Flutter – IMG.LY Blog

A Modern Video Editor SDK for your Flutter App

Jan — Fri, 13 Sep 2024 11:26:15 GMT

Video has been the only type of content with steadily growing demand, and it will remain a staple and an expected medium for users to create and consume.

With platforms such as TikTok, Instagram Reels, and YouTube Shorts dominating and shaping user habits, the ability to create and edit videos directly within your app can significantly increase engagement.

In this post, we’ll show how to integrate a video editor into a Flutter app using CreativeEditor SDK and customize it for specific use cases, like creating TikTok-style short videos.

You can check out the code for the default and custom Flutter video editor on GitHub

Why add a Video Editor to Your Flutter App?

The last decade has made one thing clear: video content is king. Particularly, short-form dominates digital content. At the forefront of this trend are apps like TikTok, which made people more comfortable creating, editing, and sharing bite-sized clips.

These apps have capitalized on their ability to let users apply filters, and add audio overlays, text, and more, empowering users at all skill levels to make professional-looking videos with minimal effort.

A host of different use cases stand to profit from this trend by enhancing their user experience with video editing features, particularly marketing tech tooling and apps with a messaging or social media component.

In general, video creation lowers the threshold for user-generated content and can positively impact distribution and product engagement.

Flutter, Google’s UI toolkit for building apps across platforms from a single code base, is a perfect fit for IMG.LY’s Video Editor. What often motivates the choice to use Flutter is that It ensures performance, flexibility, and a seamless user experience on iOS and Android devices. Similarly, our SDK is designed to offer a native cross-platform experience, while relying on the same underlying graphics processing engine, ensuring consistency and interoperability.

Getting Started: Integrating the Video Editor in Flutter

Let’s dive into how to set up a video editor in your Flutter app using CreativeEditor SDK.

Requirements

Before we get into the details, here’s what you’ll need:

Flutter 3.16.0+
Dart 2.12.0+
iOS 16 or later (as the video editor is currently only available for iOS, Android coming soon)
Swift 5.10 and Xcode 15.4

First, ensure your pubspec.yml file includes the necessary dependencies:

dependencies:
  flutter:
    sdk: flutter
  imgly_editor: 1.34.0

Once your environment is set up, you’re ready to start coding.

Setting Up the Editor

After adding the imgly_editor dependency, import the package in your code:

import "package:imgly_editor/imgly_editor.dart";

The next step is to initialize the editor by providing an instance of EditorSettings. This setup requires a license key, which you can obtain from CreativeEditor SDK, and an optional userId that helps track monthly active users (MAUs) across different devices.

Here’s a basic example of how to open the video editor:

class VideoEditorSolution {
  /// Opens the editor.
  void openEditor() async {
    final settings = EditorSettings(
        license: "YOUR_LICENSE",
        userId: "YOUR_USER_ID"
    );

    const preset = EditorPreset.video;

		/// Open the editor and retrieve the editing result.
    final result = await IMGLYEditor.openEditor(
        preset: preset,
        settings: settings
    );
  }
}

This launches the editor with the video preset, enabling users to trim, cut, and add filters, text overlays, music, and more to their videos.

Use Cases: Building a TikTok-Like Experience

Now that we have integrated the basic editor configuration into your Flutter app, let’s revisit some prominent use cases and how to configure the editor to support them.

Short-Form Video Creation

For a short-form video, TikTok-like user experience, the most important factor is the ease of use of any video editor and content such as stickers or audio overlays.

The following SDK capabilities can help you achieve that goal:

Control Video Duration and Position in Time: Users should be able to trim video clips on a timeline and position them relative to other tracks, such as audio clips.
Filters & Effects: Filters are essential for setting the tone of the video. Whether users want a retro, high contrast, or soft pastel look, filters provide creative control over the visual style.
Text & Stickers: Allow users to add text captions—especially important for content often watched on mute. Stickers and emojis can add a playful element to videos.
Music & Audio: Like TikTok, you can allow users to add background music or sound effects. Providing a library of popular tracks or sound snippets can enhance the content creation experience.
Video Templates: Give your users a head start with customizable video templates for different themes, topics, and occasions. IMG.LY’s CE.SDK comes with a web video editor to help build and deliver these templates to your Flutter app. You can explore a range of different templates in our video editor demo.

By integrating these features, you’ll empower users to create engaging, shareable content, elevating your app’s video creation experience to the level of consumer-grade social media apps.

Influencers and Marketing

If your app is targeting influencers or businesses, the ability to quickly create branded video content is key. You can offer:

Branded Templates: Pre-made templates that align with a brand’s style, allowing users to easily drop in their video footage and text while maintaining brand consistency. Again, check out the web editor demo to see how to build video templates.
Watermarks: Adding a watermark or logo as a brand signifier to videos can help with brand visibility and make sure content always points back to the creator.

This setup allows influencers and brands to create professional-looking videos that they can share across social media platforms with ease.

eCommerce and User-Generated Content

Video is a powerful medium to showcase products, especially on marketplaces that can leverage user-generated content and enable vendors as well as customers to create product or review videos.

For example, users could create unboxing videos, product reviews, or tutorials using the same trimming, filter, and music tools offered in a TikTok-style editor. These videos can then be shared on social media or used within the app to enhance the shopping experience.

Likewise, showcasing products using authentic demo videos tap into familiar patterns of video consumption and can boost sales for vendors.

