Information About DOL HDR with IMX577 on Xavier AGX

Hello everyone.

I have IMX577 camera and Xavier AGX. I want to get DOL HDR images from the camera with using nvgstcapture. I researched on the forum about DOL HDR mode and IMX series. Some people succeed but there is no information how they succeed. I want to learn fro m scratch how to set DOL HDR.

  1. How should I edit camera_overrides.isp file?
  2. How should I edit device tree?
  3. How can I get DOL HDR image with nvgstcapture?
  4. How can I get DOL HDR image with libargus?

Please help me, this is so important for our project. Thanks.

Have a reference to imx274 for the driver implement.

  1. Add these knobs to the camera_overrides.isp:
    wdr.DOL.v4.EnableDOL = TRUE;
    ae.wdr.DreMin = FER;
    ae.wdr.DreMax = FER;

  2. Setup DT properties for DOL sensor mode:
    min_exp_time = FER * short exposure time lower limit;
    max_exp_time = FER * short exposure time upper limit;
    The exposure ratio needs to be fixed value, preferably a power of 2.
    This fixed exposure ratio needs to obeys the following constraints:
    a. Short exposure time lower limit * fixed exposure ratio >= Long exposure time lower limit.
    b. Short exposure time upper limit * fixed exposure ratio <= Long exposure time upper limit.

The limits for short exposure time and long exposure time can be derived from the data sheet.
The above constraints will ensure that that long and short exposure times output by our auto exposure always maintain a fixed exposure ratio.

Once such a Fixed Exposure Ratio (let’s call it FER) value has been derived, the following changes should be made:


I asked 4 questions but you only answered one and a half. I know that changing just min/max exposure times in device tree won’t be enough. There are other parameters that you didn’t mentioned.

Please give more details. And it would be perfect to share a sample device tree that is configured for DOL HDR.

As I mention in early comment you can reference to IMX274 and it device tree.
And just switch to HDR sensor mode mode for nvgstcapture and libargus question.

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