iOS 视频截图

截取图片的一部分

-(UIImage *)getPartOfImage:(UIImage *)img rect:(CGRect)partRect  
    {  
    CGImageRef imageRef = img.CGImage;  
    CGImageRef imagePartRef = CGImageCreateWithImageInRect(imageRef, partRect);  
    UIImage *retImg = [UIImage imageWithCGImage:imagePartRef];  
    CGImageRelease(imagePartRef);  
    return retImg;  
    }

ios屏幕截图

普通截图不能截取通过openGl渲染的视频,所以截取视频是不能使用下面的方法的，需要小伙伴自己去寻找其他openGL的截图方法了

UIGraphicsBeginImageContextWithOptions(_videoRect.size, YES, 0);     //设置截屏大小

   [[_moviePlayerController.view layer] renderInContext:UIGraphicsGetCurrentContext()];

   UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();

   UIGraphicsEndImageContext();

   CGImageRef imageRef = viewImage.CGImage;

   //    CGRect rect = CGRectMake(166, 211, 426, 320);//这里可以设置想要截图的区域

   CGRect rect = _videoRect;//这里可以设置想要截图的区域

   CGImageRef imageRefRect =CGImageCreateWithImageInRect(imageRef, rect);

   UIImage *sendImage = [[UIImage alloc] initWithCGImage:imageRefRect];

   UIImageWriteToSavedPhotosAlbum(sendImage, nil, nil, nil);//保存图片到照片库

   NSData *imageViewData = UIImagePNGRepresentation(sendImage);

    

   NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

   NSString *documentsDirectory = [paths objectAtIndex:0];

   NSString *pictureName= [NSString stringWithFormat:@"screenShow_%d.png",2];

   NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:pictureName];

   NSLog(@"截屏路径打印: %@", savedImagePath);

    

   [imageViewData writeToFile:savedImagePath atomically:YES];//保存照片到沙盒目录

   CGImageRelease(imageRefRect);

视频截图一

ASSet中有两个方法可以截图，下面的方法就是其中一个，相比于(视频截图二)那个方法,这一个要快得多
但是我不能把控他得很多细节，所以推荐使用(视频截图三)

NSURL *url = [[NSURL alloc] initWithString:[NSString stringWithFormat:@"%@",urlstring]];//initFileURLWithPath:videoURL] autorelease];
    AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:url options:nil];
    AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:urlAsset];
    generator.appliesPreferredTrackTransform = NO;
    generator.maximumSize = _videoRect.size;
    NSError *error = nil;
    for (float i = 0; i < second ; i += 0.1) {
    //不会CMTime就去了解一下
    CGImageRef img = [generator copyCGImageAtTime:CMTimeMake(i, 10) actualTime:NULL error:&error];
    UIImage *image = [UIImage imageWithCGImage: img];
    [imageArray addObject:image];
    }

    NSLog(@"iamgeArray = %@",imageArray);
    return imageArray;

视频截图二

秒对应视频中得 第1秒、两秒对应视频中得第2秒 ...，而且几句代码就搞定了

NSMutableArray *imageArray = [NSMutableArray array];

MPMoviePlayerViewController * mpviemController =[[MPMoviePlayerViewController alloc] initWithContentURL:urlstring];

MPMoviePlayerController *mp=[mpviemController moviePlayer];

for (float i = 0; i < second; i += 0.1) {

    UIImage *thumbImage=[mp thumbnailImageAtTime:i timeOption:MPMovieTimeOptionExact];

    //MPMovieTimeOptionExact截取每一帧的图片，MPMovieTimeOptionNearestKeyFrame关键帧

    NSData *imagedata =UIImagePNGRepresentation(thumbImage);

    UIImage *image = [UIImage imageWithData:imagedata];

    [imageArray addObject:image];

}

return imageArray;

视频截图三

这是最快捷视频切图片的方法，Asset中的最快的方法,使用块来进行截图，速度就比其他快上贼多

//pragma mark    --- 视频截取

    -(void)cutVideoGetImageArrayWithURl:(NSURL *)urlstring Second:(float)second{

     

    _imageArray = [NSMutableArray array];

     

     

    AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:urlstring options:nil];//

    //获取视频时长，单位：秒

    AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:urlAsset];

    generator.appliesPreferredTrackTransform = YES;

    generator.maximumSize = _videoRect.size;

    //下面两句是截取每一帧的关键

    generator.requestedTimeToleranceBefore = kCMTimeZero;

    generator.requestedTimeToleranceAfter = kCMTimeZero;

     

    NSMutableArray *timeArray = [NSMutableArray array];

     

    for (int i = 1; i < second * 10 + 1 ; i++) {

    [timeArray addObject:[NSValue valueWithCMTime:CMTimeMake(i * 6, 60)]];

    }

    //开始截图

    [generator generateCGImagesAsynchronouslyForTimes:timeArray completionHandler:^(CMTime requestedTime, CGImageRef  _Nullable image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError * _Nullable error) {

    UIImage *imageSen = [UIImage imageWithCGImage:image];

    [_imageArray addObject:imageSen];

    }];

    }