From abaa45d627122205e838b1bd1f8c621efba2bbb0 Mon Sep 17 00:00:00 2001 From: David Plowman Date: Sun, 18 Jul 2021 19:51:25 +0100 Subject: ipa: raspberrypi: AGC: handle modes with different sensitivities When the sensor is switched to a mode with a different sensitivity, the target exposure values need to be adjusted proportionately to maintain the same image brightness. Signed-off-by: David Plowman Reviewed-by: Naushir Patuck Reviewed-by: Kieran Bingham Signed-off-by: Kieran Bingham --- src/ipa/raspberrypi/controller/rpi/agc.cpp | 27 ++++++++++++++++++++++----- src/ipa/raspberrypi/controller/rpi/agc.hpp | 1 + 2 files changed, 23 insertions(+), 5 deletions(-) (limited to 'src/ipa') diff --git a/src/ipa/raspberrypi/controller/rpi/agc.cpp b/src/ipa/raspberrypi/controller/rpi/agc.cpp index f57783f8..1cfdd3bb 100644 --- a/src/ipa/raspberrypi/controller/rpi/agc.cpp +++ b/src/ipa/raspberrypi/controller/rpi/agc.cpp @@ -163,7 +163,7 @@ Agc::Agc(Controller *controller) : AgcAlgorithm(controller), metering_mode_(nullptr), exposure_mode_(nullptr), constraint_mode_(nullptr), frame_count_(0), lock_count_(0), - last_target_exposure_(0s), + last_target_exposure_(0s), last_sensitivity_(0.0), ev_(1.0), flicker_period_(0s), max_shutter_(0s), fixed_shutter_(0s), fixed_analogue_gain_(0.0) { @@ -268,9 +268,12 @@ void Agc::SetConstraintMode(std::string const &constraint_mode_name) constraint_mode_name_ = constraint_mode_name; } -void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode, +void Agc::SwitchMode(CameraMode const &camera_mode, Metadata *metadata) { + /* AGC expects the mode sensitivity always to be non-zero. */ + ASSERT(camera_mode.sensitivity); + housekeepConfig(); Duration fixed_shutter = clipShutter(fixed_shutter_); @@ -292,9 +295,20 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode, filtered_.shutter = fixed_shutter; filtered_.analogue_gain = fixed_analogue_gain_; } else if (status_.total_exposure_value) { - // On a mode switch, it's possible the exposure profile could change, - // or a fixed exposure/gain might be set so we divide up the exposure/ - // gain again, but we don't change any target values. + // On a mode switch, various things could happen: + // - the exposure profile might change + // - a fixed exposure or gain might be set + // - the new mode's sensitivity might be different + // We cope with the last of these by scaling the target values. After + // that we just need to re-divide the exposure/gain according to the + // current exposure profile, which takes care of everything else. + + double ratio = last_sensitivity_ / camera_mode.sensitivity; + target_.total_exposure_no_dg *= ratio; + target_.total_exposure *= ratio; + filtered_.total_exposure_no_dg *= ratio; + filtered_.total_exposure *= ratio; + divideUpExposure(); } else { // We come through here on startup, when at least one of the shutter @@ -308,6 +322,9 @@ void Agc::SwitchMode([[maybe_unused]] CameraMode const &camera_mode, } writeAndFinish(metadata, false); + + // We must remember the sensitivity of this mode for the next SwitchMode. + last_sensitivity_ = camera_mode.sensitivity; } void Agc::Prepare(Metadata *image_metadata) diff --git a/src/ipa/raspberrypi/controller/rpi/agc.hpp b/src/ipa/raspberrypi/controller/rpi/agc.hpp index 85067dc6..82063636 100644 --- a/src/ipa/raspberrypi/controller/rpi/agc.hpp +++ b/src/ipa/raspberrypi/controller/rpi/agc.hpp @@ -126,6 +126,7 @@ private: int lock_count_; DeviceStatus last_device_status_; libcamera::utils::Duration last_target_exposure_; + double last_sensitivity_; // sensitivity of the previous camera mode // Below here the "settings" that applications can change. std::string metering_mode_name_; std::string exposure_mode_name_; -- cgit v1.2.1