I am using Iphone12 pro to test my camera app, when I record 4K 60FPS video, captureOutput didDrop will be invoked many times, the final fps only was about 45fps.
I found some weird things.
this problem is must shown on iphone12 pro, everything is fine on iphoneX.
I found some weird things.
If I move camera or let something moving front of the camera, the viewport is changing, the dropping frame will stop, If keep camera stable and static, dropping frame will start again.
I made some debug info displayed in the top of view, If I display it, the dropping frame stopped, If I hide this debug view, dropping frame start agian.
If I don't record ( with AVAssetWriter) , it will drop frame per 0.5 sec, If I start record, it drop frame very fast.
this problem is must shown on iphone12 pro, everything is fine on iphoneX.