Topics created by pierat

@lunaopp1

I did.

Turns out JFF is only using a rather weak DRM called Clearkey. And luckily someone just released a tool to extract decryption key from Clearkey last week.

So here's the steps:

Download the encrypted media files using The stream detector extension and yt-dlp.
stream detector.PNG
cmd.PNG
(After copying download command in cmd, you need to add --allow-unplayable option, otherwise yt-dlp will only download audio file.)

Using Widevine L3 Guesser Extension to acquire Clearkey decryption key pair. (You don't need to setup CDM to use the extension, since it's not about Widevine.)
guesser.PNG
(If the extension didn't detect clearkey, you can also find the entry in browser's web console in dev tools)
dev tool.PNG

Using ffmpeg and decryption key to decrypt and merge file. (Although MP4Decrypt is also a tool you can use, it outputs corrupted audio file when decrypting. No idea why.)
ffmpeg.PNG

In the future, if JFF switches to other strong DRM like Widevine, the second process of acquiring decryption key will be somewhat more complicated. But the steps to download DRM content should be the same.

Widevine L3 Guesser

https://forum.videohelp.com/threads/414140-[Release]-Widevine-L3-Guesser-Extension-Works-in-2024-Firefox-Chrome-All-OS?s=61bb0364959aecde08115a7d82631999

Useful resources

OF-Scapper (OF uses Widevine)
https://of-scraper.gitbook.io/of-scraper/cdm-options

CDRM project guide
https://cdm-project.com/How-To/Downloading-Video-and-Audio
https://cdm-project.com/How-To/Decrypting-Video-and-Audio
https://cdm-project.com/How-To/Merging-Decrypted-Video-and-Audio

there's THIS if you have the time to read carefully and follow directions. *note that this does NOT include the ones behind a paywall.