Manage video capture devices

API reference

/**
 * @brief Sets the camera zoom.
 * @param zoom The zoom factor. The value ranges from 1 to the maximum zoom value supported by the camera.
 * @return
 * - 0: Success.
 * - A non-zero value: Failure.
 * @note This API is available only on iOS and Android.
 */
public abstract int setCameraZoom(float zoom);

 /**
 * @brief Gets the maximum zoom factor of the camera.
 * @return The maximum zoom factor of the camera.
 */
public abstract float GetCameraMaxZoomFactor();

/**
 * @brief Gets the current zoom factor of the camera.
 * @return The current zoom factor of the camera.
 */
public abstract float GetCurrentZoom();

Examples

// Get zoom information.
private void initZoomSeekBar() {
    if (mAliRtcEngine != null) {
        zoomSeekBar.setEnabled(true);
        // Get the maximum zoom value.
        float maxZoom = mAliRtcEngine.GetCameraMaxZoomFactor();
        float currZoom = mAliRtcEngine.GetCurrentZoom();
        // Set the SeekBar range (from 1.0 to maxZoom, with a step of 0.1).
        if(maxZoom >= 1.0) {
            int maxProgress = (int)((maxZoom - 1) * 10);
            zoomSeekBar.setMax(maxProgress);
            int currProgress = (int)((currZoom - 1) * 10);
            zoomSeekBar.setProgress(currProgress);
        } else{
            zoomSeekBar.setEnabled(false);
        }
    }
}
// Set the zoom.
zoomSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
        if(mAliRtcEngine != null) {
            float newZoom = (float)((i+10) / 10.0);
            mAliRtcEngine.setCameraZoom(newZoom);
            zoomTextView.setText(String.format("%.1f", newZoom));
        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
    }
});

// Get zoom information.
self.cameraZoomSlider.isEnabled = true
let maxZoom = rtcEngine.getCameraMaxZoomFactor()
let currZoom = rtcEngine.getCurrentZoom()
"Get maxZoom=\(maxZoom), currZoom=\(currZoom)".printLog()

self.cameraZoomSlider.minimumValue = 1.0
if maxZoom > 1.0 {
    self.cameraZoomSlider.maximumValue = maxZoom
} else {
    self.cameraZoomSlider.isEnabled = false
}
if currZoom >= 1.0 && currZoom <= maxZoom {
    self.cameraZoomSlider.value = currZoom
    self.cameraZoomValueLabel.text = String(format: "%.1f", self.cameraZoomSlider.value)
}
else {
    self.cameraZoomSlider.value = self.cameraZoomSlider.minimumValue
    self.cameraZoomValueLabel.text = "\(self.cameraZoomSlider.minimumValue)"
}

// Set the zoom.
@IBOutlet weak var cameraZoomSlider: UISlider!
@IBOutlet weak var cameraZoomValueLabel: UILabel!
@IBAction func onCameraZoomChanged(_ sender: UISlider) {
    let currValue = sender.value
    self.cameraZoomValueLabel.text = String(format: "%.1f", currValue)
    self.rtcEngine?.setCameraZoom(currValue)
}

private handleZoomChange(value: number): void {
  if (!this.rtcEngine) {
    return;
  }

  // Calculate the zoom value based on the progress: zoom = 1.0 + (value / 10.0).
  const newZoom = 1.0 + (value / 10.0);

  // Clamp the zoom value between 1.0 and 10.0.
  const clampedZoom = Math.max(1.0, Math.min(10.0, newZoom));

  this.rtcEngine.setCameraZoom(clampedZoom);
  this.zoomValue = clampedZoom.toFixed(1);

  console.info(`Set zoom: ${clampedZoom}`);
}

API reference

/**
 * @brief Sets the camera exposure.
 * @param exposure The exposure value.
 * @return
 * - 0: Success.
 * - A non-zero value: Failure.
 */
public abstract int SetExposure(float exposure);

/**
 * @brief Gets the current camera exposure.
 * @return The current camera exposure.
 */
public abstract float GetCurrentExposure();

/**
 * @brief Gets the minimum camera exposure.
 * @return The minimum camera exposure.
 */
public abstract float GetMinExposure();

