缩略图图像时间:现在已弃用 - 有什么替代方法? [英] thumbnailImageAtTime: now deprecated - What's the alternative?

问题描述

直到 iOS7 更新我使用...

Until iOS7 update I was using...

UIImage *image = [moviePlayer thumbnailImageAtTime:1.0 timeOption:MPMovieTimeOptionNearestKeyFrame];

...取得了巨大的成功，因此我的应用可以显示用户刚刚拍摄的视频的静止图像.

...with great success, so that my app could show a still of the video that the user had just taken.

我理解这种方法，因为 iOS7 现在已弃用，我需要一个替代方法.我看到有一种方法

I understand this method, as of iOS7 has now deprecated and I need an alternative. I see there's a method of

- (void)requestThumbnailImagesAtTimes:(NSArray *)playbackTimes timeOption:(MPMovieTimeOption)option

虽然我如何从中返回图像以便将其放置在 videoReview 按钮图像中?

though how do I return the image from it so I can place it within the videoReview button image?

提前致谢，吉姆.

****编辑问题，尝试通知中心方法后***

****Edited question, after trying notification centre method***

我使用了以下代码 -

[moviePlayer requestThumbnailImagesAtTimes:times timeOption:MPMovieTimeOptionNearestKeyFrame];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(MPMoviePlayerThumbnailImageRequestDidFinishNotification::) name:MPMoviePlayerThumbnailImageRequestDidFinishNotification object:moviePlayer];

我制作了两个 NSNumber 对象的 NSArray 时间 1 &2.

I made the NSArray times of two NSNumber objects 1 & 2.

然后我尝试使用以下方法捕获通知

I then tried to capture the notification in the following method

-(void)MPMoviePlayerThumbnailImageRequestDidFinishNotification: (NSDictionary*)info{

UIImage *image = [info objectForKey:MPMoviePlayerThumbnailImageKey];

然后继续使用此缩略图作为按钮图像作为预览....但它不起作用.

Then proceeded to use this thumbnail image as the button image as a preview.... but it didn't work.

如果您能从我的编码中看到我出错的地方，我们将再次感谢您的帮助.干杯

If you can see from my coding where I've went wrong your help would be appreciated again. Cheers

推荐答案

设法找到了使用 AVAssetImageGenerator 的好方法，请参阅下面的代码...

Managed to find a great way using AVAssetImageGenerator, please see code below...

AVURLAsset *asset1 = [[AVURLAsset alloc] initWithURL:partOneUrl options:nil];
AVAssetImageGenerator *generate1 = [[AVAssetImageGenerator alloc] initWithAsset:asset1];
generate1.appliesPreferredTrackTransform = YES;
NSError *err = NULL;
CMTime time = CMTimeMake(1, 2);
CGImageRef oneRef = [generate1 copyCGImageAtTime:time actualTime:NULL error:&err];
UIImage *one = [[UIImage alloc] initWithCGImage:oneRef];
[_firstImage setImage:one];
_firstImage.contentMode = UIViewContentModeScaleAspectFit;

在头文件中，请导入

#import <AVFoundation/AVFoundation.h>

它运行良好，我已经能够从 viewDidLoad 调用它，这比从 viewDidAppear 调用已弃用的 thumbNailImageAtTime: 更快.

It works perfect and I've been able to call it from viewDidLoad, which was quicker than calling the deprecated thumbNailImageAtTime: from the viewDidAppear.

希望这能帮助遇到同样问题的其他人.

Hope this helps anyone else who had the same problem.

* ** Swift 5.1 更新 ****

有用的功能...

    func createThumbnailOfVideoUrl(url: URL) -> UIImage? {
        let asset = AVAsset(url: url)
        let assetImgGenerate = AVAssetImageGenerator(asset: asset)
        assetImgGenerate.appliesPreferredTrackTransform = true

        let time = CMTimeMakeWithSeconds(1.0, preferredTimescale: 600)
        do {
            let img = try assetImgGenerate.copyCGImage(at: time, actualTime: nil) 
            let thumbnail = UIImage(cgImage: img)
            return thumbnail
        } catch {
          print(error.localizedDescription)
          return nil
        }
    }

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