@Axemasta thank you for this submission! The changes look good to me especially given they don't effect the existing checks for a matching size (I do wonder if we could improve upon that when this shifts to the Maui Community Toolkit but that is outside of the scope of this change).

It will be nice to see if the 2 people that you tagged on the issue are able to confirm the fix, I will aim to test on some other devices I have here tomorrow to double check all is fine, I don't possess a Xiaomi device though.

@bijington

To address your comments... in reverse order 😊:

It will be nice to see if the 2 people that you tagged on the issue are able to confirm the fix, I will aim to test on some other devices I have here tomorrow to double check all is fine, I don't possess a Xiaomi device though.

I'm fortunate to have access to an affected device, mine is a Xiaomi Note 7 running Android 9. I potentially have access to more affected devices through a fork which I will add the change & observe if devices can access the camera correctly.

I've tested on 3 devices:

• Xiaomi Note 7
• Samsung A21
• Samsung A7 Tablet

Both the samsungs return valid surface mappings:
map.GetOutputSizes(Class.FromType(typeof(SurfaceTexture)))

The Xiaomi does return mappings but the aspect ratios are off, causing the checking code to completely fallthrough. I can't confirm whether its a Xiaomi or an Android flavour issue but it seems the fallback at least works for affected devices.

@Axemasta thank you for this submission! The changes look good to me especially given they don't effect the existing checks for a matching size (I do wonder if we could improve upon that when this shifts to the Maui Community Toolkit but that is outside of the scope of this change).

When looking into this issue I did some research into how the Camera2 api should be implemented and it looks like the lastest google sample implements it in a different way. The current implementation matches the following:

• Google: android-Camera2Basic
• Blog post | Backing repo with references used

Both of these use the ChooseOptimalSize method which appears to be a method google cooked up to select the smallest preview size possible.

The current google samples repo does not contain this method and whilst I've not completely wrapped my head around the differences between old & new, it appears to be using a method called getPreviewOutputSize which you can find implemented here.

Since changing the current implementation would affect more devices, perhaps it would be something that could be revisited in another pr to update the android renderers to use the latest & greatest from the google sample?

@Axemasta thanks for the guidance on the differences between this implementation and googles docs. I will add a note on the MAUI Community Toolkit proposal so we certainly don't miss this in the new implementation (CommunityToolkit/Maui#106)

Given the rest appears to work and testing my devices here (Goole Pixel 3a, One Plus Nord N100 and some cheap Umidigi device) has been fine I suspect we might not worry about changing things in this repo.

@Axemasta thanks again for this effort. It really is appreciated!

Here is a Camera2 preview control that uses the preview builder to set the preview window. This is possibly the implementation we'd want to use for the MAUI version of the control ref.