- EBU QC Id
- 0051B
- Name
- Video Signal Levels
- Status
- published
- Category
- absolute
- Lead editor
- Andy QUESTED
- Aliases
- luma-chroma violations broadcast safe colour gamut legality color gamut legality gamut errors video signal level errors
- Tags
- video
| Version | Status | Edition date | Saved by | Note |
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- 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. - References
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[https://tech.ebu.ch/docs/r/r103.pdf 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.
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[https://tech.ebu.ch/docs/r/r103v1_1.pdf 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.
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- Examples
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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)
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- Remarks
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