两个USB UVC Camera前后摄切换

os:android7.1

 

现象:
设备接用一个双目的USB Camera（IR+RGB）,但只能打开其中一个，不能切换。

 

原因:

在HAL层会根据USB的card name来设置当前是前置还是后置Camera:

                if (strstr((char*)&capability.card[0], "front") != NULL) {
                    camInfoTmp[cam_cnt&0x01].facing_info.facing = CAMERA_FACING_FRONT;
                } else {
                    camInfoTmp[cam_cnt&0x01].facing_info.facing = CAMERA_FACING_BACK;
                } 

事实上, UVC驱动返回给HAL层的card值都是&capability.card[0]=USB 2.0 Camera, 这就导致了上层APK看到的两颗Camera都是后置摄像头，而只能打开一颗了.

 

解决办法:
1. 修改驱动返回上来的card值. 比如根据UVC Camera的pid/vid不同来处理.

2.hal层判断摄像头个数大于1时候，就分别赋值前后摄属性

 

第一种：

--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -548,13 +548,26 @@ static int uvc_v4l2_release(struct file *file)
 static int uvc_ioctl_querycap(struct file *file, void *fh,
                              struct v4l2_capability *cap)
 {
-       struct video_device *vdev = video_devdata(file);
+       // struct video_device *vdev = video_devdata(file);
        struct uvc_fh *handle = file->private_data;
        struct uvc_video_chain *chain = handle->chain;
        struct uvc_streaming *stream = handle->stream;
 
+       printk("wmc idVendor:0x%x idProduct:0x%x\n ", stream->dev->udev->descriptor.idVendor, 
+               stream->dev->udev->descriptor.idProduct);
+
        strlcpy(cap->driver, "uvcvideo", sizeof(cap->driver));
+#if 0
        strlcpy(cap->card, vdev->name, sizeof(cap->card));
+#else
+       if(stream->dev->udev->descriptor.idProduct == 0xd570) {
+               printk("wmc----card:%s\n",cap->card);
+               strcpy(cap->card, "front");
+       } else {
+               printk("wmc----card1:%s\n",cap->card);
+               strcpy(cap->card, "back");
+       }
+#endif

第二种：

hardware/rockchip/camera

diff --git a/CameraHal/CameraHal_Module.cpp b/CameraHal/CameraHal_Module.cpp
index 5d776ad..599f63b 100755
--- a/CameraHal/CameraHal_Module.cpp
+++ b/CameraHal/CameraHal_Module.cpp
@@ -901,7 +901,18 @@ int camera_get_number_of_cameras(void)
                                        unsigned int mCamDriverSupportFmt[CAMERA_DRIVER_SUPPORT_FORMAT_MAX]={0};
                                        unsigned int mCamDriverPreviewFmt=0;
                                        unsigned int maxfps;
-
+                                       //add usb-cam patch by wmc
+                                       if(cam_cnt == 0)
+                                       {
+                                               camInfoTmp[cam_cnt&0x01].facing_info.facing = CAMERA_FACING_FRONT;
+                                               camInfoTmp[cam_cnt&0x01].facing_info.orientation = 0;//90;
+                                       }
+                                       else
+                                       {
+                                               camInfoTmp[cam_cnt&0x01].facing_info.facing = CAMERA_FACING_BACK;
+                                               camInfoTmp[cam_cnt&0x01].facing_info.orientation = 0;
+                                       }
+                                       //add end
                                        //add usb camera to board_profiles 
                                        rk_DV_info *pDVResolution = new rk_DV_info();
                                        memset(pNewCamInfo->mHardInfo.mSensorInfo.mSensorName, 0x00, sizeof(pNewCamInfo->mHardInfo.mSensorInfo.mSensorName));
diff --git a/CameraHal/CameraHal_Module.h b/CameraHal/CameraHal_Module.h
index 45c81ec..2b97e11 100755
--- a/CameraHal/CameraHal_Module.h
+++ b/CameraHal/CameraHal_Module.h
@@ -15,7 +15,7 @@ using namespace android;
 #if defined(TARGET_RK3399)
     #define CAMERAS_SUPPORTED_SIMUL_MAX     2
 #else
-    #define CAMERAS_SUPPORTED_SIMUL_MAX     1
+    #define CAMERAS_SUPPORTED_SIMUL_MAX     2
 #endif
 #define CAMERA_DEVICE_NAME              "/dev/video"

 

其他Android版本前后摄切换：

1.android9，android10如下修改

/hardware/interfaces/camera/device/3.4/default/ExternalCameraDevice.cpp
@@ -309,7 +309,15 @@ status_t ExternalCameraDevice::initDefaultCharsKeys(
     UPDATE(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
            &opticalStabilizationMode, 1);
 
-    const uint8_t facing = ANDROID_LENS_FACING_BACK;
+    const char* dev = mCameraId.c_str();
+    int index = (int) (*(dev + (strlen(dev) - 1)) - '0');
+    ALOGE("dev:%s index:%d", dev, index);
+    const uint8_t facing = (index / 2) % 2 ? ANDROID_LENS_FACING_FRONT : ANDROID_LENS_FACING_BACK;
     UPDATE(ANDROID_LENS_FACING, &facing, 1);

2.android11及12如下修改

/hardware/interfaces/camera/device/3.4/default/ExternalCameraDevice.cpp
@@ -309,7 +309,15 @@ status_t ExternalCameraDevice::initDefaultCharsKeys(
     UPDATE(ANDROID_LENS_INFO_AVAILABLE_OPTICAL_STABILIZATION,
            &opticalStabilizationMode, 1);
 
-    const uint8_t facing = ANDROID_LENS_FACING_BACK;
+    const char* dev = mCameraId.c_str();
+    int index = atoi(dev);
+    ALOGE("dev:%s index:%d", dev, index);
+    const uint8_t facing = (index / 2) % 2 ? ANDROID_LENS_FACING_FRONT : ANDROID_LENS_FACING_BACK;
     UPDATE(ANDROID_LENS_FACING, &facing, 1);

 参考：https://blog.csdn.net/kris_fei/article/details/53487734

https://blog.csdn.net/kris_fei/article/details/79550161

https://www.iotword.com/8242.html