Reference audio is a common method for synchronization of videos from different cameras, when more expensive equipment that does this automatically is not available. The most common use case is of course filming a scene from several different angles, but there are other setups that may require the same technique. Recently, I had to film several scenes in succession, over which the same audio was playing. I needed to extract a part from each scene, so that exactly the same audio would be playing over each scene part (they all have the same duration, of course). So far, nothing is new. However, what is surprising is how easy it is to do that with a handful of open source tools, as I will be showing here. In particular we will be using Praat, ffmpeg and Python.
The tutorial is available in PDF format: