HI3520D采集不到视频

./sample_venc 0                                                                    
[SAMPLE_COMM_SYS_CalcPicVbBlkSize]-167: w:768, u32AlignWidth:64
please choose rc mode:
        0) CBR
        1) VBR
        2) FIXQP
1
please press twice ENTER to exit this sample
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread
[SAMPLE_COMM_VENC_GetVencStreamProc]-1101: get venc stream time out, exit thread


cat /proc/umap/vi

[VIU] Version: [Hi3520D_MPP_V1.0.1.0 Debug], Build Time: [Apr  7 2013, 16:21:59]

-----MODULE PARAM--------------------------------------------------------------
detect_err_frame drop_err_frame stop_int_level  max_cas_gap
               0              0              0        28000

-----VI DEV ATTR---------------------------------------------------------------
Dev   IntfM  WkM  ComMsk0  ComMsk1 ScanM AD0 AD1 AD2 AD3   Seq   DPath DType DRev

-----VI HIGH DEV ATTR---------------------------------------------------------------
Dev  InputM  WkM  ComMsk0  ComMsk1 ScanM AD0 AD1 AD2 AD3   Seq CombM CompM ClkM  Fix FldP   DPath DType DRev

-----VI PHYCHN ATTR------------------------------------------------------------
PhyChn CapX CapY  CapW  CapH  DstW  DstH CapSel Mirror Flip IntEn PixFom SrcRat DstRat

-----VI PHYCHN MINOR ATTR------------------------------------------------------------
PhyChn CapX CapY  CapW  CapH  DstW  DstH CapSel Mirror   Flip PixFom MixCap DwScal

-----VI PHYCHN STATUS 1----------------------------------------------------------
PhyChn  Dev      IntCnt  VbFail  LosInt  TopLos  BotLos BufCnt  IntT  SendT  Field  Stride

-----VI PHYCHN STATUS 2---------------------------------------------------------
PhyChn MaxIntT IntGapT MaxGapT OverCnt LIntCnt  ThrCnt AutoDis CasAutD  TmgErr      ccErrN    IntRat

-----VI CHN STATUS-------------------------------------------------------------
ViChn   bEnUsrP   FrmTime   FrmRate     SendCnt      SwLost    Rotate

-----VI CHN CALL DSU STATUS 1-------------------------------------------------
ViChn   UsrBgnNOk   UsrCancel    UsrEndOk     UsrCbOk     CvrBgnNOk   CvrCancel    CvrEndOk     CvrCbOk

-----VI CHN CALL DSU STATUS 2-------------------------------------------------
ViChn   OsdBgnNOk   OsdCancel    OsdEndOk     OsdCbOk      ScaleNOk   SclCancel    SclEndOk     SclCbOk

-----VI CHN CALL DSU STATUS 3-------------------------------------------------
ViChn   RotateNOk   RotCancel    RotEndOk     RotCbOk        LDCNOk   LDCCancel    LDCEndOk     LDCCbOk


上面是串口的打印信息，应该是没有输入，我用的板子是HI3520D8路视频输入