If a video is posted in one channel, and another users posts the same video in another channel.. how will Stream identify it - 2 video consuming say 10 MB of single file size and shared with 2 channels, or 2 videos consuming 20 MB (10M each X 2).
Stream only counts the original file uploaded toward storage quota.
If someone uploads the exact same video file 2 times (reguardless of how it's permissioned), to Stream that is 2 different videos and will be counted as such. We do not have any logic in our system to identify videos that are technically the same binary and only host them 1 time.
However if someone uploads a video one time and then that one video is shared / permissioned such that it shows up in multiple groups/channels, that is just 1 video in our system and is only counted toward your storage quota 1 time.