100+ Free SBE CBTE Practice Questions

Explanation: SMPTE 259M defines the SD-SDI interface, and the most common rate (Level C) for 4:2:2 component digital video (480i/576i) is 270 Mbps. This carries 10-bit multiplexed Y/Cb/Cr samples over a 75-ohm coaxial cable with a BNC connector. The 143 Mbps rate is the composite NTSC variant, not the standard component rate.

Explanation: SMPTE 292M defines HD-SDI at 1.485 Gbps (and 1.485/1.001 Gbps for NTSC-related 59.94/29.97/23.98 Hz frame rates). It carries 720p and 1080i HD signals over a single coaxial link. SMPTE 259M is SD-SDI and SMPTE 424M is 3G-SDI.

Explanation: SMPTE 424M (3G-SDI) operates at 2.970 Gbps, exactly double the HD-SDI rate, and can carry 1080p60 over a single link. 6G-SDI and 12G-SDI extend to 5.94 and 11.88 Gbps for 4K/UHD. The 1.485 Gbps figure is HD-SDI.

Explanation: In 4:2:2 sampling, the two color-difference (chroma) channels Cb and Cr are each sampled at half the horizontal frequency of the luminance (Y) channel, while having full vertical resolution. For SD this means Y at 13.5 MHz and each chroma channel at 6.75 MHz. This is the standard broadcast production format because the eye is less sensitive to chroma detail than luma.

Explanation: ITU-R BT.601 specifies a luminance sampling frequency of 13.5 MHz for SD component digital video, common to both 525-line and 625-line systems. Each chroma channel is sampled at half this rate, 6.75 MHz, yielding 4:2:2. The 27 MHz figure is the multiplexed word rate that combines luma and chroma.

Explanation: The 1080i format has an active raster of 1920 x 1080 pixels with a 16:9 aspect ratio and square pixels. It is transmitted as interlaced fields (typically 1080i/29.97 or 1080i/25). The 1280 x 720 raster is the progressive 720p format.

Explanation: The ancillary (ANC) data space in the SDI blanking intervals carries non-picture payloads such as embedded AES audio groups, timecode, closed captions, and other metadata. Horizontal ancillary (HANC) typically carries audio while vertical ancillary (VANC) carries captions and metadata. The active picture occupies the non-blanking portion of each line.

Explanation: HD facilities use tri-level sync as the analog genlock reference because its bipolar (positive-then-negative) transition gives a more precise, jitter-resistant timing point at high frequencies than the older black-burst (bi-level) reference used in SD. Many sync generators output both so legacy SD and HD gear can lock to a common house reference.

Explanation: A vectorscope plots the chroma information in polar form: the angle around the display represents hue (phase) and the distance from center represents saturation (amplitude). With color bars applied, each color should land in its labeled target box. A waveform monitor, by contrast, shows luminance and signal levels versus time.

Explanation: On an NTSC waveform monitor the reference white level is 100 IRE and reference black (setup/pedestal) sits at 7.5 IRE in the original North American standard. Blanking is defined as 0 IRE and sync tip at -40 IRE. The full luminance excursion from blanking to peak white spans 0 to 100 IRE.