Develop Reference

Camera2 cameraManager.openCamera exception from time to time on some devices

I have an app which records videos, it has about 80K current installations (more than 100K downloads), Crashlytics statistics seems to be good - Crash-free users 99.66% and rating on Google Play is also OK - 4.5
But still for some of my users can happen the next errors (it may happened for such user once or a couple of times by now, so not often, but still happens from time to time):
android.hardware.camera2.CameraAccessException: CAMERA_DISABLED (1): connectHelper:1578: Camera "0" disabled by policy
android.hardware.camera2.CameraAccessException: CAMERA_DISCONNECTED (2): Camera service is currently unavailable
java.lang.IllegalArgumentException: supportsCameraApi:2096: Unknown camera ID 0
android.hardware.camera2.CameraAccessException: CAMERA_DISABLED (1): validateClientPermissionsLocked:1066: Caller "com.MY_APP_PACKAGE" (PID 10237, UID 21433) cannot open camera "1" when sensor privacy is enabled
on opening camera using camera2 API:
...
cameraManager.openCamera(cameraId, stateCallback, mainHandler)`
} catch (e: Exception) {
e.printStackTrace()
openReportErrorDialog(e) // so a user could report this issue
...
Reported devices:
Vivo 1906
Wheatek BV5500Plus
Samsung SM-N975F
Samsung SM-G988W
Samsung SM-A520F
Motorola REVVLRY
HUAWEI VOG-L09
HUAWEI STK-LX1
HUAWEI MRD-LX1
HUAWEI FIG-LX1
Coolpad CP3669AS
Infinix X655C
Android versions: from 8 to 11 (app min SDK is 6)
So basically it can work fine for a specific user for some time, no issues when opening camera, but from time to time this exception can occur for such user
I don't have any idea why it happens. I can't reproduce this issue on my own devices (two Samsung, one Lenovo, one Huawei and one Xiaomi devices), only users can report such issue from time to time...
The most nonsense exception here is Unknown camera ID 0, because before opening camera I get list of available cameras, so it's not hardcoded, it's not possible that such camera id doesn't exist, and a user said that before this error that camera was working ok
UPDATE
Found this
https://developer.android.com/guide/components/foreground-services#bg-access-restrictions
So it seems if a foreground service was started by system (on BOOT_COMPLETED broadcast, declared in manifest) and not by app (if a user launch app) then it can't access camera and microphone.
So basically after rebooting a device we can't automatically start camera anymore without user interaction.
Really bad for dashboard camera applications for car drivers...
They added ACCESS_BACKGROUND_LOCATION, but there is no ACCESS_BACKGROUND_CAMERA and ACCESS_BACKGROUND_RECORD_AUDIO...

android.hardware.camera2.CameraAccessException: CAMERA_DISABLED (1): connectHelper:1578: Camera "0" disabled by policy
That either means the device has an enterprise policy installed that disables cameras for example (employers that don't want employees photographing stuff at work), or your app is trying to open the camera in the background, on more recent Android releases.
If it's the policy, there's nothing you can do besides to tell the user that there's a policy in place and to complain to their admins.
android.hardware.camera2.CameraAccessException: CAMERA_DISCONNECTED (2): Camera service is currently unavailable
java.lang.IllegalArgumentException: supportsCameraApi:2096: Unknown camera ID 0
These usually mean something has crashed in the camera stack - until things restart (takes a few seconds usually), all cameras will be reported as unknown.
Ideally that'll never happen, but bugs unfortunately exist even on the best devices. A retry a few seconds later will probably work, unless the camera hardware on the phone is failing in some way that leads to a persistent crash.
android.hardware.camera2.CameraAccessException: CAMERA_DISABLED (1): validateClientPermissionsLocked:1066: Caller "com.MY_APP_PACKAGE" (PID 10237, UID 21433) cannot open camera "1" when sensor privacy is enabled
This means the OEM has some kind of 'shut off all cameras' feature like airplane mode is for radios. Like the enterprise policy above, this is something out of your control - the user needs to re-enable camera access, so all you can do is put up a dialog saying "cameras are disabled, sorry".

If your app targets Android 10 (API level 29) or higher and accesses location information in a foreground service, declare the location foreground service type as an attribute of your component.
<manifest>
...
<service ... android:foregroundServiceType="location|camera" />
At runtime, if the foreground service only needs access to a subset of the types declared in the manifest, you can limit the service's access using the logic in the following code snippet:
Notification notification = ...;
Service.startForeground(notification, FOREGROUND_SERVICE_TYPE_LOCATION| FOREGROUND_SERVICE_TYPE_CAMERA);
This is how you will be able to use camera in the background.

