I just posted a bug report about this for Harman here:
In a nutshell, AIR apps used to create unique timestamp-based filenames for images saved through CameraRoll.addBitmapData, but on Android 10 or newer they instead save the images as "Image.jpg", and subsequent images are saved as "Image (1).jpg", "Image (2).jpg", until it reaches 32 images with the same name and then addBitmapData silently fails after that. No AIR apps are able to save images using addBitmapData after 32 images are saved in that format, and this behavior is present on at least all versions of AIR 32 and 33 for any targetSdkVersion, including the newest 126.96.36.1995 targeting 29.
I was curious if anyone here has any suggestions of alternatives, since I'm not sure if/when this will be fixed -- if we could perhaps use File / FileStream to save to that same Android "Pictures" directory, including handling all of the various permission considerations with doing that, or if there were any ANEs that would sidestep this issue. I was looking at distriqt's Camera Roll Extended ANE, and saw under "Adding Files" that the addBitmapData functionality was duplicated in the extension, but wasn't sure if it relied on the built-in CameraRoll.addBitmapData for that where it would have the same naming issue.
We don't need any browsing/loading functionality, only saving -- the app lets users create scenes and then save them to their camera roll.
Any suggestions would be appreciated!