/**
 * @brief Gets the maximum camera exposure.
 * @return The maximum camera exposure.
 */
public abstract float GetMaxExposure();

Examples

// Get exposure information.
private void initExposureSeekBar() {
    if (mAliRtcEngine != null) {
        exposureSeekBar.setEnabled(true);
        // Get the maximum exposure value.
        float maxExposure = mAliRtcEngine.GetMaxExposure();
        // Get the minimum exposure value.
        float minExposure = mAliRtcEngine.GetMinExposure();
        float currExposure = mAliRtcEngine.GetCurrentExposure();
        if(maxExposure > minExposure) {
            // Reset the SeekBar range.
            int maxProgress = (int)((maxExposure - minExposure) * 10);
            exposureSeekBar.setMax(maxProgress);
            int currProgress = (int)((currExposure - minExposure) * 10);
            exposureSeekBar.setProgress(currProgress);
        } else {
            exposureSeekBar.setEnabled(false);
        }
    }
}
// Set the exposure.
exposureSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
        if(mAliRtcEngine != null) {
            float minExposure = mAliRtcEngine.GetMinExposure();
            float newExposure = minExposure + (float)(i / 10.0);

            mAliRtcEngine.SetExposure(newExposure);
            exposureTextView.setText(String.format("% .1f", newExposure));
        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
    }
});

// Get device exposure information.
self.cameraExposureSlider.isEnabled = true
let minExposure = rtcEngine.getMinExposure()
let maxExposure = rtcEngine.getMaxExposure()
let currExposure = rtcEngine.getCurrentExposure()
"Get minExposure=\(minExposure), maxExposure=\(maxExposure), currExposure=\(currExposure)".printLog()
if maxExposure > minExposure {
    self.cameraExposureSlider.minimumValue = minExposure
    self.cameraExposureSlider.maximumValue = maxExposure
} else {
    self.cameraExposureSlider.isEnabled = false
}
if currExposure >= minExposure && currExposure <= maxExposure {
    self.cameraExposureSlider.value = currExposure
    self.cameraExposureValueLabel.text = String(format: "%.1f", self.cameraExposureSlider.value)
}
else {
    self.cameraExposureSlider.value = self.cameraExposureSlider.minimumValue
    self.cameraExposureValueLabel.text = "\(self.cameraExposureSlider.minimumValue)"
}
// Set the exposure.
@IBOutlet weak var cameraExposureValueLabel: UILabel!
@IBOutlet weak var cameraExposureSlider: UISlider!
@IBAction func onCameraExposureChanged(_ sender: UISlider) {
    let currValue = sender.value
    self.cameraExposureValueLabel.text = String(format: "%.1f", currValue)
    self.rtcEngine?.setExposure(currValue)
}

// Handle exposure change.
private handleExposureChange(value: number): void {
  if (!this.rtcEngine) {
    return;
  }
  // Conversion formula: exposure value = progress value / 10.
  const actualValue = value / 10.0;
  // Clamp the exposure value between -12.0 and 12.0.
  const clampedExposure = Math.max(-12.0, Math.min(12.0, actualValue));
  // Update the state.
  this.exposureSliderValue = value;
  this.exposureValue = this.formatExposureValue(clampedExposure);
  // Call the RTC engine to set the exposure compensation.
  try {
    this.rtcEngine.setExposure(clampedExposure);
    console.info(`Set exposure compensation: ${clampedExposure}`);
  } catch (error) {
    console.error('Failed to set exposure compensation:', error);
  }
}

API reference

/**
 * @brief Checks whether the camera supports setting a manual exposure point.
 * @return
 * - true: Supported.
 * - false: Not supported.
 * @note This API is available only on iOS and Android and is used to check if an exposure point can be set for the current camera.
 */
public abstract boolean isCameraExposurePointSupported();
/**
 * @brief Sets the camera exposure point.
 * @param x The normalized x-coordinate. The value ranges from 0 to 1.
 * @param y The normalized y-coordinate. The value ranges from 0 to 1.
 * @return
 * - 0: Success.
 * - A non-zero value: Failure.
 * @note This API is available only on iOS and Android. After you call this method, the camera performs a one-time exposure adjustment at the specified point and maintains that exposure value.
 */
public abstract int setCameraExposurePoint(float x, float y);

