Swift开发之给视频添加水印

今天项目遇到一个给视频添加水印的需求，废话不多，直接上代码
1、直接调方法即可，inputURL：原视频路径，outputURL：添加水印后的输出路径，watermarkText：水印内容

func ht_addWatermarkToVideo(inputURL: URL, outputURL: URL, watermarkText: String, completion: @escaping (URL?, Error?) -> Void) {
        let asset = AVURLAsset(url: inputURL)
        let composition = AVMutableComposition()
        
        guard let videoTrack = asset.tracks(withMediaType: .video).first else {
            completion(nil, NSError(domain: "com.example", code: 0, userInfo: [NSLocalizedDescriptionKey: "Failed to load video track"]))
            return
        }
        
        let compositionVideoTrack = composition.addMutableTrack(withMediaType: .video, preferredTrackID: kCMPersistentTrackID_Invalid)
        
        do {
            try compositionVideoTrack?.insertTimeRange(CMTimeRange(start: .zero, duration: asset.duration), of: videoTrack, at: .zero)
        } catch {
            completion(nil, error)
            return
        }
        
        let videoSize = videoTrack.naturalSize
        let watermarkLayer = CATextLayer()
        watermarkLayer.string = watermarkText
        watermarkLayer.foregroundColor = UIColor.black.cgColor
        watermarkLayer.font = UIFont.boldSystemFont(ofSize: 80).fontName as CFTypeRef
        watermarkLayer.fontSize = 80
        watermarkLayer.alignmentMode = .center
        watermarkLayer.bounds = CGRect(x: 0, y: 0, width: KScreenWidth, height: 100)
        watermarkLayer.position = CGPoint(x: videoSize.width/2, y: videoSize.height/2)
        
        let videoLayer = CALayer()
        videoLayer.frame = CGRect(origin: .zero, size: videoSize)
        videoLayer.addSublayer(watermarkLayer)
        
        let videoComposition = AVMutableVideoComposition()
        videoComposition.renderSize = videoSize
        videoComposition.frameDuration = CMTimeMake(value: 1, timescale: 30)
        videoComposition.animationTool = AVVideoCompositionCoreAnimationTool(postProcessingAsVideoLayer: videoLayer, in: videoLayer)
        
        let instruction = AVMutableVideoCompositionInstruction()
        instruction.timeRange = CMTimeRange(start: .zero, duration: composition.duration)
        let layerInstruction = AVMutableVideoCompositionLayerInstruction(assetTrack: compositionVideoTrack!)
        instruction.layerInstructions = [layerInstruction]
        videoComposition.instructions = [instruction]
        
        guard let exportSession = AVAssetExportSession(asset: composition, presetName: AVAssetExportPresetHighestQuality) else {
            completion(nil, NSError(domain: "com.example", code: 0, userInfo: [NSLocalizedDescriptionKey: "Failed to create AVAssetExportSession"]))
            return
        }
        
        exportSession.videoComposition = videoComposition
        exportSession.outputURL = outputURL
        exportSession.outputFileType = .mp4
        exportSession.shouldOptimizeForNetworkUse = true
        
        exportSession.exportAsynchronously {
            switch exportSession.status {
            case .completed:
                completion(outputURL, nil)
            case .failed:
                completion(nil, exportSession.error)
            case .cancelled:
                completion(nil, NSError(domain: "com.example", code: 0, userInfo: [NSLocalizedDescriptionKey: "Export cancelled"]))
            default:
                break
            }
        }
    }

2、使用方法

let path = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent("Ding Move\(String(arc4random_uniform(100) + 1)).mp4")
let inputVideoURL = model.url
let outputVideoURL = path
let watermarkText = "Ding Movie"
ht_addWatermarkToVideo(inputURL: inputVideoURL, outputURL: outputVideoURL, watermarkText: watermarkText) { (outputURL, error) in
    if let error = error {
        DispatchQueue.main.async {
            HTClassWSProgressHud.hideHud()
        }
        print("Failed to add watermark: \(error.localizedDescription)")
    } else {
        print("Watermark added successfully. Output video URL: \(outputURL?.path ?? "")")
        //保存到相册
        HTClassPhotoTools.saveVideoToAlbum(videoURL: outputVideoURL) { isSuccess in
            DispatchQueue.main.async {
                HTClassWSProgressHud.hideHud()
                HTClassToastHUD.show(isSuccess ? "Saved album successfully" : "Failed to save the album, please try again")
            }
        }
    }
}