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

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.