Since digital signals that are broadcast over the air are compressed (packed smaller), once they are received by the ATSC tuner, these compressed packets of digital data are then decompressed (unpacked to their original size).
Cablecard compatible tv tuner for pc tv#
By the reverse process ( demultiplexing), an ATSC receiver first receives the combined MPEG transport stream and then decodes it to display one of its component signals on a TV set. In the US, multiple digital signals are combined and then transmitted from one antenna source to create over the air broadcasts. It is separation of a standard baseband signal from the RF carrier that was used to transmit it through the air (or down a coaxial cable or other long-distance medium.) ATSC as implemented in the US uses 8VSB modulation, which requires less power to transmit, as opposed to the also proposed COFDM modulation (used in European DVB-T, which is less prone to multipath distortion and therefore better received in mobile installations). "Demodulation" means transforming the signal from the tuner into a signal that a TV set can use to produce images and sound without further consideration for the frequency at which it was transmitted. The tuner usually performs the function of frequency-agile selection, along with rejection of unwanted out-of-band signals. Selective tuning is the process by which the radio frequency (RF) of the television channel is selected by a receiver from within a band of transmitted RF signals. ATSC tuners provide the following functions: selective tuning demodulation transport stream demultiplexing decompression error correction analog-to-digital conversion AV synchronization and media reformatting to fit the specific type of TV screen optimally.
Operation Īn ATSC tuner works by generating audio and video signals that are picked up from over-the-air broadcast television. Some ATSC receivers, mostly those in HDTV TV sets, will stretch automatically, either by detecting black bars or by reading the Active Format Descriptor (AFD). This lets the user eliminate letterboxing or pillarboxing by stretching or cropping the picture. It is commonly used to convert a low-resolution picture to a high-resolution display. Zooming is an example of resolution change. Examples of media reformatting include: interlace to progressive scan or vice versa picture resolutions aspect ratio conversions (16:9 to or from 4:3) frame rate conversion and image scaling. The receiver generates the audio and video (AV) signals needed for television, and performs the following tasks: demodulation error correction MPEG transport stream demultiplexing decompression AV synchronization and media reformatting to match what is optimal input for one's TV. It does not store any personal data.The terms "tuner" and "receiver" are used loosely, and it is perhaps more appropriately called an ATSC receiver, with the tuner being part of the receiver (see Metonymy). The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. The cookie is used to store the user consent for the cookies in the category "Performance". This cookie is set by GDPR Cookie Consent plugin. The cookies is used to store the user consent for the cookies in the category "Necessary".
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