Reddit downloads don't work when you use shortlinks

[TimothyRichardGreen]

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Checklist

• I'm reporting that a supported site is broken
• I've verified that I'm running yt-dlp version 2023.03.04 (update instructions) or later (specify commit)
• I've checked that all provided URLs are playable in a browser with the same IP and same login details
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched known issues and the bugtracker for similar issues including closed ones. DO NOT post duplicates
• I've read the guidelines for opening an issue
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Region

Ireland

Provide a description that is worded well enough to be understood

Reddit's shortlinks (at redd.it) probably don't need special-casing, as they issue a normal HTTP 301 redirect response, but the page to which they redirect is not a page that yt-dlp knows how to cope with. In a browser, Reddit loads the page and then (I think) uses history.pushState() to update the URL to the normal one that yt-dlp expects.

Since the page initially loaded does contain the video, I imagine that it would be a relatively minor tweak to yt-dlp to support these URLs.

(Te example video provided is safe for work, by the way.)

Provide verbose output that clearly demonstrates the problem

• Run your yt-dlp command with -vU flag added (yt-dlp -vU <your command line>)
• If using API, add 'verbose': True to YoutubeDL params instead
• Copy the WHOLE output (starting with [debug] Command-line config) and insert it below

Complete Verbose Output

[debug] Command-line config: ['https://redd.it/124pp33', '-vU']
[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8, error utf-8, screen utf-8
[debug] yt-dlp version stable@2023.03.04 [392389b7d] (zip)
[debug] Python 3.8.10 (CPython x86_64 64bit) - Linux-5.4.0-144-generic-x86_64-with-glibc2.29 (OpenSSL 1.1.1f  31 Mar 2020, glibc 2.31)
[debug] exe versions: ffmpeg 4.2.7, ffprobe 4.2.7
[debug] Optional libraries: Crypto-broken 2.6.1, certifi-2019.11.28, secretstorage-2.3.1, sqlite3-2.6.0
[debug] Proxy map: {}
[debug] Loaded 1786 extractors
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
Available version: stable@2023.03.04, Current version: stable@2023.03.04
Current Build Hash: 91cad9f121c1f6f0a81b747415c46ecba0ff331ed38cc6433040b4ac7b6e15ca
yt-dlp is up to date (stable@2023.03.04)
[generic] Extracting URL: https://redd.it/124pp33
[generic] 124pp33: Downloading webpage
[redirect] Following redirect to https://www.reddit.com/comments/124pp33
[generic] Extracting URL: https://www.reddit.com/comments/124pp33
[generic] 124pp33: Downloading webpage
WARNING: [generic] Falling back on generic information extractor
[generic] 124pp33: Extracting information
[debug] Looking for embeds
ERROR: Unsupported URL: https://www.reddit.com/comments/124pp33
Traceback (most recent call last):
  File "/usr/local/bin/yt-dlp/yt_dlp/YoutubeDL.py", line 1518, in wrapper
    return func(self, *args, **kwargs)
  File "/usr/local/bin/yt-dlp/yt_dlp/YoutubeDL.py", line 1594, in __extract_info
    ie_result = ie.extract(url)
  File "/usr/local/bin/yt-dlp/yt_dlp/extractor/common.py", line 694, in extract
    ie_result = self._real_extract(url)
  File "/usr/local/bin/yt-dlp/yt_dlp/extractor/generic.py", line 2510, in _real_extract
    raise UnsupportedError(url)
yt_dlp.utils.UnsupportedError: Unsupported URL: https://www.reddit.com/comments/124pp33

[bashonly]

since https://redd.it/124pp33 redirects to https://www.reddit.com/comments/124pp33, I think this is all we need to do:

diff --git a/yt_dlp/extractor/reddit.py b/yt_dlp/extractor/reddit.py
index 9dba3eca8..4aa935ac2 100644
--- a/yt_dlp/extractor/reddit.py
+++ b/yt_dlp/extractor/reddit.py
@@ -14,7 +14,7 @@
 
 
 class RedditIE(InfoExtractor):
-    _VALID_URL = r'https?://(?P<subdomain>[^/]+\.)?reddit(?:media)?\.com/(?P<slug>(?:r|user)/[^/]+/comments/(?P<id>[^/?#&]+))'
+    _VALID_URL = r'https?://(?P<subdomain>[^/]+\.)?reddit(?:media)?\.com/(?P<slug>(?:(?:r|user)/[^/]+/)?comments/(?P<id>[^/?#&]+))'
     _TESTS = [{
         'url': 'https://www.reddit.com/r/videos/comments/6rrwyj/that_small_heart_attack/',
         'info_dict': {

$ yt-dlp -F "https://redd.it/124pp33"
[generic] Extracting URL: https://redd.it/124pp33
[generic] 124pp33: Downloading webpage
[redirect] Following redirect to https://www.reddit.com/comments/124pp33
[Reddit] Extracting URL: https://www.reddit.com/comments/124pp33
[Reddit] 124pp33: Downloading JSON metadata
[Reddit] 124pp33: Downloading m3u8 information
[Reddit] 124pp33: Downloading MPD manifest
[info] Available formats for antsenjc2jqa1:
ID                  EXT RESOLUTION FPS │   FILESIZE  TBR PROTO │ VCODEC       VBR ACODEC      ABR ASR MORE INFO
──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
hls-2-audio_0       mp4 audio only     │                 m3u8  │ audio only       unknown             audio 0
hls-3-audio_0       mp4 audio only     │                 m3u8  │ audio only       unknown             audio 0
dash-audio_0_130140 m4a audio only     │ ~276.55KiB 130k https │ audio only       mp4a.40.2  130k 48k DASH audio, m4a_dash
dash-video_254485   mp4 122x220     30 │ ~540.78KiB 254k https │ avc1.4D401E 254k video only          DASH video, mp4_dash
dash-video_612003   mp4 132x240     30 │ ~  1.27MiB 612k https │ avc1.4D401E 612k video only          DASH video, mp4_dash
hls-354             mp4 158x288        │ ~752.25KiB 354k m3u8  │ avc1.42c01e 354k video only
hls-450             mp4 158x288        │ ~956.25KiB 450k m3u8  │ avc1.42c01e 450k video only
hls-560             mp4 176x320        │ ~  1.16MiB 560k m3u8  │ avc1.42c01e 560k video only
hls-656             mp4 176x320        │ ~  1.36MiB 656k m3u8  │ avc1.42c01e 656k video only
fallback            mp4 198x360        │ ~  1.66MiB 800k https │ h264        800k video only          DASH video, mp4_dash
dash-video_816954   mp4 198x360     30 │ ~  1.70MiB 817k https │ avc1.4D401E 817k video only          DASH video, mp4_dash