读取解析视频帧图片

#pragma mark - 读取解析视频帧图片
-(void)analysisVideoFrames{
    AVURLAsset *videoAsset = [[AVURLAsset alloc]initWithURL:self.videoUrl options:nil];
    //获取视频总长度 = 总帧数 / 每秒的帧数
    long videoSumTime = videoAsset.duration.value / videoAsset.duration.timescale;
    //创建AVAssetImageGenerator对象
    AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc]initWithAsset:videoAsset];
    generator.maximumSize = self.bottomView.frame.size;
    generator.appliesPreferredTrackTransform = YES;
    generator.requestedTimeToleranceBefore = kCMTimeZero;
    generator.requestedTimeToleranceAfter = kCMTimeZero;
    
    //添加需要帧数的时间集合
    self.framesArray = [NSMutableArray array];
    for (NSInteger index = 0; index < videoSumTime; index ++) {
        CMTime time = CMTimeMake(index * videoAsset.duration.timescale, videoAsset.duration.timescale);
        NSValue *value = [NSValue valueWithCMTime:time];
        [self.framesArray addObject:value];
    }
    
    
    __block long count = 0 ;
    __weak typeof(self)weakSelf = self;
    __block UIImage *showImage = [[UIImage alloc] init];
    __block CGFloat showImageViewWitd = (self.bottomView.frame.size.width - self.leftView.frame.size.width * 2)/videoSumTime;
    [generator generateCGImagesAsynchronouslyForTimes:self.framesArray completionHandler:^(CMTime requestedTime, CGImageRef  _Nullable image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError * _Nullable error) {
        if (result == AVAssetImageGeneratorSucceeded) {
            showImage = [UIImage imageWithCGImage:image];
            dispatch_async(dispatch_get_main_queue(), ^{
                UIImageView *thumImgView = [[UIImageView alloc]initWithFrame:CGRectMake( 20 +  count * showImageViewWitd , 0, showImageViewWitd, 40)];
                thumImgView.image = showImage;
                [weakSelf.showImageViewBgView addSubview:thumImgView];
                count++;
            }) ;
        }
        if (result == AVAssetImageGeneratorFailed) {
            NSLog(@"Failed with error: %@", [error localizedDescription]);
        }
        
        if (result == AVAssetImageGeneratorCancelled) {
            NSLog(@"AVAssetImageGeneratorCancelled");
        }
    }];
    
}