music-mixlisted

# Music mix Puts a music bed under a finished video. The bed is trimmed to the video's exact duration, faded out at the tail, and ducked under the voice. This is the last step of the pack: base video → b-roll overlay → burned captions → **music**. Mixing mechanics live entirely in `scripts/music_mix.py`. This file is judgment only — when to enter, what track to pick, where the music comes from, what the user sees. ## Entry condition **A finished video the user has signed off on.** Captions already burned in is the preferred input, because music is genuinely the last thing that happens. That is safe because the script copies the video stream packet for packet (`-c:v copy`) and verifies afterwards that the output's video packets hash identical to the input's — so burned captions come through bit-exact, not "re-encoded but probably fine". If the cut is still moving, wait. Remixing is cheap; re-rendering the pipeline is not. ## Track judgment - **Match the genre to the ad's mood, not to your taste.** Calm skincare and a punchy supplement ad do not want the same bed. Read the script's tone first. - **Lofi is the default** — it is what the reference edit used, and it sits under a talking head without competing with it. Depart from it deliberately, and say why. - **Always produce 2–3 named variants.** The reference edit shipped a `final-mixes` folder with `lofi-jazzy` and `lofi-warm` of the same cut. Vary the track or `--music-gain`, name them for what they are, and l