camera-samples | Multiple samples showing the best practices

I am using CameraX and want to take a photo. Of course, no one wants a blurred picture, so we should ensure focused before taking picture.

First attempt: Simply call takePicture like what is done in the official sample.

Problem: I can change the scene and quickly press the take photo button. Then, the camera has not finished auto focus when the takePicture happens. Therefore, I get a blurred photo :/

Second attempt: Before actually taking photo, firstly trigger focusing and wait for it to finish.

Code like:

The official sample of Camera2Basic for capturing images from camera.
It only shows the captured image in an activity but does not save the image to external storage

How to save that image to external storage?

I searched a lot over the internet for this, but there are all of the deprecated as of Android 11 (API 30).
Thanks!

I'm trying to implement the Camera2 API in my application. Having never done this before, I'm starting with the Camera2Basic example code provided by android.

However, within the createCaptureSession() method there is a deprecated initialization method CameraDevice.createCaptureSession(), so I changed it to the following:

I'm reading sample of code of using RenderScript (https://github.com/android/camera-samples/blob/be17bffb7b1dcc69467a52bcb94bec4306c3ca4b/HdrViewfinder/Application/src/main/rs/hdr_merge.rs#L27) and documentation (https://developer.android.com/guide/topics/renderscript/compute#writing-an-rs-kernel). There are 2 different ways of defining kernel:

I'm still practicing with Kotlin and Android Developing. As far as I understood, Camera class has been deprecated, and Android invites to use Camerax instead, because this high-level class is device-indipendent, and they've made simpler the process of implementing cameras on apps.

I've tried to read the documentation (https://developer.android.com/training/camerax) but it's written so bad I barely understood what they are trying to explain. So I went to read the entire sample code given in the documentation itself (https://github.com/android/camera-samples/tree/main/CameraXBasic). The CameraFragment code is about 500 lines long (ignoring imports and various comments).

Do I really need to write 500 lines of code to simply take a picture? How is this supposed to be considered "simpler than before"?

I mean, Android programming is at the point where I just need to write only 4 lines of code to ask the user to select an Image from his storage and retreive it and show it in an ImageView. Is there a TRUE simple way to take a picture, or do I really need to stop and lose a whole day of work to write all those lines of code?

EDIT: Take this page of the documentation: https://developer.android.com/training/camerax/architecture#kotlin It starts with this piece of code.

We have 2 distinct memory leaks(which look the same) in $ git clone https://source.codeaurora.org/quic/la/camera-samples -b iot-concam-apk.lnx.1.1 in version 2.0 and they go away on app close.

They occurs as soon as the app is launched. Switching tabs, again and again, does not increase the number of leaks which is a good thing I think.

I caught it using https://square.github.io/leakcanary/getting_started/ I noticed if we change all 'replace' to add in onCreate, the 2 leaks happen on Tab switch and not on the app launch.

Disclaimer: I'm aware of the existence of this question, but it currently stands unresolved and I'm trying to provide extra information without polluting that one with useless answers that won't solve the problem anyway.

I have a custom device with a front camera that is mirrored by default, so I want to display the preview normally and I need to horizontally flip the content of PreviewView, but I'm stuck. Other people in the past have suggested using PreviewView#setScaleX(-1) but it either doesn't work at all or it needs to be called at a very specific point in the code, which I haven't found yet.

The code below is a simplified version of CameraFragment.kt in the official CameraXBasic example; I've added comments where I've already tired calling viewFinder.scaleX = -1f with no success. Honestly I don't really think that the place makes a difference because if I call it with any value other than 1 it works fine with both scaleX and scaleY, but it always ignores the negative sign so it never flips.

There are a couple of samples to get the relative rotation from the camera sensor to the current device orientation, e.g. for using it for correcting camera preview or for MediaRecorder.setOrientationHint(int)

But the newest method from the latest official github camera samples works different than older methods (for deprecated camera2 API and method from archived camera2 sample)

Here's my sample code that uses all methods and logs all results, we can see that function computeRelativeRotationCamera2New returns different result for Surface.ROTATION_90 and Surface.ROTATION_270 display rotation

So what is the correct method to do it?

As I understand from many implementations such as :

https://github.com/android/camera-samples/tree/master/CameraXBasic

https://proandroiddev.com/android-camerax-preview-analyze-capture-1b3f403a9395

After every use case in CameraX implementation cameraProvide.bindToLifecycle() method needs to be called.

For example, if I need to switch ON the FLASH_MODE of the camera from the default OFF mode, then again bindToLifecycle() method needs to be called.

The disadvantage with this approach is that for a second or two the preview is removed and re-attached which doesn't feel like a smooth transition for an app.

Is there any better practice available or it is the limitation?

I Have attached a sample code below: