Browse Prior Art Database

External Chroma Swapping Hardware To Support MPEG-2 Video Encoder

IP.com Disclosure Number: IPCOM000123157D
Original Publication Date: 1998-Jun-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Butter, AS: AUTHOR [+2]

Abstract

Disclosed is a means whereby 4:2:2 chrominance input data to an MPEG-2 video encoder is rearranged in order to correct temporal chroma shifting effects.

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This is the abbreviated version, containing approximately 58% of the total text.

External Chroma Swapping Hardware To Support MPEG-2 Video Encoder

   Disclosed is a means whereby 4:2:2 chrominance input data
to an MPEG-2 video encoder is rearranged in order to correct
temporal chroma shifting effects.

   The overall algorithm employed is shown in Figure 1 on
page 2.  The figure shows the frame format structure of input video
data to what is called the Chroma Swapper algorithm and the resulting
frame format structure of output video data after the algorithm is
performed.  Each video frame being input to the algorithm is divided
up into a series of four pixel row segments.  The number of such
segments depends on the vertical size (vsize) of the video frame, and
is equal to vsize/4.  Each pixel row consists of several luminance
(Y) and chrominance (U or V) pixel pairs.  The number of such pairs
is equal to the horizontal size (hsize) of the video frame.  As shown
in the figure, the luminance data for each four-line segment is
merely passed through without any reordering.  The corresponding
chrominance data for video input lines 1 and 4 are also passed
through.  On the other hand, the chrominance data for the remaining
lines (2 and 3) is changed so that chrominance data lines 3 and 2 now
correspond to luminance data lines 2 and 3, respectively.  Using this
method for every four-line segment of each video frame.  Same parity
field chrominance data appears in every two pixel rows of the video
frame.  For MPEG-2 encoders which exhibit temporal ch...