How to add an image or text (Watermark) on a video/image - Flutter/Dart

Question

I'm building a Flutter application which needs to add waermark on videos and images. Is there any way to achieve this with firebase (or any other service)? I could do this on client-side but also there i can't find any flutter/Dart package related to video/image processing.

Kindly guide me how to do it.

Thanks

Solution

For videos:

• https://github.com/tanersener/flutter-ffmpeg, though I couldn’t find anything that explicitly documents a way to edit the video, such as a watermark. But it should be possible according to others https://stackoverflow.com/a/57847155/6668797.

• https://pub.dev/packages/video_manipulation

  Adding still frames to an existing video, e.g. watermarks

  .generateVideo(List<String> paths, String filename, int fps, double speed).

  Parameters paths list of input file paths. Can be images (.jpg or .png) or video files (.mp4) that are used to generate the new video. E.g.: ["documents/input.mp4", "documents/watermark.jpg]

For images:

• https://pub.dev/packages/image

  load, save and manipulate images in a variety of different file formats.

  https://github.com/brendan-duncan/image/wiki/Examples

  drawString(image, arial_24, 0, 0, 'Hello World');

As for other services, I don't know, but Firebase does not offer this service.

Otherwise, client/app-side, there’s currently not much else for videos, but there's more available for images, you can search https://pub.dev/flutter/packages?q=image+editor. However, for more options, you’ll have to seek out native Android/iOS libraries and custom integrate them through the platform channels.

Comments

[Mahesh Jamdade]

Will this work for an Image picker an usecase where I capture an image by opening a camera in the app or choosing an image from gallery

[TWL]

Yes, they all should once you've got reference to the File created.

[Nicks]

any luck using FFmpeg ?

[Bonobito]

I wonder that it will be necessary applying watermark on each frame with the previous function then probably join all the frames with the following package pub.dev/packages/flutter_ffmpeg