Force Trim - Fixed Length Video

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If you configured the trim tool to restrict the duration of the video by setting a minimum and/or maximum duration you can define the startup behavior of the VideoEditViewController as follows:

the composition or trim tool will always automatically be presented after opening for the user to review and adjust the length of the video. This corresponds to setting forceTrimMode to .always and is the default behavior.
forceTrimMode is set to .ifNeeded as in our exmaple and will only present
- the composition tool, if your initial composition is longer than maximumDuration or shorter than minimumDuration, or
- the trim tool, if your initial video is longer than maximumDuration.
Setting forceTrimMode to .silent will automatically trim the video to the maximumDuration without opening any tool.


import UIKit
import VideoEditorSDK

class TrimEnforceDurationSwift: Example, VideoEditViewControllerDelegate {
  override func invokeExample() {
    // Create a `Video` from a URL to a video in the app bundle.
    let video = Video(url: Bundle.main.url(forResource: "Skater", withExtension: "mp4")!)

    // Create a `Configuration` object.
    let configuration = Configuration { builder in
      // Configure the `TrimToolController` that lets the user
      // trim the video. The duration limits of these configuration options are
      // also respected by the `CompositionToolController`.
      builder.configureTrimToolController { options in
        // By default the editor does not have a maximum duration.
        // For this example the duration is set, e.g. for a social
        // media application where the posts are not allowed to be
        // longer than 4 seconds.
        options.maximumDuration = 4.0

        // By default the editor does not limit the maximum video duration.
        // For this example the duration is set, e.g. for a social
        // media application where the posts are not allowed to be
        // shorter than 2 seconds.
        options.minimumDuration = 2.0
      }

      // Configure the `VideoEditViewController`.
      builder.configureVideoEditViewController { options in
        // By default the editor trims the video automatically if it is
        // longer than the specified maximum duration. For this example the user
        // is prompted to review and adjust the automatically trimmed video.
        options.forceTrimMode = .ifNeeded
      }
    }

    // Create and present the video editor. Make this class the delegate of it to handle export and cancelation.
    let videoEditViewController = VideoEditViewController(videoAsset: video, configuration: configuration)
    videoEditViewController.delegate = self
    videoEditViewController.modalPresentationStyle = .fullScreen
    presentingViewController?.present(videoEditViewController, animated: true, completion: nil)
  }

  // MARK: - VideoEditViewControllerDelegate

  func videoEditViewControllerShouldStart(_ videoEditViewController: VideoEditViewController, task: VideoEditorTask) -> Bool {
    // Implementing this method is optional. You can perform additional validation and interrupt the process by returning `false`.
    true
  }

  func videoEditViewControllerDidFinish(_ videoEditViewController: VideoEditViewController, result: VideoEditorResult) {
    // The user exported a new video successfully and the newly generated video is located at `result.output.url`. Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func videoEditViewControllerDidFail(_ videoEditViewController: VideoEditViewController, error: VideoEditorError) {
    // There was an error generating the video.
    print(error.localizedDescription)
    // Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }

  func videoEditViewControllerDidCancel(_ videoEditViewController: VideoEditViewController) {
    // The user tapped on the cancel button within the editor. Dismissing the editor.
    presentingViewController?.dismiss(animated: true, completion: nil)
  }
}