将UIView层转换为UIImage [英] Convert UIView Layer to UIImage

问题描述

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

I'm playing Video using AVPlayerLayer in a View. I need to convert View to Image, I tried

[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。这种转换将同时发生0.05s。

but this gives only black image. I wanna convert that view into image with video on that time. This conversion will occur simultaneously 0.05s.

我尝试使用AVAssetImageGenerator。这使用资产给我正确的形象。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将视频转换为图像的过程。

I tried with AVAssetImageGenerator. Which gives me the right image using Asset. But it taking little more time which makes some performance issue on my application. Can any one help me how to reduce the process of converting video to image for particular CMTime.

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;
}

推荐答案

MPMoviePlayerController让它变得简单从电影中的某个点获取电影中的图像。

The MPMoviePlayerController makes it easy to get a image from a movie at a certain point in the movie.

    - (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;
}

只需使用视频路径调用此项，并在您需要的时候调用获得图像。

Just call this with the path of the video, and at the time you want to get the image.

这篇关于将UIView层转换为UIImage的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！