I am using AudioService API to play a sound effect before start video recoding, I found a weird thing that the final result video's volume is relative to sound effect volume. if sound effect volume is big, the final video's volume became so low, if sound effect volume is quite, final video's volume is big. I think the iphone's microphone or audio framework make this, maybe it detected the peak volume and balance audio record volume. I use 'playAndRecord' to record video, dosen't change it when play sound effect. need help to slove this issue, i want the video's volume is constants

if there is a huge image(10000x10000), loading it into memory will cause crash every time. so, can I load a portion of image into memory and process it, and write back this part to image file?

in ios 18, we can custom two bottom button on Lock Screen, in past, they are Flash and Camera. So I want my app's function could be display in here, and I custom it, and will show a Controls List, But I can not found my app's icon. How to make a myself Control item and add it to Control List? any guideline or tutorials are welcome :D

I am talking about AVCaptureVideoDataOutput.recommendedVideoSettings. I found sometimes it return nil, there is my test result. hevc .mov with activeColorSpace sRGB 60FPS -> ok 120FPS -> ok hevc .mov with activeColorSpace displayP3_HLG 60FPS -> nil 120FPS -> nil h264 .mov 30FPS -> ok 60FPS -> nil 120FPS -> nil so, if you don't give a recommend setting, and you don't give a document, how does developer to use it?