HDR Professional Standards & Best Practices 2 — Questions and Answers
Question 1: When delivering HDR content to a streaming platform, which metadata standard is most commonly required alongside the video stream?
- SMPTE 2084 PQ curve only
- MaxCLL and MaxFALL values embedded in SEI NAL units (Correct answer)
- A proprietary XML sidecar with peak brightness estimates
- ICC color profile attached as a separate file
Correct answer: MaxCLL and MaxFALL values embedded in SEI NAL units
MaxCLL (Maximum Content Light Level) and MaxFALL (Maximum Frame Average Light Level) are standard HDR metadata values embedded as SEI NAL units in HEVC/AVC streams per SMPTE ST 2086.
Question 2: A colorist is asked to conform an HDR master to SDR for broadcast. Which tone-mapping approach best preserves artistic intent?
- Apply a simple clip at 100 nits to remove all HDR highlights
- Use a mathematically generated LUT with no creative input
- Perform a manual trim pass in SDR to match the director's creative intent (Correct answer)
- Automatically convert using camera default settings
Correct answer: Perform a manual trim pass in SDR to match the director's creative intent
A manual trim pass allows the colorist to translate creative decisions from HDR to SDR, preserving the director's intent rather than relying on automated clipping.
Question 3: Under UHD Alliance's Mobil HDR Premium specification, what is the minimum peak luminance a display must achieve?
- 400 nits
- 600 nits
- 1000 nits (Correct answer)
- 2000 nits
Correct answer: 1000 nits
UHD Alliance Mobile HDR Premium requires a minimum peak luminance of 1000 nits for mobile device certification.
Question 4: Which color volume descriptor is used in HDR10 to characterize the mastering display's capabilities?
- SMPTE ST 2086 mastering display color volume metadata (Correct answer)
- Dolby Vision XML metadata
- HDR Vivid tone mapping parameters
- HLG ancillary data packet
Correct answer: SMPTE ST 2086 mastering display color volume metadata
SMPTE ST 2086 defines the static mastering display color volume metadata embedded in HDR10 content, describing the display's primaries, white point, and luminance range.
Question 5: When archiving an HDR production master, which container format and codec combination is considered industry best practice?
- MP4 with H.264 8-bit 4:2:0
- MXF with JPEG 2000 12-bit 4:4:4
- MOV with ProRes 4444 XQ 12-bit (Correct answer)
- AVI with DNxHR HQX 12-bit
Correct answer: MOV with ProRes 4444 XQ 12-bit
Apple ProRes 4444 XQ in a MOV container provides 12-bit depth, 4:4:4 chroma sampling, and wide industry support, making it a standard archival format for HDR masters.
Question 6: What does 'reference white' mean in an HDR grading environment, and at what luminance is it typically set for PQ-based workflows?
- The brightest specular highlight, set at 10,000 nits
- The diffuse white representing a white card in scene, typically set at 100 nits (Correct answer)
- The monitor's native white point, set at 2,000 nits
- The ambient lighting level in the grading suite, set at 48 nits
Correct answer: The diffuse white representing a white card in scene, typically set at 100 nits
Reference white in PQ workflows is the diffuse white (a white card or white wall in scene), conventionally placed at 100 nits, allowing highlights to extend above it.
Question 7: A production delivers an HDR10+ master. Which feature distinguishes HDR10+ from standard HDR10?
- HDR10+ uses HLG transfer function instead of PQ
- HDR10+ includes dynamic metadata that adjusts tone mapping scene by scene (Correct answer)
- HDR10+ requires Dolby licensing and a Vision XML file
- HDR10+ mandates a minimum 8K resolution
Correct answer: HDR10+ includes dynamic metadata that adjusts tone mapping scene by scene
HDR10+ adds Samsung-developed dynamic metadata (per-scene or per-frame) on top of the static HDR10 base, enabling displays to optimize tone mapping frame by frame.
HDR Professional Standards & Best Practices 2
When delivering HDR content to a streaming platform, which metadata standard is most commonly required alongside the video stream?