Customization Options with CreativeEditor SDK

We have designed the Flutter plugin to be adaptable to match your brand and use case-specific requirements. Soon the plugin will also support more advanced customization options such as the ability to activate or deactivate features by default.

UI Customization: Modify the look and feel of the editor to match your app’s branding. We provide options for theming, styling color palettes, and callbacks to hook into editor events.
Video Presets: You can create custom video presets based on your users’ needs. For instance, you may want to limit video length or optimize for certain resolutions, depending on the target platform.
Video Templates: You can use the CE.SDK web UI to generate any number of video templates including collages, text designs, and animations to give your users professional-looking starting points for their video designs.
Assets: Provide custom filters, fonts, and stickers to enhance the user experience. For niche apps, this can be an excellent way to engage users by offering content that feels unique to your community.

Conclusion

Integrating a video editor into your Flutter app will improve your UX, and help boost engagement, retention, and potential distribution of your product, whether you’re building a social media platform, an influencer tool, or an e-commerce app. With CreativeEditor SDK, you can create a TikTok-like video editing experience or offer specialized tools for businesses and creators.

By following the steps outlined in this post, you can bring professional-level video editing features to your users. Explore CE.SDK’s video capabilities and dive into the docs.

Stay tuned for more updates, and please reach out if you have any questions. Thank you for reading.

Over 3,000 creative professionals gain early access to our new features, demos, and updates—don’t miss out, and subscribe to our newsletter.

CreativeEditor SDK now Supports Flutter on iOS & Android

Leon — Wed, 11 Sep 2024 09:16:19 GMT

We’re excited to introduce our new official imgly_editor Flutter plugin, bringing the CreativeEditor SDK to the Flutter ecosystem for iOS and Android!

Our CreativeEditor SDK empowers developers to seamlessly integrate design, video, and photo editing capabilities into their applications. Over the past few months, we’ve been laser-focused on enhancing our mobile editor solutions—refining existing features and expanding to new use cases, like the Video Editor.

To make our CreativeEditor SDK accessible to even more developers, we’re expanding our platform lineup to include mobile cross-platform frameworks.

We’re kicking off with one of the leading cross-platform mobile development frameworks, bringing you a Flutter integration for both iOS and Android.

Checkout our Flutter Showcases app on GitHub and test the integration yourself or follow our guide to learn how to integrate IMG.LY’s video editor for Flutter into your app.

Getting Started

Using the CreativeEditor SDK in Flutter is as easy as pie. First, gather your essentials: your license from our dashboard and the asset you wish to edit (if applicable).

Then, call the IMGLYEditor.openEditor function and start creating:

import "package:imgly_editor/imgly_editor.dart";

final settings = EditorSettings(license: "YOUR_LICENSE");
final result = await IMGLYEditor.openEditor(settings: settings);

Editor UI Presets

The imgly_editor Flutter plugin is built on top of our native editor solutions, enabling you to use our existing iOS and Android editor UI variants supporting a broad range of use cases. At launch, you can choose between:

Simply specify the editor variant when opening the editor:

import 'package:imgly_editor/imgly_editor';

/// Open the editor from an existing editor configuration.
///
/// Choose between [EditorPreset.video], [EditorPreset.image],
/// [EditorPreset.design], [EditorPreset.postcard] and
/// [EditorPreset.apparel].
const preset = EditorPreset.video;
final settings = EditorSettings(license: "YOUR_LICENSE");
final result = await IMGLYEditor.openEditor(preset: preset, settings: settings);

Additionally to our existing editor variants, you can also create your own editor variant to suit your particular use case using our native api. Please refer to our documentation on further information.

The Only Truly Cross Platform SDK

Since you are using Flutter, you probably care about time to market, reduced learning overhead for your dev team and cross platform feature parity and consistency. IMG.LY’s SDK design is guided by those same objectives. It is built atop a single creative engine that is portable to any platform. Whether iOS, Android, Desktop, or the Web, every platform uses the same underlying tech.

That means:

iOS and Android make use of the same underlying API.
Cross platform feature parity is baked into the cake. Since core functionality is implemented at the engine level, features are guaranteed to be available on both platform, although the timeline might differ somewhat.
Designs are 100% interoperable and consistent between platforms. Exporting and importing design files across platforms works seamlessly and final renderings are guaranteed to be consistent.

Fully Customizable UI

The Flutter plugin provides choices for theming, styling color palettes, and callbacks to hook into editor events.

We have designed the Flutter plugin to be adaptable to match your brand and use case specific requirements. Soon the plugin will also support more advanced customization options such as the ability to activate or deactivate features by default.

Check out our documentation for more information on opening a specific editor variant and customize the editor to your needs.

What’s Next?

To showcase what the new plugin can do, we’ve prepared a public example application you can explore on GitHub. Additionally, our documentation offers all the details you need to get started. And of course, you can head to our imgly_editor pub.dev page to begin integrating the Creative Editor into your app. Remember to grab your license from our homepage and let our editor unlock the creative potential of your users.

Are you Looking for React Native?

For those awaiting a React Native release, we have great news: React Native support (iOS & Android) is up next!

Stay tuned for more updates, and please reach out if you have any questions. Thank you for reading.

Over 3,000 creative professionals gain early access to our new features, demos, and updates—don’t miss out, and subscribe to our newsletter.

