没有在视频上正确应用 CIFilter

Question

我有 2 个肖像视频。一个取自默认 iphone 相机，第二个是使用 UIIMagePickerController 从我的应用程序中记录的。

当我在视频 1 上应用 cifilter 时，过滤器会完美应用，但是当我在第二个视频上应用过滤器时，视频会放大一半，视频部分会模糊和拉伸，当我导出它时，它应该会旋转。

我的代码

AVAssetTrack *FirstAssetTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

CIFilter *filter = [CIFilter filterWithName:@"CIPhotoEffectInstant"];

player.currentItem.videoComposition  = [AVVideoComposition videoCompositionWithAsset: asset applyingCIFiltersWithHandler:^(AVAsynchronousCIImageFilteringRequest *request){
    // Clamp to avoid blurring transparent pixels at the image edges

    CIImage *source = [request.sourceImage imageByClampingToExtent];
    source = [source imageByApplyingTransform:FirstAssetTrack.preferredTransform];

    [filter setValue:source forKey:kCIInputImageKey];

    // Crop the blurred output to the bounds of the original image
    CIImage *output = [filter.outputImage imageByCroppingToRect:request.sourceImage.extent];

    // Provide the filter output to the composition
    [request finishWithImage:output context:nil];
}];

此代码不适用于第二个视频，因此对第二个视频进行一些更改这不是正确的代码，但我想检查它的大小和方向，并且在方向改变后它在 avplayer 中播放时工作正常但在导出时它被旋转

我检查了这个link我们都面临同样的问题所以我根据这个更改了我的代码但仍然无法正常工作

AVAssetTrack *FirstAssetTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
CIFilter *filter = [CIFilter filterWithName:@"CIPhotoEffectInstant"];


UIImageOrientation FirstAssetOrientation_  = UIImageOrientationUp;
BOOL  isFirstAssetPortrait_  = NO;
CGAffineTransform firstTransform = FirstAssetTrack.preferredTransform;
if(firstTransform.a == 0 && firstTransform.b == 1.0 && firstTransform.c == -1.0 && firstTransform.d == 0)  {
    FirstAssetOrientation_= UIImageOrientationRight;
    isFirstAssetPortrait_ = YES;
}
if(firstTransform.a == 0 && firstTransform.b == -1.0 && firstTransform.c == 1.0 && firstTransform.d == 0)  {
    FirstAssetOrientation_ =  UIImageOrientationLeft;
    isFirstAssetPortrait_ = YES;
}
if(firstTransform.a == 1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == 1.0)   {
    FirstAssetOrientation_ =  UIImageOrientationUp;
}
if(firstTransform.a == -1.0 && firstTransform.b == 0 && firstTransform.c == 0 && firstTransform.d == -1.0) {
    FirstAssetOrientation_ = UIImageOrientationDown;
}

player.currentItem.videoComposition = [AVVideoComposition videoCompositionWithAsset:asset applyingCIFiltersWithHandler:^(AVAsynchronousCIImageFilteringRequest * _Nonnull request) {
    // Step 1: get the input frame image (screenshot 1)
    CIImage *sourceImage = request.sourceImage;

    // Step 2: rotate the frame
    CIFilter *transformFilter = [CIFilter filterWithName:@"CIAffineTransform"];
    [transformFilter setValue:sourceImage forKey: kCIInputImageKey];
    [transformFilter setValue: [NSValue valueWithCGAffineTransform: firstTransform] forKey: kCIInputTransformKey];
    sourceImage = transformFilter.outputImage;
    CGRect extent = sourceImage.extent;
    CGAffineTransform translation = CGAffineTransformMakeTranslation(-extent.origin.x, -extent.origin.y);
    [transformFilter setValue:sourceImage forKey: kCIInputImageKey];
    [transformFilter setValue: [NSValue valueWithCGAffineTransform: translation] forKey: kCIInputTransformKey];
    sourceImage = transformFilter.outputImage;

    // Step 3: apply the custom filter chosen by the user
    extent = sourceImage.extent;
    sourceImage = [sourceImage imageByClampingToExtent];
    [filter setValue:sourceImage forKey:kCIInputImageKey];
    sourceImage = filter.outputImage;
    sourceImage = [sourceImage imageByCroppingToRect:extent];

    // make the frame the same aspect ratio as the original input frame
    // by adding empty spaces at the top and the bottom of the extent rectangle
    CGFloat newHeight = 1920 * 1920 / extent.size.height;
    CGFloat inset = (extent.size.height - newHeight) / 2;
    extent = CGRectInset(extent, 0, inset);
    sourceImage = [sourceImage imageByCroppingToRect:extent];

    // scale down to the original frame size
    CGFloat scale = 1920 / newHeight;
    CGAffineTransform scaleTransform = CGAffineTransformMakeScale(scale, scale*3.2);
    [transformFilter setValue:sourceImage forKey: kCIInputImageKey];
    [transformFilter setValue: [NSValue valueWithCGAffineTransform: scaleTransform] forKey: kCIInputTransformKey];
    sourceImage = transformFilter.outputImage;

    // translate the frame to make it's origin start at (0, 0)
    CGAffineTransform translation1 = CGAffineTransformMake(1, 0, 0, 1, 0, 0);
    [transformFilter setValue:sourceImage forKey: kCIInputImageKey];
    [transformFilter setValue: [NSValue valueWithCGAffineTransform: translation1] forKey: kCIInputTransformKey];
    sourceImage = transformFilter.outputImage;

    // Step 4: finish processing the frame (screenshot 2)
    [request finishWithImage:sourceImage context:nil];

}];

Answer 1

只需删除您的变换线，这会导致问题。

只有这个：

source = [source imageByApplyingTransform:FirstAssetTrack.preferredTransform];

并检查。 :)

AVAssetTrack *FirstAssetTrack = [[asset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];

CIFilter *filter = [CIFilter filterWithName:@"CIPhotoEffectInstant"];

player.currentItem.videoComposition  = [AVVideoComposition videoCompositionWithAsset: asset applyingCIFiltersWithHandler:^(AVAsynchronousCIImageFilteringRequest *request){
    // Clamp to avoid blurring transparent pixels at the image edges

    CIImage *source = [request.sourceImage imageByClampingToExtent];

    [filter setValue:source forKey:kCIInputImageKey];

    // Crop the blurred output to the bounds of the original image
    CIImage *output = [filter.outputImage imageByCroppingToRect:request.sourceImage.extent];

    // Provide the filter output to the composition
    [request finishWithImage:output context:nil];
}];

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