The Basics of HDTV
ByYou have surely heard about the quality of HDTV, but probably the many new terms have created a bit of confusion. In this article we will try to explain the overall concept of HDTV with a simple introduction. First of all, we will look at the technology of analog TV and then explain what HDTV
The old TV
How does the old analogue television compared to the HDTV? First of all let’s look at the method of reception of TV signal. There are three ways to receive the analog signal to TV: antenna, cable and satellite. The antenna is probably the worst, and it would be necessary to move continuously to optimally receive the signal. Moreover, for a maximum yield, should be mounted outside, at best, on the roof
Cable and satellite offer a better signal quality and in most cases uses digital signals. The broadcast station sends the digital signal which is then converted to analog by the decoder ..
In all three cases the maximum resolution of standard analog TV is 720×480 pixels, which translates into approximately 337,000 pixels.
HDTV specifications
Video
HDTV is now part of DTV (digital television), offering different screen sizes. The two main risoluzionisono 720p and 1080i. The “p” means “progressive” and “i” means “interface”. In both resolutions, every second displays 60 frames per second. The progressive resolution displays 60 frames “full” every second. The resolution interface shows only thirty frames for odd lines and then after another 30 frames. In the latter case it could be a slight flicker.
The 720p resolution reaches 1280×720 pixels, which consists of 921,600 pixels, while the 1080th reaches 1920×1080, for a total of 2,073,000 pixels
What resolution is best? Many people prefer the more stable picture donated by 720p, while others prefer the higher resolution provided dalla1080i. The best way to choose is to see for myself the real differences.
Audio
As the CD sounds better than the old audio cassettes, HDTV sounds better than the old analogical television. Also, some HDTV programs include Dolby Digital 5.1 surround sound. Obviously, to qualify for the 5.1 audio signal will need a sound system suitable
What equipment is needed?
TV
First of all you must buy an HDTV. HDTV is usually sold with an integrated tuner, which does nothing but convert the signal into a playable format. The HDTV tuner are being sold without usually called “HDTV Ready”.
Between CEA (Consumer Electronics Association) and the FCC is under a big legal war on the implementation of a tuner. FCC argues that the inclusion would help to disseminate this new technology, while CEA contends that the tuner is only for those who want to use an antenna to receive the signal, while those receiving the signal via cable or satellite would be unused.
HDTV Card
If you want to use the HDTV with the computer, you can purchase the new ATI HDTV Wonder. This is provided with an antenna to capture the HDTV signal plane. It is also available for entry signals via cable or satellite.
Using a computer you can also record and play back any signal. We explain this concept later.
Antenna, digital cable or satellite
What is better to use for HDTV signals? Only the antenna can be mounted anywhere, but you can not receive all channels. Also, you must find the right position to receive different channels. The best solution is to use a cable connection or satellite.
Unfortunately, the solution of the cable or satellite are much more expensive, so be you to judge subjectively whether the programs and the quality which you can enjoy really worth the expense.
Comparing quality
The receipt of an HDTV channel does not necessarily mean that you can enjoy all the quality that offers this technology. Some transmissions broadcast in HDTV native mode, so you may notice loss of quality, especially along the edges of images. This is because the transmission is broadcast in 4:3, compared with native 16:9 HDTV.
Only programs broadcast in HDTV 16:9 native will enjoy all the quality available. The following image is taken from a broadcast in 1080i, 1920×1080 pixels
HDTV signals using an MPEG-2 compression. HDTV 1080i signal a need for a transmission of about 19.2 megabits per second. Some providers compresses the signal, lowering the transmission rate at 5-6 megabits. Obviously more compression, the image quality will be less.
Unfortunately, it is easy for consumers to determine the bit-rate, and then the actual picture quality. Indeed, when the sale is not often reported the display mode (1080i, 720p), so make sure to ask for this type of information.
You can record HDTV programs?
With a traditional television set, you can record programs using a VCR or a Digital Video Recorder (Tivo, All-in-Wonder). With HDTV this situation changes. FCC ruled that manufacturers can include in their instruction programs that do not allow equipment to record HDTV.
With HDTV cards for PCs but you can record programs, because they ignore the signals that do not allow recording. This was possible until July 2005. Subsequently, also in the cards, by law, will be deployed anti-recording devices.
Conclusions
Use the HDTV is not difficult, provided that you follow the instructions. You will need just a TV, a tuner and antenna, or alternately a cable or satellite.
The quality of video and sound is definitely better, but only programs broadcast in HDTV format native will enjoy. HDTV is a technology very interesting, but unfortunately for now it is still very present in Italy, affordable but not cheap.
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