Question

我正在使用UIImagePickerController从库中选择视频文件。用户可以上传视频。

我也在使用videoMaximumDuration属性，而用户想要捕获视频并上传它。

我想知道如何获取所选视频文件的持续时间？这样我就可以限制用户上传持续时间超过20秒的视频。

我可以通过以下代码获得有关所选视频的一些基本信息：

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    selectedVideoUrl = [info objectForKey:UIImagePickerControllerMediaURL];
    NSError *error;
    NSDictionary * properties = [[NSFileManager defaultManager] attributesOfItemAtPath:selectedVideoUrl.path error:&error];
    NSNumber * size = [properties objectForKey: NSFileSize];
    NSLog(@"Vide info :- %@",properties);
}

但是所选视频的持续时间并不存在。

...谢谢

Answer 1

获得解决方案：我使用AVPlayerItem类和AVFoundation以及CoreMedia框架。

#import <AVFoundation/AVFoundation.h>
#import <AVFoundation/AVAsset.h>

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    selectedVideoUrl = [info objectForKey:UIImagePickerControllerMediaURL];

    AVPlayerItem *playerItem = [AVPlayerItem playerItemWithURL:selectedVideoUrl];

    CMTime duration = playerItem.duration;
    float seconds = CMTimeGetSeconds(duration);
    NSLog(@"duration: %.2f", seconds);
}

Answer 2

使用AVPlayerItem对此问题的另一个答案对我不起作用，但这确实使用了AVURLAsset：

#import <AVFoundation/AVFoundation.h>

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    NSURL *videoURL=[info objectForKey:@"UIImagePickerControllerMediaURL"];
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:videoURL options:nil];

    NSTimeInterval durationInSeconds = 0.0;
    if (asset)
        durationInSeconds = CMTimeGetSeconds(asset.duration);
}

Answer 3

Swift 4

无论使用didFinishPickingMediaWithInfo还是didFinishRecordingToOutputFileAtURL，您都可以：

// needed only for didFinishPickingMediaWithInfo
let outputFileURL = info[UIImagePickerControllerMediaURL] as! URL

// get the asset
let asset = AVURLAsset(url: outputFileURL)

// get the time in seconds
let durationInSeconds = asset.duration.seconds

Answer 4

如果您使用AVFoundation和AssetLibrary框架，则可以枚举所有资源，仅为视频应用过滤器，并使用方法- (id)valueForProperty:(NSString *)property获取每个视频的持续时间。通过ALAssetPropertyDuration获取财产。下面的代码在控制台上打印出以下内容。

视频剪辑编号0为66.80833333333334秒

视频剪辑编号1为190.06秒

视频剪辑编号2为13.74秒

- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.

if (!assetItems) {
    assetItems = [[NSMutableArray alloc] init];
} else {
    [assetItems removeAllObjects];
}

if (!assetLibrary) {
    assetLibrary = [[ALAssetsLibrary alloc] init];
}

ALAssetsLibraryGroupsEnumerationResultsBlock listBlock = ^(ALAssetsGroup *group, BOOL *stop) {
    if (group) {
        [group setAssetsFilter:[ALAssetsFilter allVideos]];
        [group enumerateAssetsUsingBlock:^(ALAsset *result, NSUInteger index, BOOL *stop) {
            if (result) {
                [assetItems addObject:result];
                NSString *duration = [result valueForProperty:ALAssetPropertyDuration];
                NSLog(@"video clip number %d is %@ seconds\n",index, duration);
            }
        }];
    }
};

ALAssetsLibraryAccessFailureBlock failBlock = ^(NSError *error) { // error handler block
    NSString *errorTitle = [error localizedDescription];
    NSString *errorMessage = [error localizedRecoverySuggestion];
    NSLog(@"%@...\n %@\n",errorTitle,errorMessage);
};
[assetLibrary enumerateGroupsWithTypes:ALAssetsGroupAll usingBlock:listBlock failureBlock:failBlock];
}

Answer 5

Swift 3.0和Swift 4

const wrapper = getWrapper();

Answer 6

是的，您可以使用MPMediaPlayerController定义的属性“duration”。请试一试并检查输出。你可以参考这里duration property

尝试使用MPMediaPlayerController播放视频，然后使用属性“duration”。你将能够清楚地了解视频的持续时间。

iPhone：如何从图书馆中选择视频的持续时间？

6 个答案: