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 = [[AVURLAssetalloc] initWithURL:videoURLoptions:nil];

    NSParameterAssert(asset);

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

    assetImageGenerator.appliesPreferredTrackTransform =YES;

    assetImageGenerator.apertureMode =AVAssetImageGeneratorApertureModeEncodedPixels;

    

    CGImageRef thumbnailImageRef =NULL;

    CFTimeInterval thumbnailImageTime = time;

    NSError *thumbnailImageGenerationError =nil;

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

    

    if(!thumbnailImageRef)

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

    

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

    

    return thumbnailImage;

}