So I just had a chat with App Review. It seems this is indeed a technical issue with the review environment, where the app doesn’t have access to the on-demand asset pack. While they are working on fixing this, I got the following recommendation: In the review notes, before submitting your app, explain this problem in detail to the reviewer. Explain the current issue with the review environment. Also explain what this asset pack is used for and what it would enable. Ideally, you would also provide a way to use the app without the asset pack, for instance, by having a demo mode the reviewer could access somehow. It’s important to put this into the review notes, as the reviewer will read this before testing the app, potentially avoiding a quick rejection. Let’s hope they will find the issue with the review environment soon. 🤞

Sorry, this is more or less a duplicate of this thread to gain visibility as the original thread was marked as solved. We also reached out to Apple Developer Support twice now (case IDs 102888358215 and 102895781178) and didn't hear back. This is really a release-blocking issue for us. Thanks for looking into this!

We are facing the same problem right now. The iOS version of our app went through review just fine, but the macOS version (Catalyst) is stuck. We have an on-demand asset pack that we download at the start of the app. We first present the user with the download size and the option to download the asset. The reviewer reports an error that indicates that even the lookup of the asset pack (assetPack(withID:)) doesn't work. On all our test devices we don't have that issue. It seems the reviewer is running the app in an environment that is unable to load the asset pack information from TestFlight. We don't know what to do here. Any help would be appreciated!

The fix turned out to be trivial: When adding the target for the BA download extension in Xcode, we forgot to change the deployment target to 26.0. Instead, the default of 26.4 was used, so the download extension was simply unavailable on older systems. 🙄🤦‍♂️

The problem might be this: Core Image uses 16-bit float RGBA as the default working format. That means that, whenever it needs an intermediate buffer for the rendering, it will create a 4-channel 16-bit float surface to render into. This also meant that your 1-channel unsigned integer values will automatically be mapped to float values in 0.0...1.0. That's probably where you lose precision. There are a few options to circumvent this: You could set the workingFormat context option to .L8 or .R8. However, this means all intermediate buffers will have that format. If you want to mix processing of the segmentation mask with other images, this won't work. If you only want to process the mask separately, you can set up a separate CIContext with this option. Note, however, that most built-in CIFilters assume a floating-point working format and might not perform well with this format. You can process your segmentation map with Metal (as you suggested) as part of your CIFilter pipeline using a CIImageProcessorKernel. For the kernel, you can set the formatForInput(...) and the outputFormat to .R8. This should tell CI that it doesn't need to convert the segmentation mask before passing it to your processor kernel. In the process method, you can access the input's Metal texture and perform custom Metal processing with it, rendering into the output's texture (which is then also R8 format). This way, you won't lose any precision. I think the second option is the best choice here as you get the best of both worlds (custom Metal processing + CI integration). Tip: You can always use CI_PRINT_TREE to check the format of the intermediate buffers CI is using during rendering.

Good question! I haven't seen the new GPU background entitlements. Good to know! My guess is that they don't want to support iPhone here because they prioritize battery over expensive processing on the mobile devices. The iPads on the other hand are more targeted towards pro use cases (and have a bigger battery). What we are currently doing in our apps is to prevent the screen from locking during video export (using UIApplication.shared.isIdleTimerDisabled = true). We also pause the processing when the app is backgrounded and resume when it's active again.

What is the pixel format of the CVPixelBuffer in question?

Is the DNG you are using for the warm-up one that was captured on iPhone? I.e., does it have the same dimensions as the ones captured by the user later?

Did you always process the same image? How is your CIContext set up? Do you maybe have a small sample project we can use to test this? Thanks!

We are suddenly getting the same warning, and we are pretty sure that we (or any library) don't use said API. Are there any other APIs that trigger the warning? Was that list recently extended?

Also filed as FB17081255, including a sample project. Thanks for looking into this!

Did you find the root cause and/or a solution for the problem? I can't reproduce the issue myself, but we have users reporting freezes of our apps that might be related to this issue.

What do you mean by "calling back to the CPU" exactly? The main CPU load of Core Image actually comes from the filter graph optimization CI does before the actual rendering. And unfortunately there is not much you can do to speed this up.

There is a newish API for deferred photo processing, which makes the whole capture process seem much faster. That's probably what the Camera app is doing under the hood. Check out this WWDC session for details.

You can easily test Apple Intelligence features in the EU on an iPad. You just have to set the system and Siri language to English (US) and sign in with a US Apple account under iCloud → Media & Purchases. It even works with sandbox accounts! So if you don’t have a US account, you can easily create a sandbox one in App Store Connect. Also note that Apple Intelligence is available on macOS in Europe without the need for a US Apple account. You just have to set the languages to English.