Android使用UVCCamera打开USBCamera-预览

导入libuvccamera.aar

写一个管理类封装UVCCamera相关API

import android.content.Context
import android.hardware.usb.UsbDevice
import android.os.Handler
import android.os.HandlerThread
import android.os.Message
import android.util.Log
import android.view.Surface
import com.serenegiant.usb.DeviceFilter
import com.serenegiant.usb.IFrameCallback
import com.serenegiant.usb.USBMonitor
import com.serenegiant.usb.UVCCamera
import java.nio.ByteBuffer


class UsbCameraManager(mContext:Context) :IFrameCallback{
    private val TAG = "UsbCameraManager"
    private var handlerThread = HandlerThread("UsbCameraManager")
    private var usbMonitor:USBMonitor?=null
    private var handler: Handler?=null
    private var uvcCamera:UVCCamera?=null
    private var mPreviewSurface: Surface? = null
    private val OPEN_CAMERA = 1
    init {
        handlerThread.start()
        handler = object : Handler(handlerThread.looper){
            override fun handleMessage(msg: Message) {
                super.handleMessage(msg)
                when(msg.what){
                    OPEN_CAMERA->{
                        openCamera(msg.obj as USBMonitor.UsbControlBlock)
                    }
                }

            }
        }
        usbMonitor = USBMonitor(mContext,object :USBMonitor.OnDeviceConnectListener{
            override fun onAttach(device: UsbDevice?) {
                Log.i(TAG, "onAttach ${device?.deviceId}")
                val filter = DeviceFilter.getDeviceFilters(mContext, com.serenegiant.uvccamera.R.xml.device_filter)
                usbMonitor?.let {
                    val devices: List<UsbDevice> = it.getDeviceList(filter[0])
                    if (devices != null && devices.isNotEmpty()) {
                        val cameraDevice = devices[0]
                        it.requestPermission(cameraDevice)
                    } else {
                        Log.i(TAG, "连接失败")
                    }
                }
            }

            override fun onDettach(device: UsbDevice?) {
                Log.i(TAG, "onDettach ${device?.deviceId}")
            }

            override fun onConnect(device: UsbDevice?, ctrlBlock: USBMonitor.UsbControlBlock?, createNew: Boolean) {
                Log.i(TAG, "onConnect ${device?.deviceId}")
                ctrlBlock?.let {
                    var message = Message().apply {
                        what = OPEN_CAMERA
                        obj = it
                    }
                    handler?.sendMessage(message)
                }
            }

            override fun onDisconnect(device: UsbDevice?, ctrlBlock: USBMonitor.UsbControlBlock?) {
                Log.i(TAG, "onDisconnect ${device?.deviceId}")
                stop()
            }

            override fun onCancel(device: UsbDevice?) {
                Log.i(TAG, "onCancel ${device?.deviceId}")
                stop()
            }

        })
    }

    public fun start(mSurface: Surface){
        mPreviewSurface = mSurface
        usbMonitor?.register()
    }
    private fun openCamera(ctrlBlock: USBMonitor.UsbControlBlock){
            if (uvcCamera != null){
                stop()
            }
            uvcCamera = UVCCamera()
            uvcCamera?.open(ctrlBlock)
            uvcCamera?.setPreviewDisplay(mPreviewSurface)
            uvcCamera?.setPreviewSize(1920,1080)
            uvcCamera?.setFrameCallback(this,UVCCamera.PIXEL_FORMAT_NV21)
            uvcCamera?.startPreview()
    }

    override fun onFrame(frame: ByteBuffer?) {
        frame?.let {
            val length = it.capacity()
            it.clear()
            var tmpBuf = ByteArray(length)
            frame[tmpBuf, 0, length]
            Log.i(TAG,"onFrame $frame.length")
        }
    }
    public fun stop(){
        uvcCamera?.stopPreview()
        uvcCamera?.close()
        uvcCamera?.destroy()
        uvcCamera = null

    }
}

添加预览界面

    <TextureView
        android:id="@+id/preview_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

获取TextureView的Surface，开启预览

		previewView = findViewById(R.id.preview_view)
        previewView?.surfaceTextureListener = object : TextureView.SurfaceTextureListener {
            override fun onSurfaceTextureAvailable(p0: SurfaceTexture, p1: Int, p2: Int) {
                val surface = Surface(p0)
                usbCameraManager?.start(surface)
            }

            override fun onSurfaceTextureSizeChanged(p0: SurfaceTexture, p1: Int, p2: Int) {

            }

            override fun onSurfaceTextureDestroyed(p0: SurfaceTexture): Boolean {
                return false
            }

            override fun onSurfaceTextureUpdated(p0: SurfaceTexture) {
            }

        }
        usbCameraManager = UsbCameraManager(mContext)