如何设置iOS相机的帧率

Question

我是 iOS 编码的新手，现在我想设置 iOS 前置摄像头的帧，比如 18 fps 或 25 fps。这是我的代码，我很困惑，无论我如何更改activeVideoMinFrameDuration和activeVideoMaxFrameDuration的值，最终的视频总是30fps。

 do {
            try videoDevice!.lockForConfiguration()
            videoDevice!.activeVideoMinFrameDuration = CMTimeMake(1, 20)
            videoDevice!.activeVideoMaxFrameDuration = CMTimeMake(1, 20)
            videoDevice!.unlockForConfiguration()
        } catch let error as NSError {
                NSLog("Could not lock device for configuration: %@", error)
      }

Answer 1

您可能还需要设置

videoFileOutput.movieFragmentInterval = CMTime(seconds: 1, preferredTimescale: 25)