Is there a reasonably straightforward way to download videos from proprietary web browser players? I have a Samsung SM-P900 tablet that I bought specifically to watch professional education videos during a long commute. Unfortunately almost immediately after that the videos I want to watch the most, generally relating to statistics and R programming and hosted on the RStudio website, switched from an easily downloadable format to hosting via the Wikia media player. I have been able to download a handful since then by looking at the page code, but it is a lot of work and the rules keep changing, and I have not been able to download the more recent videos to either my tablet or Windows machine with any amount of effort. I've faced similar problems with the JW Player and a few others. All of these videos are free and I want to download them solely for my own use.

My question: Is there a reasonably straightforward way, perhaps involving an app, of capturing such videos that works consistently over time and across  players? It seems like there's got to be a way to interpose a (software) recording device between the player and the screen, but I have not found it. It might need to reassemble streaming video from the pieces that arrive.

My OS is the Resurrection Remix versin of Android 7.1.2.
'Easier' solution: have you tried Firefox on Android and the myriad of video downloader add-ons you can get there? One of them might work. I don't have the time to test them all now but let us know if one works.

'Harder' solution: I tried digging around on that site you gave, on a desktop you just need to fire up dev tools and look for the first .bin file in the network tab (once you start playing the video) then throw it into youtube-dl [url]. Tip: use the search filter to find it. I feel there might be some way to automate this with a Python script or similar. 

https://rg3.github.io/youtube-dl/