https://watch.plex.tv/movie/borderline

i was able to grab the MPD using the firefox add-on called the stream detector
however, the movie fails to download because it is DRM protected.

How to test if an online video is DRM-protected. Please keep in mind that testing one video isn't necessarily an indication of whether all the videos on the website contain drm.

Step 1: start by checking whether the video can be played in your web browser, after disabling DRM technologies on it:

If the video could be played with DRM disabled, feel free to open a site-support request for the website.
Otherwise, move on to step 2:

I'm up against similar struggles, looking for solutions and insight about downloading painlessly from plex.tv. After some trial and error I'm able to download from plex.tv successfully some of the time. For the HLS streams, it requires locating two hls/m3u8/token links, one for the video stream and one for the audio stream, downloading each of them (as two mp4 containers), and then combining the two using FFMPEG or similar tools.

I've been looking for ways to eliminate the extra steps and legwork, to simplify the process to where both video and audio streams are downloaded and muxed together concurrently and automatically as is done with most other yt-dlp supported sites. This is the goal.

After some trial and error I'm able to download from plex.tv successfully some of the time. For the HLS streams, it requires locating two hls/m3u8/token links, one for the video stream and one for the audio stream, downloading each of them (as two mp4 containers), and then combining the two using FFMPEG or similar tools.

Assuming your links don't have DRM, pls provide logs. If it does, take the discussion elsewhere!

Neither the video nor the audio streams are scrambled or unplayable, so probably not. It's just that yt-dlp is not handling plex.tv appropriately, meaning it's not recognizing and downloading both streams concurrently and processing them together into one video file... I end up having to do that myself.

While the example in OP seems to contain DRM, not all videos do:
Eg: https://watch.plex.tv/movie/bowery-at-midnight

❯ yt-dlp "https://vod.provider.plex.tv/library/parts/6305724320112-hls.m3u8?includeAllStreams=1&X-Plex-Token=xhvsqHDKxR879-C-48Zo"
[generic] 6305724320112-hls: Requesting header
[generic] 6305724320112-hls: Downloading m3u8 information
[info] 6305724320112-hls: Downloading 1 format(s): 2405+audio-3-en__Main_
[hlsnative] Downloading m3u8 manifest
[hlsnative] Total fragments: 373
[download] Destination: 6305724320112-hls [6305724320112-hls].f2405.mp4
[download]   0.2% of ~893.59MiB at  226.98KiB/s ETA 01:07:04 (frag 0/373)

This was super useful.
Subtitles weren't found but I was able to manually find them by

1. yt-dlp -j $(URL)
2. Finding the main en audio group with cat t.txt | jq ".formats[] | {"name": .format_id, "url": .manifest_url}"
3. Downloading that .m3u8 wget -O test.m3u8 $(AUDIO_URL)
4. Visually inspecting the m3u8 file head test.m3u8
#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="subtitles-0",NAME="English",DEFAULT=NO,LANGUAGE="en",URI="/library/parts/<ID/subtitles.m3u8?duration=4432&url=https%3A%2F%2Fvod-static.plex.tv%2Fsubtitles%2F<ID>%2Feng.vtt"
5. Downloading the url-decode &url param https://vod-static.plex.tv/subtitles/<ID>/eng.vtt

Here's another example that worked fine, when you use the .m3u8 URL: https://watch.plex.tv/movie/special-when-lit

yt-dlp "https://vod.provider.plex.tv/library/parts/62be16665e5872e9508f50ab-hls.m3u8?includeAllStreams=1&X-Plex-Product=Plex+Mediaverse&X-Plex-Token=yTzrtVtCLAQgDTeZxbvD"

yt-dlp downloaded both video and audio sources and combined them automatically to get a ready-to-watch mp4 video file.

Workaround: You can use dash-mpd-cli to download a Plex media by the stream URL which ends in .mpd.

How to get the MPD URL from Plex

1. Open Plex Web App:

   • Navigate to Plex.tv and log in.
   • Play the media you want to download.

2. Open the Developer Tools:

   • Right-click anywhere on the page and select Inspect or press Ctrl+Shift+I (Windows/Linux) or Cmd+Opt+I (Mac).
   • Go to the Network tab.

3. Filter by .mpd:

   • In the search/filter bar, type mpd to narrow the results to MPD files.

4. Play the Media:

   • Start playing the desired media. Look for a request that ends with .mpd in the network activity.

5. Copy the MPD URL:

   • Right-click the .mpd request and select Copy > Copy Link Address.

Thanks @JasonLandbridge. I tried this but only get a 401 when trying to use basic auth in the command line for dash-mdp-cli. Would you be able to provide an example command to show what else might be needed for plex. Auth token as well?

Ah. Never mind @JasonLandbridge. I was able to find the full url from Video DownloadHelper plugin in chrome.

It actually looks as though you're able to download directly through that plugin with the "CoApp" installed also.

Great! An alternative is PlexRipper (shameless plug as I am the author) that does this as well.