1 Reply
      Latest reply on Aug 16, 2019 12:56 AM by rjalkuino_r
      Devgeek Level 1 Level 1 (0 points)

        I am creating an AVVideoComposition with CIFilter this way:




        videoComposition = AVMutableVideoComposition(asset: asset, applyingCIFiltersWithHandler: {[weak self] request in
                        // Clamp to avoid blurring transparent pixels at the image edges
                        let source = request.sourceImage.clampedToExtent()
                        let output:CIImage
                        if let filteredOutput = self?.runFilters(source, filters: filters)?.cropped(to: request.sourceImage.extent) {
                            output = filteredOutput
                        } else {
                            output = source
                        // Provide the filter output to the composition
                        request.finish(with: output, context: nil)


        And then to correctly handle rotation, I create a passthrough instruction which sets identity transform on passthrough layer.


        let passThroughInstruction = AVMutableVideoCompositionInstruction()
                        passThroughInstruction.timeRange = CMTimeRangeMake(start: CMTime.zero, duration: asset.duration)
                        let passThroughLayer = AVMutableVideoCompositionLayerInstruction(assetTrack: videoTrack)
                        passThroughLayer.setTransform(CGAffineTransform.identity, at: CMTime.zero) 
                        passThroughInstruction.layerInstructions = [passThroughLayer]
                        videoComposition.instructions = [passThroughInstruction]


        The problem is it crashes with the error:


        reason: '*** -[AVCoreImageFilterCustomVideoCompositor startVideoCompositionRequest:] Expecting video composition to contain only AVCoreImageFilterVideoCompositionInstruction'

        My issue is that if I do not specify this passThroughInstruction, output is incorrect if input asset's videotrack contains a preferredTransform which specifies rotation by 90 degrees. How do I use video composition with Core Image filters that correctly handles preferredTransform of video track?