从IPhone SDK中的视频网址创建缩略图

Question

我正在尝试从视频网址获取缩略图.视频是具有m3u8格式的流(HLS).我已经尝试过来自MPMoviePlayerController的requestThumbnailImagesAtTimes,但是没有用.有没有人有解决这个问题的方法？如果是这样你怎么做的？

Answer 1

如果您不想使用MPMoviePlayerController,可以这样做:

    AVAsset *asset = [AVAsset assetWithURL:sourceURL];
    AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc]initWithAsset:asset];
    CMTime time = CMTimeMake(1, 1);
    CGImageRef imageRef = [imageGenerator copyCGImageAtTime:time actualTime:NULL error:NULL];
    UIImage *thumbnail = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);  // CGImageRef won't be released by ARC

这是Swift中的一个例子:

func thumbnail(sourceURL sourceURL:NSURL) -> UIImage {
    let asset = AVAsset(URL: sourceURL)
    let imageGenerator = AVAssetImageGenerator(asset: asset)
    let time = CMTime(seconds: 1, preferredTimescale: 1)

    do {
        let imageRef = try imageGenerator.copyCGImageAtTime(time, actualTime: nil)
        return UIImage(CGImage: imageRef)
    } catch {
        print(error)
        return UIImage(named: "some generic thumbnail")!
    }
}

我更喜欢使用它AVAssetImageGenerator,MPMoviePlayerController因为它是线程安全的,并且您可以一次实例化多个.

Answer 2

从视频网址获取缩略图.

    NSString *strVideoURL = @"http://www.xyzvideourl.com/samplevideourl";
    NSURL *videoURL = [NSURL URLWithString:strVideoURL] ;
    MPMoviePlayerController *player = [[[MPMoviePlayerController alloc] initWithContentURL:videoURL]autorelease];
    UIImage  *thumbnail = [player thumbnailImageAtTime:1.0 timeOption:MPMovieTimeOptionNearestKeyFrame];
    player = nil;

将视频网址字符串替换为strVideoURL.您将获得缩略图作为输出video.缩略图是UIImage类型数据!

Answer 3

-(UIImage *)loadThumbNail:(NSURL *)urlVideo
{    
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:urlVideo options:nil];
    AVAssetImageGenerator *generate = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    generate.appliesPreferredTrackTransform=TRUE;
    NSError *err = NULL;
    CMTime time = CMTimeMake(1, 60);
    CGImageRef imgRef = [generate copyCGImageAtTime:time actualTime:NULL error:&err];
    NSLog(@"err==%@, imageRef==%@", err, imgRef);
    return [[UIImage alloc] initWithCGImage:imgRef];
}

AVFoundation在项目中添加框架,不要忘记导入<AVFoundation/AVFoundation.h> ,您必须将保存在文档目录中的视频路径作为参数传递,并将图像作为参数接收UIImage.