Examples

// Manually set the exposure point.
mLocalViewGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {
    @Override
    public boolean onDoubleTap(@NonNull MotionEvent e) {
        // Handle double-tap.
        // ...
        return true;
    }
    @Override
    public boolean onSingleTapConfirmed(@NonNull MotionEvent e) {
        // Handle single-tap.
        if(mAliRtcEngine != null && mAliRtcEngine.isCameraExposurePointSupported()) {
            float[] normalizedCoords = getNormalizedCoordinates(e.getX(), e.getY());
            if (normalizedCoords[0] != -1 && normalizedCoords[1] != -1) {
                mAliRtcEngine.setCameraExposurePoint(normalizedCoords[0], normalizedCoords[1]);
                mCameraExposurePointX.setText(String.format("%.2f", normalizedCoords[0]));
                mCameraExposurePointY.setText(String.format("%.2f", normalizedCoords[1]));
            }
        }
        return true;
    }
});

@objc func handleSeatViewTap(_ gesture: UITapGestureRecognizer) {
    guard let localSeatView = self.localPreviewSeatView else {
        return
    }
    guard let rtcEngine = self.rtcEngine, rtcEngine.isCameraExposurePointSupported() else { return }


    let tapPoint = gesture.location(in: localSeatView)
    // Convert the tap coordinates to normalized coordinates (0-1 range) of the video frame.
    let normalizedX = tapPoint.x / localSeatView.bounds.width
    let normalizedY = tapPoint.y / localSeatView.bounds.height

    rtcEngine.setCameraExposurePoint(CGPoint(x: normalizedX, y: normalizedY))
    self.cameraExposurePointXTextField.text = String(format: "%.2f", normalizedX)
    self.cameraExposurePointYTextField.text = String(format: "%.2f", normalizedY)
}

private handleSingleTap(touchX: number, touchY: number): void {
  if (!this.rtcEngine) {
    return;
  }
  // Get normalized coordinates.
  const normalizedCoords = this.getNormalizedCoordinates(touchX, touchY);
  if (normalizedCoords[0] !== -1 && normalizedCoords[1] !== -1) {
    this.rtcEngine.setCameraExposurePoint(normalizedCoords[0], normalizedCoords[1]);
    this.exposurePointX = normalizedCoords[0].toFixed(2);
    this.exposurePointY = normalizedCoords[1].toFixed(2);
    console.info('Set exposure point:', this.exposurePointX, this.exposurePointY);
  }
}

API reference

/**
 * @brief Checks whether the camera supports manual focus.
 * @return
 * - true: Supported.
 * - false: Not supported.
 * @note This API is available only on iOS and Android and is used to check if a focus point can be set for the current camera.
 */
public abstract boolean isCameraFocusPointSupported();
/**
 * @brief Sets the manual focus point for the camera.
 * @param x The x-coordinate value (normalized).
 * @param y The y-coordinate value (normalized).
 * @return
 * - 0: Success.
 * - A non-zero value: Failure.
 * @note This API is available only on iOS and Android. After you call this method, the camera performs a one-time focus adjustment at the specified point and maintains that focus value.
 */
public abstract int setCameraFocusPoint(float x, float y);

Examples

The following examples show how to set the exposure point on a single tap and the focus point on a double tap.

mLocalViewGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {
    @Override
    public boolean onDoubleTap(@NonNull MotionEvent e) {
        // Handle double-tap.
        if(mAliRtcEngine != null && mAliRtcEngine.isCameraFocusPointSupported()) {
            float[] normalizedCoords = getNormalizedCoordinates(e.getX(), e.getY());
            if (normalizedCoords[0] != -1 && normalizedCoords[1] != -1) {
                mAliRtcEngine.setCameraFocusPoint(normalizedCoords[0], normalizedCoords[1]);
                mCameraFocusPointX.setText(String.format("%.2f", normalizedCoords[0]));
                mCameraFocusPointY.setText(String.format("%.2f", normalizedCoords[1]));
            }
        }
        return true;
    }
    @Override
    public boolean onSingleTapConfirmed(@NonNull MotionEvent e) {
        // Handle single-tap.
        // ...
        return true;
    }
});

