Question 1

MPEG compression utilizes a combination of two different compression schemes, spatial and temporal.

Accepted Answer

MPEG compression uses both spatial and temporal compression techniques in order to reduce the size of video files. Spatial compression reduces redundant information within a single frame, while temporal compression reduces redundant information between frames.

Question 2

Spatial compression compares the changes between the images over time and stores the data that represents only the changes.

Accepted Answer

Spatial compression reduces file size by removing redundancies within a single image, whereas temporal compression (not spatial) compares changes between images over time.

Question 3

Temporal compression uses the same technique as JPEG compression to create an intra picture called an I frame.

Accepted Answer

Temporal compression and JPEG compression are different techniques; temporal compression involves reducing data by removing redundant information across frames in a video sequence, while JPEG compression is used for still images. An I-frame in video compression is a complete image, but it is not created using JPEG compression techniques.

Question 4

P frames contain descriptions of how the pixel blocks in the previous frame have changed to create the current frame.

Accepted Answer

P frames are predicted frames that use motion compensation to describe how each pixel block in the previous frame has moved or changed to create the current frame. This allows for efficient video compression, as only the differences between frames need to be encoded.

Question 5

B frames are similar to P frames but are different in that they look both forward and backward to compare pixel blocks.

Accepted Answer

B frames, or bidirectional frames, can use information from both the previous and future frames to find the best match for a particular pixel block, unlike P frames which only look forward.

Question 6

In sampling, each chrominance sample is shared by

Accepted Answer

In 4:2:0 sampling, each chrominance sample is shared among four luma samples, making it the only option where chrominance samples are shared in this manner. This is a common format in video compression, allowing for reduced file sizes by sampling the color information (chrominance) at a lower resolution than the brightness information (luminance).

Question 7

What form of MPEG comprises the Video CD (VCD format), the quality of which is analogous to that of the output of a VHS recorder?

Accepted Answer

MPEG-1 is the form of MPEG that comprises the Video CD (VCD) format. The quality of VCD is similar to that of the output of a VHS recorder.

Question 8

Nearly all digital video broadcast uses this standard, which results in DVD quality video and is also used to encode audio and video for broadcast satellite and cable TV.

Accepted Answer

MPEG-2 is the widely adopted standard for digital video broadcast and is used for encoding both audio and video for broadcast satellite and cable TV. It allows for high-quality video transmission, including DVD quality, and has become the standard for digital television broadcasting.

Question 9

The formal name of the MP3 audio format is .

Accepted Answer

The formal name of the MP3 audio format is MPEG-1 Audio Layer 3. There is no MPEG-2 or MPEG-3 Audio Layer 3 formats, and while there is a MPEG-4 standard, the audio format within it is called Advanced Audio Coding (AAC) and not MP3.

Question 10

Which version of MPEG was not covered in this chapter?

Accepted Answer

This chapter only covers MPEG-1, MPEG-2, and MPEG-4. MPEG-3 was actually abandoned during its development phase and never released, so it is not a valid option.

Quiz 15: Mpeg Compression