What client-side storage options are there to persist a long media recording to disk at specific intervals?

The plan is to allow users to record articles that can sometimes take up an hour or two. By recording ogg an hour in Chrome 56 comes out around 20 MB which does not seem that large but video may be added later that could crank this up. I assume that storing the recorded media to disk would make the app more memory-friendly but it could be that this is only a misconception of mine.

So I found the following options:

• DOM Storage API (localStorage and sessionStorage) that is usually limited 5 MB. There is a hack that works in most browsers (except in Firefox) since 2013 but I assume it is going to get fixed eventually.

• IndexedDB where the storage limit is usually half the size of the disk but its details are more involved.

I know that the stream could be uploaded to the server in many ways but if the user would like to edit the recording in the browser afterwards (for example with the tools on the website in case she has no preferred desktop app) then this data would need to be retrieved and resent. Probably there could be a diffing solution but this may be an overkill.