compressVideo.swift

func convertVideo(phAsset : PHAsset){

    PHImageManager.default().requestAVAsset(forVideo: phAsset, options: PHVideoRequestOptions(), resultHandler: { (asset, audioMix, info) -> Void in
        if let asset = asset as? AVURLAsset {
            do {
                let videoData = try  Data.init(contentsOf: asset.url)
                print(asset.url)
                self.orginalVideo = asset.url
                print("File size before compression: \(Double(videoData.count / 1048576)) mb")
            let compressedURL = NSURL.fileURL(withPath: NSTemporaryDirectory() + NSUUID().uuidString + ".MP4")
                print(compressedURL)
                self.compressVideo(inputURL: asset.url , outputURL: compressedURL) { (exportSession) in
                    guard let session = exportSession else {
                        return
                    }
                    switch session.status {
                    case .unknown:
                        print("unknown")
                        break
                    case .waiting:
                        print("waiting")
                        break
                    case .exporting:
                        print("exporting")
                        break
                    case .completed:
                        do {
                        let compressedData = try  Data.init(contentsOf: compressedURL)
                            self.compressVideo = compressedURL
                            print(compressedData)
                             print("File size AFTER compression: \(Double(compressedData.count / 1048576)) mb")
                        }
                        catch{
                           print(error)
                        }


                    case .failed:
                        print("failed")
                        break
                    case .cancelled:
                        print("cancelled")
                        break
                    }
                }
            } catch {
                print(error)
                //return
            }
        }
    })


}

func compressVideo(inputURL: URL, outputURL: URL, handler:@escaping (_ exportSession: AVAssetExportSession?)-> Void) {
    let urlAsset = AVURLAsset(url: inputURL, options: nil)
    guard let exportSession = AVAssetExportSession(asset: urlAsset, presetName: AVAssetExportPresetMediumQuality) else {
        handler(nil)

        return
    }
    exportSession.outputURL = outputURL
    exportSession.outputFileType = AVFileType.mp4
    exportSession.shouldOptimizeForNetworkUse = true
    exportSession.exportAsynchronously { () -> Void in
        handler(exportSession)
    }
}