一 . 視頻封面中間原圖,背景模糊效果實(shí)現(xiàn)方法( 用到的方法在文章最后)
- (void)portraitBtnClick:(id)sender {
// 0.獲取豎屏視頻
NSString *vedioPath = [[NSBundle mainBundle] pathForResource:@"portrait" ofType:@"mp4"];
NSURL *url = [NSURL fileURLWithPath:vedioPath];
dispatch_async(dispatch_get_global_queue(0, 0), ^{
// 1.獲取視頻第一幀圖片
UIImage *cover = [self getVideoPreViewImage:url];
//2.按照比例截取封面圖片
//獲取coverImg（視頻封面的UI控件）的寬高比例用于截取圖片（豎屏這里截取的圖片保持寬不變，以圖片中心為基準(zhǔn)，按照coverImg的比例裁剪的高，得到圖片）
CGFloat scale = self.coverImg.frame.size.width/self.coverImg.frame.size.height;
//獲取第一幀圖片的大小（可以根據(jù)這個(gè)判斷出來(lái)是橫屏視頻還是豎屏視頻）
CGSize size = cover.size;
CGFloat clipH = size.width/scale;
//獲取按比例裁剪后的圖片
UIImage *clipImage = [self getImageByCuttingImage:cover Rect:CGRectMake(0, size.height/2-clipH/2, size.width,clipH)];
//3.獲取模糊圖片
UIImage *dimImg = [self coreBlurImage:clipImage withBlurNumber:30.0f];
//獲取模糊圖大小
UIImage *bottom = dimImg;
CGImageRef imgRef1 = bottom.CGImage;
CGFloat w1 = CGImageGetWidth(imgRef1);
CGFloat h1 = CGImageGetHeight(imgRef1);
//4. 獲取放在封面中間的清晰圖片
UIImage *clearImg = [self thumbnailWithImageWithoutScale:cover size:CGSizeMake((size.height/h1)*w1, h1)];
//獲取清晰圖片大小
CGImageRef imgRef = clearImg.CGImage;
CGFloat w = CGImageGetWidth(imgRef);
CGFloat h = CGImageGetHeight(imgRef);
//5.合成圖片以模糊圖片大小為畫(huà)布創(chuàng)建上下文（以模糊圖片為底圖將清晰圖放到模糊圖中心）
UIGraphicsBeginImageContext(CGSizeMake(w1, h1));
[bottom drawInRect:CGRectMake(0, 0, w1, h1)];
//把清晰圖畫(huà)到上下文中
[clearImg drawInRect:CGRectMake(w1/2 - w/2, 0, w, h)];
//6.獲取合成圖片
UIImage *resultImg = UIGraphicsGetImageFromCurrentImageContext();//從當(dāng)前上下文中獲得最終圖片
//關(guān)閉上下文
UIGraphicsEndImageContext();
dispatch_async(dispatch_get_main_queue(), ^{
// 7. 改變UI
self.coverImg.image = resultImg;
});
});
}
二. 橫屏視頻封面處理(用到的方法在文章最后)
- (void)landscapeBtnClick:(id)sender {
NSString *path = [[NSBundle mainBundle] pathForResource:@"landscape" ofType:@"mp4"];
NSURL *url = [NSURL fileURLWithPath:path];
dispatch_async(dispatch_get_global_queue(0, 0), ^{
// 1.獲取視頻第一幀圖片
UIImage *cover = [self getVideoPreViewImage:url];
//2.按照比例截取封面圖片
//獲取coverImg（視頻封面的UI控件）的寬高比例用于截取圖片（橫屏這里截取的圖片保持高不變，以圖片中心為基準(zhǔn)，按照coverImg的比例裁剪的寬，得到圖片）
CGFloat scale = self.coverImg.frame.size.width/self.coverImg.frame.size.height;
CGSize size = cover.size;
CGFloat clipW = size.height*scale;
UIImage *resultImg = [self getImageByCuttingImage:cover Rect:CGRectMake(size.width/2 - clipW/2 , 0, clipW, size.height)];
dispatch_async(dispatch_get_main_queue(), ^{
//3.修改UI
self.coverImg.image = resultImg;
});
});
}
三. 共用代碼部分
//截取視頻第一針
-(UIImage*)getVideoPreViewImage:(NSURL *)path
{
AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:path options:nil];
AVAssetImageGenerator *assetGen = [[AVAssetImageGenerator alloc] initWithAsset:asset];
assetGen.appliesPreferredTrackTransform = YES;
CMTime time = CMTimeMakeWithSeconds(0.0, 600);
NSError *error = nil;
CMTime actualTime;
CGImageRef image = [assetGen copyCGImageAtTime:time actualTime:&actualTime error:&error];
UIImage *videoImage = [[UIImage alloc] initWithCGImage:image];
CGImageRelease(image);
return videoImage;
}
///裁剪正方形展示
-(UIImage *)getImageByCuttingImage:(UIImage *)image Rect:(CGRect)rect{
//大圖bigImage
//定義myImageRect，截圖的區(qū)域
CGRect myImageRect = rect;
UIImage* bigImage= image;
CGImageRef imageRef = bigImage.CGImage;
CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, myImageRect);
CGSize size;
size.width = rect.size.width;
size.height = rect.size.height;
UIGraphicsBeginImageContext(size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, myImageRect, subImageRef);
UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];
UIGraphicsEndImageContext();
return smallImage;
}
//保持原來(lái)的長(zhǎng)寬比，生成一個(gè)縮略圖
-(UIImage *)thumbnailWithImageWithoutScale:(UIImage *)image size:(CGSize)asize
{
UIImage *newimage;
if (nil == image) {
newimage = nil;
}
else{
CGSize oldsize = image.size;
CGRect rect;
if (asize.width/asize.height > oldsize.width/oldsize.height) {
rect.size.width = asize.height*oldsize.width/oldsize.height;
rect.size.height = asize.height;
rect.origin.x = (asize.width - rect.size.width)/2;
rect.origin.y = 0;
}
else{
rect.size.width = asize.width;
rect.size.height = asize.width*oldsize.height/oldsize.width;
rect.origin.x = 0;
rect.origin.y = (asize.height - rect.size.height)/2;
}
UIGraphicsBeginImageContext(asize);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSetFillColorWithColor(context, [[UIColor clearColor] CGColor]);
UIRectFill(CGRectMake(0, 0, asize.width, asize.height));//clear background
[image drawInRect:rect];
newimage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
}
return newimage;
}
//返回模糊圖效果
- (UIImage *)coreBlurImage:(UIImage *)image withBlurNumber:(CGFloat)blur{
CIContext *context = [CIContext contextWithOptions:nil];
CIImage *inputImage = [CIImage imageWithCGImage:image.CGImage];
//設(shè)置filter
CIFilter *filter = [CIFilter filterWithName:@"CIGaussianBlur"];
[filter setValue:inputImage forKey:kCIInputImageKey];
[filter setValue:@(blur) forKey:@"inputRadius"];
//模糊圖片
CIImage *result = [filter valueForKey:kCIOutputImageKey];
//CGImageRef outImage = [context createCGImage:result fromRect:[result extent]];
CIImage *im = [CIImage imageWithCGImage:image.CGImage];
CGImageRef outImage = [context createCGImage: result fromRect:[im extent]];
UIImage *blurImage = [UIImage imageWithCGImage:outImage];
CGImageRelease(outImage);
return blurImage;
}
四 . 項(xiàng)目下載地址：https://github.com/Bobo168/vedioCover
