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Managing Media Devices

TRTC needs to support the control of multiple media devices in live streaming scenario to meet various user needs during the live streaming process. This tutorial mainly introduces how to:
Turn on/off the microphone and camera
Control the camera
Turn on/off the flash
Enable/disable the face focus feature
Detect if the user is speaking after mute
Detect the status of the remote user's microphone/camera

Turn on/off the microphone and camera

TRTC provides two methods to turn on/off the microphone/camera. It is recommended to use Option 1 for microphone/camera operations.

Turn on/off the microphone

Option 1: Call muteLocalAudio
This interface is different from stopLocalAudio. Calling muteLocalAudio(true) does not release the microphone permission but continues to send very low bit rate silent packets. This is very suitable for scenarios that require Cloud Recording, because video files in formats like MP4 have high requirements for the continuity of audio data. Using stopLocalAudio will make the recorded MP4 files hard to play.
Android
iOS
Mac
Windows
// Turn the mic on
mCloud.muteLocalAudio(false);

// Turn the mic off
mCloud.muteLocalAudio(true);
// Turn the mic on
[self.trtcCloud muteLocalAudio:NO];

// Turn the mic off
[self.trtcCloud muteLocalAudio:YES];
// Turn the mic on
[self.trtcCloud muteLocalAudio:NO];

// Turn the mic off
[self.trtcCloud muteLocalAudio:YES];
// Turn the mic on
trtc_cloud_->muteLocalAudio(false);

// Turn the mic off
trtc_cloud_->muteLocalAudio(true);
Option 2: Call startLocalAudio/stopLocalAudio
Android
iOS
Mac
Windows
// Turn the mic on
mCloud.startLocalAudio(TRTCCloudDef.TRTC_AUDIO_QUALITY_SPEECH);

// Turn the mic off
mCloud.stopLocalAudio();
// Turn the mic on
[self.trtcCloud startLocalAudio:TRTCAudioQualitySpeech];

// Turn the mic off
[self.trtcCloud stopLocalAudio];
// Turn the mic on
[self.trtcCloud startLocalAudio:TRTCAudioQualitySpeech];

// Turn the mic off
[self.trtcCloud stopLocalAudio];
// Turn the mic on
trtc_cloud_->startLocalAudio(TRTCAudioQualitySpeech);

// Turn the mic off
trtc_cloud_->stopLocalAudio();

Turn the camera on/off

Option 1: Call muteLocalVideo
This interface is equivalent to the two interfaces start/stopLocalPreview when specifying TRTC_VIDEO_STREAM_TYPE_BIG, but has better response speed. This is because start/stopLocalPreview requires turning the camera on and off, and these operations are related to hardware devices, making them very time-consuming. In contrast, muteLocalVideo only needs to pause or release the data flow at the software level, thus being more efficient and more suitable for scenarios that require frequent on/off operations.
Android
iOS
Mac
Windows
// Turn the camera on
mCloud.muteLocalVideo(TRTCCloudDef.TRTC_VIDEO_STREAM_TYPE_BIG, false);

// Turn the camera off
mCloud.muteLocalVideo(TRTCCloudDef.TRTC_VIDEO_STREAM_TYPE_BIG, true);
// Turn the camera on
[self.trtcCloud muteLocalVideo:TRTCVideoStreamTypeBig mute:NO];

// Turn the camera off
[self.trtcCloud muteLocalVideo:TRTCVideoStreamTypeBig mute:YES];
// Turn the camera on
[self.trtcCloud muteLocalVideo:TRTCVideoStreamTypeBig mute:NO];

// Turn the camera off
[self.trtcCloud muteLocalVideo:TRTCVideoStreamTypeBig mute:YES];
// Turn the camera on
trtc_cloud_->muteLocalVideo(TRTCVideoStreamTypeBig, false);

// Turn the camera off
trtc_cloud_->muteLocalVideo(TRTCVideoStreamTypeBig, true);
Option 2: Call startLocalPreview/stopLocalPreview
Android
iOS
Mac
Windows
// Turn the camera on
TXCloudVideoView cameraVideo = findViewById(R.id.txcvv_main_local);
mCloud.startLocalPreview(true, cameraVideo);

