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TDA4VM: TDA4VM-X8B-About AE abnormal pulsation problem

Part Number: TDA4VM

 Dear TI engi neers, Recently, we e ncountered a problem. When we were debugging and testing the stability of AE outdoors, we found that our current AE would jump back and forth with a certain increase, which was shown in DCC as Again at 4.5-4.6 times gain, with a change of only 0.1 times gain and a strong change in the brightness of the screen. The fusion area of WDR seems to increase disharmony and the pulsation amplitude is too large. How can we solve this problem? Attached are our current H3A parameters and relevant scene pictures that are reproduced. Please inform us in time if you need any other information

  • Hi,

    Do you have some output video to show the problem (I suppose you tested under a stable lighting condition)?

    The change of gain between 4.5 and 4.6 is only about 0.2% exposure difference.
    It should not cause any large brightness difference for sensor raw images or output yuv images.

    A few things you may look into or try

    - check the AE configuration parameters in your sensor driver

    - print out the AE input and AE decision over time and debug with the AE source code

    - confirm if any other VISS parameters changed when the issue happens

  • hi, gang

    After checking the driver code of the sensor, we found that there were some calculation problems in the process of parameter shock in the register of AE driver. After modification, Ae is now stable

  • Thank you very much for the update and confirmation!

    When the output exposure time and/or gain from AE is not programmed into the sensor correctly and accurately, the problem will happen.