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Gamma Shift QC Pack

Detect and manage the QuickTime/Rec.709 display shift before delivery

Exports look different between your timeline, QuickTime, browsers, and YouTube — washed out or too dark — causing wasted time and client confusion. This recipe adds a standardized metadata inspection and verification step so you can tell whether it's a real file problem or just a player interpretation difference.

House RecipeCreative9 min setup

INGREDIENTS

🔔Notifications✉️Email

PROMPT

Create a skill called "Gamma Shift QC Pack". Inputs: - export_watch_path - sample_timestamps - generate_control_clip_seconds (optional) Behavior: - When a new export appears, run ffprobe color tag inspection. - Output a QC pack folder with stills and a short control clip (optional). - Send me a checklist explaining how to validate by re-importing into the editor and cross-checking in at least two playback contexts.

How It Works

This skill inspects your export's color metadata with ffprobe, generates a QC pack with

still frames and an optional control clip, and gives you a checklist for validating

appearance across multiple playback contexts.

What You Get

  • Color metadata inspection: color primaries, transfer characteristics, colorspace
  • QC pack folder with still frames at key timestamps
  • Optional short control clip (e.g., 10 seconds) for quick comparison
  • Player sanity checklist: compare in at least two players (QuickTime vs VLC, browser, editor)
  • Re-import instruction: bring the export back into your timeline and compare scopes

Setup Steps

  1. Point to your export watch folder
  2. Set sample timestamps for still frame extraction (e.g., 00:00:05, 00:02:10, 00:10:00)
  3. Optionally enable control clip generation (default: 10 seconds)
  4. Run on every final export or as a manual pre-delivery command

Tips

  • The QuickTime gamma shift is a display issue, not a file issue — knowing that saves hours of re-grading
  • Always check in at least two players before concluding the file is wrong
  • Rec.709 tagging issues are most visible in highlights and skin tones — pick sample timestamps accordingly
  • Pair with Proxy-to-Original Integrity Check for a complete pre-delivery QC pipeline
Tags:#color#gamma-shift#rec709#qc