裁剪區域與iOS中的選定區域不同？

Question

這裏是鏈接github https://github.com/spennyf/cropVid/tree/master來試試你的自我，看看我在說什麼，它將需要1分鐘的時間來測試。謝謝！

我正在拍攝帶有方形的視頻以顯示vid的哪部分將被裁剪。就像這樣：

現在我做了一張紙，4號線在廣場上的這一點，並在頂部和底部半年線的差異。然後，我使用的代碼，我將發佈作物的視頻，但後來當我顯示視頻我看到這個（忽略背景和綠色圓圈）：

正如你可以看到有超過四線，所以我將它設置爲裁剪某個部分，但是當我使用相機中顯示的同一個矩形以及用於裁剪的同一個矩形時，它將添加更多內容。

所以我的問題是爲什麼裁剪不一樣的大小？

這裏是我做的產量和顯示：

//this is the square on the camera 
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height-80)]; 
    UIImageView *image = [[UIImageView alloc] init]; 
    image.layer.borderColor=[[UIColor whiteColor] CGColor]; 
image.frame = CGRectMake(self.view.frame.size.width/2 - 58 , 100 , 116, 116); 
    CALayer *imageLayer = image.layer; 
    [imageLayer setBorderWidth:1]; 
[view addSubview:image]; 
    [picker setCameraOverlayView:view]; 

//this is crop rect 
CGRect rect = CGRectMake(self.view.frame.size.width/2 - 58, 100, 116, 116); 
[self applyCropToVideoWithAsset:assest AtRect:rect OnTimeRange:CMTimeRangeMake(kCMTimeZero, CMTimeMakeWithSeconds(assest.duration.value, 1)) 
        ExportToUrl:exportUrl ExistingExportSession:exporter WithCompletion:^(BOOL success, NSError *error, NSURL *videoUrl) { 
//here is player 
AVPlayer *player = [AVPlayer playerWithURL:videoUrl]; 

          AVPlayerLayer *layer = [AVPlayerLayer playerLayerWithPlayer:player]; 
layer.frame = CGRectMake(self.view.frame.size.width/2 - 58, 100, 116, 116); 
}]; 

這裏是代碼，不會對作物：

- (UIImageOrientation)getVideoOrientationFromAsset:(AVAsset *)asset 
{ 
    AVAssetTrack *videoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; 
CGSize size = [videoTrack naturalSize]; 
CGAffineTransform txf = [videoTrack preferredTransform]; 

if (size.width == txf.tx && size.height == txf.ty) 
    return UIImageOrientationLeft; //return UIInterfaceOrientationLandscapeLeft; 
else if (txf.tx == 0 && txf.ty == 0) 
    return UIImageOrientationRight; //return UIInterfaceOrientationLandscapeRight; 
else if (txf.tx == 0 && txf.ty == size.width) 
    return UIImageOrientationDown; //return UIInterfaceOrientationPortraitUpsideDown; 
else 
    return UIImageOrientationUp; //return UIInterfaceOrientationPortrait; 
} 

這裏是種植代碼的其餘部分：

- (AVAssetExportSession*)applyCropToVideoWithAsset:(AVAsset*)asset AtRect:(CGRect)cropRect OnTimeRange:(CMTimeRange)cropTimeRange ExportToUrl:(NSURL*)outputUrl ExistingExportSession:(AVAssetExportSession*)exporter WithCompletion:(void(^)(BOOL success, NSError* error, NSURL* videoUrl))completion 
{ 

// NSLog(@"CALLED"); 
//create an avassetrack with our asset 
AVAssetTrack *clipVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0]; 

//create a video composition and preset some settings 
AVMutableVideoComposition* videoComposition = [AVMutableVideoComposition videoComposition]; 
videoComposition.frameDuration = CMTimeMake(1, 30); 