How to Add Stickers and Overlays to a Video in Flutter

Natalia — Fri, 24 Mar 2023 09:32:33 GMT

When working with interactive content, it may happen that you will need to add remote or local assets on top of your video file. The assets varying from images and stickers to videos and fonts are usually grouped and deployed within your application and are available at runtime. This tutorial will teach you how to apply stickers and overlays to a video in Flutter and make your video content more personalizable and user-oriented. We start by considering the prerequisites for successful video integration, then talk about how Flutter manages overlays in order to personalize our video file.

How does Flutter handle video assets?

Unlike images, Flutter displays a video file by employing a special video_player plugin that provides playback, stores a file, and manages speed and sound control. For iOS-based applications, the video is integrated via AVPlayer, whereas the Android system employs ExoPlayer. Crucially, to create a simple video player, one should follow the steps below:

First, to ensure that pubspec.yaml file contains the video_player dependency;
Then permit access to videos for the application;
Make a VideoPlayerController and set it up;
Finally, don’t forget to display and play the video player;

So, let’s closely look at the setup process.

Prerequisites:

We start by adding the following dependencies of video_player plugin to pubspec.yaml file.

dependencies:
  flutter:
    sdk: flutter
  video_player: ^2.4.7

Afterwards, change configurations of both android and ios systems to guarantee that an application has the proper authorization for video streaming: e.g. for Android-oriented programs, proceed to the <project root>/android/app/src/main/AndroidManifest.xml directory – where it’s necessary to add the next line to the AndroidManifest.xml.

<manifest xmlns:android="<http://schemas.android.com/apk/res/android>">
    <application ...>

    </application>

    <uses-permission android:name="android.permission.INTERNET"/>
</manifest>

For iOS-based apps the Info.plist file is stored at <project root>/ios/Runner/Info.plist. Once again, don’t forget to add the following specification to the original code:

<key>NSAppTransportSecurity</key>
<dict>
  <key>NSAllowsArbitraryLoads</key>
  <true/>
</dict>

Successful video integration in Flutter is managed through the VideoPlayer widget and a VideoPlayerController, which sets the connection to the asset and initialize the controller for playback.

/// Stateful widget to fetch and then display video content.
class VideoApp extends StatefulWidget {
  const VideoApp({Key? key}) : super(key: key);

  @override
  _VideoAppState createState() => _VideoAppState();
}

class _VideoAppState extends State<VideoApp> {
  late VideoPlayerController _controller;

  @override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.asset('assets/bee.mp4')

      /// Specify the path to your video asset here
      ..initialize().then((_) {
        /// Ensure the first frame is shown after the video is initialized,
        /// even before the play button has been pressed.
        setState(() {});
      });
  }

  @override
  void dispose() {
    super.dispose();
    _controller.dispose();
  }
}

Note that video tends to take up as much space on the screen as possible by default, which can significantly deteriorate the video’s quality. Therefore, the Flutter team suggests employing the AspectRatiowidget to adjust the video proportions.

? AspectRatio(
    aspectRatio: _controller.value.aspectRatio)

Adding Overlay Stickers and Text to a Video in Flutter

To see the complete code of our demo application, you can clone the GitHub repository or put the following command to your Terminal:

git clone git@github.com:nataliakzm/Adding_Stickers_and_Overlays_to_video_in_Flutter.git

Similarly to how we handled resizing images in Flutter, the same method is used when overlaying an object on a video. The above example consists basically of three containers, one with a sticker, another with the textual watermark and the last with a local video asset. However, the critical difference here is that a Container filled with a sticker and a Container filled with a textual watermark cannot be simply listed one by one in your code but rather must be both placed within a Stack widget.

The Stack container is designed as a “mother”-widget which retains multiple layers of widgets on the screen. Stack structures these branches of children into a hierarchical system from bottom to top. Thus, the uppermost widget goes to the background, and the bottommost item is displayed in the foreground.

Stack(
  children: <Widget>[
    BottomWidget(),
    MiddleWidget(),
    TopWidget(),
  ]),

Since the size of the Stack widget is aimed to be the largest size among layers, we will place our video asset on this layer. Then, to implement the overlays, it’s essential to position and/or align each child’s container.


child: Stack(children: [
  VideoPlayer(_controller),

  /// Don't forget to align the position of the Сontainer
  Positioned( bottom: 5, left: 10,
      child: Container( width: 80, height: 40,

        /// In case you want to check the position/size of the Container uncomment the next line
        //color: Color(0xff0360da),
        child: Align(
            alignment: Alignment.center,

            /// Integrate Sticker overlay into a video
            child: Image.asset('assets/sticker.png')))),

  Positioned( top: 5, right: 10,
      child: Container( width: 80, height: 40,
        child: Align(
            alignment: Alignment.center,

            /// Integrate Text overlay into a video
            child: Text("IMG.LY",
                style: TextStyle(
                    color: Colors.white,
                    fontSize: 20,
                    fontWeight: FontWeight.bold))))),
                        ]))

  /// If there is no video, a blank page will be return   : Container()),

Summing up

Thus, you can see from the code below that integrating multiple layers over interactive assets can be a tricky task which requires bearing in mind the position and order of each layer, as well as managing how the children are aligned to a video file and the screen size of the user. Conversely, the discussed method allows personalizing an application without significant modifications to the original file.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

/// Import video_player package to integrate a video asset
import 'package:video_player/video_player.dart';

void main() => runApp(const VideoApp());

