CBT CBT Digital Broadcasting Standards 2 — Questions and Answers
Question 1: In digital video, what does 4:2:2 chroma subsampling mean?
- 4 bits luma, 2 bits each chroma
- Full luma, half horizontal chroma resolution, full vertical chroma (Correct answer)
- Full luma, quarter chroma resolution both axes
- 4 frames luma sampled per 2 chroma frames
Correct answer: Full luma, half horizontal chroma resolution, full vertical chroma
4:2:2 subsampling retains full horizontal and vertical luma resolution while halving horizontal chroma resolution, commonly used in professional broadcast.
Question 2: What frame rate and scan format is designated as 1080i/59.94 in broadcast production?
- 1080 lines, progressive, 59.94 fps
- 1080 lines, interlaced, 29.97 fields per second
- 1080 lines, interlaced, 59.94 fields per second (Correct answer)
- 1080 lines, progressive, 29.97 fps
Correct answer: 1080 lines, interlaced, 59.94 fields per second
1080i/59.94 means 1080 interlaced lines delivered at 59.94 fields per second (equivalent to 29.97 complete frames per second).
Question 3: What is the purpose of a PSIP (Program and System Information Protocol) in ATSC broadcasting?
- To encrypt conditional access content
- To provide channel guide, time, and virtual channel data to receivers (Correct answer)
- To synchronize audio and video essence
- To manage IP addressing in ATSC 3.0
Correct answer: To provide channel guide, time, and virtual channel data to receivers
PSIP provides receivers with virtual channel numbers, program guide data, rating information, and timing synchronization for ATSC broadcasts.
Question 4: Which color space standard is used for standard-definition digital television in the US?
- BT.709
- BT.2020
- BT.601 (Correct answer)
- P3-D65
Correct answer: BT.601
ITU-R BT.601 defines the color matrix, sampling rates, and color primaries for standard-definition digital television.
Question 5: What is the primary advantage of HEVC (H.265) over AVC (H.264) for broadcast applications?
- Lower decoder complexity
- Approximately 50% better compression efficiency at equivalent quality (Correct answer)
- Wider color gamut support
- Lower encoding latency
Correct answer: Approximately 50% better compression efficiency at equivalent quality
HEVC achieves approximately 50% better compression efficiency than AVC at the same perceptual quality level, enabling 4K at practical broadcast bitrates.
Question 6: In MPEG transport streams, what is the PID used for?
- Packet Identification — uniquely identifies each elementary stream within the multiplex (Correct answer)
- Program Index Data — lists available channels
- Physical Interface Descriptor — defines the RF modulation
- Packet Insertion Delay — measures buffering latency
Correct answer: Packet Identification — uniquely identifies each elementary stream within the multiplex
The PID (Packet Identifier) is a 13-bit value in MPEG-2 TS packet headers that uniquely identifies which elementary stream each 188-byte packet belongs to.
CBT CBT Digital Broadcasting Standards 2
In digital video, what does 4:2:2 chroma subsampling mean?