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Osprey-300 User’s Guide
YUY2 mode, sometimes referred to as 4:2:2
packed mode, consists of a single array of mixed
Y, U, and V data. Each pixel has one Y (intensity)
byte. Each pixel shares its U and V bytes with
one of the pixels horizontally next to it:
YUY2 uses the same number of aggregate bytes
per pixel as RGB15, which is two. However, YUY2
is more efficient than RGB15 because it stores
relatively more of the intensity information to
which that the human eye is most sensitive.
UYVY mode is very similar to YUY2 except that
the bytes are swapped as follows:
YVU9 and YVU12 are “planar” modes - the Y,
U, and V components are in three separate
arrays. It is easiest to explain the format with
an example: Let’s say you have a 320x240 YVU9
format. The buffer has 320x240 bytes of Y data,
followed by 80x60 bytes of V data, followed by
80x60 bytes of U data. So each U and each V
byte together contain the color information for a
4x4 block of pixels.
Similarly, a 320x240 YUV12 format has a
320x240 Y array, followed by a 160x120 U array,
and then a 160x120 V array.
Note that in the I420 format used by Osprey, the
order of the U and V arrays is reversed from the
order in the YVU9 format.
C
LOSED
C
APTIONING
(CC)
The Osprey AVStream driver performs raw
capture of NTSC closed caption (CC) character
pairs. The character pairs are emitted as a raw,
uninterpreted, DirectShow-standard CC Category
stream. Downstream filters can capture this
data or render it onto video. “CCApp”, shown
in figure 14, is included with the driver as a
simple example of CC functionality, and its
source code is provided in the Osprey AVStream
SDK. Osprey CC pins work with Windows Media
Encoder 9.
Pix
els 1
&
2 Byte 1= y1
Byte 1 Intensity
Byte 2= u1/2
shared U color
information for bytes 1
and 2
Byte 3= y2
Byte 2 Intensity
Byte 4= v1/2
shared V color
information for bytes 1
and 2
Pix
els 3
&
4
Byte 5= y3
Byte 6= u3/4
Byte 7= y4
Byte 8= v3/4
Pix
els 1
&
2 Byte 1= u1/2
Byte 1 Intensity
Byte 2= y1
shared U color
information for bytes 1
and 2
Byte 3= v1/2
Byte 2 Intensity
Byte 4= y2
shared V color
information for bytes 1
and 2
Pix
els 3
&
4
Byte 5= u3/4
Byte 6= y3
Byte 7= v3/4
Byte 8= y4
Summary of Contents for Osprey-300
Page 1: ...Osprey 300 User s Guide...