/// Stateful widget to fetch and then display video content.
class VideoApp extends StatefulWidget {
  const VideoApp({Key? key}) : super(key: key);

  @override
  _VideoAppState createState() => _VideoAppState();
}

class _VideoAppState extends State<VideoApp> {
  late VideoPlayerController _controller;

  @override
  void initState() {
    super.initState();
    _controller = VideoPlayerController.asset('assets/bee.mp4')

      /// Specify the path to your video asset here
      ..initialize().then((_) {
        /// Ensure the first frame is shown after the video is initialized,
        /// even before the play button has been pressed.
        setState(() {});
      });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        home: Scaffold(
            appBar: AppBar(
                title: Text('How to add Stickers and Overlays'),
                backgroundColor: Color(0xff0360da)),
            body: Center(
                child: _controller.value.isInitialized

                    /// First, we specify the AspectRatio of a video frame
                    ? AspectRatio(
                        aspectRatio: _controller.value.aspectRatio,

                        /// Then, we initialize a Stack widget
                        child: Stack(children: [
                          VideoPlayer(_controller),

                          /// Don't forget to align the position of the Сontainer
                          Positioned( bottom: 5, left: 10,
                              child: Container( width: 80, height: 40,

                                  /// Uncomment the following line to check the position/size of the Container
                                  //color: Color(0xff0360da),
                                  child: Align(
                                      alignment: Alignment.center,

                                      /// Integrate Image overlay into a video
                                      child: Image.asset('assets/sticker.png')))),

                          Positioned( top: 5, right: 10,
                              child: Container( width: 80, height: 40,
                                  child: Align(
                                      alignment: Alignment.center,

																			/// Integrate some Text overlay into a video
                                      child: Text("IMG.LY",
                                          style: TextStyle(
                                              color: Colors.white,
                                              fontSize: 20,
                                              fontWeight: FontWeight.bold))))),
                        ]))

                    /// If there is no video, a blank page will be return
                    : Container()),
            floatingActionButton: FloatingActionButton.extended(
                backgroundColor: const Color(0xff0360da),
                foregroundColor: Colors.white,
                onPressed: () {
                  setState(() {
                    _controller.value.isPlaying
                        ? _controller.pause()
                        : _controller.play();
                  });
                },
                icon: Icon(_controller.value.isPlaying
                    ? Icons.pause
                    : Icons.play_arrow),
                label: Text('Play for IMG.LY'))));
  }

  @override
  void dispose() {
    super.dispose();
    _controller.dispose();
  }
}

Adding Overlays to a Video with Flutter package for VideoEditor SDK

However, if you would like to offer more advanced sticker and overlay functionality to your user and you might need a more complex UI structure. Since this can be an extremely time consuming undertaking you might want to opt for a ready-to-use solution such as VideoEditor SDK which among a host of other essential video editing features allows users to easily add stickers and different overlays to their videos.

To replicate the example above, go to the official documentation to discover how to get started with VideoEditor SDK or follow our guide on how to integrate video editor for Flutter into your app. Try to upload your video file and modify it with various stickers, text and other overlays. Alternatively, you can download our free mobile demo app from the App Store or Google Play, and test a comprehensive set video editing tools.

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How to Apply Filters and Effects to an Image in Flutter

Natalia — Tue, 15 Nov 2022 10:51:25 GMT

Introduction

Having previously discussed how Flutter deals with resizing and various overlays, in this tutorial, we will talk about a more popular type of image manipulation; applying filters and effects. At least since the ubiquity of social media platforms such as Instagram, Snapchat or more recently TikTok, applying various filters and effects has become an expected feature of any application dealing with image manipulation.

Applying Filters and Effects in Flutter demo application

In this tutorial, we go through the process of applying filters and effects to images in Flutter. Like the example given in the video, we will examine the options for developing an image editor and the effects available in the Flutter framework. The Git repository supporting this article can be cloned with the command provided below:

git clone git@github.com:nataliakzm/Applying_Filters_and_Effects_to_Images_Flutter.git

One of the leading solutions proposed by the Flutter team on this issue was the ImageFiltered class. Overall, the widget deals with major image manipulations (from blurring to matrix transformation, rotation etc.), transforming and rearranging image pixels. To create an ImageFilter, you need to follow a particular structure and apply the ImageFilter class to its child elements:

Moreover, in order to start working with ImageFiltered within your Flutter application, first, don’t forget to import this library on the top of your .dart file.

const ImageFiltered({
  super.key,
  required this.imageFilter,
  super.child,
  this.enabled = true,
}) : assert(imageFilter != null);

import 'dart:ui';

Then, ImageFiltered offers several filter choices for image processing, depending on the specification of your app or visual asset.

So, for example, with the help of ImageFilter.blur or the so-called Gaussian blur, the pixels of the image can be blurred, which can, for instance, be used to create a graphic element that can serve as a background image.
On the other hand, two other filters such as ImageFilter.dilate and ImageFilter.erode affect the pixels’ value by either enlarging them to the max significance within the specified range along the x and y axes or by shrinking pixels to their minimum values;
You can also easily rotate, scale and change your asset in other ways by transforming its matrix with ImageFilter.matrix;
Finally, ImageFilter.compose is handy for merging two filters and combining their effects.

