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0051B - Video Signal Levels
Summary
EBU QC ID
0051B
Name
Video Signal Levels
Status
published
Category
absolute
Lead editor
Andy Quested (BBC)
Aliases
luma-chroma violations broadcast safe colour gamut legality color gamut legality gamut errors video signal level errors
Tags
video
Versions
Version Status Edition date Saved by Note
Details
Description
Video signal errors are often referred to as "gamut" errors but they are a measurement of the individual components of the signal and any signal that is made from the components (e.g. Luminance created from RGB signals).

For example, the tolerance allowed by EBU R103 is calculated as ±5% of "Expected Range" in code values. For and 8 bit signal, the Expected Range is 16-235. The tolerance is therefore 5% of 220 = 11. The 8bit minimum is 16 - 11 = code value 5 and the maximum is 235 + 11 = code value 246. In the case of a 10 bit signal the Expected Range is 64-940 making the tolerance ±5% of 877 = 43.8 which is rounded to ± 44.
Definition
In Checks the system shall check for and may optionally report, video signal values lying outside the acceptable range. That is, the RGB components and the corresponding Luminance (Y) signal should not normally exceed the users' acceptable range of digital sample levels. PAL/NTSC gamut testing is optional.

In Reports the the system shall report video signal values lying outside the acceptable range. That is, the RGB components and the corresponding Luminance (Y) signal should not normally exceed the users' acceptable range of digital sample levels. PAL/NTSC gamut testing is optional.
CheckResult definition v3
not in this version
Analysis method v3
not in this version
References
  • EBU R 103 v2

    Remark: EBU R 103 v2 should be used for digital measurements, EBU R 103 v1.1 is still valid for some analogue operations and measurements.

  • EBU R 103 v1.1

    Remark: EBU R 103 v1.1 is still valid for some analogue operations and measurements. It is recommended that EBU R 103 v2 is used for digital measurements.

Examples
  • Input: "Low Luminance Threshold" = 0%
    Input: "High Luminance Threshold" = 0%
    Input: "Low Chrominance Threshold" = 0%
    Input: "High Chrominance Threshold" = 0%
    Input: "Minimum Duration" = 10 frames
    Output: "Check Result" = true
    Output: "High Luminance Error Segment" from 00:00:00:14 to 00:00:01:00 (113% measured vs. 103% maximum level)


  • Input: "Low Luminance Threshold" = 0%
    Input: "High Luminance Threshold" = 0%
    Input: "Low Chrominance Threshold" = 0%
    Input: "High Chrominance Threshold" = 0%
    Input: "Minimum Duration" = 10 frames
    Output: "Low Chrominance Error Segment" from 00:00:01;14 to 00:00:03;02 (-6% measured vs. -5% minimum level)

Organisations (experimental)

No Organisation has tagged this Item.

What does this mean?
Parameter hierarchy
Inputs
  • Low Luminance Threshold LowLuminanceThreshold
  • High Luminance Threshold HighLuminanceThreshold
  • Low Chrominance Threshold LowChrominanceThreshold
  • High Chrominance Threshold HighChrominanceThreshold
  • Minimum Duration MinimumDuration
  • Minimum Screen Area MinimumScreenArea
Outputs
  • Check Result CheckResult
  • Low Luminance Error Segment LowLuminanceErrorSegment  locator (v1/v2)
  • High Luminance Error Segment HighLuminanceErrorSegment  locator (v1/v2)
  • Low Chrominance Error Segment LowChrominanceErrorSegment  locator (v1/v2)
  • High Chrominance Error Segment HighChrominanceErrorSegment  locator (v1/v2)

A 'structural' badge marks a node with no Value of its own; its value, if any, lives on its children instead (Annex C).

Input parameters
Name Default value Description Data model name Unit Positioning (Has*) v3
Output parameters
Name Alias Description Data model name Unit Positioning (Has*) v3
Test material
Title Version Download
Remarks
Remarks
User discussions
Title Author Last update

Colour key: v3 Only in API v3 (data model 2026-04); v1/v2 only Only for API v1/v2 (legacy versions); derived, read-only; untinted: both.