With technology being readily available for the consumer as well as the professional, there is a drive to constantly push the quality of the image that is captured to a higher standard. High Definition (HDTV) as we know it today, is rapidly become the preferred video format in which to view programming in many television throughout the world. The purpose of this article is to give you the dispel some of the myths and misconceptions of HDTV as well as give a history and insight as to where this technology is heading in the future.
Misconceptions
The major misconception is that HDTV is a relatively new phenomenon. The term high definition or HDTV, is used to describe a series of television systems from the 1930s and 1940s, starting with the British 405-line black-and-white system which was originally introduced in 1936. This also included the American 525-line NTSC system established in 1941. However, these systems were only "high definition" when compared to earlier systems. Another common misconception is that that 24P is always an HD format, and this is simply not true. The term "high definition" refers to the number of lines of resolution contained in the image you are capturing--which bears no correlation to the frame rate, which is what the "P" in 24P refers to.
The Facts
There are many different types of HD resolutions, the most common of which is 1920x1080, which is also referred to as 1080p or 1080i (interlaced). Simply put, interlaced makes the image look more like " standard" video, whereas 24 progressive is the video equivalent of film and gives the image a softer or " film" look. The reason it gives that " film look" look is because it eliminates the artifacting caused by the interlaced frames. So, let's take a small trip down memory lane and see where HDTV originated.
History of
Keeping in mind that by today's standards, these following HDTV formats would be considered standard def, but back in the day, there were in fact high definition. All of these following systems used interlaced video (as opposed to progressive) with the 4:3 aspect ratio. In 1936: System-A was used in the UK. This system had 405 lines at 50 hz--the system was discontinued in 1986. In 1938: Several European countries began using a 441 line system, with France being the last to discontinue this system in 1956. The USA began using the System-M in 1939. This system, which had 525 lines at 60 hz. European, beginning in 1952 and ending in 1956, adopted the system of 625 lines at 50 hz with both PAL and SECAM color entering in 1956. Also in 1956, the French (monochrome) system of 819 line at 50 hz system began it's launch and was used for 50 years, finally being discontinued in 1986. Since the formal adoption of DVB's widescreen HDTV transmission modes in the early 2000s, the 525-line NTSC (and PAL-M) systems as well as the European 625-line PAL and SECAM systems are now regarded as (so called) standard definition television systems.
Identification
In 1986, Sony began it's introduction of what we know today as High Definition Television. Today when someone, the consumer for example, uses the term HDTV, they commonly are using shorthand for the 1080i, format of high-definition video mode. The number 1080i notates the amount of horizontal scan lines (1080) also known as vertical resolution, while the letter "i" stands for interlaced and "p" stands for progressive scan. Also, in 1080i high-definition television (HDTV) video mode, one usually assumes as a widescreen aspect ratio of 16:9, implying a horizontal resolution of 1920 pixels and a frame resolution of 1920 í-- 1080 or about 2.07 million pixels. However this HDTV notation is slowly being replaced by it's more preferred cousin, the progressive format.
Evolution
Although the interlaced format is the more commonly broadcast format, the progressive format is slowly become more and more prevalent, especially amongst production companies who want their shows to have the softer "film" look that progressive video offers. The progressive format 1080p is also being foreseen as the future of broadcasting standard not only in the United States, but in other countries as well. 1080p is the shorthand name for a category of display resolutions, just like 1080i, in that the number "1080" represents 1,080 lines of vertical resolution (1080 horizontal scan lines) while the letter "p" stands for progressive scan, which simply means that the image is not interlaced. 1080p can also be referred to as full HD or full high definition to differentiate it from other HDTV video modes. When you uses the term 1080p, you also assume a widescreen aspect ratio of 16:9. This implies a horizontal resolution of 1920 pixels. This creates a frame resolution of 1920í--1080, or 2,073,600 pixels in total.
Effects
The effects is that as the industry embraces progressive over interlaced, the consumer will see more programming broadcast in the progressive video format, which may mean an upgrade in your home systems. Both ATSC Standards and DVB support 1080p video at the frame rates of 24, 25 and 30 frames per second, which breaks down to 1080p24, 1080p25 and 1080p30. Higher resolutions will require higher bandwidth to broadcast. So, higher frame rates, such as 1080p50 and 1080p60 could only be sent with more bandwidth or if a more advanced codec, such as H.264/MPEG-4 AVC and AVS, were used. Keep in mind that higher frame rates such as 1080p50 and 1080p60 are foreseen as the future broadcasting standard for production. So really what this means to the consumer is that they will need to ensure the television they are purchasing now will accommodate the newer video formats.
Expert Insight
Having produced both programming in standard def and high def, there is a significant increase in the networks' delivery requirements to deliver shows in both formats. The future for 1080i looks like it is going the way of the dinosaur as the entertainment industry has embraced 1080p24 as a mastering format in both native 24p form and in 24PsF form. This may be the first universal video standard which transcends continental boundaries. This is an area previously reserved for film. Wrapping progressive video into the interlaced stream allows the video to maintain the progressive format, while minimizing bandwidth requirements using interlaced equipment.
Tags: progressive format, progressive video, resolution 1920, 1080p also, aspect ratio, film look, frame rates