Web solution for onscreen capturing video/audio in chrome browser or mozilla firefox -- 2

I am looking for web solution (best will be extension or web page) for chrome/mozilla browser which will be for capturing any onscreen video or audio which is playing on webpage. User must be able to select specific area in browser (please see some example in attached pic) which user want record. For audio user will be able record any audio which is playing on browser. Also user must be able to select quality of video/audio after capturing. User must be also able to add timestamps to video or audio. When user will finish with capturing, adding timestamps and changing quality extension system will upload his data to server. User will have some simple UI where he will be able to make description of video also system will detect url and save this url and also date of creating and uploading will be stored. Description and information about capturing will be saved in mysqli database.