I'm a newbie to Swift. I'm trying to add a watermark with reference to code from SO. My original video resolution is 1280 X 720, but the output video is a shrinked version.
Here are the before and after pictures
Here is my function to create a watermark.
private func watermark(video videoAsset:AVAsset, watermarkText text : String!, image : CGImage!, saveToLibrary flag : Bool, completion : ((_ status : AVAssetExportSessionStatus?, _ session: AVAssetExportSession?, _ outputURL : URL?) -> ())?) { DispatchQueue.global(qos: DispatchQoS.QoSClass.default).async { let mixComposition = AVMutableComposition() let compositionVideoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: Int32(kCMPersistentTrackID_Invalid)) let clipVideoTrack = videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0] do { try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: clipVideoTrack, at: kCMTimeZero) } catch { print(error.localizedDescription) } let videoSize = clipVideoTrack.naturalSize print("Video size", videoSize.height) //720 print("Video size", videoSize.width) //1280 let parentLayer = CALayer() let videoLayer = CALayer() parentLayer.frame = CGRect(x: 0.0, y: 0.0, width: videoSize.width, height: videoSize.height) videoLayer.frame = CGRect(x: 0.0, y: 0.0, width: videoSize.width, height: videoSize.height) parentLayer.addSublayer(videoLayer) if text != nil { let titleLayer = CATextLayer() titleLayer.backgroundColor = UIColor.red.cgColor titleLayer.string = text titleLayer.font = "Helvetica" as CFTypeRef titleLayer.fontSize = 15 titleLayer.alignmentMode = kCAAlignmentCenter titleLayer.bounds = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height) parentLayer.addSublayer(titleLayer) } else if image != nil { let imageLayer = CALayer() imageLayer.contents = image let width: CGFloat = (self.imageView.image?.size.width)! let height: CGFloat = (self.imageView.image?.size.height)! print("Video size", height) //720 print("Video size", width) //1280 imageLayer.frame = CGRect(x: 0.0, y: 0.0, width: width, height: height) imageLayer.opacity = 0.65 parentLayer.addSublayer(imageLayer) } let videoComp = AVMutableVideoComposition() videoComp.renderSize = videoSize videoComp.frameDuration = CMTimeMake(1, Int32(clipVideoTrack.nominalFrameRate)) videoComp.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer) let instruction = AVMutableVideoCompositionInstruction() instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration) _ = mixComposition.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack let layerInstruction = self.videoCompositionInstructionForTrack(track: compositionVideoTrack, asset: videoAsset) instruction.layerInstructions = [layerInstruction] videoComp.instructions = [instruction] let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] let dateFormatter = DateFormatter() dateFormatter.dateStyle = .long dateFormatter.timeStyle = .short let date = dateFormatter.string(from: Date()) let url = URL(fileURLWithPath: documentDirectory).appendingPathComponent("watermarkVideo-\(date).mov") let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality) exporter?.outputURL = url exporter?.outputFileType = AVFileTypeQuickTimeMovie exporter?.shouldOptimizeForNetworkUse = true exporter?.videoComposition = videoComp exporter?.exportAsynchronously() { DispatchQueue.main.async { if exporter?.status == AVAssetExportSessionStatus.completed { let outputURL = exporter?.outputURL if flag { if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(outputURL!.path) { PHPhotoLibrary.shared().performChanges({ PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: outputURL!) }) { saved, error in if saved { completion!(AVAssetExportSessionStatus.completed, exporter, outputURL) } } } } else { completion!(AVAssetExportSessionStatus.completed, exporter, outputURL) } } else { // Error completion!(exporter?.status, exporter, nil) } } } } } While the size of watermark image is absolutely correct, the video is really shrinked.