At this point, the purpose of each effect seems much clearer, but we still miss some crucial steps to implement these filters in your Flutter application. Let’s see some real examples:

ImageFilter.blur constructor

To apply a blurring effect on your image, you have to call an ****ImageFiltered.blur(), and adjust the values of sigmaX and sigmaY arguments for blurring the image. Note that the asset must be called as a child element of the filter to achieve the desired effect.

Container(
		child: Center(
				child: Column(
						mainAxisAlignment: MainAxisAlignment.center,
						children: [
      // Blur an Image
      ImageFiltered(
					imageFilter: ImageFilter.blur(sigmaY: 5, sigmaX: 5),
					child: Image.asset("assets/logo.png"))

ImageFilter.matrix constructor

The situation is slightly different with ImageFilter.matrix filter since the effect can be initialized by one of two methods – Float64List.fromList or Matrix4.rotationZ . Thus, for the first method, the user needs to directly provide the matrix as a Float64List as it is done below:

// Matrix Transformation
ImageFiltered(
		imageFilter: ImageFilter.matrix(Float64List.fromList([
			1, 0.5, 0.0, 0.0,
			0.0, 1, 0.0, 0.0,
			0.0, 0.0, 1.0, 0.0,
			0.0, 0.0, 0.0, 1.0,
    ])),
		child: Image.asset("assets/logo.png", scale: 3.5)) // Note that scale is optional and depends on the image size

While the Matrix4 class simply provides rotation in Z directions:

// Matrix4 Rotation
ImageFiltered(
		imageFilter: ImageFilter.matrix(Matrix4.rotationZ(0.2).storage),
		child: Image.asset("assets/logo.png", scale: 6)) //Note that scale is optional and depends on the image size

ColorFiltered Effects

Alternatively, Flutter has several options to integrate some filters without calling any extra library. One such example is the ColorFilter function executed within the widget of the same name. ColorFiltered processes two colors and outputs only one of them, which is eventually displayed at the top of the layer.

 // Black & White Effect
ColorFiltered(
		colorFilter: const ColorFilter.mode(Colors.grey, BlendMode.saturation),
		child: Image.asset("assets/logo.png"))

Users can also engage with several construction methods: from directly calling the sRGB gamma curve with ColorFilter.linearToSrgbGamma() widget or its inverse prototype with ColorFilter.srgbToLinearGamma() to transforming the color by a 5x5 matrix within ColorFilter.matrix() function or simply applying the blend mode with a given color specified in ColorFilter.mode().

Final Thoughts

In conclusion, Flutter’s image processing capabilities are limited by a small variety of effects and often depend on the developer’s ability to handle complex concepts like matrix or sRGB curves. In this article, we reviewed some of the main image processing techniques proposed by the Flutter team and examined how to integrate them into photo editing apps. However, it is not always possible to allocate several days to calculate the correct matrix for transforming just one image when it comes to processing a large number of graphic assets. In such cases, you may want to think about using the PhotoEditor SDK for your next Flutter app. Just like in the interactive example below, PhotoEditor SDK has many different effects and filters that will suit any of your requests.

Applying Filters via PhotoEditor SDK

To learn more, check out our article on PhotoEditor SDK and how to set it up in your app and official PE.SDK guides. You can also follow our guide on how to integrate video editor for Flutter into your app. For any of your questions that might occur in the process, you can contact our Support, who will be glad to help you.

How To Resize Images in Flutter

Natalia — Tue, 27 Sep 2022 15:03:53 GMT

Static images are a core part of mobile applications. Usually, you store them in the directory in their original sizes, which requires you to adjust the sizes now and then, depending on where they are displayed. This article discusses how to resize images in Flutter and adjust their width, height, and size with efficient lines of code.

Resizing Methods

For image editing tools, Flutter offers an excellent and easy-in-use Boxfit property that works within the fit parameter, and you can easily integrate it into your application.

child: Image.asset( 'images/pexels.jpg', fit: BoxFit.cover)

Depending on your needs, you can choose between multiple attributes. For example, .cover and .fitHeight properties are similar when called, and both result in maximum frame coverage. Yet, although the image is widened proportionally, these methods can significantly affect the quality of crop image borders if they overfill. On the contrary, with .fitWidth or .scaledown, the asset is resized to the container’s width boundaries, which could be helpful when multiple images are needed to be displayed simultaneously. If you are dealing with a static image of small size, you can also employ .fill attribute that helps stretch your assets without cropping any critical information.

Alternatively, by calling .scale 0.5 the fit parameter will return you a graphical asset based on the scale you define. Note that any value less than 1 would reduce the image size.

Adjusting Image Size with Flutter

Now, let’s look at how Flutter allows applying these image manipulation techniques. The crucial difference from the other frameworks is that in Flutter, images should be stored in a specific folder. In other words, once you upload graphic files, go to the pubspec.yaml file and add the path to the directory around under assets(Note: by default the dependencies corresponding to ****assetsare usually placed around 45-46th lines in the code and need to be uncommented first by eliminating # and one space).