Accelerometer event frequency slows down first 5 min using Angular Ionic on Android device

I am using
window.addEventListener('devicemotion', event => this.watchDeviceMotion(event))
watchDeviceMotion(event: any) {
let motionData = {
x: event.acceleration.x,
y: event.acceleration.y,
z: event.acceleration.z,
}
let rotationData = {
alpha: event.rotationRate.alpha,
beta: event.rotationRate.beta,
gamma: event.rotationRate.gamma
}
if (this.getSensorData) {
// console.log(JSON.stringify(motionData))
// console.log(JSON.stringify(rotationData))
this.userData.motionData.push(motionData)
this.userData.rotationData.push(rotationData)
}
}
to access accelerometer data on an Android device using Ionic with Angular. When inside the app, the event works at a frequency of 60 Hz but when the app is switched to background, the frequency drops around 9-10 Hz for the first 5 mins and at some point while still in background it goes back at 60 Hz and remains like that indefinitely.
I am also using the background plugin with
this.backgroundMode.enable();
this.backgroundMode.on('activate').subscribe(() => {
this.backgroundMode.disableWebViewOptimizations();
});
I tried to add disableBatteryOptimizations() to the background plugin with the corresponding condition in config.xml but still no luck.
I also tried the plugins for Device Motion and Gyroscope but they behave the same.
How should I prevent the frequency from slowing down?
Has anyone else encountered this problem before?

It is unclear which version of Android you are using, but working against the system usually leads nowhere. Guess you might have tested that with an elder version, because since Android 9, the sampling rate should have a frequency of 0Hz, when the application is in the background.
This is due to a new power management with "App Standby Buckets", where only the "active" one isn't restricted.
See the Android 9 behavior changes:
Limited access to sensors in background
Android 9 limits the ability for background apps to access user input and sensor data. If your app is running in the background on a device running Android 9, the system applies the following restrictions to your app:
Your app cannot access the microphone or camera.
Sensors that use the continuous reporting mode,
such as accelerometers and gyroscopes, don't receive events.
Sensors that use the on-change or one-shot reporting modes don't receive events.
The only way to prevent this is manually setting the bucket to "active":
adb shell am set-standby-bucket packagename active|working_set|frequent|rare
Source: Test power-related issues and there's also an UsageStatsManager.

Calibration server not working on ARToolKit5 . Unable to fetch calibration file on Android device

When ever I run ARToolKit5 android project , it takes hell lot of time to open up camera and I am getting this log -
E/libar: Error performing CURL operation: Error (7). Failed to connect to omega.artoolworks.com port 443: Connection timed out.
E/libar: Error -4 returned from cparamSearch.
E/nftSimpleNative: Unable to automatically determine camera parameters. Using default.
Is there is any other way to get calibration file for different device , because using default calibration file causes problem when I change the resolution of the device.
P.S. - Turning off internet is not an option, I need calibration file specific to each device.

The calibration service previously provided by DAQRI is offline as of October 2017. A new project named artoolkitX is now providing a calibration service which can be used by ARToolKit 5. See https://github.com/artoolkitx/artoolkit5/commit/47e0100441e211cfc4496d5599de0f8fe5531131 and http://www.artoolkitx.org/docs/downloads/

How to handle Google Tango errors caused by user

When a user hold a Tango device the wrong way/blocks the device cameras, the OS displays following message:
"Nothing detected:
Keep the device at least an arm's length from object..."
Is it possible in the Unity Google Tango SDK to detect when this happens?
It's causing my app to become inaccurate and previously placed 3d objects appear at the wrong location.
It would be useful if this error could be handled in code, so the app can show a message to request the user to recalibrate to the app.

Cannot set temperature interval on sensortag

I'm creating an android application that interfaces with the texas instruments sensortag. One of the things the app needs to do is be able to change the frequency in which the temperature is reported to the app. I am able to change it through the official TI app which is great, but I cannot seem to get it working in my app.
When viewing the official app (iOS, can't run the android one?), it shows the temperature GATT service, which contains 3 characteristics. When I inspect the characteristics discovered by my app however, it only seems to find two - the data, and the notifications. Not the interval. I have attempted to construct this characteristic myself and write it however it doesn't do anything - no error, no success, just nothing.
The steps I've taken are essentially:
bluetoothGatt.discoverServices();
...
services = bluetoothGatt.getServices();
...
BluetoothGattService service = bluetoothGatt.getService(serviceUUID);
System.out.println("Characteristic = " + service.getCharacteristic(SensorTagGatt.UUID_IRT_PERI));
The output yields null. Is there something obvious I'm missing or that I should be doing that I might not be?
EDIT:
I've installed another app onto the phone written by another developer, and using this to inspect the services and characteristics available shows that it too is unable to find it, so I'm assuming there is something wrong with the android service discovery? The official iOS app is working as expected, and showing all characteristics. Unfortunately, the official android app seems to be incompatible with the version 1.5 firmware and crashes when trying to connect but I assume it too will fail to find the characteristic.
Has anyone else run into this issue and if so been able to get around it?