2 Answers
Answers 1
can you try this function
private func watermark(video videoAsset: AVAsset, watermarkText text : String!, image : CGImage!, saveToLibrary flag : Bool, completion : ((_ status : AVAssetExportSessionStatus ?, _ session: AVAssetExportSession ?, _ outputURL : URL ?) -> ())?) { DispatchQueue.global(qos: DispatchQoS.QoSClass.default).async { let mixComposition = AVMutableComposition() let compositionVideoTrack = mixComposition.addMutableTrack(withMediaType: AVMediaTypeVideo, preferredTrackID: Int32(kCMPersistentTrackID_Invalid)) let clipVideoTrack = videoAsset.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack do { try compositionVideoTrack.insertTimeRange(CMTimeRangeMake(kCMTimeZero, videoAsset.duration), of: clipVideoTrack, at: kCMTimeZero) } catch { print(error.localizedDescription) } let videoSize = clipVideoTrack.naturalSize let parentLayer = CALayer() let videoLayer = CALayer() parentLayer.frame = CGRect(x: 0.0, y: 0.0, width: videoSize.width, height: videoSize.height) videoLayer.frame = CGRect(x: 0.0, y: 0.0, width: videoSize.width, height: videoSize.height) parentLayer.addSublayer(videoLayer) // if text != nil { // let titleLayer = CATextLayer() // titleLayer.backgroundColor = UIColor.red.cgColor // titleLayer.string = text // titleLayer.font = "Helvetica" as CFTypeRef // titleLayer.fontSize = 15 // titleLayer.alignmentMode = kCAAlignmentCenter // titleLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height) // parentLayer.addSublayer(titleLayer) // } else if image != nil { let imageLayer = CALayer() imageLayer.contents = image let width: CGFloat = (self.imageView.image ?.size.width)! let height: CGFloat = (self.imageView.image ?.size.height)! // print("Video size", height) print("Video size", width) imageLayer.frame = CGRect(x: 0, y: 0, width: width, height: height) // imageLayer.frame = CGRect(x: 0, y: 0, width: videoSize.width, height: videoSize.height) imageLayer.opacity = 1 parentLayer.addSublayer(imageLayer) } let videoComp = AVMutableVideoComposition() videoComp.renderSize = videoSize videoComp.frameDuration = CMTimeMake(1, Int32(clipVideoTrack.nominalFrameRate)) videoComp.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: parentLayer) let instruction = AVMutableVideoCompositionInstruction() instruction.timeRange = CMTimeRangeMake(kCMTimeZero, mixComposition.duration) let videotrack = mixComposition.tracks(withMediaType: AVMediaTypeVideo)[0] as AVAssetTrack let layerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: videotrack) // let layerInstruction = self.videoCompositionInstructionForTrack(track: compositionVideoTrack, asset: videoAsset) instruction.layerInstructions = [layerInstruction] videoComp.instructions = [instruction] let documentDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] let dateFormatter = DateFormatter() dateFormatter.dateStyle = .long dateFormatter.timeStyle = .short let date = dateFormatter.string(from: Date()) let url = URL(fileURLWithPath: documentDirectory).appendingPathComponent("watermarkVideo-\(date).mp4") guard let exporter = AVAssetExportSession(asset: mixComposition, presetName: AVAssetExportPresetHighestQuality) else { return} exporter.videoComposition = videoComp exporter.outputFileType = AVFileTypeMPEG4 exporter.outputURL = url exporter.exportAsynchronously() { DispatchQueue.main.async { if exporter.status == AVAssetExportSessionStatus.completed { let outputURL = exporter.outputURL if flag { // Save to library // let library = ALAssetsLibrary() if UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(outputURL!.path) { PHPhotoLibrary.shared().performChanges({ PHAssetChangeRequest.creationRequestForAssetFromVideo(atFileURL: outputURL!) }) { saved, error in if saved { completion!(AVAssetExportSessionStatus.completed, exporter, outputURL) } } } // if library.videoAtPathIs(compatibleWithSavedPhotosAlbum: outputURL) { // library.writeVideoAtPathToSavedPhotosAlbum(outputURL, // completionBlock: { (assetURL:NSURL!, error:NSError!) -> Void in // // completion!(AVAssetExportSessionStatus.Completed, exporter, outputURL) // }) // } } else { completion!(AVAssetExportSessionStatus.completed, exporter, outputURL) } } else { // Error completion!(exporter.status, exporter, nil) } } } } } Answers 2
The code above for creating the watermarked video seems not to be the reason for the smaller output resolution.
Problem
The resolution depends on what kind of AVAsset is put into the watermark method.
Example: Frequently an UIImagePickerController is used. There is the delegate method
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) There one often can see something like this:
let url = info[UIImagePickerControllerMediaURL] as? URL let videoAsset = AVAsset(url: url!) self.watermark(video: videoAsset, watermarkText: nil, image: self.imageView.image?.cgImage ... But with the lines above a downsized input image is used, e.g. instead of having a video with 1920x1080 one has a reduced video size of 1280x720.
Solution
A method for determining the AVAsset from the PHAsset could look like this:
private func videoAsset(for asset: PHAsset, completion: @escaping (AVAsset?) -> Void) { let requestOptions = PHVideoRequestOptions() requestOptions.version = .original PHImageManager.default().requestAVAsset(forVideo: asset, options: requestOptions, resultHandler: { (avAsset, avAudioMix, info) in completion(avAsset) }) } And where to get the PHAsset from? It can also be determined in the didFinishPickingMediaWithInfo method by using UIImagePickerControllerPHAsset:
let asset = info[UIImagePickerControllerPHAsset] as? PHAsset Quick Test
For a quick test one could use:
func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : Any]) { if let asset = info[UIImagePickerControllerPHAsset] as? PHAsset { picker.dismiss(animated: true, completion: { [weak self] in self?.videoAsset(for: asset, completion: { (avAsset) in if let videoAsset = avAsset { DispatchQueue.main.async { self?.watermark(video: videoAsset, watermarkText: nil, image: self?.imageView.image?.cgImage, saveToLibrary: true) { (exportStat: AVAssetExportSessionStatus? , session: AVAssetExportSession?, url: URL?) in print("url: \(String(describing: url?.debugDescription))") } } } }) }) } } The result is a video in the original resolution with a watermark on the lower left, see screenshot of resulting video:
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