# Don't forget to define the assets folder in your directory
# To do so, find lines 45 - 46 in the **pubspec.yaml** file
# and uncomment the assets section like this:
assets:
  - images/ #Note that this should correspond to the name of your folder

Alternatively, you can specify the path to each image in the list:

assets:
  - assets/images/your_image.jpg
  - assets/images/your_image2.jpg

When the image is uploaded to Flutter, it seeks to occupy as much size as possible. But let’s presume that we have a “frame” or container that differs in size from the visual asset. One way to see the differences in sizes of both canvases is to color one frame, like color: Colors.indigo. Then we provide Flutter with the size specification and render our image in a child node child: Image.asset(‘images/pexels.jpg’). Thus, now we can see the image is placed inside the frame, and we need only to assign one of the filling methods (for example, fit: BoxFit.cover) discussed above.

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(const ImgApp());
}

class ImgApp extends StatelessWidget {
  const ImgApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: const ResizePage(),
    );
  }
}

class ResizePage extends StatelessWidget {
  const ResizePage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('How to Resize Images'),
          backgroundColor: Color(0xffe55586),
        ),

        body: Center(
            // Enabling the Image Frame
            child: Container(
                color: Colors.indigo, // To see the difference between the image's original size and the frame
                height: 550,
                width: 300,

                // Uploading the Image from Assets
                child: Image.asset(
                  'images/pexels.jpg',

                  // Resizing the Image to the Frame Size
                  fit: BoxFit.cover,
                ))));
  }
}

You can find the associated to this tutorial Git repository ― here. Otherwise, run the following command to clone the complete code to your system:

git clone <https://github.com/nataliakzm/Resizing_Images_with_Flutter>

Conclusion

This article covered Flutter’s approach to the image resizing problem and saw how to use it in practice. However, despite the diversity of suggested methods that could fulfill basic users’ needs, Flutter fails to provide a comfortable integration. Just imagine you are building an app similar to Instagram in its functionality and you need not only upload various images from different assets but also resize them differently. If you want to avoid spending your time writing and maintaining a ton of code, then you may consider using PhotoEditor SDK in your next project.

PhotoEditor SDK is available for various frameworks: first, read this article from the official documentation to set up dependencies for your Flutter-based project. You can also follow our guide on how to integrate video editor for Flutter into your app.

In case you encounter any difficulties with the installation process, don’t hesitate to contact our support who will be happy to help you. Then, as shown in the example below, you can efficiently resize, crop, rotate or flip your visual assets with the transform tool.

How to Crop and Trim Videos in Flutter

Michael H. — Tue, 27 Sep 2022 08:45:16 GMT

If you are looking for a package that crops and trims videos in Flutter, you must have already come across the video_trimmer Flutter package. This package can trim videos but does not provide video cropping (at least not out-of-the-box). In fact, none of the packages on pub.dev, as of today, allow cropping a video in Flutter. If you have dug deeper, you might have come across FFmpeg — a powerful video editing command line tool, that is not the easiest to get started with. See the Ultimate Guide to FFmpeg for help.In this article we will use the FFmpeg library to crop and trim a video in a Flutter project.

Here is a list of packages that we will be using; ffmpeg_kit_flutter package for cropping and trimming videos, the path_provider package to get the path to the application or external directory where the video files will be stored, and the video_player package to play the video preview.

This article will not cover building any UI for cropping and trimming. But, it will discuss in brief how to crop the video using the video_trimmer library as well. If you want to package this workflow for production, check out our guide on running FFmpeg inside a Docker container. Also, you can try out the code used in this article from this GitHub repository.

Get Started

The end result of this tutorial will be a simple app that would look like the following screenshot.

When you tap the Save Video, the preview will refresh with the cropped and trimmed video replacing the original video. Follow the instructions in this article, and you will be able to develop a similar Flutter app.

First, let us start by adding dependencies to a new Flutter project.

Add Dependencies

In your project’s pubspec.yaml file add the following 3 dependencies.

dependencies:
  ...
  ffmpeg_kit_flutter: ^4.5.1
  path_provider: ^2.0.11
  video_player: ^2.4.6

Then, execute flutter pub get command from the project folder root.

Set Minimum SDK Version and Platform Version

The ffmpeg_kit_flutter plugin runs on Android SDK API level 24+ and iOS SDK 12.1+. Therefore, modify the module level build.gradle file to declare the minSdkVersion.

android {
  defaultConfig {
    ...
    minSdkVersion 24
    ...
  }
}

Then, modify the Podfile to declare the minimum global platform.

# Uncomment this line to define a global platform for your project
platform :ios, '12.1'

Add a Video Asset

For simplicity, we will be using a video asset instead of implementing a file picker. Choose a video file you would like to work with or download this sample video file. Next, copy the video file to a new directory named assets at the root of your project folder.

And then reference the video file from the pubspec.yaml file.

flutter:
  assets:
    - assets/file1.mp4

Execute flutter pub get again.

Having added the required dependencies, let us move on to coding.

Implement Video Crop and Trim

Replace the code in your main.dart file with the following code in the code block. This will be our starter code.

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Crop and Trim Demo',
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key}) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Flutter Crop and Trim"),
      ),
      body: Column(
        children: [

        ],
      ),
    );
  }
}

Initialize the Input Player

Add the following code to the _MyHomePageState class.

import 'dart:io';

...
import 'package:flutter/services.dart';
import 'package:path_provider/path_provider.dart';
import 'package:video_player/video_player.dart';

...

class _MyHomePageState extends State<MyHomePage> {
  late String inputPath;
  VideoPlayerController? controller;
  String outputPath = "";

  ...

