How to organize audio and video encryption in a mobile application?

Question

Android

Good day!
In a mobile application, it is necessary to organize mechanisms for encrypting downloaded audio and video files, with further storage on the device. The questions are as follows:
1. Is it worth encrypting the file after downloading it on a mobile device, or storing already encrypted files on the server, but then it will be necessary to write a decryption script for browsers, since this application is a wrapper for a regular web application?
2. How to actually encode? Advise, in your opinion, the best practices, the file will be decoded in the future and immediately played

Answer 1

You did not specify in your question what kind of application, where the files come from, what does the server have to do with it, for what reasons do you want to encrypt?
Therefore, it is completely unclear where it is worth encrypting and whether it is worth doing it at all.