CGFloat cropOffX = cropRect.origin.x; 
CGFloat cropOffY = cropRect.origin.y; 
CGFloat cropWidth = cropRect.size.width; 
CGFloat cropHeight = cropRect.size.height; 
// NSLog(@"width: %f - height: %f - x: %f - y: %f", cropWidth, cropHeight, cropOffX, cropOffY); 

videoComposition.renderSize = CGSizeMake(cropWidth, cropHeight); 

//create a video instruction 
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction]; 
instruction.timeRange = cropTimeRange; 

AVMutableVideoCompositionLayerInstruction* transformer = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:clipVideoTrack]; 

UIImageOrientation videoOrientation = [self getVideoOrientationFromAsset:asset]; 

CGAffineTransform t1 = CGAffineTransformIdentity; 
CGAffineTransform t2 = CGAffineTransformIdentity; 

switch (videoOrientation) { 
    case UIImageOrientationUp: 
     t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.height - cropOffX, 0 - cropOffY); 
     t2 = CGAffineTransformRotate(t1, M_PI_2); 
     break; 
    case UIImageOrientationDown: 
     t1 = CGAffineTransformMakeTranslation(0 - cropOffX, clipVideoTrack.naturalSize.width - cropOffY); // not fixed width is the real height in upside down 
     t2 = CGAffineTransformRotate(t1, - M_PI_2); 
     break; 
    case UIImageOrientationRight: 
     t1 = CGAffineTransformMakeTranslation(0 - cropOffX, 0 - cropOffY); 
     t2 = CGAffineTransformRotate(t1, 0); 
     break; 
    case UIImageOrientationLeft: 
     t1 = CGAffineTransformMakeTranslation(clipVideoTrack.naturalSize.width - cropOffX, clipVideoTrack.naturalSize.height - cropOffY); 
     t2 = CGAffineTransformRotate(t1, M_PI ); 
     break; 
    default: 
     NSLog(@"no supported orientation has been found in this video"); 
     break; 
} 

CGAffineTransform finalTransform = t2; 
[transformer setTransform:finalTransform atTime:kCMTimeZero]; 

//add the transformer layer instructions, then add to video composition 
instruction.layerInstructions = [NSArray arrayWithObject:transformer]; 
videoComposition.instructions = [NSArray arrayWithObject: instruction]; 

//Remove any prevouis videos at that path 
[[NSFileManager defaultManager] removeItemAtURL:outputUrl error:nil]; 

if (!exporter){ 
    exporter = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetHighestQuality] ; 
} 
// assign all instruction for the video processing (in this case the transformation for cropping the video 
exporter.videoComposition = videoComposition; 
exporter.outputFileType = AVFileTypeQuickTimeMovie; 
if (outputUrl){ 
    exporter.outputURL = outputUrl; 
    [exporter exportAsynchronouslyWithCompletionHandler:^{ 
     switch ([exporter status]) { 
      case AVAssetExportSessionStatusFailed: 
       NSLog(@"crop Export failed: %@", [[exporter error] localizedDescription]); 
       if (completion){ 
        dispatch_async(dispatch_get_main_queue(), ^{ 
         completion(NO,[exporter error],nil); 
        }); 
        return; 
       } 
       break; 
      case AVAssetExportSessionStatusCancelled: 
       NSLog(@"crop Export canceled"); 
       if (completion){ 
        dispatch_async(dispatch_get_main_queue(), ^{ 
         completion(NO,nil,nil); 
        }); 
        return; 
       } 
       break; 
      default: 
       break; 
     } 
     if (completion){ 
      dispatch_async(dispatch_get_main_queue(), ^{ 
       completion(YES,nil,outputUrl); 
      }); 
     } 

    }]; 
} 

return exporter; 
} 

所以我的問題是爲什麼視頻區域不同於作物/相機區域，當我使用完全相同的座標和s正方形？

Answer 1

也許Check This Previous Question。

它看起來可能與您所遇到的類似。對這個問題的用戶提示裁剪這種方式：

CGImageRef imageRef = CGImageCreateWithImageInRect([originalImage CGImage], cropRect); 
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef]; 
CGImageRelease(imageRef); 

我希望這會有所幫助，或者至少讓你在正確的方向開始。