What is HDTV (High Definition Television)?

HDTV stands for high-definition television. It is part of digital television. This format offers a better quality of broadcast. It surpasses older systems like PAL, NTSC, and SECAM.

Consequently, viewers enjoy more explicit images and improved sound. Overall, HDTV enhances the television experience significantly.

HDTV Features and Usage in Some Countries

The HDTV screen has a 16:9 aspect ratio. This format allows for more detail than standard-definition TV. It uses high-resolution images, improving clarity significantly.

Several codecs can compress these images, such as MPEG-2, H.264, and WMV-HD. However, MPEG-2 is less efficient than the others.

Television images can be up to five times sharper than standard TV. For example, the 1920×1080 resolution typically uses interlaced mode.

This method scans lines 60 times per second, similar to NTSC. This format is known as 1080i or 1080i60.

In regions using the PAL standard, 1080i50 operates at 50 Hz. Additionally, progressive formats at 60 frames per second are standard.

Overall, 1280×720 is generally better and is called 720p. Many American TV stations now offer real-time streaming in 720p at 60 frames per second.

HDTV Old Systems

MUSE

Japan pioneered the first HD TV system in 1979. In the early 1990s, it began broadcasting analog signals. This used a 1035 interlaced line resolution (1035i).

The Japanese MUSE system was developed in the 1980s by NHK’s research labs. It utilized filtering systems to reduce the signal.

This approach also lowered the required bandwidth—for instance, three frame elements on a line use three separate hatches.

Later, Japan transitioned to an ISDB-based digital HD TV system. This change occurred because a complete camera panorama lost 50% of the horizontal resolution.

HD-MAC

The European Commission introduced a standard for digital HD TV in 1986. This standard was called the MAC directive.

However, broadcast stations did not widely adopt it. Despite this, all high-power satellite broadcasters were required to use MAC.

As technology advanced, medium-power satellites by SES Astra changed the landscape. These stations operated without MAC, which helped reduce transmission costs. Meanwhile, HD-MAC became useful for intercontinental satellite connections.

The main reason HD-MAC failed was its inability to use the 36 MHz frequency. This frequency is crucial for high-definition signals in terrestrial broadcasts.

However, HD-MAC could still be beneficial for cable and satellite companies. They can utilize higher bandwidth when available.

Despite its advantages, analog HD television failed to replace traditional PAL/SECAM SDTV. This made HD-MAC a preferable option for some.

Unfortunately, the HD-MAC standard was discontinued in 1993. Since then, all developments in the EU and EBU have focused on DVB technology. This technology supports both SDTV and HDTV effectively.

HDTV New Systems

Europe

EDTV with DVB features is popular in Europe. While HD televisions use DVB-T, other countries prefer more channels.

For example, the US, Canada, Japan, and Australia favor having many channels over a single HDTV. In Europe, HD TV isn’t suited for terrestrial broadcasting.

One HDTV channel replaces four SDTV channels. Thus, some governments chose digital over reallocating VHF frequencies.

Meanwhile, DVB-S2, combined with the H.264/AVC codec, has boosted HDTV use in Europe.

Additionally, EICTA introduced HD Ready technology for devices meeting specific standards.

Equipment must support resolutions of 720p and 1080i at both 50 and 60 Hz. Thus, screens need YUV, DVI, or HDMI interfaces. Finally, they must have a vertical resolution of at least 720 lines.

European Union

The European Union studied the global use of digital broadcasts. They focused on 16:9 broadcast status and HD documents.

Unfortunately, European consumers missed the chance to try HDTV. Previous targets for HDTV’s introduction in 1999 did not succeed. The market prioritized easier digital technologies and services instead.

Several reasons explain this failure. First, European market leaders doubt HDTV’s success. Additionally, broadcasters prefer cheaper multi-channel SDTV options. Finally, SDTV is more cost-effective in the long run.

Other Countries

In France, M6 and TF1 plan to broadcast some programs in HD. However, they will not use it for their digital terrestrial TV. Instead, they chose H.264/MPEG-4 AVC to enable premium content.

In Germany, three HD channels began streaming in November 2005. This was through the Premiere payment platform. Initially, their content included movies, sports events, and documentaries.

Meanwhile, Cubans can access two unique HD channels without any extra devices. In the UK, the BBC has broadcast some documentaries in HD for foreign markets like the USA and Japan. Later, they expanded their HD broadcasts to all programs.

Due to limited bandwidth, paid platforms like Freeview offer digital terrestrial broadcasts. Subsequently, Sky launched HD satellite services.

Japan led the way in HDTV with its analog application. Unfortunately, the old systems are not compatible with newer ones. However, ISDB-T’s terrestrial HD broadcasts started in December 2003, selling two million HD receivers.

In South Korea, the government and broadcasters decided to adopt the ATSC format instead of DVB-T. In Australia, HD broadcasting began in January 2002. Most cities with over 40,000 residents received at least one digital terrestrial TV channel.

Finally, in the early 1990s, Mexican television company Televisa partnered with Japan’s NHK. They began experimental HDTV broadcasts, marking an essential development in the region.

DVR (Digital Video Recorder)

You can record broadcasts on a digital video recorder (DVR) that supports HDTV.

A standard DVR in the United States is D-VHS. D-VHS records in digital format at 28.2 Mb.

It uses a FireWire (IEEE 1394) connection to link with the modulator. This setup compresses the MPEG-2 frame before sending it to the recorder.

However, storing uncompressed data requires enormous capacity. This need can be a significant drawback.

Therefore, MPEG-2 real-time compression is often avoided due to its high cost. Furthermore, analog tape recorders that can store HD signals, like W-VHS, are no longer used.