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DocumentationTencent Real-Time Communication

ITXDeviceManager

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Last updated: 2025-08-04 16:27:13
Copyright (c) 2021 Tencent. All rights reserved.

Module: audio/video device management module

Description: manages audio/video devices such as camera, mic, and speaker.
ITXDeviceManager

ITXDeviceObserver

FuncList
DESC
The status of a local device changed (for desktop OS only).

ITXDeviceManager

FuncList
DESC
Querying whether the front camera is being used (for mobile OS).
Switching to the front/rear camera (for mobile OS).
Getting the maximum zoom ratio of the camera (for mobile OS).
Setting the camera zoom ratio (for mobile OS).
Querying whether automatic face detection is supported (for mobile OS).
Enabling auto focus (for mobile OS).
Adjusting the focus (for mobile OS).
Enabling/Disabling flash, i.e., the torch mode (for mobile OS).
Setting the audio route (for mobile OS).
Setting the device to use (for desktop OS).
Getting the device currently in use (for desktop OS).
Setting the system volume type (for mobile OS).

StructType

FuncList
DESC
Camera acquisition parameters.
Audio/Video device information (for desktop OS).

EnumType

EnumType
DESC
System volume type (for mobile OS).
Audio route (the route via which audio is played).
Device type (for desktop OS).
Device operation.
Camera acquisition preferences.

onDeviceChanged

onDeviceChanged
void onDeviceChanged
(String deviceId


TXMediaDeviceState state)

The status of a local device changed (for desktop OS only).

The SDK returns this callback when a local device (camera, mic, or speaker) is connected or disconnected.
Param
DESC
deviceId
Device ID
state
Device status. 0 : connected; 1 : disconnected; 2 : started
type
Device type

isFrontCamera

isFrontCamera

Querying whether the front camera is being used (for mobile OS).

switchCamera

switchCamera
int switchCamera
(bool frontCamera)

Switching to the front/rear camera (for mobile OS).

getCameraZoomMaxRatio

getCameraZoomMaxRatio

Getting the maximum zoom ratio of the camera (for mobile OS).

setCameraZoomRatio

setCameraZoomRatio
int setCameraZoomRatio
(double zoomRatio)

Setting the camera zoom ratio (for mobile OS).

Param
DESC
zoomRatio
Value range: [1, 5]. 1 indicates the widest angle of view (original), and 5 the narrowest angle of view (zoomed in).The maximum value is recommended to be 5. If the value exceeds 5, the video will become blurred.

isAutoFocusEnabled

isAutoFocusEnabled

Querying whether automatic face detection is supported (for mobile OS).

enableCameraAutoFocus

enableCameraAutoFocus
int enableCameraAutoFocus
(bool enabled)

Enabling auto focus (for mobile OS).

After auto focus is enabled, the camera will automatically detect and always focus on faces.

setCameraFocusPosition

setCameraFocusPosition
int setCameraFocusPosition
(int x

int y)

Adjusting the focus (for mobile OS).

This API can be used to achieve the following:
1. A user can tap on the camera preview.
2. A rectangle will appear where the user taps, indicating the spot the camera will focus on.
3. The user passes the coordinates of the spot to the SDK using this API, and the SDK will instruct the camera to focus as required.
Param
DESC
position
The spot to focus on. Pass in the coordinates of the spot you want to focus on.
Note
Before using this API, you must first disable auto focus using enableCameraAutoFocus.

Return Desc:

0: operation successful; negative number: operation failed.

enableCameraTorch

enableCameraTorch
int enableCameraTorch
(bool enabled)

Enabling/Disabling flash, i.e., the torch mode (for mobile OS).

setAudioRoute

setAudioRoute
int setAudioRoute
(TXAudioRoute route)

Setting the audio route (for mobile OS).

A mobile phone has two audio playback devices: the receiver at the top and the speaker at the bottom.
If the audio route is set to the receiver, the volume is relatively low, and audio can be heard only when the phone is put near the ear. This mode has a high level of privacy and is suitable for answering calls.
If the audio route is set to the speaker, the volume is relatively high, and there is no need to put the phone near the ear. This mode enables the "hands-free" feature.

setCurrentDevice

setCurrentDevice
int setCurrentDevice
(TXMediaDeviceType type

String deviceId)

Setting the device to use (for desktop OS).

Param
DESC
deviceId
Device ID. You can get the ID of a device using the getDevicesList API.
type
Device type. For details, please see the definition of TXMediaDeviceType .

Return Desc:

0: operation successful; negative number: operation failed.

getCurrentDevice

getCurrentDevice
TXDeviceInfo getCurrentDevice
(TXMediaDeviceType type)

Getting the device currently in use (for desktop OS).

setSystemVolumeType

setSystemVolumeType
int setSystemVolumeType
(TXSystemVolumeType type)

Setting the system volume type (for mobile OS).

