Android平台如何通过OTG外接UVC摄像头实时预览并回传到GB28181平台

public void initCameraHelper() {
	Toast.makeText(this, "initCameraHelper", Toast.LENGTH_SHORT).show();

	if (mCameraHelper == null) {
		mCameraHelper = new CameraHelper();
		mCameraHelper.setStateCallback(mStateListener);
	}
}

private final ICameraHelper.StateCallback mStateListener = new ICameraHelper.StateCallback() {
	@Override
	public void onAttach(UsbDevice device) {
		selectDevice(device);
	}

	@Override
	public void onDeviceOpen(UsbDevice device, boolean isFirstOpen) {
		mCameraHelper.openCamera();
	}

	@Override
	public void onCameraOpen(UsbDevice device) {

		mCameraHelper.startPreview();
		mCameraHelper.addSurface(mCameraViewMain.getHolder().getSurface(), false);
	}

	@Override
	public void onCameraClose(UsbDevice device) {

		if (mCameraHelper != null) {
			mCameraHelper.removeSurface(mCameraViewMain.getHolder().getSurface());
		}

		clearFPS();
	}

	@Override
	public void onDeviceClose(UsbDevice device) {
	}

	@Override
	public void onDetach(UsbDevice device) {
	}

	@Override
	public void onCancel(UsbDevice device) {
	}

};

mCameraHelper.setFrameCallback(frame -> {
    ...
	int w = size.width, h = size.height;
	int y_stride =  size.width, uv_stride =  size.width;
	int y_offset = 0, uv_offset =  size.width * size.height;
	int is_vertical_flip = 0, is_horizontal_flip = 0;
	int rotation_degree = 0;
	int scale_w = 0, scale_h = 0, scale_filter_mode = 0;

	for (LibPublisherWrapper i : publisher_array_)
	{
		i.PostLayerImageNV21ByteBuffer(0, 0, 0,
			frame, y_offset, y_stride, frame, uv_offset, uv_stride, w, h,
			is_vertical_flip, is_horizontal_flip, scale_w, scale_h, scale_filter_mode, rotation_degree);
	}

}, UVCCamera.PIXEL_FORMAT_NV21);

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" ></uses-permission>
<uses-permission android:name="android.permission.INTERNET" ></uses-permission>
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>

static {  
    System.loadLibrary("SmartPublisher");
    System.loadLibrary("SmartPlayer");
}

splits {
    abi {
        enable true
        reset()
        // Specifies a list of ABIs that Gradle should create APKs for
        include 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64' //select ABIs to build APKs for
        // Specify that we do not want to also generate a universal APK that includes all ABIs
        universalApk true
    }
}

<string name="app_name">SmartPublisherSDKDemo</string>

public class MainActivity extends Activity implements ViewTreeObserver.OnGlobalLayoutListener, Camera2Listener,
        GBSIPAgentListener, GBSIPAgentPlayListener, GBSIPAgentAudioBroadcastListener,
        GBSIPAgentDeviceControlListener, GBSIPAgentQueryCommandListener, 
        GBSIPAgentTalkListener, 
        GBSIPAgentQueryRecordInfoListener{
}

public interface GBSIPAgentListener
{
    /*注册成功
    * @param dateString: 服务器日期，用来校准设备端时间，用户自行决定是否校准设备时间
    */
    void ntsRegisterOK(String dateString);

    /*
    *注册超时
    */
    void ntsRegisterTimeout();

    /*
    *注册网络传输层异常
    */
    void ntsRegisterTransportError(String errorInfo);

    /*
    *心跳达到异常次数
    */
    void ntsOnHeartBeatException(int exceptionCount, String lastExceptionInfo);

    /*
     * 设备位置请求, 这个主要用在移动设备位置订阅上
     * @param interval 请求间隔, 单位是毫秒
     */
    void ntsOnDevicePositionRequest(String deviceId, int interval);
}

public interface GBSIPAgentPlayListener {

    /*
     *收到s=Play的实时视音频点播
     */
    void ntsOnInvitePlay(String deviceId, SessionDescription sessionDescription);

    /*
     *发送play invite response 异常
     */
    void ntsOnPlayInviteResponseException(String deviceId, int statusCode, String errorInfo);

    /*
     * 收到CANCEL play INVITE请求
     */
    void ntsOnCancelPlay(String deviceId);

    /*
     * 收到Ack
     */
    void ntsOnAckPlay(String deviceId);

    /*
     * 收到Bye
     */
    void ntsOnByePlay(String deviceId);

    /*
     * 不是在收到BYE Message情况下， 终止Play
     */
    void ntsOnTerminatePlay(String deviceId);

    /*
     * Play会话对应的对话终止, 一般不会出发这个回调,目前只有在响应了200K, 但在64*T1时间后还没收到ACK,才可能会出发
    收到这个, 请做相关清理处理
    */
    void ntsOnPlayDialogTerminated(String deviceId);
}

public interface GBSIPAgentAudioBroadcastListener {

    /*
     *收到语音广播通知
     */
    void ntsOnNotifyBroadcastCommand(String fromUserName, String fromUserNameAtDomain, String sn, String sourceID, String targetID);

    /*
     *需要准备接受语音广播的SDP内容
     */
    void ntsOnAudioBroadcast(String commandFromUserName, String commandFromUserNameAtDomain, String sourceID, String targetID);

    /*
     *音频广播, 发送Invite请求异常
     */
    void ntsOnInviteAudioBroadcastException(String sourceID, String targetID, String errorInfo);

    /*
     *音频广播, 等待Invite响应超时
     */
    void ntsOnInviteAudioBroadcastTimeout(String sourceID, String targetID);

    /*
     *音频广播, 收到Invite消息最终响应
     */
    void ntsOnInviteAudioBroadcastResponse(String sourceID, String targetID, int statusCode, SessionDescription sessionDescription);

    /*
     * 音频广播, 收到BYE Message
     */
    void ntsOnByeAudioBroadcast(String sourceID, String targetID);


    /*
     * 不是在收到BYE Message情况下， 终止音频广播
     */
    void ntsOnTerminateAudioBroadcast(String sourceID, String targetID);
}

public interface GBSIPAgentDeviceControlListener {

    /*
     * 收到远程启动控制命令
     */
    void ntsOnDeviceControlTeleBootCommand(String deviceId, String teleBootValue);

    /*
    * 云台控制
     */
    void ntsOnDeviceControlPTZCmd(String deviceId, String typeValue);
}

public interface GBSIPAgentQueryCommandListener {

    /*
     * 设备预置位查询
     */
    void ntsOnDevicePresetQueryCommand(String fromUserName, String fromUserNameAtDomain, String sn, String deviceId);
}