CBT CBT Signal Processing & Distribution 2 — Questions and Answers
Question 1: What is 'black burst' used for in an analog broadcast facility?
- A test pattern for black level calibration
- A composite sync reference signal for synchronizing equipment (Correct answer)
- A type of video noise measurement
- An emergency color-bar signal required by the FCC
Correct answer: A composite sync reference signal for synchronizing equipment
Black burst is a composite video signal containing sync and color burst but with no picture information, used as a house reference to synchronize all equipment in an analog broadcast plant.
Question 2: What does the term 'return loss' indicate in a broadcast signal path?
- The amount of signal reflected back due to impedance mismatch (Correct answer)
- The delay introduced by a signal processor
- The loss of audio level after a downmix
- The difference in gain between input and output stages
Correct answer: The amount of signal reflected back due to impedance mismatch
Return loss is a measure of how well impedance is matched; a high return loss (in dB) means little signal is reflected back, indicating a good impedance match.
Question 3: What is the bit rate of uncompressed standard-definition serial digital video (SD-SDI)?
- 143 Mb/s
- 270 Mb/s (Correct answer)
- 1.485 Gb/s
- 3 Gb/s
Correct answer: 270 Mb/s
SD-SDI operates at 270 Mb/s per the SMPTE 259M standard, carrying uncompressed 4:2:2 digital video for standard-definition broadcast.
Question 4: Which color space model is most commonly used in digital broadcast video production?
- RGB
- CMYK
- YCbCr (Correct answer)
- HSV
Correct answer: YCbCr
YCbCr separates luminance (Y) from color difference components (Cb and Cr), allowing efficient bandwidth use in broadcast systems by exploiting human visual sensitivity.
Question 5: What is the purpose of equalization in a long-run SDI cable installation?
- To boost audio levels at the receive end
- To compensate for high-frequency signal loss caused by cable length (Correct answer)
- To convert balanced audio to unbalanced
- To reduce electromagnetic interference from power cables
Correct answer: To compensate for high-frequency signal loss caused by cable length
Cable equalization restores high-frequency components that are attenuated more than low frequencies over long coaxial runs, ensuring the receiver can recover the digital data.
Question 6: What does a frame synchronizer do in a broadcast signal path?
- Converts frame rates between 23.98 and 29.97 fps
- Aligns an asynchronous input video source to house sync timing (Correct answer)
- Generates a test signal for monitor calibration
- Removes freeze frames caused by transmission errors
Correct answer: Aligns an asynchronous input video source to house sync timing
A frame synchronizer buffers an incoming video signal and outputs it re-timed to the facility's reference sync, allowing asynchronous sources such as satellite feeds to be used live.
CBT CBT Signal Processing & Distribution 2
What is 'black burst' used for in an analog broadcast facility?