首先需要在相关部分添加uvc的功能，这里参考一下：rockchip rk3588添加uvc及uvc,adb的复合设备_uvc.gs6-CSDN博客

setprop sys.usb.config none;setprop sys.usb.config uvc
或者setprop sys.usb.config none;setprop sys.usb.config uvc,adb
使rk3588 进入uvc的device模式。

然后我们开始uvc_app的开发：

由于涉及到UVC协议和V4L2标准接口，所以通过调用JNI接口来实现UVC的功能。

上述进入device模式之后，会在/dev下生成一个video节点，通过ls /sys/class/video4linux来确认节点

1、对这个节点，我们需要先配置需要监听的事件

static void uvc_events_init(struct uvc_device *dev)
{struct v4l2_event_subscription sub;unsigned int payload_size;switch (dev->fcc) {case V4L2_PIX_FMT_YUYV:payload_size = dev->width * dev->height * 2;break;case V4L2_PIX_FMT_MJPEG:payload_size = dev->imgsize;break;}uvc_fill_streaming_control(dev, &dev->probe, 0, 0);uvc_fill_streaming_control(dev, &dev->commit, 0, 0);if (dev->bulk) {/* FIXME Crude hack, must be negotiated with the driver. */dev->probe.dwMaxPayloadTransferSize = dev->commit.dwMaxPayloadTransferSize = payload_size;}memset(&sub, 0, sizeof sub);sub.type = UVC_EVENT_SETUP;ioctl(dev->uvc_fd, VIDIOC_SUBSCRIBE_EVENT, &sub);sub.type = UVC_EVENT_DATA;ioctl(dev->uvc_fd, VIDIOC_SUBSCRIBE_EVENT, &sub);sub.type = UVC_EVENT_STREAMON;ioctl(dev->uvc_fd, VIDIOC_SUBSCRIBE_EVENT, &sub);sub.type = UVC_EVENT_STREAMOFF;ioctl(dev->uvc_fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
}

主要分为连接、断开、数据传输、流的开启或关闭

2、监听事件

static void uvc_events_process(struct uvc_device *dev)
{struct v4l2_event v4l2_event;struct uvc_event *uvc_event = (void *)&v4l2_event.u.data;struct uvc_request_data resp;int ret;ret = ioctl(dev->uvc_fd, VIDIOC_DQEVENT, &v4l2_event);if (ret < 0) {printf("VIDIOC_DQEVENT failed: %s (%d)\n", strerror(errno), errno);return;}memset(&resp, 0, sizeof resp);resp.length = -EL2HLT;switch (v4l2_event.type) {case UVC_EVENT_CONNECT:return;case UVC_EVENT_DISCONNECT:dev->uvc_shutdown_requested = 1;printf("UVC: Possible USB shutdown requested from ""Host, seen via UVC_EVENT_DISCONNECT\n");return;case UVC_EVENT_SETUP:uvc_events_process_setup(dev, &uvc_event->req, &resp);break;case UVC_EVENT_DATA:ret = uvc_events_process_data(dev, &uvc_event->data);if (ret < 0)break;return;case UVC_EVENT_STREAMON:if (!dev->bulk)uvc_handle_streamon_event(dev);return;case UVC_EVENT_STREAMOFF:/* Stop V4L2 streaming... */if (!dev->run_standalone && dev->vdev->is_streaming) {/* UVC - V4L2 integrated path. */v4l2_stop_capturing(dev->vdev);dev->vdev->is_streaming = 0;}/* ... and now UVC streaming.. */if (dev->is_streaming) {uvc_video_stream(dev, 0);uvc_uninit_device(dev);uvc_video_reqbufs(dev, 0);dev->is_streaming = 0;dev->first_buffer_queued = 0;}return;}ret = ioctl(dev->uvc_fd, UVCIOC_SEND_RESPONSE, &resp);if (ret < 0) {printf("UVCIOC_S_EVENT failed: %s (%d)\n", strerror(errno), errno);return;}
}

3、初始化节点，也就是对UVC流控制端口的配置，配置传输速率、包大小、端点序号等。

static void uvc_events_process_streaming(struct uvc_device *dev, uint8_t req, uint8_t cs, struct uvc_request_data *resp)
{struct uvc_streaming_control *ctrl;printf("streaming request (req %02x cs %02x)\n", req, cs);if (cs != UVC_VS_PROBE_CONTROL && cs != UVC_VS_COMMIT_CONTROL)return;ctrl = (struct uvc_streaming_control *)&resp->data;resp->length = sizeof *ctrl;switch (req) {case UVC_SET_CUR:dev->control = cs;resp->length = 34;break;case UVC_GET_CUR:if (cs == UVC_VS_PROBE_CONTROL)memcpy(ctrl, &dev->probe, sizeof *ctrl);elsememcpy(ctrl, &dev->commit, sizeof *ctrl);break;case UVC_GET_MIN:case UVC_GET_MAX:case UVC_GET_DEF:uvc_fill_streaming_control(dev, ctrl, req == UVC_GET_MAX ? -1 : 0, req == UVC_GET_MAX ? -1 : 0);break;case UVC_GET_RES:CLEAR(ctrl);break;case UVC_GET_LEN:resp->data[0] = 0x00;resp->data[1] = 0x22;resp->length = 2;break;case UVC_GET_INFO:resp->data[0] = 0x03;resp->length = 1;break;}
}

除了上述还有其他配置，比如亮度、曝光、闪光灯等配置，就不再一一赘述了。

4、最后是开启UVC流

static int uvc_handle_streamon_event(struct uvc_device *dev)
{int ret;ret = uvc_video_reqbufs(dev, dev->nbufs);if (ret < 0)goto err;if (!dev->run_standalone) {/* UVC - V4L2 integrated path. */if (IO_METHOD_USERPTR == dev->vdev->io) {/** Ensure that the V4L2 video capture device has already* some buffers queued.*/ret = v4l2_reqbufs(dev->vdev, dev->vdev->nbufs);if (ret < 0)goto err;}ret = v4l2_qbuf(dev->vdev);if (ret < 0)goto err;/* Start V4L2 capturing now. */ret = v4l2_start_capturing(dev->vdev);if (ret < 0)goto err;dev->vdev->is_streaming = 1;}/* Common setup. *//* Queue buffers to UVC domain and start streaming. */ret = uvc_video_qbuf(dev);if (ret < 0)goto err;if (dev->run_standalone) {uvc_video_stream(dev, 1);dev->first_buffer_queued = 1;dev->is_streaming = 1;}return 0;err:return ret;
}

在这个函数里面我们就可以通过采集摄像头的数据，来写入到UVC节点里面

最后是JNI函数的封装

在我们自定义的类中可以声明该函数

 public static native int prepareCamera(String uvcDevName,String v4lDevName);

然后通过 javac -h命令把这个类生成一个头文件，实现头文件里声明的函数，将以上的流程添加到这个函数里，最后在对应地方调用即可

UVC实现源码：https://github.com/wlhe/uvc-gadget