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, every prompt naming the sound the scene itself makes (heels on wet asphalt, room tone) after "diegetic sound only:" and nothing else, plus "sound": 0.2 in the edit file. Name no instrument or genre, however well it fits the track, and no exclusion such as "no music": an instrument invites a score, one run failed on an output-audio content check for an added "distant guitar", and the exclusion has failed that check too. 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