Module D Exercise > Modd_qb05_eng

Chapter 5 Video

Chapter 5

Question Bank

Video

Multiple Choice Questions (U06C05L01Q001) For a video, the number of frames displayed per second is known as its A. frame rate B. frame speed C. frame size D. frame number Answer A (U06C05L01Q002) For a digitised video, the attributes include (1) frame rate (2) image size (3) colour depth A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer D (U06C05L01Q003) Which of the following is required to digitise an analog video signal? A. sound card B. RAM C. video capture card D. video camera Answer C

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Chapter 5 Video

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(U06C05L01Q004) Which of the following are video file formats? (1) AVI (2) GIF (3) MPEG A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer B (U06C05L01Q005) Which of the following are the functions of a video-editing program? (1) Save video files in different file formats. (2) Remove frames. (3) Move frames around in a file. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer D (U06C05L01Q006) Which of the following is NOT a TV display standard? A. PAL B. NTSC C. NICAM D. SECAM Answer C

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Chapter 5 Video

(U06C05L01Q007) Digitised video consists of (1) a control section (2) a sequence of frames (3) an A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer C

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track

(U06C05L01Q008) Compression of video files CANNOT A. reduce the amount of data needed to reproduce video. B. save storage space. C. increase access speed. D. enhance video quality. Answer D (U06C05L01Q009) Which of the following are the factors that affect the file size of a video? (1) Codec (2) Frame size (3) Frame rate A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer D

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Chapter 5 Video

Question Bank

(U06C05L01Q010) Which of the following are the advantages of saving video files in QuickTime format? (1) It can be played in different platforms by QuickTime Player. (2) It supports VR format which can display 360° panoramas of scenic. (3) The compression of the video file is not a lossy one. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Answer A

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Chapter 5 Video

Question Bank

Conventional Questions (U06C05L02Q001) Miss Wong is a computer teacher. She has uploaded some educational videos to the school web site for her students to view and learn by their own. She uploaded the videos in both low bandwidth version and high bandwidth version. (a) (i) Explain the term “bandwidth”. (1 mark) (ii) Explain why Miss Wong provides two versions of videos. (2 marks) (iii) What are the differences between these two bandwidth versions? List TWO of them. (2 marks) (b) Is the download speed of the high bandwidth version faster than that of the low bandwidth version? Why? (3 marks) In constructing educational videos, Miss Wong sometimes works with the school technician to take movies using a video camera. The movie is saved in video tapes originally, and convert to digitised video files later. (c) (i) Give TWO advantages of storing movies in digitised video files. (2 marks) (ii) Name TWO hardware that are required to convert the movies into video files. (2 marks) (iii) Suggest TWO video file formats for Miss Wong so that the video files can be played by Windows Media Player. (2 marks) (iv) How can the video files be stored and pass along the teachers conveniently? (1 mark)

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Chapter 5 Video

Question Bank

Answers (a) (i) Bandwidth determine the amount of information allocated per second during video encoding. (1) (ii) Low bandwidth version is suitable for the students with lower network connection speeds. (e.g. dial-up access) (1) High bandwidth version is suitable for the students with higher network connection speeds. (e.g. broadband access) (1) (iii) The high bandwidth version may have larger file sizes / higher video resolution / higher frame rate (Any 2 × 1) (b) No. (1) The download speed depends on the Internet connection service provided for the users. (1) It also relies on the workload of the server at the downloading moment. (1) (c) (i) Advantages: Easy and more direct to access the video files through the computer. (1) The video files can be stored in secondary storage devices permanently. (1) (ii) video capture card (1) and sound card (1) (iii) MPEG (1), AVI (1) (iv) The video files can be stored in CD-ROM. (1)

