Attach them after the CVPixelBufferCreate call. The attributes dictionary that can be passed to CVPixelBufferCreate is just to setup the pixel format, not to attach other attributes. So call CVBufferSetAttachments after the CVPixelBuffer is created and set them. P.S.: modifying CVPixelBuffer attributes is quite expensive, do it only as needed.

Yes, there are some borders. So just make the image you insert into icon composer a bit smaller, and that's it. The colors look the same here, but it could be your original image hadn't a color profile assigned, and it looked differently on a DCI-P3 display. Assign a color profile before importing it in Icon Composer.

Maybe you need to set the window style to NSWindowStyleMaskFullSizeContentView.

I guess you have to use Bt. 1886 instead: https://en.wikipedia.org/wiki/ITU-R_BT.1886

There is no magic, macOS just checks which version of the SDK was used when compiling the app, if the SDK version is 26 or higher, it will make it go through the new UI path, if not it will get the previous UI. I don't know how the Python bridge works, but it clearly needs to be updated or recompiled with the new SDK.

https://developer.apple.com/download/applications/

A downloadable version is still available on https://developer.apple.com/download/

There will be no Rosetta for normal apps in the next major release, so I guess it will be technically fixed then 🤷‍♂️

Apple made no announcement about the removal of OpenGL, so no, it won't be removed in version 26 of Apple operating systems. And for the future, there is no way to know until they say something.

There is nothing like hyperthreading on current Apple Silicon chips.

I guess you don't remember the icon from iOS 6 and earlier.

Show an NSOpenPanel, and ask the user to open the Documents folder, then store the security scoped bookmark. Anyway, please don't litter the Documents folder with unwanted things.

https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html#//apple_ref/doc/uid/20001431-101685

Do you set the CMSampleBuffer kCMSampleBufferAttachmentKey* keys for keyframes? I don't think AVAssetWriter will scan the bitstream for that info, it's something you will have to provide yourself.

WebGPU is still in preview and disabled by default in Safari too, anyway was usual I don't think there are any public roadmaps-