參數(shù)資料
型號: BT849A
英文描述: Single-Chip Video Capture for PCI
中文描述: 單芯片的PCI視頻捕捉
文件頁數(shù): 26/141頁
文件大小: 1149K
代理商: BT849A
Bt848/848A/849A
Single-Chip Video Capture for PCI
Brooktree
16
F
UNCTIONAL
D
ESCRIPTION
UltraLock
L848A_A
The example illustrated in Figure 4 shows three successive lines of video being
decoded for square pixel NTSC output. The first line is shorter than the nominal
NTSC line time interval of 63.5
μ
s. On this first line, a line time of 63.2
μ
s sampled
at 4*Fsc (14.32 MHz) generates only 905 pixels. The second line matches the
nominal line time of 63.5
μ
s and provides the expected 910 pixels. Finally, the
third line is too long at 63.8
μ
s within which 913 pixels are generated. In all three
cases, UltraLock outputs only 780 pixels.
UltraLock can be used to extract any programmable number of pixels from the
original video stream as long as the sum of the nominal pixel line length (910 for
NTSC and 1,135 for PAL/SECAM) and the worst case line length variation from
nominal in the active region is greater than or equal to the required number of out-
put pixels per line, i.e.,
It should be noted that, for stable inputs, UltraLock guarantees the time between
the falling edges of HRESET only to within one pixel. UltraLock does, however,
guarantee the number of active pixels in a line as long as the above relationship
holds.
Figure 4. UltraLock Behavior for NTSC Square Pixel Output
Analog
Waveform
63.2
μ
s
63.5
μ
s
63.8
μ
s
905 pixels
910 pixels
913 pixels
Line
Length
Pixels
Per Line
780 pixels
780 pixels
780 pixels
Pixels
Sent to
the FIFO
by
UltraLock
P
Nom
P
Var
+
P
Desired
where:
P
Nom
= Nominal number of pixels per line at 4*Fsc sample rate
(910 for NTSC, 1,135 for PAL/SECAM)
= Variation of pixel count from nominal at 4*Fsc (can be a
positive or negative number)
P
Desired
= Desired number of output pixels per line
P
Var
相關(guān)PDF資料
PDF描述
BT8510EPJC PCM Transceiver
BT857KPJ Color Encoder Circuit
BT8958EHJ50 xDSL Interface
BT8953AEPFC xDSL Interface
BT8953AEPJ xDSL Interface
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
BT849AKPF 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Single-Chip Video Capture for PCI
BT850-SA 功能描述:BTV4.2 DUAL MODE USB HCI MODULE 制造商:laird - wireless & thermal systems 系列:* 零件狀態(tài):在售 標準包裝:1
BT850-SA-T/R 功能描述:BTV4.2 DUAL MODE USB HCI MODULE 制造商:laird - wireless & thermal systems 系列:* 零件狀態(tài):在售 標準包裝:2,500
BT850-ST 功能描述:BTV4.2 DUAL MODE USB HCI MODULE 制造商:laird - wireless & thermal systems 系列:* 零件狀態(tài):在售 標準包裝:1
BT850-ST-T/R 功能描述:BTV4.2 DUAL MODE USB HCI MODULEE 制造商:laird - wireless & thermal systems 系列:* 零件狀態(tài):在售 標準包裝:2,500