You can share large files on WhatsApp by first uploading them to Google Drive, then sharing the link with your contacts on WhatsApp. Anyone who has a link to the file can access it on Google Drive.
If the video you want to share on WhatsApp, if it is a big video to share, then you can always try to compress it and share it. Just download Video Compressor & Video Cutter app from Google Play Store and compress videos.
Sometimes, high-quality photos can be too large to send over WhatsApp. You can overcome this problem by changing the size of your photos. You can resize photos by simply downloading the Photo & Picture Resizer app from the Google Play Store. Also you can resize it with Online Photo & Picture Resizer.
Like Google Drive, Dropbox is a cloud storage service that you can use to store and share large files with your friends. Simply download Dropbox to your phone and press the ‘+’ icon to upload any file, photo or audio. Once you have successfully uploaded the file to Dropbox, you can share the file link with your contacts on WhatsApp.