Improvement Suggestion: faster dateafter (and datebefore) parameters

[ben569]

I regularly download all the videos from youtube channels. But I only need the most recent videos, I keep the old ones on a server at home. For that, I use the following line in my bash script:
youtube-dl -c --dateafter $date_after --yes-playlist -o '~/Youtube-DL/%(uploader)s/%(title)s.%(ext)s' -f 141/140 --external-downloader aria2c --external-downloader-args '-s 8' $chaine
In $chaine, I usually put URLs along the lines of this: https://youtube.com/user/SOME_YOUTUBER/videos.
Of course, I specify the last time I downloaded the channel in $date_after. By the way, don't hesitate to suggest a cleaner way to eliminate the videos I have already downloaded.
However, since in these URLs the videos are classed by date by youtube, much time is wasted on checking wether or not a video has been posted recently enough, particularly when a channel has several thousands videos.
Maybe this time could be spared by assuming that as soon as a video is found to be out of date, all the remaining are, too.
On a side note, did I setup aria2c right for establishing 8 simultaneous connections? EDIT: I have CN:1 during the downloads.
If needed, I can provide you with my entire script - 23 lines.

[yan12125]

If I'm correct, in case of youtube, user pages do not give accurate upload date. (Only inaccurate descriptions like "2 weeks ago"). As a result, it's necessary to extract all videos and compare one by one. Would you like to provide a concrete example URL?

[ben569]

While the exact upload dates of the videos are not given, the videos on this page are sorted by upload date. As a consequence, youtube-dl could be optimized by checking the upload date of each video (and the other tasks assigned - download, encode, tag...) only until a single video is out of the date range as all the other videos will not make it. It's valid in three cases:

• Youtube-dl processes the playlist from the lastest to the oldest video and the --dateafter parameter is given. As of the last video within the date range, all the others are too old.
• Youtube-dl processes the playlist from the oldest to the lastest video and the --datebefore parameter is given. As of the last valid video within the date range, all the others are too recent.
• Both parameters are given. No matter the way youtube-dl processes the playlist, as of the last video within the date range, all the others are either too recent or too old.

I hope that I was clear enough...

An example URL: https://www.youtube.com/user/MrSuicideSheep/videos. Sorry for the inconvenience, I couldn't think of a youtube channel on top of my head, so I wrote SOME_YOUTUBER so you could swap it with whoever you want.

[dstftw]

Duplicate of #1502.