参数资料
型号: ADV7180BSTZ
厂商: Analog Devices Inc
文件页数: 90/116页
文件大小: 0K
描述: IC VIDEO DECODER SDTV 64-LQFP
产品变化通告: ADV7180 Metal Mask Edit 22/Oct/2009
设计资源: Low Cost Differential Video Receiver Using ADA4851 Amplifier and ADV7180 Video Decoder (CN0060)
Low Cost Video Multiplexer for Video Switching Using ADA4853-2 Op Amp with Disable Function (CN0076)
标准包装: 1
类型: 视频解码器
应用: 数码相机,手机,便携式视频
安装类型: 表面贴装
封装/外壳: 64-LQFP
供应商设备封装: 64-LQFP(10x10)
包装: 托盘
产品目录页面: 788 (CN2011-ZH PDF)
配用: EVAL-ADV7180LQEBZ-ND - BOARD EVALUATION ADV7180
EVAL-ADV7180LFEBZ-ND - BOARD EVAL FOR ADV7180 LFCSP
Data Sheet
ADV7180
Rev. I | Page 75 of 116
Letterbox Detection
Incoming video signals may conform to different aspect ratios
(16:9 wide screen or 4:3 standard). For certain transmissions in
the wide-screen format, a digital sequence (WSS) is transmitted
with the video signal. If a WSS sequence is provided, the aspect
ratio of the video can be derived from the digitally decoded bits
that WSS contains.
In the absence of a WSS sequence, letterbox detection can be
used to find wide-screen signals. The detection algorithm examines
the active video content of lines at the start and end of a field. If
black lines are detected, this may indicate that the currently
shown picture is in wide-screen format.
The active video content (luminance magnitude) over a line of
video is summed together. At the end of a line, this accumulated
value is compared with a threshold, and a decision is made as to
whether or not a particular line is black. The threshold value
needed may depend on the type of input signal; some control is
provided via LB_TH[4:0].
Detection at the Start of a Field
The ADV7180 expects a section of at least six consecutive black
lines of video at the top of a field. After those lines are detected,
LB_LCT[7:0] reports the number of black lines that were actually
found. By default, the ADV7180 starts looking for those black
lines in sync with the beginning of active video, for example,
immediately after the last VBI video line. LB_SL[3:0] allows the
user to set the start of letterbox detection from the beginning of
a frame on a line-by-line basis. The detection window closes in
the middle of the field.
Detection at the End of a Field
The ADV7180 expects at least six continuous lines of black video
at the bottom of a field before reporting the number of lines
actually found via the LB_LCB[7:0] value. The activity window
for letterbox detection (end of field) starts in the middle of an
active field. Its end is programmable via LB_EL[3:0].
Detection at the Midrange
Some transmissions of wide-screen video include subtitles
within the lower black box. If the ADV7180 finds at least two
black lines followed by some more nonblack video, for example, the
subtitle followed by the remainder of the bottom black block, it
reports a midcount via LB_LCM[7:0]. If no subtitles are found,
LB_LCM[7:0] reports the same number as LB_LCB[7:0].
There is a two-field delay in reporting any line count parameter.
There is no letterbox detected bit. Read the LB_LCT[7:0] and
LB_LCB[7:0] register values to determine whether the letterbox-
type video is present in the software.
LB_LCT[7:0], Letterbox Line Count Top, Address 0x9B[7:0];
LB_LCM[7:0], Letterbox Line Count Mid, Address 0x9C[7:0];
LB_LCB[7:0], Letterbox Line Count Bottom, Address 0x9D[7:0]
Table 98. LB_LCx Access Information
Signal Name
Address
LB_LCT[7:0]
0x9B
LB_LCM[7:0]
0x9C
LB_LCB[7:0]
0x9D
LB_TH[4:0], Letterbox Threshold Control,
Address 0xDC[4:0]
Table 99. LB_TH Function
LB_TH[4:0]
Description
01100 (default)
Default threshold for detection of black lines
01101 to 10000
Increase threshold (need larger active video
content before identifying nonblack lines)
00000 to 01011
Decrease threshold (even small noise levels
can cause the detection of nonblack lines)
LB_SL[3:0], Letterbox Start Line, Address 0xDD[7:4]
The LB_SL[3:0] bits are set at 0100 by default. For an NTSC
signal, this window is from Line 23 to Line 286.
By changing the bits to 0101, the detection window starts on
Line 24 and ends on Line 287.
LB_EL[3:0], Letterbox End Line, Address 0xDD[3:0]
The LB_EL[3:0] bits are set at 1101 by default. This means that the
letterbox detection window ends with the last active video line.
For an NTSC signal, this window is from Line 262 to Line 525.
By changing the bits to 1100, the detection window starts on
Line 261 and ends on Line 254.
相关PDF资料
PDF描述
VI-BWR-MX-F3 CONVERTER MOD DC/DC 7.5V 75W
VE-2W3-IW-F1 CONVERTER MOD DC/DC 24V 100W
ADV7611BSWZ-P IC RCVR HDMI 165MHZ LP 64LQFP
MAX3483ECPA+ IC TXRX RS485/422 250KBPS 8-DIP
VI-BWR-MX-F1 CONVERTER MOD DC/DC 7.5V 75W
相关代理商/技术参数
参数描述
ADV7180BSTZ 制造商:Analog Devices 功能描述:Video IC
ADV7180BSTZ-REEL 功能描述:IC VIDEO DECODER SDTV 64-LQFP RoHS:是 类别:集成电路 (IC) >> 线性 - 视频处理 系列:- 标准包装:250 系列:- 类型:电平移位器 应用:LCD 电视机/监控器 安装类型:表面贴装 封装/外壳:28-WFQFN 裸露焊盘 供应商设备封装:28-WQFN(4x4)裸露焊盘 包装:带卷 (TR) 其它名称:296-32523-2TPS65198RUYT-ND
ADV7180KCP32Z 功能描述:IC VIDEO DECODER 10BIT 32LFCSP RoHS:是 类别:集成电路 (IC) >> 线性 - 视频处理 系列:- 产品变化通告:Product Discontinuation 07/Mar/2011 标准包装:3,000 系列:OMNITUNE™ 类型:调谐器 应用:移动电话,手机,视频显示器 安装类型:表面贴装 封装/外壳:65-WFBGA 供应商设备封装:PG-WFSGA-65 包装:带卷 (TR) 其它名称:SP000365064
ADV7180KCP32Z-RL 功能描述:IC VIDEO DECODER 10BIT 32LFCSP RoHS:是 类别:集成电路 (IC) >> 线性 - 视频处理 系列:- 产品变化通告:Product Discontinuation 07/Mar/2011 标准包装:3,000 系列:OMNITUNE™ 类型:调谐器 应用:移动电话,手机,视频显示器 安装类型:表面贴装 封装/外壳:65-WFBGA 供应商设备封装:PG-WFSGA-65 包装:带卷 (TR) 其它名称:SP000365064
ADV7180KST48Z 功能描述:IC VID DECOD SDTV 10BIT 48LQFP RoHS:是 类别:集成电路 (IC) >> 线性 - 视频处理 系列:- 产品变化通告:Product Discontinuation 07/Mar/2011 标准包装:3,000 系列:OMNITUNE™ 类型:调谐器 应用:移动电话,手机,视频显示器 安装类型:表面贴装 封装/外壳:65-WFBGA 供应商设备封装:PG-WFSGA-65 包装:带卷 (TR) 其它名称:SP000365064