[Reddit] Original GIF images from dead Lensdump links available at a different location in the preview metadata

[taskhawk]

Found out that for Reddit posts linking to dead Lensdump GIF files the original GIF is still available for recovery in the preview at a slightly different location.

The current code downloads the fallback from here but this ends up being a still image:
preview['images'][N]['source']['url']

The GIF file can be found at:
preview['images'][N]['variants']['gif']['source']['url']

There's also a MP4 variant available:
preview['images'][N]['variants']['mp4']['source']['url']

Examples (NSFW):
https://new.reddit.com/r/NewYorkNine/comments/13qok1t/
https://new.reddit.com/r/NewYorkNine/comments/174qdbn/
https://new.reddit.com/r/NewYorkNine/comments/17ljnx1/
https://new.reddit.com/r/NewYorkNine/comments/14az0wx/

[mikf]

Which variant should be prioritized here? I personally lean towards gif since they are closer to the original file, I'd think, but mp4s are significantly smaller.

[taskhawk]

gif since they are actually the original file and what would have been downloaded if the file still existed on Lensdump (I think they don't serve mp4 variants, right?).

NSFW:

https://new.reddit.com/r/NewYorkNine/comments/13qok1t/

gallery-dl -K "https://new.reddit.com/r/NewYorkNine/comments/13qok1t/"

...
url
  https://i3.lensdump.com/i/kw8bix.gif
...

https://web.archive.org/web/20230524201956/https://i3.lensdump.com/i/kw8bix.gif

Same file size as the Reddit preview gif.

Don't know if this would be worth an option to choose preview format.

[taskhawk]

Related, what's your opinion on supporting Archive.org files for dead links? I saw it mentioned on this issue: #4322

Taking as example one of my previous issues (#5296):

NSFW:
https://www.reddit.com/r/NewYorkNine/comments/11pgu91/

gallery-dl -K "https://www.reddit.com/r/NewYorkNine/comments/11pgu91/"

...
preview['reddit_video_preview']['fallback_url']
  https://v.redd.it/qnz7y43g40bb1/DASH_1080.mp4
...
url
  https://i.imgur.com/d3xDLw9.gifv
...

https://web.archive.org/web/20230508182847/https://i.imgur.com/d3xDLw9.gifv

The highest quality preview Reddit offers is a 9.6 MiB video with a resolution of 608x1080 px, while the Archive.org copy is a 20.8 MiB video with a resolution of 960x1706 px.

[mikf]

Related, what's your opinion on supporting Archive.org files for dead links?

Eventually, but not with the current code base. There's just too much duct tape holding everything somewhat together to be adding a bigger feature like this.