Digital Media Chapter 6

The _____ is encoded using only the information within that frame.

I-frame

The _____ is the least compressed.

I-frame

_____ compression refers to the type of compression method that preserves the original data.

Lossless

_____ compression refers to the type of compression method that discards or alters some of the original data.

Lossy

HDTV is in _____ format.

MPEG-2

Which of the following support the DVD-video, high-definition video, and HDTV standards?

MPEG-2

Which of the following also targets mobile applications, such as cell phones?

MPEG-4

True/False: A typical MPEG-2 consists of a repeating GOP structure.

True

True/False: A very long video, even with low data rate, can have a large file size.

True

True/False: In progressive download, the file usually remains on the user's device after playback, for example, in the Web browser's cache.

True

True/False: Progressive download and pseudo streaming allow the video to start playing as soon as enough of the video data has arrived.

True

True/False: The frame aspect ratio of all six HDTV formats is 16:9.

True

True/False: The signals of digital television are broadcast or transmitted digitally.

True

True/False: There is only one I-frame in a GOP structure.

True

True/False: True streaming requires a streaming server.

True

Which of the following provides a measure for predicting the smoothness of video playback? If the value of that property is too high for the playback device to handle, the playback of the video will be choppy.

data rate

The numbers 720 and 1080 in the high-definition video picture format notations such as 720/30p and 1080/60i designate the _____.

height (in pixels) of the frame size

Progressive scan displays the frame by scanning the lines of a frame _____.

in one pass from top to bottom

Which of the following is the most common color model for video?

luminance-chrominance

4. In the YUV color model, the Y-component is _____, the U-component is ______, and the V component is _____.

luminance; chrominance; chrominance

The letters "p" and "i" in the high-definition video picture format notations such as 720/30p and 1080/60i stand for _____ and _____, respectively.

progressive; interlaced

Motion compensation is a key technique in _____ compression.

temporal

Which of the following compression methods achieves higher compression for videos without much motion difference, such as for talking heads?

temporal compression

The pixel aspect ratio of a standard-format, standard-definition video is _____.

0.9

The pixel aspect ratio of a wide-screen-format, standard-definition video is _____.

1.2

Suppose your target audience uses a broadband connection with a speed of 6 Mbps. What is the maximum file size for your 30-second video to have a smooth playback using pseudo streaming on the Web? Show your calculations.

6 Megabites per second * 30 second = 180 bits / 8 bits = 22.5 Megabyte

The frame aspect ratio of a high-definition video is _____.

16:9

The frame aspect ratio of a wide-screen-format, standard-definition video is _____.

16:9

The frame rate for motion-picture film is _____ fps.

24

The frame rate for the PAL system is _____ fps.

25

The frame rate for the NTSC system is _____ fps.

29.97

The frame aspect ratio of a standard-format, standard-definition video is _____.

4:3

The frame size for NTSC standard-definition DV is _____ pixels, and _____ pixels for the PAL system.

720 x 480; 720 x 576

_____ compression refers to the type of compression method in which the amount of time and the complexity required to compress and decompress are significantly different.

Asymmetric

The _____ is encoded using the previous and subsequent I- and/or P-frames as the reference frames.

B-frame

Explain why, in general, the longer GOP structure allows more file size compression. (Hint : Consider the number of I-frames in a GOP structure and the different levels of compression for different frame types.)

Each GOP has one I‐frame and an I‐frame is the least compressed frame. Longer GOP structure means that there are less GOPs in a video. This means that there are less I‐frames in a video. Thus the file size is smaller with a longer GOP.

11. True/False: There is no sampling and quantization involved in capturing motion in digital video.

False

21. True/False: The timecode representing the 35th frame is either 00:00:00:35 or 00;00;00;35.

False

22. True/False: The drop-frame timecode drops or discards frames to preserve the time accuracy of a video.

False

True/False: For streaming video, the file usually remains on the user's device after playback, for example, in the Web browser's cache.

False

True/False: Progressive download requires a streaming server.

False

True/False: The MP3 audio is a MPEG-3

False

True/False: The pixel per inch (ppi) is an important attribute for video resolution and should be

False

True/False: There is only one I-frame in an MPEG video.

False

Which of the following is the television broadcast standard for the United States and Japan?

NTSC

The _____ is encoded using only the previous I- or P-frame as the reference frame.

P-frame

Which of the following is the television broadcast standard for most of the Asian countries?

PAL

"After the entire video has been played once in a Web browser, it can be replayed without having to wait for download again." Which of the following modes of video playback matches this description?

Progressive download or pseudo-streaming

Which of the following compression methods works best with large areas of solid color, such as in a cartoon animation?

QuickTime Animation

Name several strategies to reduce the file size of a video.

Reduce frame, lower frame rate, compress video

_____ compression refers to the type of compression method that aims at compacting individual frames.

Spatial

If a frame with a pixel aspect ratio of 1.2 is displayed on a device using a pixel aspect ratio of 1.0, the image will be _____.

Stretched Vertically

_____ compression refers to the type of compression method that exploits the similarity of the subsequent frame content.

Temporal

Which of the following is the drop-frame timecode format?

b00;00;00;00

Chroma subsampling reduces the storage of pixel information by assigning fewer bits to store the _____ components.

chrominance

What does the term codec stand for?

compressor/decompressor

Interlaced scan displays the frame by scanning the lines of a frame _______.

in two passes: even-numbered lines in one pass and odd-numbered lines in the second

The comb-like artifact in a digital video, as shown in Figure 6.18, occurs in the _____ video.

interlaced

Which timecode format is preferable for the NTSC system?

non-drop frame

The M parameter of the GOP refers to _____.

one plus the number of frames between the non-B -rames

The frame size of a video refers to the video's _____.

resolution

Which of the following types of video can be compressed the most with temporal compression?

slow, continuous motion

.Suppose you are on broadband connection with a speed of 6 Mbps. For a 1-minute video file with a file size of 20 MB, its playback through pseudo streaming on the Web very likely will be _____.

smooth

Suppose you are on broadband connection with a speed of 6 Mbps. For a 5-second video file with a file size of 20 MB, its playback through pseudo streaming on the Web very likely will be _____.

smooth

Pixel aspect ratio means _____.

the ratio of a pixel's width to its height D. the ratio of a pixel's height to its width

The format of Chroma subsampling is designated with three numbers separated by colons (for example, 4:2:2) to represent ______.

the ratio of the luminance to the two chrominance components

The N parameter of the GOP refers to _____.

the total number of frames in a GOP