音频慢动作,如使用240FPS的默认Slo-Mo相机功能

Question

我想实现慢动作视频像Slo-Mo相机的Defalut功能,我使用下面的代码,它适用于视频.但在音频轨道中该视频无法正常工作.

   double videoScaleFactor =8.0;


 compositionAudioTrack scaleTimeRange:CMTimeRangeMake(kCMTimeZero, videoDuration)
                                     toDuration:CMTimeMake(videoDuration.value* videoScaleFactor,videoDuration.timescale)];
 [compositionVideoTrack scaleTimeRange:CMTimeRangeMake(kCMTimeZero, videoDuration)
   toDuration:CMTimeMake(videoDuration.value* videoScaleFactor, videoDuration.timescale)];

 this scenario is woking properly for video slowmotion.But in audio slow-motion it is not working...

请帮我..

Answer 1

我找到了Audio SlowMotion的解决方案

double videoScaleFactor = 8.0;

[compositionAudioTrack scaleTimeRange:CMTimeRangeMake(kCMTimeZero,videoDuration)toDuration:CMTimeMake(videoDuration.value*videoScaleFactor,videoDuration.timescale)];

它工作正常但不能在AVPlayer中工作,所以你必须设置AVPlayerItem的以下属性

AVPlayerItem*playerItem = nil;

playerItem.audioTimePitchAlgorithm = AVAudioTimePitchAlgorithmVarispeed;