// Turn the camera off
mCloud.stopLocalPreview();
// Turn the camera on
[self.trtcCloud startLocalPreview:YES view:self.view];

// Turn the camera off
[self.trtcCloud stopLocalPreview];
// Turn the camera on
[self.trtcCloud startLocalPreview:YES view:self.view];

// Turn the camera off
[self.trtcCloud stopLocalPreview];
// Turn the camera on
trtc_cloud_->startLocalPreview(true, local_view);

// Turn the camera off
trtc_cloud_->stopLocalPreview();

Control the camera

Switch between front and rear cameras: For mobile devices, you can call switchCamera to switch between front and rear cameras.
Android
iOS
// Default to front camera, switch to rear camera
TXDeviceManager manager = mCloud.getDeviceManager();
if(manager.isFrontCamera()) {
    manager.switchCamera(false);
}

// Switch to front camera
TXDeviceManager manager = mCloud.getDeviceManager();
manager.switchCamera(true);
// Default to front camera, switch to rear camera
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
if([deviceManager isFrontCamera]) {
    [deviceManager switchCamera:false];
}

// Switch to front camera
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
[deviceManager switchCamera:true];
Set camera zoom factor: For mobile devices, you can call setCameraZoomRatio to set the camera's zoom factor.
Android
iOS
TXDeviceManager deviceManager = mCloud.getDeviceManager();

float msg = deviceManager.getCameraZoomMaxRatio(); // Get the camera's maximum zoom factor
deviceManager.setCameraZoomRatio(5); // Set the camera's zoom factor to 5
TXDeviceManager *deviceManager = [self.trtcCloud getDeviceManager];
float cameraZoomMaxRatio = [deviceManager getCameraZoomMaxRatio]; // Get the camera's maximum zoom factor
[deviceManager setCameraZoomRatio:5]; // Set the camera's zoom factor to 5

Turn on/off the flash

For mobile devices, after turning on the rear-facing camera, you can call enableCameraTorch to turn the flash on/off.
Android
iOS
// Turn on the flash when switching to the rear-facing camera
TXDeviceManager manager = mCloud.getDeviceManager();
manager.enableCameraTorch(true);

// Turn the flash off
TXDeviceManager manager = mCloud.getDeviceManager();
manager.enableCameraTorch(false);
// Turn on the flash when switching to the rear-facing camera
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
if(![deviceManager isFrontCamera]) {
    [deviceManager enableCameraTorch:true];
}

// Turn off the flash
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
[deviceManager enableCameraTorch:false];

Enable/Disable Face Focus

Calling isAutoFocusEnabled can check if the current mobile device supports automatic face position recognition. If the result is true, it indicates that the device supports this feature. At this point, calling enableCameraAutoFocus can enable the face auto-focus feature.
Android
iOS
// If the device supports automatic face position recognition, enable the auto-focus feature
TXDeviceManager manager = mCloud.getDeviceManager();
if (manager.isAutoFocusEnabled()) {
    manager.enableCameraAutoFocus(true); 
}

// Turn off the auto-focus feature
TXDeviceManager manager = mCloud.getDeviceManager();
manager.enableCameraAutoFocus(false); 
// If the device supports automatic face position recognition, enable the auto-focus feature
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
if([deviceManager isAutoFocusEnabled]) {
    [deviceManager enableCameraAutoFocus:true];
}

// Turn off the auto-focus feature
TXDeviceManager * deviceManager = [self.trtcCloud getDeviceManager];
[deviceManager enableCameraAutoFocus:false];

