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,--durationcome 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-holdwhen 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-blackonly when black mid-video is designed (a dip to black between chapters). Say so in the check note.- It writes
checks/qc-<name>.jsonandchecks/<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
- 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. - 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. - 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