@objc func handleSeatViewDoubleTap(_ gesture: UITapGestureRecognizer) {
    guard let localSeatView = self.localPreviewSeatView else {
        return
    }
    guard let rtcEngine = self.rtcEngine, rtcEngine.isCameraFocusPointSupported() else { return }
    
    let tapPoint = gesture.location(in: localSeatView)
    // Convert the tap coordinates to normalized coordinates (0-1 range) of the video frame.
    let normalizedX = tapPoint.x / localSeatView.bounds.width
    let normalizedY = tapPoint.y / localSeatView.bounds.height
    
    rtcEngine.setCameraFocus(CGPoint(x: normalizedX, y: normalizedY))
    self.cameraFocusPointXTextField.text = String(format: "%.2f", normalizedX)
    self.cameraFocusPointYTextField.text = String(format: "%.2f", normalizedY)
}

private handleDoubleTap(touchX: number, touchY: number): void {
  if (!this.rtcEngine) {
    return;
  }
  // Get normalized coordinates.
  const normalizedCoords = this.getNormalizedCoordinates(touchX, touchY);
  if (normalizedCoords[0] !== -1 && normalizedCoords[1] !== -1) {
    this.rtcEngine.setCameraFocusPoint(normalizedCoords[0], normalizedCoords[1]);
    this.focusPointX = normalizedCoords[0].toFixed(2);
    this.focusPointY = normalizedCoords[1].toFixed(2);
    console.info('Set focus point:', this.focusPointX, this.focusPointY);
  }
}

API reference

/**
 * @brief Checks whether the camera supports the auto-focus on faces feature.
 * @return
 * - true: Supported.
 * - false: Not supported.
 * @note This API is available only on iOS and Android. It returns false if the camera is off. 
 *       If the camera is on and supports both face detection and auto-focus, it returns true.
 */
public abstract boolean isCameraAutoFocusFaceModeSupported();

/**
 * @brief Enables or disables the auto-focus on faces feature.
 * @param enable
 * - true: Enable.
 * - false: Disable.
 * @return
 * - true: Success.
 * - false: Failure.
 * @note This API is available only on iOS and Android. If {@link AliRtcEngine#isCameraAutoFocusFaceModeSupported} returns true
 *       and you set enable to true, the camera continuously focuses on the detected faces.
 */
public abstract boolean setCameraAutoFocusFaceModeEnabled(boolean enable);

Examples

if (mAliRtcEngine.isCameraAutoFocusFaceModeSupported()) {
    mAliRtcEngine.setCameraAutoFocusFaceModeEnabled(isChecked);
}

@IBAction func onCameraAudoFocusSwitch(_ sender: UISwitch) {
    if ((self.rtcEngine?.isCameraAutoFocusFaceModeSupported()) != nil) {
        self.rtcEngine?.setCameraAutoFocusFaceModeEnabled(sender.isOn)
    }
}

API reference

/**
 * @brief Turns the camera flashlight on or off.
 * @param flash Specifies whether to turn on the flashlight.
 * @return
 * - 0: Success.
 * - A non-zero value: Failure.
 * @note This API is available only on iOS and Android. Typically, only the rear camera has a flashlight.
 */
public abstract int setCameraFlash(boolean flash);

Examples

mCameraFlashSwitch = findViewById(R.id.camera_flash_switch);
mCameraFlashSwitch.setEnabled(false);
mCameraFlashSwitch.setOnCheckedChangeListener((buttonView, isChecked) -> {
    if (mAliRtcEngine != null) {
        mAliRtcEngine.setCameraFlash(isChecked);
    }
});

@IBOutlet weak var cameraFlashSwitch: UISwitch!
@IBAction func onCameraFlashSwitch(_ sender: UISwitch) {
    if self.rtcEngine?.getCurrentCameraDirection() == .back {
        self.rtcEngine?.setCameraFlash(sender.isOn)
    }
}

private handleFlashChange(value: boolean): void {
  if (!this.rtcEngine) {
    return;
  }

  this.rtcEngine.setCameraFlash(value);
}