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;
}