I want to release my proprietary software as open source but don't want people to use it with the same purpose as I do, for example imagine you have made a video streaming app but you want to be the only one to use it for cooking videos. How should I go about this?
You cannot. One of the fundamental principles of open source (as defined by the Open Source Definition) is
- No Discrimination Against Fields of Endeavor
The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.