possible to create a video file from RGB frames using AV Foundation

I have an iOS app that I want to record some of its visual output into a video. It looks like the way to create a video on iOS is to use AVMutableComposition and feed AVAssets to it via insertTimeRange.

All the documentation and examples that I can find only add video and audio assets to an AVMutableComposition. Is there a way to add image data to it (i.e. add an image for each frame of the video)? I can get this image data as straight RGB, PNG, JPG, UIImage, or whatever is easiest to feed to AV Foundation (if it's even possible).

If it's not possible to feed images into an AVMutableComposition for the video frames, is there another way to generate an .mp4 file 开发者_如何转开发from frames in iOS.

To generate movies from frame you can use AVAssetWriter, here is a question that sort of covers that here on SO, question