UVCPermissionTest

Test app to confirm whether or not app can get USB permission for UVC device with verious target SDK version.

Copyright (c) 2019 saki [email protected]

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Background

As documents on Android Developers shows, app that use USB WebCam(UVC device) needs CAMERA permission if it runs on Android 9 and later. But even if app has CAMERA permission, app can't get USB permission to access UVC device on Android 10 if target SDK version is 28 and later.

The result of my tests

OK in following tables means app could get USB permission NG means app could't get permission.

• targe SDK version <= 27

	UVC, has CAMERA permission	UVC, has no CAMERA permission	other USB device
Android <= 8	OK	OK	OK
Android 9	OK	NG(expected)	OK
Android 10	OK	NG(expected)	OK

• targe SDK version >= 28

	UVC, has CAMERA permission	UVC, has no CAMERA permission	other USB device
Android < 8	OK	OK	OK
Android 9	OK	NG(expected)	OK
Android 10	NG (unexpected)	NG(expected)	OK

• Test devices:
  • Android 10:
    • Pixel3
    • Essential Phone PH-1
  • Android 9:
    • Moto g(6) plus
  • Android 8:
    • Moto Z Play
    • Moto Z2 Play
    • ASUS ZenPhone 4 Pro

Note:

When app request permission, or when user give permission from system permission dialog, Android output error message on logCat regardless app has CAMERA permission or not.

UsbUserSettingsManager: Camera permission required for USB video class devices