Final pass — QC every render before anyone sees it

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name: final-pass description: Check a rendered video before anyone else sees it: format, black or frozen frames, loudness, true peak, and a frame sheet to look at. Use before submitting any animatic or final, and before mfx step done on a build.

Final pass

Two halves, both required: the script checks what a machine can, and you look at what it can't.

1. Run the checks

node .claude/skills/final-pass/qc.mjs out/final.mp4 --size 1920x1080 --fps 30 --duration 60

• --size, --fps, --duration come from the brief (shape, length). Duration passes within 5%.
• Loudness: --lufs -14 (web default) and --true-peak -1. Change them only if the brief names a platform with other targets.
• --end-hold when the video is meant to end on a still hold (a logo that settles): that stretch then passes and its length is reported. A frozen stretch anywhere else still fails.
• --allow-black only when black mid-video is designed (a dip to black between chapters). Say so in the check note.
• It writes checks/qc-<name>.json and checks/<name>-sheet.png, and exits 1 on any FAIL.

Fix every FAIL and run it again. A frozen stretch can be a designed hold: then it's a pass, and the check's note says which hold it is.

2. Look

1. The frame sheet. View checks/<name>-sheet.png (about a frame a second). Every frame must make visual sense: nothing half-loaded, no placeholder text, no element stuck at a wrong position, nothing cut off at an edge.
2. Three full-size frames at the busiest moments: ffmpeg -ss 12.5 -i out/final.mp4 -frames:v 1 checks/f-12.5.png. Read every word on them.
3. Listen through once on the waveform's loudest and quietest parts: no clicks, pops, distortion, or words swallowed by the music.

3. Report

Map the results onto the step's error checks (mfx checks <step>): frame-sheet and format from the script plus your look, loudness from the audio lines. Keep the JSON and the sheet in checks/. Submit the frame sheet as a second item with every final: the owner can scan it in a second.

Fixing loudness

Two-pass loudnorm on the mix, never on a file you've already normalized:

ffmpeg -i mix.wav -af loudnorm=I=-14:TP=-1.5:LRA=11:print_format=json -f null -       # read the measured values
ffmpeg -i mix.wav -af loudnorm=I=-14:TP=-1.5:LRA=11:measured_I=..:measured_TP=..:measured_LRA=..:measured_thresh=..:offset=..:linear=true mix-14.wav