ViewCast Osprey-300, Руководство пользователя

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Chapter 6: Video Driver Topics
Some Data Points: The following measurements are cpu percent utilization on a fairly old, 600 MHz machine
– the relative performances of the pathways are more important than the absolute percents. The video
size is 640x480. The screen depth is 32 bits, so that RGB32 renders more than RGB555 in this case. The
following abbreviations are used:
VR = Video Renderer
VMR7 = Video Mixing Renderer 7
VMR9 = Video Mixing Renderer 9
AVI = AVI Decompressor
CSC = Color Space Converter
V
IDEO
S
TANDARDS AND
S
IZES
Video Standard refers to whether the video
signal format is NTSC, PAL, or SECAM.
Depending on the exact product version you
have, some or all of the following standards will
be available:
525-line formats:
* NTSC-M – North America
* NTSC-J – Japan
* PAL-M – Brazil
625-line formats:
* PAL-B, D, G, H, I – many countries in
Europe and elsewhere. B, D, G, H, and I refer to
five nearly identical subformats.
* PAL-N, NC – Argentina, Paraguay, Uruguay
* SECAM – France and some other countries.
Full-sized NTSC-M, NTSC-J, and PAL-M have 525
lines total, 480 lines visible, per frame and a
display rate of 59.94 fields per second, or 29.97
interlaced frames per second. Although capture-
to-PC applications normally use only 480 video
lines, the full NTSC frame actually contains 485
video lines, and the AVStream driver provides a
control to capture all 485 lines. The control is
located on the RefSize property tab.
Full-sized PAL (other than PAL-M) and SECAM
have 625 lines total, 576 lines visible, per frame
and a display rate of 50 fields per second, or 25
interlaced frames per second.
Rendering Pathway
CPU
Usage
V
id
eo
R
en
d
er
er YUY2 -> AVI -> VR
100%
RGB32 -> VR 22%
RGB555 -> VR unable
to
render
at 30fps
O
ve
rla
y Mix
er
+ V
ide
o
R
en
d
er
er YUY2 -> OVL -> VR
20%
RGB32 -> OVL -> VR 29%
RGB555 -> CSC -> OVL ->
VR
24%
VM
R
7
YUY2 -> VMR7 2%
RGB32 -> VMR7 2%
RGB555 -> CSC -> VMR7
Format changed to RGB32
20%
VM
R9 YUY2 -> VMR7
10%
RGB32 -> VMR7 15%
RGB555 -> CSC -> VMR7
format changed to RGB32
25%