HE tambah beberapa info tentang DTV, yang membolehkan fungsi HDTV.
What is digital television (DTV)? Digital television (DTV) is a new type of broadcasting technology that will transform television as we now know it around the world. DTV refers to the complete digitisation of the TV signal from transmission to reception. By transmitting TV pictures and sounds as 'data bits' (as does a computer) and compressing them, a digital broadcaster can carry more information than is currently possible with analogue broadcast technology. This will allow for transmission of pictures with higher resolution for dramatically better picture and sound quality than is currently available, or of several 'standard definition' TV programmes all at once. The DTV technology can also be used to transmit large amounts of other data that you may be able to access using your computer or your television set.
Why is Digital Video Broadcasting (DVB) being chosen as the national DTV standard?One of the key considerations in making the choice is based on the robustness of the signal under both fixed and mobile conditions, and the effectiveness of signal coverage. The chosen system must also have the flexibility of interoperability with other telecommunications and information technology networks. This is to cater to the increasing convergence of communications technology. Also the standard must have growth potential and provide opportunities for developing applications such as interactive services, on-demand services and so on. The European DVB standard has proven to meet these considerations and the adoption decision was announced on May 1999.
What will happen to current TV transmission services when DTV is introduced?Analogue transmissions will continue for a specified number of years and will eventually be phased out, but it is difficult to estimate the exact date.
What are the key features and benefits offered by DTV? With DTV, viewers can expect to enjoy the following benefits:
Better Picture QualityDTV provides clearer, sharper pictures without interference and ghosting that currently affects viewers in built-up areas and places that are prone to reception problems. DTV gives robust signals even in moving vehicles. This means that TV sets can be installed in buses, cars and other vehicles with commuters enjoying the same high quality reception as they do at home. DTV also includes High Definition Television (HDTV) which gives about twice the vertical and horizontal resolution of today's analogue system. HDTV also contains about five times as much picture information as conventional TV, thereby enhancing picture quality.
Better Sound QualitySimilar to CD player or cinema, digital sound is free from static or distortions that is common in analog audio. It enables new television features like multiple languages, audio enhancements for visually impaired and Dolby Digital Surround Sound Format.
Wider Screen Format 16:9Wider screen similar to the cinema effect, which means you view more of the original image's width. For conventional TVs or analog TVs which is only 4:3 format, movies or similar programs are trimmed down to size.
Introduction of New ServicesDTV enables us to have more services in the Ultra-High Frequency (UHF) band.
Digital signal can be compressed allowing it to carry far more information using the same amount of broadcast bandwidth as an existing analog signal. Hence, digitisation increases the capacity for new materials to be offered alongside regular TV programmes. Such materials can take the form of additional TV programmes, or multimedia and data services.
Multi-Language Transmission and Multi-Lingual Closed Captioning / SubtitlingWith DTV, a viewer can choose to listen to his preferred language when watching TV, so long as the programme has been already been dubbed into various languages and are transmitted simultaneously in the bitstream. The same goes for multi-lingual closed captioning / subtitling.
Interactive TVInteractive TV will introduce new applications such as Home Shopping, Electronic Banking, 'Online Quizzes', Viewers Polls, Interactive Advertising, Email, Chat etc. It can also tie in with the Internet to provide Web Browsing, downloading of files etc.
Multi-Channel EnvironmentWith broadcast bandwidth highly compressed in DTV, it means there will be excess bandwidth for the carriage of at least 5 to 6 digital channels for every analogue channel. This means the possibility of increased channels to cater to viewers' both mass and niche viewing needs.
Personalised TVWith the inclusion of a hard disk in the STB or DTV receiver, viewers can virtually personalise their programming needs, digitally recording television shows, without videotape. This means viewers can watch what they want at their convenience. It allows them to have more control. For example they can pause or instant replay "live" TV. Or, with the simple click of a button, they can tell their TV set to automatically find and record their favourite programs every time they air. They can even 'tell' their TV what they like and do not like, so it can suggest other shows they may want to record and watch, based on their interests.
Electronic Programme Guide (EPG)TV viewers no longer need to search for their TV Guides to know which are the better programmes to watch. An electronic programme guide (EPG) will allow viewers to navigate the programmes available using the remote control, and will be able to show the schedule and synopses of these programmes with short captivating, video previews.
What will the new DTV sets look like?New DTV sets will have wider screens (16:9 ratio) than current TV sets (4:3 ratio), allowing the pictures to be viewed more like those experienced in a movie theatre. The wider picture, especially in larger set sizes, is expected to enhance audience viewing, making you feel more involved in the action, as well as rendering more realistic pictures.
What is the difference between digital TV and high definition TV?Standard Definition Digital TV The new integrated DTVs can receive both digital (DVB) and analog (PAL) signals. High Definition TV High-end DTV i.e. HDTV gives you the clearest, sharpest picture and are built for wide screen format, which gives cinema-quality experience and Dolby Digital surround audio. All DTV picture resolutions will produce a higher quality picture than todayís PAL-compatible sets can. But not all DTV products will support the highest resolutions required to be called high definition.
Will I need a special new antenna in order to receive DTV?The Digital Video Broadcasting-Terrestrial (DVB-T) standard adopted, means that reception of signals is via aerial / antenna. In most places, indoor antennas are sufficient to receive DTV signals. No special antenna is required.
How will DTV affect the lives of people?DTV brings about new services and applications. Applications such as home shopping, home banking will bring much convenience to the users, right in the comfort of their home couches. Interactive TV can allow programme-related information to be called up on demand thus enhancing viewing pleasure. This spells a technical progression.
