One of those would be to:

Upload the original media file to IPFS and get the CID.
ffmpeg convert file to HLS format. Although proprietary is still the best to do adaptive streams.
HLS is stored inside an IPFS folder.
CID of HLS folder is stored referencing the CID of original media.

How to insert new CID in old post?

Use another database to convert old media file CID to new HLS CID.
- Don't like this one. Too many database references must be queried.
Give community owner posting authority so it can automatically replace CID.
- Don't like this one either.
Upload media first, wait for HLS to be ready before publishing.
- This sounds good if conversion doesn't take too long.
- Posts can be scheduled by giving community owner posting authority.
  - Schedules can be "as soon as conversion is ready" and "at specific date/time + after conversion is ready".

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