使用AVFoundation录制视频时自定义相机放大/缩小 [英] Custom Camera zoom in/out while recording video using AVFoundation

问题描述

在最新的iOS 7.1中 本地相机应用程序可以在录制视频时放大/缩小，并且保存在照片"中的视频确实显示了放大/缩小效果.

In the latest iOS 7.1 the native camera app can zoom in/out while recording video, and the video saved in the Photos indeed shows the zoom in/out effect.

现在，我正在使用AVFoundation实施自定义视频. 通过使用videoMaxScaleAndCropFactor修改AVCaptureVideoPreviewLayer，可以在录制视频时放大/缩小.但是，保存的视频不会显示放大/缩小效果.

now, I am using AVFoundation to implement custom Video. I can zoom in/out while recording video by using videoMaxScaleAndCropFactor to modify AVCaptureVideoPreviewLayer. However, the saved video doesn't show the zoom in/out effect.

是否有实现此功能的提示?

Is there any hint to implement this function ????

推荐答案

我也在搜索.下面的链接提供了缩放视频的解决方案.

I am also searching for that. The link below gives a solution for zooming video.

http://www. iphonelife.com/blog/87/imaging-video-guru-reporting-lossless-video-zooming-ios7

缩放视频的逻辑是:

int selectedAVCaptureDeviceFormatIdx = 15;

[self.videoDevice lockForConfiguration:nil];

AVCaptureDeviceFormat* currdf = [self.videoDevice.formats objectAtIndex:selectedAVCaptureDeviceFormatIdx];
self.videoDevice.activeFormat = currdf;
if (selectedAVCaptureDeviceFormatIdx==12 || selectedAVCaptureDeviceFormatIdx==13)
    self.videoDevice.activeVideoMaxFrameDuration = CMTimeMake(1,60);

NSLog(@"%f", self.videoDevice.activeFormat.videoMaxZoomFactor);
NSLog(@"videoZoomFactorUpscaleThreshold: %f", self.videoDevice.activeFormat.videoZoomFactorUpscaleThreshold);

// If you want to zoom to the threshold of possible zooming before binning occurs
self.videoDevice.videoZoomFactor = videoDevice.activeFormat.videoZoomFactorUpscaleThreshold;
// If you want to set your own zoom factor
//self.videoDevice.videoZoomFactor = 3.0f;// here zoom given in CGFloat like 1, 2, 3, 4, 5.

[self.videoDevice unlockForConfiguration:nil];

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