Three numbers, from the recording itself: each stream's length, the drift implied by a length
mismatch (a clock problem), and the residual offset between mouth motion and speech (a constant
problem). Per-3s window table with correlations, so a weak reading announces itself instead of
reporting a confident wrong number, and a median over only the strongly-correlated windows — a
whole-clip search on periodic speech locks onto the wrong beat and returns nonsense (it said
-400 ms at the search limit on the clip where the windows said -185).
Validated on ty-20261112-1228-457-0000.mp4: lengths 13.271/13.305 s (match, so no drift) and
-185 ms (sound early), which agrees with the independent visual read of the same clip.
The creator is deaf, so "does it sound right" cannot be the loop. This is.
Needs numpy; uses the bundled ffmpeg.exe.
gramps
b216cbc56f
