How to trim the video using AVFoundation

Question

Iam able to record the video by using AVFoundation or UIImagePickerController. But i am unable to trim the video from one particular second to another particular duration/ti

Answer 1

Swift version of above

import UIKit
import AVFoundation
import MobileCoreServices

func pickVideo(){
    if UIImagePickerController.isSourceTypeAvailable(.Camera) {
        let videoRecorder = UIImagePickerController()
        videoRecorder.sourceType = .Camera
        videoRecorder.mediaTypes = [kUTTypeMovie as String]
        videoRecorder.allowsEditing = true
        videoRecorder.delegate = self

        presentViewController(videoRecorder, animated: true, completion: nil)
    }
}


func imagePickerController(picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [String : AnyObject]) {
    picker.dismissViewControllerAnimated(true, completion: nil)
    let manager = NSFileManager.defaultManager()

    guard let documentDirectory = try? manager.URLForDirectory(.DocumentDirectory, inDomain: .UserDomainMask, appropriateForURL: nil, create: true) else {return}
    guard let mediaType = info[UIImagePickerControllerMediaType] as? String else {return}
    guard let url = info[UIImagePickerControllerMediaURL] as? NSURL else {return}

    if mediaType == kUTTypeMovie as String || mediaType == kUTTypeVideo as String {
        let asset = AVAsset(URL: url)
        let length = Float(asset.duration.value) / Float(asset.duration.timescale)
        print("video length: \(length) seconds")

        let start = info["_UIImagePickerControllerVideoEditingStart"] as? Float
        let end = info["_UIImagePickerControllerVideoEditingEnd"] as? Float


        var outputURL = documentDirectory.URLByAppendingPathComponent("output")


        do {
            try manager.createDirectoryAtURL(outputURL, withIntermediateDirectories: true, attributes: nil)
            outputURL = outputURL.URLByAppendingPathComponent("output.mp4")
        }catch let error {
            print(error)
        }

        //Remove existing file
         _ = try? manager.removeItemAtURL(outputURL)


        guard let exportSession = AVAssetExportSession(asset: asset, presetName: AVAssetExportPresetHighestQuality) else {return}
        exportSession.outputURL = outputURL
        exportSession.outputFileType = AVFileTypeMPEG4

        let startTime = CMTime(seconds: Double(start ?? 0), preferredTimescale: 1000)
        let endTime = CMTime(seconds: Double(end ?? length), preferredTimescale: 1000)
        let timeRange = CMTimeRange(start: startTime, end: endTime)

        exportSession.timeRange = timeRange
        exportSession.exportAsynchronouslyWithCompletionHandler{
            switch exportSession.status {
            case .Completed:
                print("exported at \(outputURL)")

            case .Failed:
                print("failed \(exportSession.error)")

            case .Cancelled:
                print("cancelled \(exportSession.error)")

            default: break
            }
        }
    }
}