iphone 4 - 如何在视频顶部录制视频叠加？

Question

Does anyone know how to do this?

Is anyone able to provide an example? I believe this is out of NDA now as was available in version 4.0 ?

Answer 1

Take a look to AVFoundation framework , specially to avcapture avsession avinputdevice, etc. You can find some listings in the iPhone dev center forums: search "avcapture" AVFoundation is the framework you want to use to record, modify raw frames, show them, an offcourse add some overlay

If you want to do only overlay then, UIImagePickerController should b enough.

Answer 2

If i understand, what you are trying to do corectly, you have set up video capture someting like suggested by Apple in this Q&A: http://developer.apple.com/iphone/library/qa/qa2010/qa1702.html

From there it shouldn't be much of a Problem to use the method described in this answer: blend two uiimages based on alpha/transparency of top image to blend the preview with your overlay, provided you draw it in a UIImage first. Feed the resulting images to a buffer and save it accordingly.

Though, this method most certainly wouldn't give you a lot of frames per second.