Detect if the user is speaking after mute

Invoke enableAudioVolumeEvaluation to enable audio volume indication. After enabling this feature, the SDK will provide feedback on audio volume evaluation information for local or remote users in the TRTCCloudListener's onUserVoiceVolume callback, including volume level, voice detection, audio spectrum, etc.
Android
iOS
Mac
Windows
private TRTCCloud mCloud;
mCloud = TRTCCloud.sharedInstance(getApplicationContext());
mCloud.startLocalAudio(TRTCCloudDef.TRTC_AUDIO_QUALITY_SPEECH); // Turn on the microphone

mCloud.muteLocalAudio(true); // Turn off the microphone

// Create a new TRTC instance to detect microphone volume
private TRTCCloud mNewCloud;
mNewCloud = TRTCCloud.sharedInstance(getApplicationContext());
mNewCloud.setListener(new TRTCCloudListener() {
    // Obtain mCloud's audio volume evaluation information through the onUserVoiceVolume callback
    @Override
    public void onUserVoiceVolume(ArrayList<TRTCCloudDef.TRTCVolumeInfo> userVolumes, int totalVolume) {
        super.onUserVoiceVolume(userVolumes, totalVolume);
        // Update the UI here, for example, update the height of the sound column
    }
});

// Set the TRTCAudioVolumeEvaluateParams parameters
TRTCCloudDef.TRTCAudioVolumeEvaluateParams audioVolumeEvaluateParams = new TRTCCloudDef.TRTCAudioVolumeEvaluateParams();
audioVolumeEvaluateParams.enablePitchCalculation = false; // Whether to enable local voice frequency calculation
audioVolumeEvaluateParams.enableSpectrumCalculation = false; // Whether to enable sound spectrum calculation
audioVolumeEvaluateParams.enableVadDetection = false; // Whether to enable local voice detection
audioVolumeEvaluateParams.interval = 100; // Set the trigger interval for the onUserVoiceVolume callback to 100 ms

// Turn on the volume level prompt
mNewCloud.enableAudioVolumeEvaluation(true, audioVolumeEvaluateParams);
// AppDelegate.h
@interface AppDelegate : UIResponder <UIApplicationDelegate, TRTCCloudDelegate> // Add TRTCCloudDelegate interface declaration

@property (nonatomic, strong) TRTCCloud *trtcCloud; // Declare the trtcCloud instance
@property (nonatomic, strong) TRTCCloud *newTRTCCloud; // Declare the newTRTCCloud instance


// AppDelegate.m
_trtcCloud = [TRTCCloud sharedInstance];
_trtcCloud.delegate = self;
[self.trtcCloud startLocalAudio:TRTCAudioQualitySpeech]; // Turn the mic on

[self.trtcCloud muteLocalAudio:YES]; // Turn off the mic

// Initialize a new TRTC instance
_newTRTCCloud = [TRTCCloud sharedInstance];
_newTRTCCloud.delegate = self;

// Set the TRTCAudioVolumeEvaluateParams parameters
TRTCAudioVolumeEvaluateParams *trtcAudioVolumeEvaluateParams = [[TRTCAudioVolumeEvaluateParams alloc] init];
trtcAudioVolumeEvaluateParams.enablePitchCalculation = NO; // Enable local voice frequency calculation
trtcAudioVolumeEvaluateParams.enableSpectrumCalculation = NO; // Enable sound spectrum calculation
trtcAudioVolumeEvaluateParams.enableVadDetection = NO; // Enable local voice detection
trtcAudioVolumeEvaluateParams.interval = 100; // Set the trigger interval of the onUserVoiceVolume callback to 100 ms

// Enable volume level prompt
[self.newTRTCCloud enableAudioVolumeEvaluation:YES withParams:trtcAudioVolumeEvaluateParams];

// Implement TRTCCloudDelegate callback method
- (void)onUserVoiceVolume:(NSArray<TRTCVolumeInfo *> *)userVolumes totalVolume:(NSInteger)totalVolume {
    // Process user volume information
    for (TRTCVolumeInfo *volumeInfo in userVolumes) {
        NSLog(@"User ID: %@, Volume: %ld", volumeInfo.userId, (long)volumeInfo.volume);
        // Update the UI here, such as updating the height of the volume bar
    }
}
// AppDelegate.h
@interface AppDelegate : NSObject <NSApplicationDelegate, TRTCCloudDelegate> // Add TRTCCloudDelegate interface declaration

@property (nonatomic, strong) TRTCCloud *trtcCloud; // Declare the trtcCloud instance
@property (nonatomic, strong) TRTCCloud *newTRTCCloud; // Declare the newTRTCCloud instance


