Gallery app is compresing videos to share and loses quality. I used to share videos to edit apps and it worked great. But now with automatic compression quality is bad.
Thank you
If you're using MMS to send the videos that will compress them. Try using something like Hangouts or WhatsApp or uploading your video to YouTube privately and sharing the link to your friends.
Pretty much any sharing will compress and reduce quality for large files Sometimes they ask. Sometimes they don't. The only real alternative is to upload to online storage and share a link. The issue there is to not run out of online storage space.
Google Photos sharing will send full size photos and videos. If you're on Android, you've got it or can easily get it, and it's also available for iOS for sending to non-Android users. I use it to share photos with my family, most of whom use iPhones.