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Browse Prior Art Database

Method to Enhance Connectivity of Video Streams to Slow Busses

IP.com Disclosure Number: IPCOM000117871D
Original Publication Date: 1996-Jul-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Flurry, G: AUTHOR [+3]

Abstract

Disclosed is a method to connect video streams to slow personal computers. A buffer memory is placed between the Analog-to-Digital (A/D) conversion circuit and the bus interface to allow continuous video capture while data is retrieved over a slow bus interface.

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

Method to Enhance Connectivity of Video Streams to Slow Busses

      Disclosed is a method to connect video streams to slow personal
computers.  A buffer memory is placed between the Analog-to-Digital
(A/D) conversion circuit and the bus interface to allow continuous
video capture while data is retrieved over a slow bus interface.

      Today's video host bus interface logic, while providing the
basic host interface, lacks a graceful recovery from an internal
First In First Out (FIFO) buffer overflow.  This condition is when
the host is unable to maintain sustained transfers and the FIFO fills
beyond its capacity.  The interface generally discards the whole
field and starts over.

      To solve this problem, a field buffer is installed between the
A/D conversion circuits and the bus interface circuits.  The A/D
circuits convert the analog video signal into a digital signal and
scales the resulting digital image to the appropriate resolution.
The results of this operation include the individual pixel
information as well as control signals that indicate the end of a
line, the end of a field and whether it is an odd or even field.  All
these signals are standard.  The approach we are disclosing involves
storing the pixel information in its own field buffer and adding a
second buffer to store the control signals.  The particular buffers
act as FIFO's and allow the data to be written in by one process
while the memory is asynchronously read by another process.

      The buffer memory is constan...