How to use AVFoundation to apply a different text for different segments of a video

Question

I'm trying to watermark a video's elapsed time onto the video frames. But I could only render a static text using AVVideoCompositionCoreAnimationTool and CALayer into for the entire video duration.

How can I apply change the text that is overlaid on the video every second?

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Answer 1

You can refer

http://www.raywenderlich.com/30200/avfoundation-tutorial-adding-overlays-and-animations-to-videos

you just need to CABasicAnimation and add your title layer to it. Just check it out to changing the needed parameters its working fine. I Have done it in my one of project

CATextLayer *title = [CATextLayer layer];
// code for title layer setting
// code for the opacity animation which will remove the text
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
[animation setDuration:0];
[animation setFromValue:[NSNumber numberWithFloat:1.0]];
[animation setToValue:[NSNumber numberWithFloat:0.0]];
[animation setBeginTime:1];
[animation setRemovedOnCompletion:NO];
[animation setFillMode:kCAFillModeForwards];
[title addAnimation:animation forKey:@"animateOpacity"];