All ABC7 program information is available online on our TV listings page at kgo.titantv.com. HDTV (High-Definition Television) programs are indicated. (KGO-TV Digital broadcasts are transmitted on UHF Channel 24)
What is HDTV?
High-definition television is a new format for broadcasting TV programming. The existing format is called NTSC (National Television Standards Committee) and is analog. By contrast, the signals in HDTV are digital.
Do I need a new television set to watch HDTV?
Yes. You must have a high-definition tuner and monitor to properly decode HDTV signals and display them accurately. ABC's programs are also broadcast in standard format, so today, no programs are ONLY for HDTV users. Your regular television set simply ignores HDTV signals that are being broadcast. When you want to step up to watching HDTV, you'll need to get a new high-def TV set.
What's different about HDTV versus the existing signals?
The HDTV signal is digital resulting in crystal clear, noise-free pictures and CD quality sound. For the technophile, there are about 20 megabits per second of information per broadcast channel. HDTV has many viewer benefits.
Benefit: Aspect Ratio
Most televisions today are manufactured in a 4 by 3 aspect ratio, which means the screen is 4 units wide by 3 units high. But theatrically released movies are usually in a much wider aspect, taking advantage of the human field of vision (which is wider across horizontally). HDTV signals are sent in a 16 by 9 aspect ratio, mimicking the wide scope of movies. HDTV's aspect ratio makes for a more immersive and intense viewing experience.
Benefit: Picture Resolution
Resolution is a measure of picture sharpness. Current analog television contains about 480 active scanning lines resulting in a picture resolution of about 330 lines of resolution. By comparison today's VHS VCR's have about 240 lines of resolution which is why VHS recordings don't look as sharp as the original picture. DVD's offer higher resolution typically on the order of 400-480 lines of resolution. (Note the number of scanning lines does not equal resolution. For example, both the VHS and DVD formats have 480 active scanning lines but have different resolutions.) HDTV offers resolution that is at least twice that of analog television. You can expect razor sharp images from HDTV.
I have heard that there are two HDTV formats -- 720p and 1080i. Is there a difference between these formats and can my television receive both these formats?
Regardless of the HDTV format being broadcast, all new HDTV receivers can receive both formats. New HDTV televisions will convert any received signal to a format that is compatible with your new display. The 720p format uses progressive scanning, which is just like your computer monitor. Progressive scan offers crystal clear images that virtually eliminates those scanning lines that are visible on most large screen televisions. ABC broadcasts all of its programming using the 720p format except in Dallas, where the ABC station broadcasts in 1080i. Many new flat panel displays use progressive scan.
The 1080i format uses interlace scanning just like today's analog televisions. Scanning lines are less visible on big screens due to the number of lines. Most older projection HDTV's use 1080i.
Benefit: Digital Sound
Just as your CDs sound better than your old audiocassette tapes, HDTV's digital audio signal sounds better than standard television's analog sound. Also, some HDTV programs include Dolby Digital 5.1 surround sound. Properly decoded, each audio track can be sent to a different speaker, creating a three-dimensional sound field in your living room. Many of ABC's prime time programs contain Dolby Digital surround sound for your listening pleasure.
What do I need to receive HDTV?
In most areas, HDTV is only available as an over-the-air broadcast signal. This requires the use, in most cases, of an outdoor antenna pointed in the direction of the broadcaster's tower. You will also need a new HDTV receiver that can decode the digital signals. HDTV channels are typically different than your cable or over-the-air channel.
Please see the attached list of those cities where ABC HDTV programs are available.
Is HDTV replacing standard television?
Not immediately. ABC and other broadcasters will continue to offer programs in the standard format for at least the next several years. However, the federal government hopes broadcasters and consumers adopt the new format by 2006. Thus, the next few years will be a transition, as television networks add more digital broadcasting to their offerings.
