安卓使用uvc协议调用usb外接摄像头

Java 自带的camera api只能获取简单的拍摄，无法实现类似手机的调倍数和调焦距。自己使用github上项目为大家试试能不能成功。

目前比较简单直接拉取就可以使用的是UVCAndroid这个项目源码。其他的只要你们能搜索到，我都尝试了，要不是libusb这个编译不出来，要不就是缺少ndk。

我接下来试试用ndk看可以运行成功不。

我的需求是，用代码页面滚动条控制摄像头的参数。有些usb摄像头还真的不好搞。有大佬成功过没。

下面代码是camera。可以运行成功，对一些没那么高要求的摄像头还是没问题的。

package com.hs.smart.cabinet.ui;

import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.ImageFormat;
import android.hardware.Camera;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.Surface;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;

import com.donkingliang.imageselector.ImageSelectorActivity;
import com.hs.smart.cabinet.R;
import com.hs.smart.cabinet.helper.CameraControlsDialogFragment;
import com.hs.smart.cabinet.helper.ProcessPhotoAsyncTask;
import com.hs.smart.cabinet.utils.MyField;

import java.io.IOException;
import java.util.List;
import android.widget.SeekBar;

/************************************
 *@desc：这是拍照页面，使用第三个摄像头拍照
 * 即涉案涉财柜中的第三个摄像头
 *@Author: admin
 *@DateTime:2024/4/2 11:59
 *@Copyright: hskj
 *************************************/
public class TakePhotoActivity extends AppCompatActivity
        implements View.OnClickListener, Camera.PreviewCallback {
    private SurfaceView surfaceView;
    private Button photograph;
    private Button switchs;
    private CameraControlsDialogFragment mControlsDialog;

    private Button camerasettings;
    private int rotation;
    private int shortSize;
    private int longSize;
    private Camera camera;
    private Camera.CameraInfo cameraInfo;
    private Camera.Parameters parameters;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_take_photo);
        initView();
    }

    private void initView() {
        surfaceView = (SurfaceView) findViewById(R.id.camera_view);
        photograph = (Button) findViewById(R.id.photograph);
        switchs = (Button) findViewById(R.id.switchs);
        camerasettings = (Button) findViewById(R.id.camerasettings);
        photograph.setOnClickListener(this);
        switchs.setOnClickListener(this);
        camerasettings.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.photograph:    //拍照
                if (camera == null) {
                    Toast.makeText(this, "请打开相机", Toast.LENGTH_SHORT).show();
                    return;
                }
                parameters = camera.getParameters();
                parameters.setPictureFormat(ImageFormat.JPEG);
                camera.setParameters(parameters);
                camera.startPreview();
                camera.takePicture(null, null, new Camera.PictureCallback() {
                    @Override
                    public void onPictureTaken(byte[] data, Camera camera) {
                        ProcessPhotoAsyncTask myTask = new ProcessPhotoAsyncTask(TakePhotoActivity.this,
                                cameraInfo.facing,
                                data,
                                camera,
                                processImageHandler
                        );
                        myTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
                    }
                });

                break;

            case R.id.switchs:
                gotoTakePhoto();
                break;
            case R.id.camerasettings:
                showCameraControlsDialog();
                break;
        }
    }
    private void showCameraControlsDialog() {
        if (mControlsDialog == null) {
            mControlsDialog = new CameraControlsDialogFragment();
        }

        // When DialogFragment is not showing
        if (!mControlsDialog.isAdded()) {
            mControlsDialog.show(getSupportFragmentManager(), "controls_dialog");
        }
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus) {
            int[] a = new int[2];
            surfaceView.getLocationOnScreen(a);
            shortSize = surfaceView.getHeight();     //横屏为宽度，竖屏为高度
            longSize = surfaceView.getWidth();
            rotation = getWindowManager().getDefaultDisplay().getRotation();
            cameraInfo = new Camera.CameraInfo();
            checkCameraPermission();
        }
    }

    private Handler processImageHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case 1:
                    String filePath = (String) msg.obj;
                    Intent data = new Intent();
                    data.putExtra(MyField.KEY_CARGO_PHOTO_PATH, filePath);
                    setResult(RESULT_OK, data);
                    finish();
                    break;
                default:
                    break;
            }
        }
    };


    // 1.申请相机权限---------------------------------------------------------------------------
    private void checkCameraPermission() {
        //检查是否有相机权限
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED &&
                ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            //没权限，请求权限
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA, Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    1);
        } else {
            //有权限
            //Log.d("MainActivity", "有权限");
            getCameras(0);  //0为后摄，1为前摄
        }
    }

    //权限请求回调
    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode) {
            case 1:
                if (grantResults != null && grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    //用户同意权限
                    getCameras(0);  //0为后摄，1为前摄
                } else {
                    // 权限被用户拒绝了，可以提示用户,关闭界面等等。
                    Toast.makeText(this, "拒绝权限，请去设置里面手动开启权限", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }

    //预览数据监听
    @Override
    public void onPreviewFrame(byte[] data, Camera camera) {
        camera.addCallbackBuffer(data);
    }

    /*
   3.查找指定摄像头ID，根据摄像头ID打开指