My use case is making music videos where I am playing multiple instruments overdubbed. I currently have to use audacity or ardour to record the audio overdubbing, because it is crucial to have each recorded audio track start at exactly the same time. Both those programs' overdub feature will place the recorded audio at exactly the timestamp where the user started the overdub. Very importantly, those programs compensate for the playback-to-recording roundtrip latency, which the user determines by directly connecting the computer's playback output into the recording input, and subtracting the difference in those timestamps. The user enters this value into the program's settings, and then the whenever a new track is recorded, the program places that video at the timestamp of the start of playback minus this latency.

I don't know of an open-source video editor which will record a new video into a new track at exactly the latency-corrected timestamp. Currently I have to record the video separately from the audio because of this, and then I have to import the video into kdenlive and use the auto-align feature or manually align the video to the audio track. But this ends up being a lot of extra unnecessary work that distracts me from the creative process of recording music. So, I would very much love for an open-source video editor to be able to do this latency compensation automatically, without requiring the user to manually adjust the track's position to line up, since it needs to be as close to millisecond-resolution as possible.

I would very much be willing to implement such a feature. I have experience contributing code to MuseScore project and so I'm familiar with Qt and working with open-source.