Creating a soundtrack

Hi all,

let’s say I want to soundtrack an .mp4 video, in real time, while I watch it and I play the MIDI keyboard (which is recorded to a MIDI track). What’s the best way to do this, using Ardour? Are there better methods? For example, use another program in parallel?
The important thing is audio-video synchrony.
[Ardour 8.1 on Linux]

Thank you,
a.

First, start by reading the video section of the Ardour manual:

Thank you.
What if I wanted to connect a camera, so that video is recorded directly into Ardour?
The audio part would be recorded simultaneously to a MIDI track playing a keyboard.
Audio video-recording, all in Ardour. What connections do I need?

Ardour is not a video recorder, it records audio only.

If you want the sound from the synth/sampler you’re using with your MIDI keyboard to end up in a simultaneous video recording you should be able to use program OBS Studio, set up to using JACK as audio input.

And if you also want the MIDI information recorded at the same time you can run Ardour or any other JACK-capable MIDI sequencer and do that.