The following problem must be familiar to many Mudcatters: I have a professional sound recording and an amateur video - with camera sound - of the same concert; now we want to use the recording as the video soundtrack. A quick Google research, including Mudcat and some self-declared experts, showed advice such as "clap your hands once before the concert, or look for singers pronouncing consonants ..." - very tedious and imprecise. Software should do it automatically, searching the two sound tracks for matching frequencies etc., and skipping or doubling single frames whenever necessary. I guess thousands of YouTubers do it like that, whereas tens of thousands do it the tedious way.

How do the real experts proceed? What video software does it best, and cheaply? (Unfortunately I have never used such software at all, and none of my friends is an expert. The software descriptions I have read are not helpful either.)