视频根据url获取第一帧图片,获取任一帧图片

- (UIImage*) thumbnailImageForVideo:(NSURL *)videoURL atTime:(NSTimeInterval)time
{

    

    AVURLAsset *asset = [[AVURLAsset
alloc] initWithURL:videoURL
options:nil];

    NSParameterAssert(asset);

    AVAssetImageGenerator *assetImageGenerator =[[AVAssetImageGenerator
alloc]
initWithAsset:asset];

    assetImageGenerator.appliesPreferredTrackTransform =
YES;

    assetImageGenerator.apertureMode =
AVAssetImageGeneratorApertureModeEncodedPixels;

    

    CGImageRef thumbnailImageRef =
NULL;

    CFTimeInterval thumbnailImageTime = time;

    NSError *thumbnailImageGenerationError =
nil;

    thumbnailImageRef = [assetImageGenerator copyCGImageAtTime:CMTimeMake(thumbnailImageTime,
60)actualTime:NULL
error:&thumbnailImageGenerationError];

    

    if(!thumbnailImageRef)

        NSLog(@"thumbnailImageGenerationError %@",thumbnailImageGenerationError);

    

    UIImage*thumbnailImage = thumbnailImageRef ? [[UIImage
alloc]initWithCGImage: thumbnailImageRef] :
nil;

    

    return thumbnailImage;

}