If your QC report shows a Red, Green or Blue High Gamut Failure or Low Gamut Failure in red, some colours in your picture are outside the range broadcast TV can show.
RGB gamut – reading the QC report
- There are six gamut-failure checks: Red, Green and Blue, each with a High Gamut Failure and a Low Gamut Failure.
- High Gamut Failure means that colour goes above the legal range. Low Gamut Failure means it goes below it.
- Red/Green/Blue Max Peak and Minimum show the highest and lowest levels of each colour in your file.
RGB gamut – what it means
Every picture is made of red, green and blue. Broadcast video can only show a limited range of colours. In the diagram, that range is the triangle inside the full range of visible colours. Colours outside the legal range can be clipped or distorted on TV. The QC measures colour to the EBU R103 standard: chroma levels 16–240, equivalent to a maximum of 100% RGB.
RGB gamut – likely cause
This is usually a file fault. Common causes:
- Very saturated colours in the grade, such as bright reds or deep blues.
- Graphics, logos or packshots made in RGB with brand colours outside the broadcast range.
- The file was exported using full range (0–255) instead of video (legal) range.
If Luma High Gamut Failure or Luma Low Gamut Failure also shows in red, fix both at the same time (see File failed QC: Luma High Gamut Failure or Luma Low Gamut Failure).
RGB gamut – fix
- Apply a broadcast-safe or legaliser filter (sometimes called a colour limiter) to the timeline or on export, so colours stay within the legal range.
- Re-export the file using the matching Export Guide.
- Upload the file again.
RGB gamut – when to contact Customer Success
- You’ve exported the file using the specification shown by the View Specs link for the ad in your campaign, but it still fails this check.
Comments
1 comment
Can you explain the units that you reference in your illegal colour level rejection notices?
Example rejection notes:
Blue High Gamut Failure 13
EBU R103 Blue Level Too Low (min- 11) -14
How do the numbers in the rejection notices relate to the allowable 16-240 8-bit chroma range cited in this article?
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