From e875503bc4a40e5043fb045942535b865692ff60 Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Mon, 24 Jan 2022 10:31:06 +0000 Subject: ipa: raspberrypi: Limit the maximum sensor gain used Limit the gain code to the maximum value reported by the sensor controls when sending to DelayedControls. The AGC algorithm will handle a lower gain used by the sensor, provided it knows the actual gain used. This change ensures that DelayedControls will never report an unclipped gain used. Signed-off-by: Naushir Patuck Reviewed-by: David Plowman Reviewed-by: Kieran Bingham Signed-off-by: Laurent Pinchart --- src/ipa/raspberrypi/raspberrypi.cpp | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/ipa/raspberrypi/raspberrypi.cpp b/src/ipa/raspberrypi/raspberrypi.cpp index 0ed41385..a72d516f 100644 --- a/src/ipa/raspberrypi/raspberrypi.cpp +++ b/src/ipa/raspberrypi/raspberrypi.cpp @@ -173,6 +173,9 @@ private: /* Frame duration (1/fps) limits. */ Duration minFrameDuration_; Duration maxFrameDuration_; + + /* Maximum gain code for the sensor. */ + uint32_t maxSensorGainCode_; }; int IPARPi::init(const IPASettings &settings, ipa::RPi::SensorConfig *sensorConfig) @@ -357,6 +360,8 @@ int IPARPi::configure(const IPACameraSensorInfo &sensorInfo, return -1; } + maxSensorGainCode_ = sensorCtrls_.at(V4L2_CID_ANALOGUE_GAIN).max().get(); + /* Setup a metadata ControlList to output metadata. */ libcameraMetadata_ = ControlList(controls::controls); @@ -1113,6 +1118,13 @@ void IPARPi::applyAGC(const struct AgcStatus *agcStatus, ControlList &ctrls) { int32_t gainCode = helper_->GainCode(agcStatus->analogue_gain); + /* + * Ensure anything larger than the max gain code will not be passed to + * DelayedControls. The AGC will correctly handle a lower gain returned + * by the sensor, provided it knows the actual gain used. + */ + gainCode = std::min(gainCode, maxSensorGainCode_); + /* GetVBlanking might clip exposure time to the fps limits. */ Duration exposure = agcStatus->shutter_time; int32_t vblanking = helper_->GetVBlanking(exposure, minFrameDuration_, maxFrameDuration_); -- cgit v1.2.1