LESSON 45

DVD VIDEO. DVD DISCS [4]

Task 1. Read and translate the text:

Задание 1. Прочитайте и переведите текст:

DVD — video discs require a DVD — drive with a MPEG - 2 decoder. DVD movies are encoded using a combination of MPEG - 2 compressed video and audio of varying formats. Typical data rates for DVD movies range from 3-10 Mbit / s, and the bit rate is usually adaptive. The video resolution on NTSC discs is 720x480 and on PAL discs is 720x576.

The audio data on a DVD movie can be of the format PCM, DTS, MP2, or Dolby Digital (AC - 3). DVDs can contain more than one channel of audio to go together with the video content. In many cases, sound tracks in more than one language are present.

DVD Video may also include one or more subtitle tracks in various languages. They are stored as images with transparent background which are overlaid over the video during playback.

DVD Video may contain Chapters for easy navigation.

There are several possible successors to DVD being developed by different consortiums: Sony's Blu-ray Disc, Hitachi / Toshiba's HD DVD, the Holographic Versatile Disc, and Maxell's holographic disc.

The first generation of holographic media with 300 GB of storage capacity and a 160 Mbit / s transfer rate is scheduled for release in Late 2006 by Maxell and its partner, InPhase.

On April 15, 2004, in a co-operation project with TOPPAN Printing Co., the electronic giant Sony Corp. successfully developed the paper disc, a storage medium that is made out of 51 % paper and offers up to 25 GB of storage, about five times more than the standard 4.7 Gb DVD. The disc can be easily cut with scissors and recycled, offering foolproof data security and an environment - friendly storage media.

In 2006 it is not yet clear which technology will win the format war over DVD. HD DVD discs contain less information than Blu-ray discs (15GB vs. 25GB for single layer, and 30GB 50GB for dual layer), but Blu – ray requires changes in manufacturing machinery and techniques.

DVDs are made from a 0.6 mm thick disc of polycarbonate plastic coated with a much thinner reflective aluminum layer. Two such discs are glued together to form a 1.2 mm disc.

A single-layer DVD can store 4.7 gigabytes (Gb), which is around seven times as much a standard CD disc. By employing a red laser at 650 nm, before it was 780 nm, wavelength and a numerical aperture of 0.6 before it was 0.45, the read-out resolution is increased by a factor 1.65. DVD uses a more efficient coding method. As a result, the DVD format is 47 percent more efficient with respect to CD disc.

A DVD can contain simple data, video data and audio data. There are three writing formats: plus, minus and RAM. As to the DVD disc itself, DVD discs may have one or two sides, and one or two layers of data per side; the number of sides and layers determines the disc capacity. So, there are 5 types of DVD discs: DVD — 5, DVD-9, DVD — 10, DVD-14, DVD — 18.

DVD-5 means single sided, single layer disc. It is 4.7 gigabytes (GB) and may contain 4.38 gigabytes (Gb) of information.

DVD — 9 means single sided, double layer DVD disc which capacity is 8.5 Gb (7.92 Gb).

DVD — 10 means double sided, single layer on both sides DVD disc. It is a 9.4 Gb (8.75 Gb) disc.

DVD — 14 means double sided, double layer on one side, single layer on other. It is 13.3 Gb disc which can contain up to 12.3 Gb of information.

DVD — 18 of f ers the highest capacity. It is double sided, double layer on both sides disc with 17.1 Gb and can contain up to 15.9 Gb.

The capacity of a DVD disc can be visually determined by noting the number of data sides, and looking at the data sides of the disc. Double-layered sides are sometimes gold-coloured, while single-layered sides are silver-coloured, like a CD. One additional way to tell if a DVD contains one or two layers is to look at the centre ring on the underside of the disc. If there are two barcodes, it is a dual layer disc. If there is one barcode, there is only one layer.

The «+» (plus) and «-» are similar technical standards and are partially compatible. As of 2004, both formats are equally popular, with about half of the industry supporting «+», and the other half «-». All DVD readers are supposed to read both formats, though real-world compatibility is around 90% for both formats. There is the third writing format. It is DVD-RAM (RAM — Random Access Memory). This standard is not as popular as «+» or «-».

The data transfer rate of a DVD drive is given in multiples of 1350 Kb /s, which means that a drive with 16x speed designation allows a data transfer rate of 16x1350 = 21600 kB/s(21.09MB/s). As CD drive speeds are given in multiples of 150 kB/s, one DVD «speed» equals nine CD «speeds,» so an 8x DVD drive should have a data transfer rate similar to that of a 72x CD drive. In physical rotation terms (spins per second), one DVD «speed» equals three CD «speeds,» so an 8x DVD drive has the same rotational speed as 24 x CD drive.

Task 2. Answer the following questions:

Задание 2. Ответьте на следующие вопросы:

1. How are DVD movies encoded?

2. What is a typical range for DVD movies?

3. What is the DVD video resolution on NTSC discs?

4. What is the DVD video resolution on PAL discs?

5. What audio formats on a DVD movie do you know?

6. How are subtitle tracks stored?

7. What possible successors to DVD are there?

8. What company successfully developed the paper disc in 2004?

9. How much information can Blu — ray discs contain?

10. How much information can HD DVD discs contain?

11. What materials are used for DVD production?

12. How much information can a single — layer DVD store?

13. What efficiency has a DVD format with respect to CD disc?

14. How many writing formats are there?

15. What determines a DVD disc capacity?

16. How many types of DVD disc are there?

17. What does DVD - 5 mean?

18. What does DVD — 9 mean?

19. What does DVD — 10 mean

20. What does DVD — 14 mean?

21. What does DVD — 18 mean?

22. How can the capacity of a DVD disc be visually determined?

23. What is DVD — RAM?

24. What can you tell about DVD speed comparing with CD speed?

Task 3. Find the English equivalents for the words and word — combinations given below in the text:

Задание 3. Найдите эквиваленты следующих слов в тексте:

требовать, дешифратор, переменный, приспосабливающийся, субтитр, прозрачный, воспроизведение, перемещать, ножницы, слой, длинна волны, двойной, штриховой код, совместимость.

Task 4. Translate the following words and word — combinations into Russian:

Задание 4. Прочтите следующие слова и словосочетания и переведите их на русский язык:

require, content, In many cases, sound tracks, playback, possible, scissors, recycled, glue, efficient, respect, the disc capacity, to contain, The Additional, a dual layer, partially, compatible, both, means, multiples, transfer, rotation, rotational speed.

Task 5. Make the sentences interrogative:

Задание 5. Поставьте следующие предложения в вопросительную форму:

1. The data transfer rate of a DVD drive is given in multiples of 1350 kB / s.

2. The first generation of holographic media with 300 GB of storage capacity and a 160 Mbit / s transfer rate is scheduled for release in Late 2006 by Maxell and its partner, InPhase.

3. Two such discs are glued together to form a 1.2 mm disc.

4. There are several possible successors to DVD being developed by different consortiums.

5. The capacity of a DVD disc can be visually determined by noting the number of data sides, and looking at the data sides of the disc.