// AppDelegate.m
_trtcCloud = [TRTCCloud sharedInstance];
_trtcCloud.delegate = self;
[self.trtcCloud startLocalAudio:TRTCAudioQualitySpeech]; // Turn the mic on

[self.trtcCloud muteLocalAudio:YES]; // Turn off the mic

// Initialize a new TRTC instance
_newTRTCCloud = [TRTCCloud sharedInstance];
_newTRTCCloud.delegate = self;

// Set the TRTCAudioVolumeEvaluateParams parameters
TRTCAudioVolumeEvaluateParams *trtcAudioVolumeEvaluateParams = [[TRTCAudioVolumeEvaluateParams alloc] init];
trtcAudioVolumeEvaluateParams.enablePitchCalculation = NO; // Enable local voice frequency calculation
trtcAudioVolumeEvaluateParams.enableSpectrumCalculation = NO; // Enable sound spectrum calculation
trtcAudioVolumeEvaluateParams.enableVadDetection = NO; // Enable local voice detection
trtcAudioVolumeEvaluateParams.interval = 100; // Set the trigger interval of the onUserVoiceVolume callback to 100 ms

// Enable volume level prompt
[self.newTRTCCloud enableAudioVolumeEvaluation:YES withParams:trtcAudioVolumeEvaluateParams];

// Implement TRTCCloudDelegate callback method
- (void)onUserVoiceVolume:(NSArray<TRTCVolumeInfo *> *)userVolumes totalVolume:(NSInteger)totalVolume {
    // Process user volume information
    for (TRTCVolumeInfo *volumeInfo in userVolumes) {
        NSLog(@"User ID: %@, Volume: %ld", volumeInfo.userId, (long)volumeInfo.volume);
        // Update the UI here, such as updating the height of the volume bar
    }
}
// .h file
public: 
    ITRTCCloud* trtc_cloud_;
    ITRTCCloud* new_trtc_cloud;
public: 
    virtual void onUserVoiceVolume(TRTCVolumeInfo* userVolumes, uint32_t userVolumesCount, uint32_t totalVolume) override;

// .cpp file
trtc_cloud_ = getTRTCSharedInstance();
trtc_cloud_ -> addCallback(this); 

trtc_cloud_ -> startLocalAudio(TRTCAudioQualitySpeech); // Turn the mic on

trtc_cloud_ -> muteLocalAudio(true); // Turn off the mic

// Create a new TRTC instance to detect microphone volume
new_trtc_cloud_ = getTRTCSharedInstance();
new_trtc_cloud_ -> addCallback(this); 

TRTCAudioVolumeEvaluateParams trtcAudioVolumeEvaluteParams;
trtcAudioVolumeEvaluateParams.enablePitchCalculation = false; // Enable local voice frequency calculation
trtcAudioVolumeEvaluateParams.enableSpectrumCalculation = false; // Enable sound spectrum calculation
trtcAudioVolumeEvaluateParams.enableVadDetection = false; // Enable local voice detection
trtcAudioVolumeEvaluateParams.interval = 100; // Set the trigger interval of the onUserVoiceVolume callback to 100 ms

// Enable volume level prompt
new_trtc_cloud_ -> enableAudioVolumeEvaluation(true, trtcAudioVolumeEvaluateParams);

// Implement TRTCCloudDelegate callback method, replace CLASSNAME with your class name
void CLASSNAME::onUserVoiceVolume(TRTCVolumeInfo* userVolumes, uint32_t userVolumesCount, uint32_t totalVolume) {
    // Update the UI here, such as updating the height of the volume bar
}

Detect the status of the remote user's microphone/camera

This feature is typically used to confirm the on/off status of a remote user's microphone and camera.
Assuming there are currently two users, A and B.
1. When A successfully enters the room, and B also successfully enters the room, A will receive the onRemoteUserEnterRoom event notification.
2. At this time, A assumes that B has not yet turned on their microphone or camera.
3. When A receives onUserAudioAvailable(userId, true) or onUserVideoAvailable(userId, true) from B, it indicates that Remote User B has published their audio/main video stream.
4. When A receives onUserAudioAvailable(userId, false) or onUserVideoAvailable(userId, false) from B, it indicates that Remote User B has canceled the publication of their audio/main video stream.

Contact us

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