Follow these Steps:
Warning!: Not Recommended for Low Memory Mobiles ( Less Than 1 MB)!
1. Download Total Video Converter (Button at The Bottom).
2. Now Open it and Click on New Task/Add Video.
3. Then Open your Desired Video
4. Now a Window will Pop out Like the Below:
5. Then click on Web and then GIF.
6. Now click on Convert.
7. Now copy the Converted File into your mobile and Use it as Wallpaper/Screen Saver and Enjoy!!!