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Chapter 5 Video

Question Bank

(U06C05L02Q002) Martin owns a property management company. He is designing web pages showing the details of the flats to be sold, and choosing which of the four multimedia modes can be combined to give the best result on the flat information: still picture, video, VR Panorama and GIF animation. (a) (i) Martin finally decides to use the above first three modes and not to use GIF animation. Suggest ONE reason why he makes such decision. (1 mark) (ii) Martin also wants to add sound to the web pages besides graphics and videos. Suggest how he can use all these multimedia methods to promote the flat sale. (2 marks) (iii) For the two different video format: downloadable file and video streaming, Martin prefers to use the latter one rather than the former one. State ONE advantages of using video streaming to show the videos. (1 marks) (iv) State an algorithm which can compress the video files. Give ONE advantage of compressing video files. (2 marks) The network technician Johnson helps Martin in designing the web pages of the company. He is required to capture the company advertisement from video tapes which create a video file to post on the web pages. (b) (i) List THREE attributes of the video that Johnson needs to specify before he captures the video. (3 marks) (ii) Johnson needs to choose one of the following standards to save the video file: AVI, MPEG-1, MPEG-2, MPEG-4. Describe each of these standards. (4 marks) (iii) After Johnson saved the file and put it on the web page, he found that the quality of the video shown on Internet is not as good as that played from video tape. Suggest TWO reasons for this. (2 marks)

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Chapter 5 Video

Question Bank

Answers (a) (i) It is because GIF animation can only use 256 colours for the images which is less attractive than the MPEG videos. (1) (ii) The still pictures can be used to show the interior and exterior design of the flats in the web pages, / and the VR Panorama assists to display the environment inside the flats further. / Background sound may be used for the web pages. / Videos with voice descriptions for the flats can be viewed by clicking the corresponding buttons on the web pages. (Any 2 × 1) (iii) Video streaming allows users to watch the video without having to wait for downloading the whole video file. (1) (iv) Codec (1) Storage space can be saved. / The access speed increases. (Any 1 × 1) (b) (i) frame size / frame rate / bandwidth / colour depth (Any 3 × 1) (ii) AVI: Video format for Microsoft’s Video for Windows standard (1) MPEG-1: Video format for video CD and interactive CD-ROMs (1) MPEG-2: Video format for DVD and digital TV broadcast (1) MPEG-4: Specifying a description of digital AV scenes in the form of “AV objects” that have certain relations in space and time (1) (iii) The video has undergone lossy compression and some video details has lost. (1) The computer is not fast enough to decompress the file while the file is playing. (1)

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Chapter 5 Video

Question Bank

(U06C05L02Q003) Mr. Chan is a Biology teacher in a secondary school. He is responsible for developing a web site for the subject. (a) Mr. Chan would like to use a digital camera to take photos on some important experiments. He can save the images taken in JPEG or TIFF format. Which format is more suitable for his purpose? Why? (2 marks) (b) Mr. Chan has found some useful images from other web pages. Suggest TWO methods to get the images from the web pages. (2 marks) (c) Suggest TWO more multimedia items to be included in the web site that students will find them useful. (2 marks) Connie and Sara are Mr. Chan’s students. They joined an overseas study tour to Australia during summer holiday. They have to produce a multimedia web page to share their experience with their classmates on the Internet. (d) Connie will prepare the text and graphics for the web page, and Sara will provide materials in other multimedia elements. Name TWO multimedia elements Sara can use? (2 marks) (e) Connie prepares the graphics by scanning the photos taken. However, she finds that the quality of the scanned photos is not satisfactory. State TWO ways that she can edit the images. (2 marks) (f) Sara thinks that the graphics prepared by Connie are vector graphics. Do you agree with her? Explain briefly. (2 marks) (g) Sara has prepared a video clip to be included in the web page, but she finds it too large to upload to the Internet. Suggest THREE methods to reduce its file size. (3 marks) Answers (a) JPEG is more suitable, (1) as it has a smaller file size. (1) (b) Download and save the images. (1) Perform screen captures and save the captured images. (1) (c) Video clips on experiments (1); animation demonstrating important concepts (1) (any reasonable answer) (d) sound / video / animation (Any 2 × 1) (e) She can edit the images by adjusting colours / contrast / brightness. (Any 2 × 1) (f) No. (1) A scanner store images as bitmap graphics. (1) (g) Decrease the frame rate / Decrease the image size / Decrease the colour depth / Compress the video (Any 3 × 1) Computer & Information Technology for HKCEE (Module D)

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