7

iPhone/iPadで撮影した動画(*.mov)のサムネイルを取得したい。これに AVFoundation ライブラリを使用しようとすると、次のエラーが発生します。

couldn't generate thumbnail, error:Error Domain=AVFoundationErrorDomain Code=-11822 "Cannot Open" UserInfo=0x15d90a30 {NSLocalizedDescription=Cannot Open, NSLocalizedFailureReason=This media format is not supported.}

コード：

NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentDir=[paths objectAtIndex:0];
NSString *videoPath=[documentDir stringByAppendingPathComponent:[NSString stringWithFormat:@"videos/%@.mov",videoName]];


    AVURLAsset *asset=[[AVURLAsset alloc] initWithURL:videoPath options:nil];
    AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    generator.appliesPreferredTrackTransform=TRUE;

    CMTime thumbTime = CMTimeMakeWithSeconds(0,30);

    AVAssetImageGeneratorCompletionHandler handler = ^(CMTime requestedTime, CGImageRef im, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error){
        if (result != AVAssetImageGeneratorSucceeded) {
            NSLog(@"couldn't generate thumbnail, error:%@", error);
        }
        self.img.image=[UIImage imageWithCGImage:im];
    };

    CGSize maxSize = CGSizeMake(320, 180);
    generator.maximumSize = maxSize;
    [generator generateCGImagesAsynchronouslyForTimes:[NSArray arrayWithObject:[NSValue valueWithCMTime:thumbTime]] completionHandler:handler];

アプリで動画を録画しましたが、それらのサムネイルを表示したいと考えています。

4

4 に答える 4

15

ここにあります...（このリンクからピックアップ-サムネイルのビデオスナップショットを取得する）

- (UIImage *)thumbnailImageFromURL:(NSURL *)videoURL {
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL: videoURL options:nil];
    AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    NSError *err = NULL;
    CMTime requestedTime = CMTimeMake(1, 60);     // To create thumbnail image
    CGImageRef imgRef = [generator copyCGImageAtTime:requestedTime actualTime:NULL error:&err];
    NSLog(@"err = %@, imageRef = %@", err, imgRef);

    UIImage *thumbnailImage = [[UIImage alloc] initWithCGImage:imgRef];
    CGImageRelease(imgRef);    // MUST release explicitly to avoid memory leak

    return thumbnailImage;
}
于 2013-10-23T01:04:12.503 に答える
2

コメントするほどの評判はありませんが、上記の例がありませCGImageRelease(imageRef)ん...

最終的なメソッドは次のようになります。

- (UIImage*)loadImage {

    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:vidURL options:nil];
    AVAssetImageGenerator *generate = [[AVAssetImageGenerator alloc] initWithAsset:asset];
    NSError *err = NULL;
    CMTime time = CMTimeMake(1, 60);
    //Grab image
    CGImageRef imgRef = [generate copyCGImageAtTime:time actualTime:NULL error:&err];
    NSLog(@"err==%@, imageRef==%@", err, imgRef);

    UIImage* finalImage = [[UIImage alloc] initWithCGImage:imgRef];
    CGImageRelease(imageRef);
    return finalImage;
}

気付くのに時間がかかりました...だから多分それは誰かを助けるでしょう.

于 2015-02-11T10:00:16.420 に答える
1

2 つの方法で迅速に生成できます。 1. AVAssetImageGenerator 2. MPMoviePlayerController

1. 

    func generateThumnail(url : NSURL) -> UIImage{
            var asset : AVAsset = AVAsset.assetWithURL(url) as AVAsset
            var assetImgGenerate : AVAssetImageGenerator = AVAssetImageGenerator(asset: asset)
            assetImgGenerate.appliesPreferredTrackTransform = true
            var error       : NSError? = nil
            var time        : CMTime = CMTimeMake(1, 30)
            var img         : CGImageRef = assetImgGenerate.copyCGImageAtTime(time, actualTime: nil, error: &error)
            var frameImg    : UIImage = UIImage(CGImage: img)!

            return frameImg
        }

2. 

    override func viewDidLoad() {
            super.viewDidLoad()
            var moviePlayer         : MPMoviePlayerController!  = MPMoviePlayerController(contentURL: moviePlayManager.movieURL)
            moviePlayer.view.frame   = CGRect(x: self.view.frame.origin.x, y: self.view.frame.origin.y, width:
                                       self.view.frame.size.width, height: self.view.frame.height)
            moviePlayer.fullscreen   = true
            moviePlayer.controlStyle = MPMovieControlStyle.None
            NSNotificationCenter.defaultCenter().addObserver(self,
        selector: "videoThumbnailIsAvailable:",
        name: MPMoviePlayerThumbnailImageRequestDidFinishNotification,
        object: nil)


        let thumbnailTimes = 3.0
        moviePlayer.requestThumbnailImagesAtTimes([thumbnailTimes],
                timeOption: .NearestKeyFrame)
        }

    func videoThumbnailIsAvailable(notification: NSNotification){

        if let player = moviePlayer{
            let thumbnail =
            notification.userInfo![MPMoviePlayerThumbnailImageKey] as? UIImage

            if let image = thumbnail{

                /* We got the thumbnail image. You can now use it here */
                println("Thumbnail image = \(image)")
            }
        }
于 2015-03-09T07:01:11.840 に答える