Scenario Seedance Music Video

Overview

Five steps: song, lyrics, story, frames, video. The supplied master is the only score, and no shot writes its own. scripts/build.py lays the master over the cut once, at the end, and proves the file untouched by hash. scripts/song.py reads the master so cuts land on its structure. The scripts need ffmpeg and ffprobe on PATH, and numpy for song.py.

Connection and the core generation loop: see the scenario skill in this repo. The Seedance parameter contract and conditioning traps: see the scenario-seedance skill. If a sibling skill named here is missing from your available skills, ask the user to install it (npx skills add scenario-labs/skills --skill <name>); unattended, proceed from tool schemas and flag the gap.

The two soundtracks

Music written inside a shot restarts in a new key at every cut, so the score comes from outside the video model: the supplied master. What Seedance makes is the sound bolted to the picture. The choice sets generateAudio on every shot, so make it before generating:

• Song alone: generateAudio: false everywhere. build.py stream-copies the master whenever MP4 allows, so the delivered soundtrack is the supplied file, bit for bit.
• Song over the shots' own sound: generateAudio: true with "diegetic sound only, no music, no score" in every prompt, plus "sound": 0.2 in the edit file. build.py cuts each clip's audio to its slot, mixes it under the master at that gain, and refuses a mix that would clip. The delivery is then one AAC encode, trading the bit-for-bit guarantee for the sound; the master file stays hash-checked.

Quick reference