  @override
  void initState() {
    super.initState();
    copyVideoToApplicationDirectory().then((path) async {
      inputPath = path;
      controller = VideoPlayerController.file(File(inputPath));
      await controller?.initialize();
      await controller?.play();
      setState(() {});
      outputPath = await getOutputPath();
    });
  }

  ///Copy input file to ApplicationStorage Directory
  ///returns path to copied video
  Future<String> copyVideoToApplicationDirectory() async {
    const filename = "file1.mp4";
    var bytes = await rootBundle.load("assets/file1.mp4");
    String dir = (await getApplicationDocumentsDirectory()).path;
    writeToFile(bytes, '$dir/$filename');

    return '$dir/$filename';
  }

  ///Write to Path.
  Future<void> writeToFile(ByteData data, String path) {
    final buffer = data.buffer;
    return File(path).writeAsBytes(
        buffer.asUint8List(data.offsetInBytes, data.lengthInBytes));
  }
}

The copyVideoToApplicationDirectory method is copying the video from Assets to the Application directory on the phone’s file system. The resulting path is then stored in the inputPath variable which is then supplied to the FFmpeg command. For large‑scale workloads, you can move this FFmpeg command to AWS Spot Instances; our AWS guide shows how to configure a cloud environment for scalable video processing.

Next, add the VideoPlayer widget to the Column widget.

body: Column(
  children: [
    (controller != null)
        ? AspectRatio(
        aspectRatio: controller!.value.aspectRatio,
        child: VideoPlayer(controller!))
        : const SizedBox(),
  ],
),

Run the app and the video should start playing.

In the next step, we will add the FFmpeg command, but before that add the following 2 more methods to the _MyHomePageState class.

...

import 'package:ffmpeg_kit_flutter/ffmpeg_kit.dart';
import 'package:ffmpeg_kit_flutter/log.dart';
import 'package:ffmpeg_kit_flutter/return_code.dart';

...

class _MyHomePageState extends State<MyHomePage> {
  ...

  /// Output path with a file name where the result will be stored.
  Future<String> getOutputPath() async {
    final appDirectory = Platform.isAndroid
        ? await getExternalStorageDirectory()
        : await getApplicationDocumentsDirectory();
    final externalPath = '${appDirectory?.path}/out_file.mp4';
    return externalPath;
  }

  ///Executes the FFMPEG [command]
  ///Note: Green bar on the right is a Flutter issue. <https://github.com/flutter/engine/pull/24888>
  ///Should get fixed in a 3.1.0+ stable release <https://github.com/flutter/engine/pull/24888#issuecomment-1212374010>
  Future<void> ffmpegExecute(String command) async {

    final session = await FFmpegKit.execute(command);

    final returnCode = await session.getReturnCode();
    if (ReturnCode.isSuccess(returnCode)) {

      print("Success");
      //Replace the preview video
      await controller?.pause();
      await controller?.dispose();
      controller = VideoPlayerController.file(File(outputPath));
      await controller?.initialize();
      await controller?.play();
      setState(() {});

    } else if (ReturnCode.isCancel(returnCode)) {

      print("Cancel");

    } else {

      print("Error");
      final failStackTrace = await session.getFailStackTrace();
      print(failStackTrace);
      List<Log> logs = await session.getLogs();
      for (var element in logs) {
        print(element.getMessage());
      }

    }
  }
}

The getOutputPath method provides the path where the resulting video will be saved. The outputPath will be passed to the FFmpeg command whereas the ffmpegExecute method is where the FFmpeg magic takes place.

The ffmpegExecute method expects a valid FFmpeg String command. The String command is then passed to the FFmpegKit.execute method which returns an instance of FFMpegSession . It will tell us whether our command was executed successfully or not. If it was not executed successfully, we can extract error logs from it.

FFmpeg Execute Command

Add a TextButton from where the FFmpeg command shall be sent.

TextButton(
  child: Text('Save Video'),
  onPressed: () async {
    //TODO: Call FFMPEG Execute
  },
),

Next, call the following ffmpegExecute method from the onPressed property.

ffmpegExecute('-ss 0:00:15 -to 0:00:45 -y -i $inputPath -filter:v "crop=320:150" -c:a copy $outputPath');

Run the app and tap the Save Video button. You will notice that the player is now playing the new cropped and trimmed video.

If you were able to successfully follow the instructions up till here, it is time to dig a little deeper into the FFmpeg command that we just ran earlier.

Understanding the FFmpeg Command

Because command FFmpeg is a command line tool, it expects string-only commands. For this reason, we do not have any dart Classes, Methods, or Parameters to work with that we usually get when working with a dart plugin. Let us dissect the above command line command that is helping us crop and trim a video.

Command	Description
-ss 0:00:15	Seeks to position on the input video. The trim starts from this position.
-to 0:00:45	Stops reading at the position in the input video. The trim stops at this position. The total length of the video is 0:02:05.
-y	Overwrite output files. Helpful when the Save Video button is tapped more than once.
-i $inputPath	Input file location. This is the file on which the crop and trim are applied.
-filter:v	Apply a filter to the video stream.
”crop=320:150”	Apply a crop filter from the center of the video that is 320 pixels wide and 150 pixels tall. The original dimensions of the video were 320 x 240.
-c:a copy $outputPath	Specifies the codec with which the output file must be encoded. Here, copy is a special value to indicate the stream is not to be re-encoded. The a after the colon is a stream specifier for the audio stream.

