Question

我正在尝试从视频中获取（第一帧的）缩略图，以便我可以显示它。有人做过这样的成功吗？如果是这样，你怎么做？

Answer 1

首先使用AssetImageGenerator的方法有很多： -

- (UIImage *)imageFromVideoURL 
{
// result 
UIImage *image = nil;

// AVAssetImageGenerator
AVAsset *asset = [[AVURLAsset alloc] initWithURL:appDelegate.videoURL options:nil];; 
AVAssetImageGenerator *imageGenerator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
imageGenerator.appliesPreferredTrackTransform = YES;

// calc midpoint time of video
Float64 durationSeconds = CMTimeGetSeconds([asset duration]);
CMTime midpoint = CMTimeMakeWithSeconds(durationSeconds/2.0, 600); 

// get the image from 
NSError *error = nil; 
CMTime actualTime;
CGImageRef halfWayImage = [imageGenerator copyCGImageAtTime:midpoint actualTime:&actualTime error:&error];

if (halfWayImage != NULL) 
{
    // cgimage to uiimage
    image = [[UIImage alloc] initWithCGImage:halfWayImage];
    [dic setValue:image forKey:kImage];
    NSLog(@"Values of dictonary==>%@", dic);
    NSLog(@"Videos Are:%@",appDelegate.videoURLArray);
    CGImageRelease(halfWayImage);
}
return image;
}

这是使用MPMoviePlayerController的另一种方法的最佳方法： -

MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentURL:url];
UIImage *thumbnail = [player thumbnailImageAtTime:1.0 timeOption:MPMovieTimeOptionNearestKeyFrame];
[player stop];

这可能对你有所帮助:)）

Answer 2

首先你应该有视频的videoURL或nsdata。现在添加MediaPlayer框架和#import MediaPlayer / MPMoviePlayerController.h。将此添加到您想要视频缩略图的地方

MPMoviePlayerController *player = [[MPMoviePlayerController alloc] initWithContentURL:url];
UIImage *thumbnail = [player thumbnailImageAtTime:1.0 timeOption:MPMovieTimeOptionNearestKeyFrame];
//Player autoplays audio on init
[player stop];
[player release];

Iphone sdk显示缩略图

2 个答案: