Okay, I will ask about the program using for timing run in C&C series. I have experienced in C&C 3 run using WSplit to record time play, but it cannot overlap or show on gameplay. What program should I use for these game including the former like Tiberian Sun and Red Alert as C&C series don't have windowed mode to config the screen and use timer to overlap or show the RTA in each single run?

If there is no program, I will notice that I should calculate with paper and submit the video with just written description. No timer for more concrete evidence.

There are a few ways I can remember:

1. Run in -win mode. I tried this and became frustrated with the cursor always leaving the window, so I didn't bother with this. It also requires 16-bit mode...
2. DxWnd can supposedly let old games run in windowed mode, but I couldn't figure out how to get it to work.
3. VMware to run a separate instance of windows inside windows. It's what I use, but it's fairly convoluted for anyone not tech-savvy. Has some side benefits like save states, albeit slow to use.

I wouldn't be too worried about showing a timer on the screen; if you use a stable encoder I can get the times from the video timestamps. As far as I know OBS uses a really good encoder, so use that to record with. You might be able to use the OBS plugin for LiveSplit to have it display on screen, though you might not be able to see it yourself.

Edit: I plan on looking into ways to make it easier to record the older games.