Browse Prior Art Database

Programmatic Computer Television Tuner Scan Function

IP.com Disclosure Number: IPCOM000118700D
Original Publication Date: 1997-May-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Flurry, GA: AUTHOR [+2]

Abstract

Disclosed is a method for a programmatic interface and implementation on an AIX* (UNIX**) operating system to perform a TV Tuner Scan function. The scan function will seek to the next "available" television channel. An "available" channel contains a signal meeting an agreed upon criteria for being "tuned".

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Programmatic Computer Television Tuner Scan Function

      Disclosed is a method for a programmatic interface and
implementation on an AIX* (UNIX**) operating system to perform a TV
Tuner Scan function.  The scan function will seek to the next
"available" television channel.  An "available" channel contains a
signal meeting an  agreed upon criteria for being "tuned".

      The software scan function will run on an AIX (UNIX) system
that contains video input hardware with a TV tuner.  In the current
embodiment, the hardware does not contain any scan logic so this
function was implemented in software.  The scan function allows the
user to automatically tune the next available channel without having
to increment or decrement through many channels manually.

The interface to the scan function is defined as follows:
     int seek_to_next_avail_channel (Direction direction);

      The type Direction is an enumerated type with values Up and
Down.  This parameter will control the direction of the channel
search.  A value of Up will indicate that the channel values will
increase as the scan progresses.  Likewise, a Direction of down will
cause the channel values to decrease as the scan progresses.

      The seek_to_next_avail_channel function calculates the
boundaries of the current television transmission system.  These
boundaries are based on whether the transmission is cable or
off-the-air, whether it is NTSC or PAL, and whether the tuner is an
M/N, B/G, or I format tuner.  The next step in the function is to
setup a loop.  The loop will execute until a channel with programming
is found or a round-trip is made around the channel dial.  If the
channel is not found  and the channels have not been exhausted,...