Offline operation (content cache/archival)

[Atemu]

Describe the feature

As Youtube enshittifies further and further, the risk increases that beloved videos become inaccessible to Piped or even entirely inaccessible. It's easy to imagine scenarios where existing videos become DRM'd (I'm honestly surprised it hasn't happened for Music videos yet), whole channels deleted and/or piped instances blocked.

To mitigate this, it'd be amazing if the piped back-end could download/archive/cache videos before that happens. The users and/or admins would populate this archive via commands and policies such as:

• Specific videos (manual)
• Entire channels or playlists (manual)
• Any video that is watched or opened
• Any new upload from subscribed channels (or a subset)
• Popular videos in some category
• Visited Channel/Video/Playlist metadata

Piped would then download the videos and metadata to be archived in a configurable maximum resolution.

When Piped would later fail to reach upstream YouTube for content that had been downloaded previously, the cache/archive would transparently be used to serve the data.

Basically, piped should be able to operate in a limited degree without Youtube being present.

Why would this be useful to add?

• Ensure availability of the most valuable content, even when YT inevitably reaches the end of its ensittification journey
• Partial availability during upstream outages (breaking YT change but no NPE update yet, instance blocked, internet outages in a LAN setting, ...)
• Users could still browse and manage subscriptions and playlists, even if their contents are not available at the moment (or will no longer be)

Concept(s)

No response

Additional context

This would require quite a bit of storage space of course but storage is cheap these days; I'd gladly pay a couple dozen EUR to store a few TiB worth of my favourite creators past creations.

Download quality could also be decided based on the policy which triggered it. I.e. super low resolution versions for downloads automatically triggered by users watching a video. 144p needs <20KiB per second of video cached/archived (including audio) and even that is immeasurably better than nothing at all. At 15€/TiB (common price for large HDDs), that's about 0.001€ per hour of video; for 100€, you could archive 100,000h of content or about 400,000 15min videos.

Acknowledgements

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