IOS获取视频每一帧的图片方法

// 获取视频每一帧

- (UIImage *)getVideoPreViewImageByTime:(float)t

{

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

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

    gen.appliesPreferredTrackTransform = YES;

    CMTime time = CMTimeMakeWithSeconds(t, 1); //0.0  600

    NSError *error = nil;

    CMTime actualTime;

    CGImageRef image = [gen copyCGImageAtTime:time actualTime:&actualTime error:&error];

    UIImage *img = [[UIImage alloc] initWithCGImage:image];

    CGImageRelease(image);

    // 创建一个亮度的滤镜

    GPUImageBrightnessFilter *passthroughFilter = [[GPUImageBrightnessFilter alloc] init];

    passthroughFilter.brightness = 0.5f;

    // 设置要渲染的区域

    [passthroughFilter forceProcessingAtSize:img.size];

    // ???

    [passthroughFilter useNextFrameForImageCapture];

    // 获取数据源

    GPUImagePicture *stillImageSource = [[GPUImagePicture alloc] initWithImage:img];

    // 添加上滤镜

    [stillImageSource addTarget:passthroughFilter];

    // 开始渲染

    [stillImageSource processImage];

    // 获取渲染后的图片

    UIImage *nearestNeighborImage = [passthroughFilter imageFromCurrentFramebuffer];

    // 加载出来处理后的

    UIImageView *imageView = [[UIImageView alloc] initWithImage:nearestNeighborImage];

    imageView.backgroundColor = [UIColor redColor];

    imageView.image = nearestNeighborImage;

    imageView.frame = CGRectMake(0, pointY, 100, 60);

    [self.view addSubview:imageView];

    pointY += 70;

    NSLog(@"� %g", t);

    [self.imageArr addObject:nearestNeighborImage];

    return img;

}

// 在需要时调用:(此处是每0.1秒调用一次)

    AVAsset *movieAsset = [AVAsset assetWithURL:fileUrl]; // fileUrl:文件路径

    int second = (int)movieAsset.duration.value / movieAsset.duration.timescale; // 获取视频总时长,单位秒

    NSLog(@"movie duration : %d", second);

    for (float i = 0.0; i < second;) {

        [self getVideoPreViewImageByTime:i];

        i += 0.1;

    }