问题
I am using AVFoundation to create a video and have added in an effect to clip the video so there is a clear background. What file format should I save this as to preserve the transparency in my iOS app.
回答1:
AVAnimator is a library with which you can display video with an alpha channel on iOS, it is however not free to use for commercial products.
I don't think it's natively possible.
来源：https://stackoverflow.com/questions/28258575/file-format-for-saving-video-with-alpha-channel-in-ios