V. Fill in the prepositions if necessary.

A popular use … the DVD device is to play movies. The user buys a movie DVD and inserts the DVD … the DVD device. The DVD device converts the DVD signal … a video signal … a television connected … the DVD device. DVD players have many … CD player features, such as the ability to play selections … any order desired and the ability to read information … any point … the disc. The audio data recorded in a DVD-Video has a much higher quality than that in a CD since the audio data … the DVD has a higher sampling frequency and larger numbers of quantization bits and channels than that … the CD. Thus, the DVD player reproduces … high quality audio data … multiple channels. DVD players have an advantage … video cassette players because DVD players can quickly and accurately access specific segments … data anywhere … the medium.

VI. Answer the questions.

1. What device is called a digital video disk?

2. What devices are commonly used to store audio and video image data?

3. In what formats does a digital video disk store information?

4. Into what two types is the data stored in the digital video categorized?

5. Why have DVD systems become so popular in recent years?

6. What is the information storage capacity of a typical DVD?

7. Of what three logical units is a digital versatile disc player generally composed?

8. Where are mobile A/V devices often utilized?

9. What are the results of smaller size with ever-increasing capability of portable DVDs?

10. What display devices are used in portable DVD players?

11. List the advantages of OLED displays.

Read the text.

Think what device is described in the text.

Define the main idea of the text.

These players are portable audio players that store, organize and play digital music files using MPEG layer 3. This format is a compression system for digital music that helps reduce the size of a digitized song without degrading the sound quality. Generally, this player is a type of digital data player for processing digital data files. It is portable digital audio equipment capable of readily downloading and reproducing desired music from a computer communication network using an audio data compression coding technique prescribed in MPEG layer 3. The player is small in size and light in weight, thereby allowing high activity uses such as being carried during physical exercise. For these reasons, this product is being touted as an alternative to a portable cassette tape recorder and compact disk (CD) player. Audio players and specifically, portable audio players have developed dramatically since their innovations. Music players of widely varying type have evolved through various forms over the years, from portable single transistor radios to tape cassette players to compact disc players and more recently to players, which enable a user to download audio material from an internet site and store it in storage medium of a player in this format for subsequent selective listening. Audio and video files, before being compressed, typically consist of 16-bit samples recorded at a sampling rate more than twice the actual audio bandwidth, which yields more than 1.4 Mbit to represent just one second of stereo music in CD quality. Since such vast amounts of data are unwieldy, data compression is required. Audio and video information may be compressed to remove redundancy within the information and allows the information to be stored using less memory. Digital audio is a basic component of any video or multimedia application. Due to the large bandwidth occupied by digital audio in any such application, compression of the audio data is an important part of the encoding process. There are two main high-fidelity audio compression techniques: the Motion Picture Expert Group (MPEG) audio standard and the Dolby Digital audio compression algorithms developed by the Dolby Laboratories. MPEG (Motion Picture Experts Group) provides standards for compressing digital audio and video signals. In order to accommodate different levels of audio quality with the compression method, MPEG is further divided into Layer1, Layer2 and Layer3. Generally speaking, the higher the level of the layer, the more complicated the compression method, the distortion of the corresponding recovered audio signal is much less, and the effect is better.