That will be either the application directory or the external directory of the application, depending on whether the app is running on iOS or Android.

You can check out the app’s code and play with it by downloading it from this GitHub Repository. This project allows you to tweak the duration of the trim and dimensions of the crop, so it has more code, but at the heart of it, it still uses the above FFmpeg command.

Cropping Using the video_trimmer Plugin

As a bonus, here is a tip on how to use the video_trimmer plugin for cropping videos.

The video_trimmer plugin also uses FFmpeg at its core and allows us to pass on an FFmpeg command while saving the video. For this reason, it is an easy task for us to apply the crop to a video using the video_trimmer plugin.

To do this, pass the following command to the saveTrimmedVideo method’s ffmpegCommand parameter as shown in the code block below. The video_trimmer package expects the customVideoFormat parameter argument when the ffmpegCommand parameter is used.

await _trimmer
    .saveTrimmedVideo(
        startValue: _startValue,
        endValue: _endValue,
        ffmpegCommand:
            '-filter:v "crop=320:150"',
        customVideoFormat: '.mp4')
    .then((value) {
  setState(() {
    _value = value;
  });
});

Limitations of this Approach

The crop that we are applying is from the center of the frame. The present command would also need starting coordinates to crop a non-center frame.

The project will need a refined UI for cropping and trimming videos to offer a complete app experience to users. The current approach is miles away from creating that experience.

But perhaps the most significant limitation is FFmpeg’s licensing. FFmpeg is available with both LGPL and GPL licenses, so you must ensure your project is compatible with those licenses. For many commercial projects, this is a non-starter. Alternatively, you can run FFmpeg on Google Cloud Platform; our GCP tutorial walks you through setup.

Commercial Alternative

VideoEditor SDK (VE.SDK) from IMG.LY provides powerful video editing features, including cropping and trimming videos in a Flutter project. You will receive staples of video editing, including straightening videos, filters, brightness, color adjustments, and more. Follow our guide to learn how to integrate IMG.LY’s video editor for Flutter into your app.

Conclusion

While still a complex topic, video manipulation is more attainable to implement on Flutter than on native Android. Nevertheless, FFmpeg is the only open-source, free-to-use option to edit videos on Flutter right now. To automate cropping and trimming across many files or build a transcoding server, see our article on building a production‑ready batch video processing server.

Flutter: Our new plugins made for Dart developers

Leon — Thu, 11 Mar 2021 14:12:09 GMT

Flutter enables developers to build native iOS and Android applications with a single Dart codebase whilst the application’s performance is kept at a very high native-like level. This is even more ensured by the huge amount of Flutter plugins, which wrap native code for the use in Dart.

With the rising demand for photo and video editing solutions, we were committed to provide plugins that enable developers to use our native PhotoEditor SDK and our native VideoEditor SDK within their Flutter applications. This said we are proud to announce that the Flutter plugins photo_editor_sdk and video_editor_sdk are now extending our list of cross-platform modules. The combination of both products allows you to add comprehensive image and video editing tools to your Flutter application for iOS and Android - within minutes.

Usage

While building the plugins, we focused on making the use and integration of our existing SDKs as easy as possible and minimizing the required platform-specific knowledge and skillset. Therefore, using the plugins is as easy as writing a single line of Dart code:

Customization

Furthermore, we wanted to keep the high level of customization options like cropping or resizing that our customers are used to in our products. In this sense, we created a dedicated Configuration Dart class which serves the option to customize the SDK to your needs without ever leaving the Flutter world.
Using the configuration is fast and easy:

Where to go from here?

Feel free to explore our packages, usage examples as well as the API documentation on pub.dev and/ or GitHub.
We released our new Flutter plugins under open-source licenses, so feedback and pull requests are welcome.

Flutter – IMG.LY Blog

A Modern Video Editor SDK for your Flutter App

Why add a Video Editor to Your Flutter App?

Getting Started: Integrating the Video Editor in Flutter

Requirements

Setting Up the Editor

Use Cases: Building a TikTok-Like Experience

Short-Form Video Creation

Influencers and Marketing

eCommerce and User-Generated Content

Customization Options with CreativeEditor SDK

Conclusion

CreativeEditor SDK now Supports Flutter on iOS & Android

Getting Started

Editor UI Presets

The Only Truly Cross Platform SDK

Fully Customizable UI

What’s Next?

Are you Looking for React Native?

How to Add Stickers and Overlays to a Video in Flutter

How does Flutter handle video assets?

Prerequisites:

Adding Overlay Stickers and Text to a Video in Flutter

Summing up

Adding Overlays to a Video with Flutter package for VideoEditor SDK

How to Apply Filters and Effects to an Image in Flutter

Introduction

Flutter ImageFiltered Widget

ImageFilter.blur constructor

ImageFilter.matrix constructor

ColorFiltered Effects

Final Thoughts

How To Resize Images in Flutter

Resizing Methods

Adjusting Image Size with Flutter

Conclusion

How to Crop and Trim Videos in Flutter

Get Started

Add Dependencies

Set Minimum SDK Version and Platform Version

Add a Video Asset

Implement Video Crop and Trim

Initialize the Input Player

FFmpeg Execute Command

Understanding the FFmpeg Command

Cropping Using the video_trimmer Plugin

Limitations of this Approach

Commercial Alternative

Conclusion

Flutter: Our new plugins made for Dart developers

Usage

Customization

Where to go from here?