将UIView层转换为UIImage

Question

我在视图中使用AVPlayerLayer播放视频.我需要将View转换为Image,我试过了

[myview.layer renderInContext:context];

但这只给出了黑色图像.我想在那个时候用视频将那个视图转换成图像.此转换将同时发生0.05秒.

我试过AVAssetImageGenerator.这给了我使用Asset的正确图像.但它花费的时间更多,这使我的应用程序出现性能问题.任何人都可以帮助我减少如何减少特定CMTime的视频转换为图像的过程.

以下是我的编码.

- (UIImage *)currentItemScreenShot
{
    AVPlayer *abovePlayer = [objVC player];
    if(imageGenerator == nil)
    {
        AVAsset *asset = [[[objVC player] currentItem] asset];
        imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    }

    CMTime time = [[abovePlayer currentItem] currentTime];
    if ([imageGenerator respondsToSelector:@selector(setRequestedTimeToleranceBefore:)] && [imageGenerator respondsToSelector:@selector(setRequestedTimeToleranceAfter:)]) {
        [imageGenerator setRequestedTimeToleranceBefore:kCMTimeZero];
        [imageGenerator setRequestedTimeToleranceAfter:kCMTimeZero];
    }

    CGImageRef imgRef = [imageGenerator copyCGImageAtTime:time
                                               actualTime:NULL
                                                    error:NULL];
    if (imgRef == nil) {
        if ([imageGenerator respondsToSelector:@selector(setRequestedTimeToleranceBefore:)] && [imageGenerator respondsToSelector:@selector(setRequestedTimeToleranceAfter:)]) {
            [imageGenerator setRequestedTimeToleranceBefore:kCMTimePositiveInfinity];
            [imageGenerator setRequestedTimeToleranceAfter:kCMTimePositiveInfinity];
        }
        imgRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
    }
    UIImage *image = [UIImage imageWithCGImage:imgRef];
    CGImageRelease(imgRef);

    image = [self reverseImageByScalingToSize:image.size :image];
    return image;
}

Answer 1

MPMoviePlayerController可以轻松地从电影中的某个点获取电影中的图像.

    - (UIImage*)imageFromVideoAtPath:(NSString *)path atTime:(NSTimeInterval)time {
    NSURL *videoURL = [NSURL fileURLWithPath:path];
    MPMoviePlayerController *moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:videoURL];
    [moviePlayer prepareToPlay];
    UIImage *thumbnail = [moviePlayer thumbnailImageAtTime:time timeOption:MPMovieTimeOptionNearestKeyFrame];
    [moviePlayer stop];
    return thumbnail;
}

只需用视频的路径调用它,然后在想要获取图像时.

Answer 2

您可以将 UIView 作为图像保存在文档目录中，如下所示：

-(IBAction)ViewTOimage:(id)sender
{


    UIGraphicsBeginImageContext(self.view.bounds.size); //instad of self.view you can set your view IBOutlet name 
    [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *saveImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();
    NSData *imageData = UIImagePNGRepresentation(saveImage);
    NSFileManager *fileMan = [NSFileManager defaultManager];

    NSString *fileName = [NSString stringWithFormat:@"%d.png",1];
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *pdfFileName = [documentsDirectory stringByAppendingPathComponent:fileName];
    [fileMan createFileAtPath:pdfFileName contents:imageData attributes:nil];



}