Cable and satellite TV providers both boast about having the most high definition channels and the best HD picture quality in an attempt to attract new customers. A lot of factors are involved in displaying the highest-quality picture, however, and some of them are not directly attributed to the provider. Still, there are differences between the two services when it comes to HD.
The video quality of an image on a TV screen is measured in lines of resolution. High definition is a term that describes a resolution of at least 1,280 horizontal lines by 720 vertical lines and can be as high as 1,920-by-1,080 lines. The images are also broadcast using either a progressive-scan or interlaced format which, when paired with the vertical resolution, creates the shorthand terms of 720p, 1080i and 1080p, with 1080p delivering the highest resolution.
Every HDTV set has a native resolution specification, which is the maximum resolution possible based on the number of pixels the screen contains. Some HDTVs have a native resolution of 720p, while others, including the majority of models in stores today, offer 1080p capability. If the source being viewed, whether it be cable or satellite, has more pixels than the screen allows, the picture will lose a bit of sharpness and detail, as it has to be downscaled to be displayed on that screen. Also, the HDTV must be connected to the cable or satellite set-top box/DVR via HDMI cable to enable the highest-quality video possible.
As of 2011, none of the major networks are broadcasting 1080p video, which is the maximum, so neither cable or satellite has an advantage over the other in terms of the signal source. Satellite TV delivers an uncompressed signal, however, while cable TV transmissions must employ video compression in order to deliver the total number of channels available within the bandwidth allowed, which causes a loss of data to some degree. This gives satellite TV the advantage in providing a clearer HD picture under ideal conditions.
Because of the finite bandwidth that exists with cable TV, satellite also has the advantage in the total number of HD channels available to the subscriber. Many of these HD channels are regional channels that only satellite providers offer, however. For example, DirecTV and Dish Network offer all Fox Sports regional channels, while cable providers are likely to offer only the one specific to your region. In terms of national channels offered, the number of total HD channels is nearly even, though that depends on the programming package chosen and the particular cable provider and location. Also, cable companies are more likely to charge an additional monthly fee to receive HD channels than satellite providers.
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