Help automating key extraction for UK TV Downloader app (Channel 4, ITVX, M

[DiCamolla]

Hi everyone,

I hope this is worthy of a new thread.

I’ve been working on a macOS app called UKTVDownloader, which I built with the help of some AI tools (mostly Claude and ChatGPT). It’s a Python-based GUI that lets users download content from UK streaming platforms like Channel 4, ITVX, and Channel 5. It supports MPD detection, subtitle downloads, and merging with ffmpeg and N_m3u8DL-RE.

GitHub repo:
https://github.com/Padraig74/UKTVDownloader

Right now, the only manual step left is getting the DRM key (KID:KEY). I can extract the PSSH from the MPD, but the user still has to manually input the decryption key — usually using Widevine CDM tools or browser extensions.


What I’m asking for:
• Is there any way to automate the process of getting the DRM key from the PSSH, via existing tools?
• Has anyone integrated something like this into a script or app before?
• Any advice on how I could approach this for macOS users would be really appreciated.

I’m not a professional coder — I’ve stitched this together mostly by learning as I go and tweaking with AI assistance — so if anyone has tips, examples, or even partial solutions, I’d be really grateful.

Thanks in advance!
Padraig

[Obo]

You maybe want to look at https://github.com/aarubui/yt-dlp-mp4decrypt, which should have support for Channel 4 and ITV among others.