@deprecated This API is not recommended after v9.5. Please use the startLocalAudio(quality) API in TRTCCloud instead, which param quality is used to decide audio quality.

TXSystemVolumeType(Deprecated)

TXSystemVolumeType(Deprecated)

System volume type (for mobile OS).

@deprecated It is not recommended to use since version v9.5.

Modern smartphones generally have two system volume types, namely "call volume" and "media volume".

Call volume: The volume type designed specifically for making and receiving calls. It has built-in echo cancellation (AEC) function and supports picking up sound through the microphone on the Bluetooth headset. The disadvantage is that the sound quality is average.
When you use the volume button on the side of the phone to turn down the volume of the phone, if it cannot be adjusted to zero (that is, it cannot be completely muted), it means that your phone is currently in call volume.

Media volume: The volume type designed specifically for music scenes on the phone cannot use the system's AEC function and does not support picking up sound through the microphone of the Bluetooth headset, but has better music playback effect.
When you use the volume button on the side of the phone to turn down the volume of the phone, if the phone volume can be adjusted to completely mute, it means that your phone is currently in media volume.

The SDK currently provides three control modes for system volume types: Auto, Media volume, and Call volume mode.
Enum
Value
DESC
TXSystemVolumeTypeAuto
0
Auto
TXSystemVolumeTypeMedia
1
Media volume
TXSystemVolumeTypeVOIP
2
Call volume

TXAudioRoute

TXAudioRoute

Audio route (the route via which audio is played).

Audio route is the route (speaker or receiver) via which audio is played. It applies only to mobile devices such as mobile phones.
A mobile phone has two speakers: one at the top (receiver) and the other the bottom.
If the audio route is set to the receiver, the volume is relatively low, and audio can be heard only when the phone is put near the ear. This mode has a high level of privacy and is suitable for answering calls.
If the audio route is set to the speaker, the volume is relatively high, and there is no need to put the phone near the ear. This mode enables the "hands-free" feature.
Enum
Value
DESC
TXAudioRouteSpeakerphone
0
Speakerphone: the speaker at the bottom is used for playback (hands-free). With relatively high volume, it is used to play music out loud.
TXAudioRouteEarpiece
1
Earpiece: the receiver at the top is used for playback. With relatively low volume, it is suitable for call scenarios that require privacy.

TXMediaDeviceType

TXMediaDeviceType

Device type (for desktop OS).

This enumerated type defines three types of audio/video devices, namely camera, mic and speaker, so that you can use the same device management API to manage three types of devices.
Enum
Value
DESC
TXMediaDeviceTypeUnknown
-1
undefined device type
TXMediaDeviceTypeMic
0
microphone
TXMediaDeviceTypeSpeaker
1
speaker or earpiece
TXMediaDeviceTypeCamera
2
camera

TXMediaDeviceState

TXMediaDeviceState

Device operation.

This enumerated value is used to notify the status change of the local device onDeviceChanged.
Enum
Value
DESC
TXMediaDeviceStateAdd
0
The device has been plugged in
TXMediaDeviceStateRemove
1
The device has been removed
TXMediaDeviceStateActive
2
The device has been enabled
TXMediaDefaultDeviceChanged
3
system default device changed

TXCameraCaptureMode

TXCameraCaptureMode

Camera acquisition preferences.

This enum is used to set camera acquisition parameters.
Enum
Value
DESC
TXCameraResolutionStrategyAuto
0
Auto adjustment of camera capture parameters.
SDK selects the appropriate camera output parameters according to the actual acquisition device performance and network situation, and maintains a balance between device performance and video preview quality.
TXCameraResolutionStrategyPerformance
1
Give priority to equipment performance.
SDK selects the closest camera output parameters according to the user's encoder resolution and frame rate, so as to ensure the performance of the device.
TXCameraResolutionStrategyHighQuality
2
Give priority to the quality of video preview.
SDK selects higher camera output parameters to improve the quality of preview video. In this case, it will consume more CPU and memory to do video preprocessing.
TXCameraCaptureManual
3
Allows the user to set the width and height of the video captured by the local camera.

TXCameraCaptureParam

TXCameraCaptureParam

Camera acquisition parameters.

This setting determines the quality of the local preview image.
EnumType
DESC
height
Field description: height of acquired image
mode
Field description: camera acquisition preferences,please see TXCameraCaptureMode
width
Field description: width of acquired image

TXMediaDeviceInfo

TXMediaDeviceInfo

Audio/Video device information (for desktop OS).

This structure describes key information (such as device ID and device name) of an audio/video device, so that users can choose on the UI the device to use.
EnumType
DESC
deviceName
device name (UTF-8)
devicePID
device id (UTF-8)
deviceProperties
device properties
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