Discovery on ElevenLabs v4

Four complete soundtracks per ad, one per tag. Pick a take, nudge the timing, set the loudness, and the page tells you whether it costs a mux or a re-render.

Winchesterbuilt tonightMade from scratch: data, 12 v4 takes, four soundtracks, After Effects picture, all four formats. Plays the real ad against whichever mix you choose. Gerrards CrossThe same four-angle build, audio only. The comparison test. Leamington SpaYour locked recipe applied cold: 3 generations, no alternates.

After Effects owns the picture. The mix it rendered with is the deliverable, and ffmpeg only lays a different soundtrack on when you reject that mix, by video stream copy, about 2 seconds per format. A caption word moving more than 0.30 s is the only audio-side change that sends it back to After Effects.