The easiest way for the 8821AU Realtek Wifi chipset / TP-Link T2U Plus:
Bus 002 Device 003: ID 2357:0120 TP-Link Archer T2U PLUS [RTL8821AU]
First install your kernel headers/source:
sudo apt install linux-headers-`uname -r`
Clone this github repo with the driver:
git clone https://github.com/morrownr/8821au-20210708
Run the compile/install:
You just add on "non-free" at the end of each repo, like the example below:
If you wanted contributed packages then you could also add "non-free contrib" to each repo line.
Don't forget to do an "apt update" to see the new packages, this is especially handy for getting more drivers for devices with the firmware-linux-nonfr........
Just run this apt install command
sudo apt install pepperflashplugin-nonfree browser-plugin-freshplayer-pepperflash
After this restart your browser and check Adobe's site to verify if your Pepper flash is working and showing at least version 32.
As you'll see below it will download the latest version which is currently 32 and this was not possible with the old/crappy deprecated adobe-flash plu........
When things go wrong your video is basically unplayable or the first video plays fine and then freezes when moving on to the next. Generally if both videos weren't produced with the exact 100% same settings you will have issues. You can try the basic concat but it often won't work right.
Solution for me:
My example uses 3 videos in total so "n=3" and a=1 to include audio.
ffmpeg -threads 12 -i file1.mp4 -........