Record Voice Over a Video?

Question

I want to be able to record my voice from a microphone while watching a video, and to have the recorded sound be in sync with the video. My requirements are,

• Compatiable with Linux
• Open source

Answer 1

OBS-Studio / Open Broadcaster Software

1. Can take multiple Inputs and overlays(video, screen, single, window, audio...)
2. Open source
3. Cross platform (linux, Mac, Windows)

it is very easy to use and the default settings should be fine in most cases. just add the desired inputs and you are good to go. Take a look at their website.

ffmpeg

1. Open source
2. Cross Platform
3. command based (there are some GUI programms using ffmpeg)

you would have to record your voice seperately and then combine with one of the commands described in this superuser post. Simplest would be

ffmpeg -i video.mp4 -i audio.wav output.mp4

But that might not work best or be good in any way so evaluate the descibed options yourself.