[libcamera-devel] [PATCH v3 2/2] ipa: raspberrypi: Handle AEC/AGC flicker controls

[Kieran Bingham]

Resending this to reply to the correct mail thread for patchworks sake:

Content added below is from Maarten in 
Message-ID <022b6380-7d78-8d1c-20ee-0ae211a65653 at lankhorst.se>


Quoting David Plowman via libcamera-devel (2023-03-28 09:55:21)
> We handle the flicker modes by passing the correct period to the
> AEC/AGC algorithm which already contains the necessary code.
> 
> The "Auto" mode, as well as reporting the detected flicker period via
> the "AeFlickerDetected" metadata, are unsupported for now.
> 

This series removes the power line flickering on my pi v3 camera when
using libcamerasrc (with some modifications there).

Tested-by: Maarten Lankhorst <dev at lankhorst.se>



> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> ---
>  src/ipa/raspberrypi/raspberrypi.cpp | 80 +++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
> 
> diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp
> index 13757955..d485b851 100644
> --- a/src/ipa/raspberrypi/raspberrypi.cpp
> +++ b/src/ipa/raspberrypi/raspberrypi.cpp
> @@ -91,6 +91,8 @@ static const ControlInfoMap::Map ipaControls{
>         { &controls::AeConstraintMode, ControlInfo(controls::AeConstraintModeValues) },
>         { &controls::AeExposureMode, ControlInfo(controls::AeExposureModeValues) },
>         { &controls::ExposureValue, ControlInfo(-8.0f, 8.0f, 0.0f) },
> +       { &controls::AeFlickerMode, ControlInfo(controls::AeFlickerModeValues) },
> +       { &controls::AeFlickerCustom, ControlInfo(100, 1000000) },
>         { &controls::AwbEnable, ControlInfo(false, true) },
>         { &controls::ColourGains, ControlInfo(0.0f, 32.0f) },
>         { &controls::AwbMode, ControlInfo(controls::AwbModeValues) },
> @@ -230,6 +232,12 @@ private:
>         /* Track the frame length times over FrameLengthsQueueSize frames. */
>         std::deque<Duration> frameLengths_;
>         Duration lastTimeout_;
> +
> +       /* The current state of flicker avoidance. */
> +       struct FlickerState {
> +               int32_t mode;
> +               Duration customPeriod;
> +       } flickerState_;
>  };
>  
>  int IPARPi::init(const IPASettings &settings, bool lensPresent, IPAInitResult *result)
> @@ -962,6 +970,78 @@ void IPARPi::queueRequest(const ControlList &controls)
>                         break;
>                 }
>  
> +               case controls::AE_FLICKER_MODE: {
> +                       RPiController::AgcAlgorithm *agc = dynamic_cast<RPiController::AgcAlgorithm *>(
> +                               controller_.getAlgorithm("agc"));
> +                       if (!agc) {
> +                               LOG(IPARPI, Warning)
> +                                       << "Could not set AeFlickerMode - no AGC algorithm";
> +                               break;
> +                       }
> +
> +                       int32_t mode = ctrl.second.get<int32_t>();
> +                       bool modeValid = true;
> +
> +                       switch (mode) {
> +                       case controls::FlickerOff: {
> +                               agc->setFlickerPeriod(0us);
> +
> +                               break;
> +                       }
> +
> +                       case controls::FlickerFreq50Hz: {
> +                               agc->setFlickerPeriod(10000 * 1.0us);
> +
> +                               break;
> +                       }
> +
> +                       case controls::FlickerFreq60Hz: {
> +                               agc->setFlickerPeriod(8333.333 * 1.0us);
> +
> +                               break;
> +                       }
> +
> +                       case controls::FlickerCustom: {
> +                               agc->setFlickerPeriod(flickerState_.customPeriod);
> +
> +                               break;
> +                       }
> +
> +                       default:
> +                               LOG(IPARPI, Error) << "Flicker mode " << mode << " is not supported";
> +                               modeValid = false;
> +
> +                               break;
> +                       }
> +
> +                       if (modeValid)
> +                               flickerState_.mode = mode;
> +
> +                       break;
> +               }
> +
> +               case controls::AE_FLICKER_CUSTOM: {
> +                       RPiController::AgcAlgorithm *agc = dynamic_cast<RPiController::AgcAlgorithm *>(
> +                               controller_.getAlgorithm("agc"));
> +                       if (!agc) {
> +                               LOG(IPARPI, Warning)
> +                                       << "Could not set AeFlickerCustom - no AGC algorithm";
> +                               break;
> +                       }
> +
> +                       uint32_t customPeriod = ctrl.second.get<int32_t>();
> +                       flickerState_.customPeriod = customPeriod * 1.0us;
> +
> +                       /*
> +                        * We note that it makes no difference if the mode gets set to "custom"
> +                        * first, and the period updated after, or vice versa.
> +                        */
> +                       if (flickerState_.mode == controls::FlickerCustom)
> +                               agc->setFlickerPeriod(flickerState_.customPeriod);
> +
> +                       break;
> +               }
> +
>                 case controls::AWB_ENABLE: {
>                         RPiController::AwbAlgorithm *awb = dynamic_cast<RPiController::AwbAlgorithm *>(
>                                 controller_.getAlgorithm("awb"));
> -- 
> 2.30.2
>