

General notes

PreOptionCamera

Structure

Capture options CameraCaptureOptions

Publish options VideoPublishOptions

Built-in presets

Custom publish parameters: PublishCustomOptions

Fields

Recommendations

​General notes

​PreOptionCamera

​Structure

​Capture options CameraCaptureOptions

​Publish options VideoPublishOptions

​Built-in presets

​Custom publish parameters: PublishCustomOptions

​Fields

​Recommendations

General notes

PreOptionCamera

Structure

Capture options CameraCaptureOptions

Publish options VideoPublishOptions

Built-in presets

Custom publish parameters: PublishCustomOptions

Fields

Recommendations