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Video Captured shakes when the Camera's exposure inscrease

Eason Wang
Genius 13460 points

Hi,

My ctm report that when the camera side manually increase exposure by user, the video captured is shaking.

Please find the video record below:

I have asked ctm to increase the scenario's light suddenly, which will cause exposure increase too, BUT there is no such issue.   So I believe there is something wrong with the mechanism the camera do exposure adjustment by user,   which makes me doubt there is problem on CVBS signal.

But,  this issue never happen when the camera is connected to TV directly.

The interface to user is just  brighter <---> darker, no detail about the mechenism how it is adjusted...

Could you give some comment?

BR,

Eason

BR,

Eason

  • 0
    TI__Mastermind 43875 points

    Eason,

    You need to look at the analog video waveform going in to the TVP to see what changing the exposure actually does to the analog waveform.


    My guess is that it corrupts the syncs somehow.

    BR,

    Steve

  • 0 in reply to Steve Clynes
    TI__Genius 13460 points
    Hi Steve,
    This issue is solved and below is the explanation
    Ctm involved the FAE of the mainchip and by analyzing the code they find that the F V bit embedded in BT656 data changes frequently when the exposure increases. Thus the code will be triggerred to change from PAL/NTSC capture. I Still we are not sure whether the camera or TVP is the root cause.
    By increase the tolerrance of F V value, the issue is solved. I also advice customer to read back status register from TVP before the mainchip make decision to change video standard.

    BR,
    Eason
  • 0 in reply to Eason Wang
    TI__Mastermind 43875 points

    As I mentioned previously it sounds like the camera is corrupting the syncs somehow when the exposure is changed.

    Glad a solution has been identified though.

    BR,

    Steve