我试图在一个更大的视图中截取 AVPlayer 的屏幕截图。我只想构建一个测试框架，因此私有的 APIs 或任何方法都可以使用，因为该框架将不会在发布到 AppStore 时包含。
我已经尝试过使用：
UIGetScreenImage()：在模拟器上运行良好，但在设备上无效。snapshotviewafterscreenupdates：它显示了视图，但我无法从中创建一个 UIImage。drawViewInHierarchy 和 renderInContext 将无法与 AVPlayer 一起使用。AVAssetGenerator 来从视频中获取图像，因为很难获得视频播放器作为其他视图的子视图的正确坐标。我知道你不想使用AVAssetImageGenerator，但是我也进行了广泛的研究，我相信目前唯一的解决方案就是使用AVAssetImageGenerator。获取正确的坐标并不像你说的那么困难，因为你应该能够获取播放器的当前时间。在我的应用程序中，以下代码完美地工作：
-(UIImage *)getAVPlayerScreenshot
{
AVURLAsset *asset = (AVURLAsset *)self.playerItem.asset;
AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
imageGenerator.requestedTimeToleranceAfter = kCMTimeZero;
imageGenerator.requestedTimeToleranceBefore = kCMTimeZero;
CGImageRef thumb = [imageGenerator copyCGImageAtTime:self.playerItem.currentTime
actualTime:NULL
error:NULL];
UIImage *videoImage = [UIImage imageWithCGImage:thumb];
CGImageRelease(thumb);
return videoImage;
}
以下是Bob答案的Swift版本。我正在使用AVQueuePlayer，但对于普通的AVPlayer也适用。
public func getImageSnapshot() -> UIImage? {
guard let asset = player.currentItem?.asset else { return nil }
let imageGenerator = AVAssetImageGenerator(asset: asset);
imageGenerator.requestedTimeToleranceAfter = CMTime.zero;
imageGenerator.requestedTimeToleranceBefore = CMTime.zero;
do {
let thumb = try imageGenerator.copyCGImage(at: player.currentTime(), actualTime: nil);
let image = UIImage(cgImage: thumb);
return image;
} catch {
print("⛔️ Failed to get video snapshot: \(error)");
}
return nil;
}
AVPlayer使用GPU渲染视频，因此无法使用核心图形方法进行捕获。
但是，可以使用AVAssetImageGenerator捕获图像，您需要指定一个CMTime。
更新:
忘记截取整个屏幕的截图。 AVPlayerItemVideoOutput 是我的最终选择，它支持视频流。
这里是截取整个屏幕（包括AVPlayer）的代码。您只需要在视频播放器上方添加一个UIImageView，它一直隐藏，直到我们截取屏幕时再显示，然后再次隐藏。
func takeScreenshot() -> UIImage? {
//1 Hide all UI you do not want on the screenshot
self.hideButtonsForScreenshot()
//2 Create an screenshot from your AVPlayer
if let url = (self.overlayPlayer?.currentItem?.asset as? AVURLAsset)?.url {
let asset = AVAsset(url: url)
let imageGenerator = AVAssetImageGenerator(asset: asset)
imageGenerator.requestedTimeToleranceAfter = CMTime.zero
imageGenerator.requestedTimeToleranceBefore = CMTime.zero
if let thumb: CGImage = try? imageGenerator.copyCGImage(at: self.overlayPlayer!.currentTime(), actualTime: nil) {
let videoImage = UIImage(cgImage: thumb)
//Note: create an image view on top of you videoPlayer in the exact dimensions, and display it before taking the screenshot
// mine is created in the storyboard
// 3 Put the image from the screenshot in your screenshotPhotoView and unhide it
self.screenshotPhotoView.image = videoImage
self.screenshotPhotoView.isHidden = false
}
}
//4 Take the screenshot
let bounds = UIScreen.main.bounds
UIGraphicsBeginImageContextWithOptions(bounds.size, true, 0.0)
self.view.drawHierarchy(in: bounds, afterScreenUpdates: true)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
//5 show all UI again that you didn't want on your screenshot
self.showButtonsForScreenshot()
//6 Now hide the screenshotPhotoView again
self.screenshotPhotoView.isHidden = true
self.screenshotPhotoView.image = nil
return image
}
如果你想要拍下当前屏幕截图，只需要在任何动作事件上调用以下方法即可获得Image对象。
-(UIImage *) screenshot
{
UIGraphicsBeginImageContext(self.view.bounds.size);
[self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *sourceImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//now we will position the image, X/Y away from top left corner to get the portion we want
UIGraphicsBeginImageContext(sourceImage.size);
[sourceImage drawAtPoint:CGPointMake(0, 0)];
UIImage *croppedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
//To write image on divice.
//UIImageWriteToSavedPhotosAlbum(croppedImage,nil, nil, nil);
return croppedImage;
}
CGRect grabRect = CGRectMake(0,0,320,568);// size you want to take screenshot of.
if ([[UIScreen mainScreen] respondsToSelector:@selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(grabRect.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(grabRect.size);
}
CGContextRef ctx = UIGraphicsGetCurrentContext();
CGContextTranslateCTM(ctx, -grabRect.origin.x, -grabRect.origin.y);
[self.view.layer renderInContext:ctx];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();